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Purpose : Monitoring players' training load allows practitioners to enhance physical performance while reducing injury risk. The aim of this study was to identify the key external load indicators in professional U19 soccer. Methods : Twenty-four-professional Italian young (U19) soccer players were monitored by using the rating of perceived exertion (CR-10 RPE scale) and a wearable inertial sensor during the competitive season. Three main components were detected by a Principal Component Analysis (PCA): i) volume metabolic related component, ii) intensity mechanical stimuli component, and iii) intensity metabolic/mechanical component. We hence computed two scores (i.e. Performance [PERF] and total workload [WORK]) permitting to investigate the weekly microcycle. Results : Correlation analysis showed that scores (i.e. PERF and WORK) are low correlated ( r  = -0.20) suggesting that they were independent. Autocorrelation analysis showed that a weekly microcycle is detectable in all the scores. Two-way ANOVA RM showed a statistical difference between match day (MD) and playing position for the three PCA components and PERF score. Conclusion : We proposed an innovative approach to assess both the players' physical performance and training load by using a machine learning approach allowing reducing a large dataset in an objective way. This approach may help practitioners to prescribe the training in the microcycle based on the two scores.

Novelty: This study is novel in classifying bodybuilding posing training as vigorous intensity exercise using metabolic equivalents (METs) and heart rate (HR) responses. It provides empirical evidence showing that posing training meets the vigorous intensity benchmarks, with METs and %HRmax values comparable to established vigorous exercise standards. The research highlights the novel finding that stimulant usage and the peak week phase of preparation significantly influence physiological responses and perceived exertion in bodybuilders. Specifically, athletes using stimulants and those in peak week displayed higher ratings of perceived exertion (RPE) and maximum heart rates, indicating that these factors notably affect the intensity and perceived difficulty of posing training., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The primary aim of the study was to assess differences in strength performance, neuromuscular fatigue, and perceived exertion across phases of the menstrual cycle [MC; early follicular (eFP), late follicular (lFP), and mid-luteal phase (mLP)] and oral contraceptives [OCs; active pill phase (aPP) and nonactive pill phase (nPP)]. The secondary aim was to analyze the influence of fluctuating serum 17β-estradiol and progesterone concentrations on these parameters in naturally menstruating women. Thirty-four women (21 with a natural MC and 13 using OCs) completed three or two experimental sessions, respectively. Mean propulsive velocity (MPV mean ) and total number of repetitions (REP total ) were assessed during a power [3 × 8 at 60% 1RM (one-repetition maximum)] and hypertrophy squat loading (3 sets to failure at 70% 1RM), respectively. Changes in bench press and squat MPV at 60% 1RM in response to the loadings were used as surrogates for nonlocal and local fatigue, respectively. Total blood lactate accumulation (BLA A ) and markers of perceived exertion were assessed in each session. No significant differences between any of the MC or OC phases were observed for MPV mean , REP total , nonlocal and local fatigue, and markers of perceived exertion (all P > 0.050). A higher intraindividual 17β-estradiol concentration was significantly associated with a lower MPV mean ( P = 0.019). BLA A was significantly higher in the lFP than in the mLP ( P = 0.019) and negatively associated with the intraindividual progesterone concentration ( P = 0.005). Although 17β-estradiol may negatively influence the MPV, it appears that fluctuations of both sex hormones across the MC and OC phases are not prominent enough to induce significant or practically relevant changes in the assessed parameters. NEW & NOTEWORTHY Although a high intraindividual 17β-estradiol concentration was associated with a lower movement velocity, markers of strength performance and surrogates for nonlocal and local fatigue remained unaffected by MC and OC phases. Blood lactate accumulation was significantly reduced in the mLP. Furthermore, our findings suggest that the impact of the MC phases varies greatly among individuals. Individuals with high fluctuations in sex hormone concentrations may experience relevant changes in the assessed parameters.

This study aimed to: (i) analyze the variations in psychophysiological demands (mean heart rate, meanHR; rate of perceived exertion, RPE) and technical performance (umber of successful and unsuccessful passes, and occurrences of ball loss) between 2v2 and 4v4 small-sided games (SSGs) formats, and (ii) examine the relationships of aerobic capacity measured in Yo-Yo Intermittent Recovery Test (YYIRT) on psychophysiological and technical performance during SSGs. This study used a cross-sectional design with repeated measures, where the same players participated in both 2v2 and 4v4 formats across two training sessions per format. Twenty-four talent/developmental male youth soccer players, aged 16.6 ± 0.5 years. The meanHR, measured through heart rate sensors, the RPE, assessed using the CR6-20 scale, and the number of successful and unsuccessful passes, along with occurrences of ball loss, recorded using an ad hoc observational tool, were evaluated in each repetition. Players during the 2v2 format had significantly greater mean HR (+4.1%; p < 0.001; d = 2.258), RPE (+12.2%; p < 0.001; d = 2.258), successful passes (+22.2%; p = 0.006; d = 0.884), unsuccessful passes (+62.5%; p < 0.001; d = 1.197) and lost balls (+111.1%; p < 0.001; d = 2.085) than 4v4 format. The YYIRT was significantly and largely correlated with unsuccessful passes (r = 0.502; p = 0.012) and lost balls (r = 0.421; p = 0.041) in 2v2 format. In conclusion, this study suggests that engaging in 2v2 activities constitutes a more intense form of practice, significantly enhancing individual participation in technical aspects. Moreover, aerobic capacity may influence the smaller formats of play and how players perform key technical actions. Therefore, coaches must consider this to ensure the necessary performance in such games., (© Journal of Sports Science and Medicine.)

Post-exercise hot (HWI) and cold (CWI) water immersion are popular strategies used by athletes in a range of sporting contexts, such as enhancing recovery or adaptation. However, prolonged heating bouts increase neuroendocrine responses that are associated with perceptions of fatigue. Fourteen endurance-trained runners performed three trials consisting of two 45-min runs at 95% lactate threshold on a treadmill separated by 6 h of recovery. Following the first run, participants completed one of HWI (30 min, 40°C), CWI (15 min, 14°C) or control (CON, 30 min rest in ambient conditions) in a randomised order. Perceived effort and recovery were measured using ratings of perceived exertion (RPE) and the Acute Recovery and Stress Scale (ARSS), whilst physiological responses including venous concentrations of a range of neuroendocrine markers, superficial femoral blood flow, heart rate and rectal temperature were measured. Exercise increased neuroendocrine responses of interleukin-6, adrenaline and noradrenaline (all P < 0.001). Additionally, perceptions of overall recovery (P < 0.001), mental performance capacity (P = 0.02), physical performance capability (P = 0.01) and emotional balance (P = 0.03) were reduced prior to the second run. However, there was no effect of condition on these variables (P > 0.05), nor RPE (P = 0.68), despite differences in rectal temperature, superficial femoral blood flow following the first run, and participants' expected recovery prior to the intervention (all P < 0.001). Therefore, athletes may engage in post-exercise hot or cold-water immersion without negatively impacting moderate-intensity training sessions performed later the same day., (© 2024 The Author(s). Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)

Ratings of Perceived Exertion (RPE) are frequently used to prescribe exercise intensity. A central assumption of using RPE scales is that the subjective perception of effort maps onto objective performance in a consistent way. However, the degree and shape of how RPE aligns with objective performance is not fully understood. Here, we investigate the degree and shape of alignment, as well as how time (i.e., how frequently an effort needs to be performed) and mental effort (i.e., if one has to invest mental effort and physical effort) correspond with the alignment. In a randomized within-subjects experiment, we used a grip-to-scale method that asked participants (N = 43) to repeatedly squeeze a handgrip dynamometer with four to-be-produced RPE target levels relative to their subjective maximum strength (representing 20%, 40%, 60%, or 80%). We found that the RPE-force alignment was not the same across RPE-levels: Whereas subjective differences from 20-40% and 40-60% were met by comparable differences in produced force, a substantially larger difference was observed for the 60-80% interval. Interestingly, exploratory post-hoc analyses revealed that this was mirrored by an increase in variance at the higher effort levels. In addition, at constant RPE-levels, participants produced less force over time, and this effect was more pronounced at lower RPE target levels. Lastly, anticipating mental effort after the physical effort slightly altered the alignment as a function of the to-be-produced RPE-level and experimental duration. Taken together, our results indicate that the mapping of perceived effort on objective performance is intricate, and several factors affect the degree and shape of how RPE and performance align. Understanding the dynamic adjustment of RPE-performance alignment across different RPE levels is particularly relevant for contexts that use RPE as a tool for training load prescription., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Rewitz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Microcycles are fundamental structures for training prescription and load management, helping to optimise training effects and performance. This study quantified external and internal loads of Italian Serie A youth soccer players across competitive weeks and their periodisation within microcycles. Data were collected from 90 players belonging to four age groups (under-19, -17, -16, -15) across a season. Methods of monitoring external [duration and global navigation satellite systems (GNSS)] and internal load [heart rate (HR) and rating of perceived exertion (RPE)] were employed. Linear mixed models determined differences in training loads across age groups, training days and player positions. Under-19 and under-17 players trained five times per week, while younger players trained four times. Late-stage academy players (under-19 and -17) demonstrated higher weekly accumulated external and sRPE training load compared to their younger counterparts ( p  < 0.05 between groups). Weekly accumulated HR internal loads were higher in under-15 players ( p  < 0.05 between groups). Marked fluctuations of daily load were observed across microcycles in under-19 and under-17 groups ( p  < 0.05 between days). These findings highlight progressive increases in training load throughout the development pathway, with late-stage academy players training with higher frequency, volume and marked periodisation compared to younger players.

Background: This study examined the influence of physical fitness qualities, individual characteristics, and contextual factors on perceived exertion and recovery responses to official games in youth basketball players., Methods: Twenty-six males (age: 15.8±1.2 years; 12 guards, 9 forwards, and 5 centers) and 7 females (age: 16.1±0.9 years; 3 guards, 4 forwards) were monitored for an entire basketball season (N.=635 observations). Yo-Yo Intermittent Recovery (level 1) and countermovement jump (CMJ) tests were administered, with players categorized as high and low Yo-Yo and CMJ groups according to test results. Ratings of perceived exertion (RPE) were collected after each official game. Before the game and the day after, the Total Quality of Recovery (scores) were collected, and the difference between post- and pregame TQR was calculated (TQRΔ). Separate linear mixed models evaluated the effects of sex (M; F), fitness qualities (high Yo-Yo; low Yo-Yo) (high CMJ; low CMJ), playing position (guard; forward; center), game outcome (won; loss) and game location (home; away)., Results: Male players reported higher RPE (7.0±0.3) than females (5.5±0.4) (P=0.003, effect size [ES]: moderate). Players with high Yo-Yo performance also reported higher RPE (6.7±0.4) than low Yo-Yo (5.8±0.3) (P=0.049, ES: small). TQRΔ was higher in guards (-1.3±0.2) than forwards (-0.8±0.2) (P=0.041, ES: trivial), and lower after lost games (-0.8±0.2) compared to won games (-1.2±0.2) (P=0.002, ES: small)., Conclusions: In youth basketball, postgame perceived exertion and recovery responses are influenced by players' sex, intermittent endurance capacity, and game outcome. Current findings can help youth basketball practitioners to better understand their players' performances and perceptual responses.

Ratings of perceived exertion (RPE) are frequently used to monitor and prescribe exercise intensity. However, studies examining the shape and robustness of how feelings of effort map onto objective outputs are limited and report inconsistent results. To address this, we investigated whether (1) producing isometric forces according to RPE levels reliably leads to differences in force output, (2) if feelings of effort map linearly or non-linearly onto force output, and (3) if this mapping is robust when visual feedback and social facilitation are present. In a counterbalanced repeated measures design, N = 26 participants performed isometric handgrip contractions prescribed by ten levels of the Borg CR-10 scale. They did so either with or without the availability of concurrent visual feedback regarding their force production, and in the presence or absence of another person performing the same task simultaneously. We found that subjects reliably produced different force outputs that corresponded to each RPE level. Furthermore, concurrent visual feedback led to a linearization of force output, while in the absence of feedback, the produced forces could also be described by quadratic and cubic functions. Exploratory post-hoc analyses revealed that participants perceived moderate RPE levels to be more challenging to produce. By shedding light on the dynamic nature of the mapping between RPE and objective performance, our findings provide helpful insights regarding the utility of RPE scales., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: To quantify the change in session rating of perceived exertion training impulse (RPE-TRIMP) that may occur in response to increased running distance at 3 running velocity ranges in elite sprinters., Methods: We monitored training load in elite sprinters (women: n = 7; men: n = 11) using wearable Global Positioning System technology and RPE-TRIMP for a total of 681 individual training sessions during a 22-week competition-preparation period. Internal training load was operationalized by RPE-TRIMP, and external training load was operationalized by distance covered in 3 velocity ranges. A linear mixed-effects model with athlete as a random effect was fit to RPE-TRIMP with total distance covered at ≤69.99% (low-velocity running [LVR]), 70% to 84.99% (high-velocity running [HVR]), and 85% to 100% (very-high-velocity running [VHVR]) of individual maximum velocity., Results: Increased running distance in all 3 velocity ranges (LVR, HVR, and VHVR) resulted in a significant (P < .001) increase in RPE-TRIMP. Coefficients (95% CIs) were .10 (.08-.11) for LVR, .23 (.18-.28) for HVR, and .44 (.35-.53) for VHVR. A 50-m increase in running distance covered in the LVR, HVR, and VHVR velocity ranges was associated with increases in RPE-TRIMP of 5, 11.5, and 22 arbitrary units, respectively., Conclusions: Internal training load, calculated as RPE-TRIMP, increased with increases in total distance covered in the LVR, HVR, and VHVR velocity ranges (P < .001). RPE-TRIMP can be a practical solution for monitoring global training-session load in elite sprinters.

Purpose : The aim of this study was to evaluate the reliability of a single-trial determination of maximal accumulated oxygen deficit (MAOD) achieved via the aid of perceptually-regulated incremental exercise. Methods : 14 trained male cyclists (age: 45 ± 8 yrs; height: 1.82 ± 0.06 m; mass: 79.7 ± 6.7 kg; V ˙ O 2 max : 4.09 ± 0.57 L·min -1 ) performed three trials of a submaximal incremental cycling test followed by a test to exhaustion at 116% of predicted V ˙ O 2 max . The intensity for each stage of the incremental test was regulated by participants to elicit perceived exertion levels of 9-15 on the Borg (6-20) scale. Linear regression was used to estimate V ˙ O 2 max at a perceived exertion level of 19. MAOD was calculated from the difference between predicted and actual oxygen demand in the test to exhaustion, reported in oxygen equivalents (O 2 eq). A separate incremental test was used to measure V ˙ O 2 max directly. Results : Correlation coefficients between perceived exertion and V ˙ O 2 across trials were strong ( r ≥0.99), and there were no between-trial differences in predicted V ˙ O 2 max (4.03 ± 1.04, 3.76 ± 0.53, and 3.69 ± 0.64 L·min -1 , respectively; p  = .142) or MAOD (2.75 ± 2.28, 2.50 ± 1.53, and 2.93 ± 1.40 L O 2 eq, respectively; p  = .633). Nevertheless, the coefficients of variation for predicted V ˙ O 2 max (14.2%) and MAOD (142.8%) were poor. Conclusions : The prediction of V ˙ O 2 max from perceptually-regulated exercise displays a level of test-retest reliability which prevents its use as a means of evaluating MAOD reliably in a single-trial.

Background: Ratings of perceived exertion (RPE) can be used to regulate exercise intensity. This study examined the effect of anchor scheme on performance fatigability and neuromuscular responses following fatiguing forearm flexion tasks., Methods: Twelve men (age 20.9±2.2 years; height 179.8±5.3 cm; body mass 80.2±9.9 kg) performed sustained, isometric forearm flexion tasks to failure anchored to RPE=6 (RPEFT) and the torque (TRQFT) that corresponded to RPE=6. Pre-test and post-test maximal voluntary isometric contractions (MVIC) were performed to quantify changes in the amplitude (AMP) and mean power frequency (MPF) of the electromyographic (EMG) and mechanomyographic (MMG) signals. Neuromuscular efficiency (NME) was calculated by dividing normalized torque by normalized EMG AMP. A dependent t-test was used to assess the mean difference for time to task failure (TTF). Repeated measures ANOVAs were used to compare mean differences for performance fatigability and normalized neuromuscular parameters., Results: The RPEFT had a greater TTF than the TRQFT (P<0.001). MVIC and NME decreased from pre-test to post-test following the RPEFT and TRQFT (P<0.05) with no differences between anchor schemes. Following the TRQFT, normalized EMG MPF decreased from pre-test to post-test (P=0.004). Following the RPEFT, normalized MMG MPF increased from pre-test to post-test (P=0.021). There were no changes in normalized EMG AMP or MMG AMP (P>0.05)., Conclusions: These findings indicated anchor scheme-specific neuromuscular responses and TTF, despite no difference in performance fatigability. Furthermore, performance fatigability was likely due to peripheral fatigue (based on normalized EMG MPF and NME) following the TRQFT, but peripheral and central fatigue (based on normalized MMG MPF and NME) following the RPEFT.

Purpose: Studies indicate that the rated perceived exertion (RPE) during physical exercise can be lower in field environments than indoors. The environmental conditions of those studies are explored. Furthermore, we study if the same phenomenon is valid when cycling indoors versus in cycle commuting environments with high levels of stimuli from both traffic and suburban-urban elements., Methods: Twenty commuter cyclists underwent measurements of heart rate (HR) and oxygen uptake ([Formula: see text]O2) and RPE assessments for breathing and legs, respectively, while cycling in both laboratory and field conditions. A validated mobile metabolic system was used in the field to measure [Formula: see text]O2. Three submaximal cycle ergometer workloads in the laboratory were used to establish linear regression equations between RPE and % of HR reserve (%HRR) and %[Formula: see text]O2max, separately. Based on these equations, RPE from the laboratory was predicted and compared with RPE levels at the participants' individual cycle commutes at equal intensities. The same approach was used to predict field intensities and for comparisons with corresponding measured intensities at equal RPE levels., Results: The predicted RPE levels based on the laboratory cycling were significantly higher than the RPE levels in cycle commuting at equal intensities (67% of HRR; 65% of [Formula: see text]O2max). For breathing, the mean RPE levels were; 14.0-14.2 in the laboratory and 12.6 in the field. The corresponding levels for legs were; 14.0-14.2 and 11.5. The range of predicted field intensities in terms of %HRR and %[Formula: see text]O2max was 46-56%, which corresponded to median differences of 19-30% compared to the measured intensities in field at equal RPE., Conclusion: The cycle commuters perceived a lower exertion during their cycle commutes compared to ergometer cycling in a laboratory at equal exercise intensities. This may be due to a higher degree of external stimuli in field, although influences from other possible causes cannot be ruled out., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Olsson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Rating of perceived exertion (RPE) is considered a valid method for prescribing prolonged aerobic steady-state exercise (SSE) intensity due to its association with physiological indicators of exercise intensity, such as oxygen uptake (V̇O 2 ) or heart rate (HR). However, these associations between psychological and physiological indicators of exercise intensity were found during graded exercise tests (GXT) but are currently used to prescribe SSE intensity even though the transferability and validity of the relationships found during GXT to SSE were not investigated. The present study aims to verify whether (a) RPE-HR or RPE-V̇O 2 relations found during GXTs are valid during SSEs, and (b) the duration and intensity of SSE affect these relations., Methods: Eight healthy and physically active males (age 22.6 ± 1.2 years) were enrolled. On the first visit, pre-exercise (during 20 min standing) and maximal (during a GXT) HR and V̇O 2 values were measured. Then, on separate days, participants performed 4 SSEs on the treadmill by running at 60% and 80% of the HR reserve (HRR) for 15 and 45 min (random order). Individual linear regressions between GXTs' RPE (dependent variable) and HRR and V̇O 2 reserve (V̇O 2 R) values (computed as the difference between maximal and pre-exercise values) were used to predict the RPE associated with %HRR (RPE HRR ) and %V̇O 2 R (RPE V̇O2R ) during the SSEs. For each relation (RPE-%HRR and RPE-%V̇O 2 R), a three-way factorial repeated measures ANOVA ( α  = 0.05) was used to assess if RPE (dependent variable) was affected by exercise modality ( i.e. , RPE recorded during SSE [RPE SSE ] or GXT-predicted), duration ( i.e. , 15 or 45 min), and intensity ( i.e. , 60% or 80% of HRR)., Results: The differences between RPE SSE and GXT-predicted RPE, which were assessed by evaluating the effect of modality and its interactions with SSE intensity and duration , showed no significant differences between RPE SSE and RPE HRR . However, when RPE SSE was compared with RPE V̇O2R , although modality or its interactions with intensity were not significant, there was a significant ( p  = 0.020) interaction effect of modality and duration yielding a dissociation between changes of RPE SSE and RPE V̇O2R over time. Indeed, RPE SSE did not change significantly ( p  = 0.054) from SSE of 15 min (12.1 ± 2.0) to SSE of 45 min (13.5 ± 2.1), with a mean change of 1.4 ± 1.8, whereas RPE V̇O2R decreased significantly ( p  = 0.022) from SSE of 15 min (13.7 ± 3.2) to SSE of 45 min (12.4 ± 2.8), with a mean change of -1.3 ± 1.5., Conclusion: The transferability of the individual relationships between RPE and physiological parameters found during GXT to SSE should not be assumed as shown by the results of this study. Therefore, future studies modelling how the exercise prescription method used (e.g., RPE, HR, or V̇O 2 ) and SSE characteristics ( e.g. , exercise intensity, duration, or modality) affect the relationships between RPE and physiological parameters are warranted., Competing Interests: Carlo Ferri Marini, Matteo Vandoni, and Luca Correale are Academic Editors for PeerJ. Luca Zoffoli is employed by Technogym S.p.A., Cesena, FC, Italy., (©2024 Ferri Marini et al.)

Abstract: Ortega, DG, Housh, TJ, Smith, RW, Arnett, JE, Neltner, TJ, Schmidt, RJ, and Johnson, GO. The effects of anchoring a fatiguing forearm flexion task to a high versus low rating of perceived exertion on torque and neuromuscular responses. J Strength Cond Res 38(5): e219-e225, 2024-This study examined the torque and neuromuscular responses following sustained, isometric, forearm flexion tasks anchored to 2 ratings of perceived exertion (RPE). Nine men (mean ± SD: age = 21.0 ± 2.4 years; height = 179.5 ± 5.1 cm; body mass = 79.6 ± 11.4 kg) completed maximal voluntary isometric contractions (MVIC) before and after sustained, isometric, forearm flexion tasks to failure anchored to RPE = 2 and RPE = 8. The amplitude (AMP) and mean power frequency (MPF) of the electromyographic (EMG) signal were recorded from the biceps brachii. Normalized torque was divided by normalized EMG AMP to calculate neuromuscular efficiency (NME). A dependent t-test was used to assess the mean difference for time to task failure (TTF). Repeated-measures analysis of variances was used to compare mean differences for MVIC and normalized neuromuscular parameters. There was no significant difference in TTF between RPE = 2 and RPE = 8 (p = 0.713). The MVIC decreased from pretest to posttest at RPE = 2 (p = 0.009) and RPE = 8 (p = 0.003), and posttest MVIC at RPE = 8 was less than that at RPE = 2 (p < 0.001). In addition, NME decreased from pretest to posttest (p = 0.008). There was no change in normalized EMG AMP or EMG MPF (p > 0.05). The current findings indicated that torque responses were intensity specific, but TTF and neuromuscular responses were not. Furthermore, normalized EMG AMP and EMG MPF remained unchanged but NME decreased, likely due to peripheral fatigue and excitation-contraction coupling failure. Thus, this study provides information regarding the neuromuscular responses and mechanisms of fatigue associated with tasks anchored to RPE, which adds to the foundational understanding of the relationship between resistance exercise and the perception of fatigue., (Copyright © 2023 National Strength and Conditioning Association.)

Purpose: The present study examined the effects of sustained, isometric low- versus high-intensity tasks on time to task failure (TTF), performance fatigability (PF), ratings of perceived exertion (RPE), and the perceived causes of task termination from a post-test questionnaire (PTQ)., Methods: Ten men (mean ± SD: age = 21.1 ± 2.3 years; height = 180.2 ± 5.7 cm; body mass = 79.5 ± 8.8 kg) performed maximal voluntary isometric contractions (MVICs) before and after fatiguing, isometric forearm flexion tasks anchored to the torque corresponding to RPE values of 2 (TRQ2FT = 23.8 ± 7.1 N·m) and 8 (TRQ8FT = 60.9 ± 11.4 N·m). In addition, the subjects completed a PTQ which surveyed whether the perceived sensations of fatigue or pain, and/or the psychological factors of loss of focus and motivation contributed to the decision to terminate the task. Repeated measures ANOVAs, Wilcoxon-Signed Rank tests, and Spearman's Rank-Order Correlations were used to analyze the data., Results: Across the fatiguing tasks, there were similar decreases in MVIC torque (95.2 ± 20.3 vs. 68.9 ± 15.6 N·m; p < 0.001) and RPE values (p = 0.122) at task failure for TRQ2FT (7.4 ± 2.7) and TRQ8FT (8.9 ± 1.0), but a longer (p = 0.005) TTF for the TRQ2FT (245.0 ± 177.0 s) than TRQ8FT (36.8 ± 11.1 s)., Conclusions: Despite reaching task failure, the subjects were able to perform MVICs that were 100-300% greater than the target torque values within seconds of terminating the tasks. Thus, we hypothesized that task failure was not caused by an inability to produce sufficient torque to sustain the tasks, but rather an unwillingness to continue the task., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: Corrêa Neto, VG, Silva, DdN, Palma, A, de Oliveira, F, Vingren, JL, Marchetti, PH, da Silva Novaes, J, and Monteiro, ER. Comparison between traditional and alternated resistance exercises on blood pressure, acute neuromuscular responses, and rating of perceived exertion in recreationally resistance-trained men. J Strength Cond Res 38(5): e211-e218, 2024-The purpose of this study was to compare the acute effects of traditional and alternated resistance exercises on acute neuromuscular responses (maximum repetition performance, fatigue index, and volume load), rating of perceived exertion (RPE), and blood pressure (BP) in resistance-trained men. Fifteen recreationally resistance-trained men (age: 26.40 ± 4.15 years; height: 173 ± 5 cm, and total body mass: 78.12 ± 13.06 kg) were recruited and performed all 3 experimental conditions in a randomized order: (a) control (CON), (b) traditional (TRT), and (c) alternated (ART). Both conditions (TRT and ART) consisted of 5 sets of bilateral bench press, articulated bench press, back squat, and Smith back squat exercises at 80% 1RM until concentric muscular failure. The total number of repetitions performed across sets in the bench press followed a similar pattern for TRT and ART, with significant reductions between sets 3, 4, and 5 compared with set 1 (p < 0.05). There was a significant difference for set 4 between conditions with a lower number of repetitions performed in the TRT. The volume load was significantly higher for ART when compared with TRT. TRT showed significant reductions in BP after 10-, 40-, and 60-minute postexercise and when compared with CON after 40- and 60-minute postexercise. However, the effect size illustrated large reductions in systolic BP during recovery in both methods. Thus, it is concluded that both methods reduced postexercise BP., (Copyright © 2024 National Strength and Conditioning Association.)

Purpose: The aim of this study was 2-fold: (1) to examine the relationships between psychophysiological responses and locomotor demands with variations in technical performance during 2v2 and 4v4 conditioned games and (2) to compare psychophysiological and locomotor responses among players exhibiting higher and lower technical performance levels during the conditioned games., Methods: Twenty-four male youth soccer players (16.3 ± 0.8 y old) participating at the trained/developmental level underwent monitoring for psychophysiological responses (including heart rate, rating of perceived exertion, and visual analog scale), locomotor demands (such as distance covered), and technical performance variables (including successful and unsuccessful passes and shots, as well as lost balls) across 2v2 and 4v4 formats. These formats were applied 4 times within a single session and were replicated twice over 2 weeks., Results: Large correlations between the number of lost balls per minute and mean heart rate were found in both the 2v2 and 4v4 games (r = .586 and r = .665, respectively). Successful shots were inversely and largely correlated with mean heart rate (r = -.518) in 4v4 games. The number of interceptions per minute was inversely and significantly correlated with the visual analog scale in 2v2 and 4v4 games (r = -.455 and r = -.710, respectively). The frequency of lost balls was significantly higher among players who attained a higher mean heart rate (2v2: +42.9%, P = .031, d = -0.965; 4v4: +57.1%, P < .001, d = -2.072)., Conclusions: Coaches should be aware that highly psychophysiologically demanding scenarios may significantly impair technical performance. Therefore, prioritizing technical performance by deliberately adjusting the intensity should be considered.

Purpose: The monitoring of training loads and quantification of physical performance are common practices in youth soccer academies to support coaches in prescribing and programming training for individuals. The interaction between training load and physical performance is unknown during a preseason period in youth soccer players. The current study assessed changes in training load and physical assessments across a 4-week preseason period. The relationship between physical performance and match playing time in youth male soccer players was also investigated., Methods: The training loads of 25 professional youth academy male soccer players were monitored throughout a 4-week preseason period. Assessments of power, agility, speed, and aerobic capacity were undertaken in the first training session. Session ratings of perceived exertion (sRPE) and well-being questionnaires were collected during all training sessions and preseason matches. Playing time during subsequent competitive matches was recorded., Results: T test and 30-m-sprint assessments, conducted on the first day of preseason, were predictors of sRPE throughout preseason (t test χ2/df = 2.895, poor adjustment; 30-m sprint χ2/df = 1.608, good adjustment). YoYo Test performance was related with changes in perceived fatigue (χ2/df = 0.534, very good adjustment). Faster players reported higher values of sRPE, and players with higher aerobic capacity reported higher levels of fatigue across preseason. Well-being, perceived fatigue and soreness, and sRPE decreased across preseason. Greater match durations were related to higher levels of fatigue during preseason (P < .05)., Conclusion: The current study highlights the relationship between training load, physical assessments, and playing time. Coaches and practitioners can use physical test data at the start of preseason as an indication of players that report higher sRPE, perceived fatigue, and reduced well-being across preseason, supporting decisions around individualized training prescriptions.

This is a two-part study to determine one or more reliable physiological anchors for perception of effort. The purpose of Study 1 was to compare ratings of perceived exertion (RPE) at the ventilatory threshold (VT) in running, cycling, and upper body exercise with the premise that if RPE at VT did not differ across exercise modes, VT might provide a unique set of physiological inputs for perception of effort. For 27 participants, values for VT and for RPE at VT (Borg 6 to 20 scale) averaged 9.4 km⋅h -1 ( SD = 0.7) and 11.9 km⋅h -1 ( SD = 1.4) respectively in running, 135 W ( SD = 24) and 12.1 W ( SD = 1.6) in cycling, and 46 W ( SD = 5) and 12.0 W ( SD = 1.7) in upper body exercise. RPE did not differ, suggesting that VT may anchor effort perception. In Study 2, 10 participants performed cycle ergometer exercise for 30 minutes at their VT ( M = 101 W, SD = 21), at their maximal lactate steady state ( M = 143 W, SD = 22), and at their critical power (CP; M = 167 W, SD = 23). Mean end-exercise RPE were 12.1 ( SD = 2.1), 15.0 ( SD = 1.9), and 19.0 ( SD = 0.5), respectively. The very close clustering of RPE during exercise at CP hints that the confluence of physiological responses at CP may (also) serve as a determinant in perception of effort.

Abstract: SantaBarbara, NJ, Nosrat, S, Whitworth, JW, Ciccolo, JT. acute psychological effects of resistance exercise in men with symptoms of muscle dysmorphia: A pilot study. J Strength Cond Res 37(2): 277-283, 2023-This study tested the acute psychological effects of resistance exercise in men with symptoms of muscle dysmorphia. Twenty-one men completed 4 on-site sessions including a single session of moderate- (70% of 10 repetition maximum [RM]) and high- (100% of 10RM) intensity resistance exercise in a counter balanced order separated by at least 48 hours. State body image, perceived muscle size, exercise enjoyment, and ratings of perceived exertion (RPE) were assessed before, during, and after each session, and statistical significance was set a priori at p < 0.05. State body image significantly improve from pre to post during both sessions ( p < 0.01), with greater effect sizes seen for the high- ( d = 0.57) compared with the moderate- ( d = 0.39) intensity session. Perceived muscle size improved from pre to post during the high-intensity only ( p < 0.01, d = 0.66), and subjects enjoyed the high-intensity session significantly more than the moderate-intensity session ( p = 0.01), despite significantly higher RPE at each timepoint ( p < 0.01). Results contend with previous findings that show more positive psychological effects of moderate- compared with high-intensity resistance exercise. Education and client observation are essential to be aware of the potential for muscle dysmorphia. In instances where muscle dysmorphia is suspected, referral to qualified mental health professionals is recommended., (Copyright © 2022 National Strength and Conditioning Association.)

The purpose of this study was to investigate the relationship between mental fatigue induced by a demanding cognitive task and impaired physical performance in endurance due to a higher perception of effort. A total of 12 healthy adults and volunteers, who had previously practiced endurance activities for 4 to 8 h per week, performed a one-hour cognitive task involving either the process of response inhibition (Stroop task) or not (visualization of a documentary as control task), then 20 min of pedaling on a cycle ergometer at a constant perception of effort while cardio-respiratory and neuromuscular functions were measured. The Stroop task induces subjective feelings of mental fatigue (vigor: 3.92 ± 2.61; subjective workload: 58.61 ± 14.57) compared to the control task (vigor: 5.67 ± 3.26; p = 0.04; subjective workload: 32.5 ± 10.1; p = 0.005). This fatigue did not act on the produced perceived effort, self-imposed, and did not affect the cardio-respiratory or neuromuscular functions during the subsequent physical task whose type was medium-term endurance. Regardless of the mental condition, the intensity of physical effort is better controlled when the participants in physical activity control their perception of effort. Mental fatigue does not affect subsequent physical performance but estimated perceived exertion, which increases with the intensity and duration of the exercise.

Perceived fatigability, which has perception of physical strain and of mental strain as its components, can impact exercise tolerance. Upon ascent to high altitude, low landers experience reduced exercise capacity and reduced tolerance for a given absolute submaximal work rate. It is established that perceived physical strain tracks with relative exercise intensity. However, it is not known how altitude ascent affects perceived mental strain relative to perceived physical strain. We tested the hypothesis that when exercising at the same relative exercise intensity perceived physical strain will remain unchanged whereas perceived mental strain will decrease on ascent from low to high altitude in the Everest region in Nepal. Twelve hours after arriving at each of three elevations; 1400 m, 3440 m, and 4240 m, 12 untrained participants used the task effort awareness (TEA) and physical-rating of perceived exertion (P-RPE) scales to report perceived mental and physical strain during a 20 min walking test at a self-monitored heart rate reserve (HRR) range of 40-60% (Polar HR Monitor). TEA and P-RPE were recorded twice during exercise (5-7 min and 14-16 min). Neither P-RPE (1400 m: 11.1 ± 1.8, 3440 m: 10.7 ± 1.2, 4240 m: 11.5 ± 1.5) nor %HRR (1400 m: 55.25 ± 7.34, 3440 m: 51.70 ± 6.70, 4240 m: 50.17 ± 4.02) changed as altitude increased. TEA decreased at 4240 m (2.05 ± 0.71) compared to 1400 m (3.44 ± 0.84)--this change was not correlated with any change in %HRR nor was it due to a change in core affect. These findings support our hypothesis and demonstrate the independence of perceived physical and perceived mental strain components of perceived fatigability. Implications for exercise tolerance remain to be determined., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

This study examined whether an inertial measurement unit (IMU), in combination with machine learning, could accurately predict two indirect measures of bowling intensity through ball release speed (BRS) and perceived intensity zone (PIZ). One IMU was attached to the thoracic back of 44 fast bowlers. Each participant bowled 36 deliveries at two different PIZ zones (Zone 1 = 24 deliveries at 70% to 85% of maximum perceived bowling effort; Zone 2 = 12 deliveries at 100% of maximum perceived bowling effort) in a random order. IMU data (sampling rate = 250 Hz) were downsampled to 125 Hz, 50 Hz, and 25 Hz to determine if model accuracy was affected by the sampling frequency. Data were analysed using four machine learning models. A two-way repeated-measures ANOVA was used to compare the mean absolute error (MAE) and accuracy scores (separately) across the four models and four sampling frequencies. Gradient boosting models were shown to be the most consistent at measuring BRS (MAE = 3.61 km/h) and PIZ (F-score = 88%) across all sampling frequencies. This method could be used to measure BRS and PIZ which may contribute to a better understanding of overall bowling load which may help to reduce injuries.

Background: Although aquabiking has become widespread, the assessment of the intensity for aquatic cycling remains poorly defined., Methods: This study investigated the validity of differentiated ratings of perceived exertion (dRPE) recorded from the chest (RPE-chest) and legs (RPE-legs) during aquatic cycling and aimed to determine a simple and accurate estimate of dRPE to regulate aquabiking. Twelve active young subjects performed a pedaling task on an immersed ergocycle using randomly imposed cycling cadences ranging from 50 to 100 rpm in 3-minute steps interspersed by 3-minute active recovery periods. dRPE and cardiorespiratory responses (heart rate [HR]; percentage of heart rate peak value [%HRpeak]; oxygen uptake [V̇O2]; and percentage of peak oxygen uptake [%V̇O2peak]) were measured during the last minute of each level., Results: The data described three-step relationships between dRPE and rpm. RPE-chest and RPE-legs increased linearly only for cadences between 60 and 90 rpm (r=0.81 and r=0.88, respectively; P<0.001). At these cadences, significant relationships were also observed between dRPE and all the physiological data (highest Pearson product moment for %V̇O2peak: 0.81 for RPE-chest and 0.88 for RPE-legs, P<0.0001). Last, the classic signal dominance from the legs was observed (RPE-legs>RPE-chest, P<0.0001) but was reduced compared with data obtained during dryland cycling, suggesting a modulating effect of the aquatic medium., Conclusions: Cycling cadence was the better estimator of RPE-legs, which seemed to be the more appropriate dRPE to regulate the intensity of aquabiking in a safe range of pedaling rates.

Background: Although the effects of sub-maximal continuous aerobic training (SCT) and high-intensity interval training (HIIT) are well studied in performance athletes and in several patient groups, there is not much evidence about the effects of these exercises in sedentary healthy young population. The aim of the study was to compare the effects of these two different types of aerobic exercises on respiratory parameters, aerobic capacity and perceived stress in healthy university students., Methods: Thirty-six healthy, young subjects with a mean age of 20.83±0.97 years were included in the study (N.=19 in HIIT and N.=17 in SCT). Pulmonary function tests (PFTs) and respiratory muscle strength (RMS) assessments were done using a desktop spirometer. Aerobic capacity was estimated with the Bruce treadmill exercise test. The Perceived Stress Scale (PSS) was used for the assessment of stress perception. All participants exercised 3 times per week for 4 weeks (a total of 12 sessions)., Results: After 12 sessions, the peak expiratory flow parameter (a PFT value) of both groups showed significant increases, but there was no difference between the groups. The RMS of the subjects increased significantly in both the groups (P<0.05), but there was no significant difference between the groups. Both groups showed significant increases in terms of aerobic capacity (P>0.05), and the improvement was significantly higher in the HIIT group. Perceived stress values showed a significant increase in the SCT group., Conclusions: Based on the results of this study, the two exercise types were found to have similar effects on RMS. Also, when compared with SCT, HIIT was found to have more effect on aerobic capacity.

Purpose : To analyze the contribution of physical measures and external load in the match-based internal load of elite soccer players. Methods : Twenty-three elite soccer players (n = 23, age 26.69 ± 3.93 years, body mass 78.04 ± 5.03 kg, height 178.04 ± 5.19 cm, body fat 10.98 ± 1.25%) from a first division soccer team of the Brazilian Championship were evaluated first with anthropometric and physical measures (flexibility and muscle power of lower limbs), and after 24 hrs they were asked to perform an incremental treadmill test (VO 2 max and ventilatory thresholds). Subsequently, athletes were monitored for 6 weeks during nine official matches of a regional championship. On match days, the external load data (e.g., player load) were collected by triaxial accelerometers with GPS systems and post 30 min after the end of the match the internal load was assessed with the Session Rating of Perceived Exertion method (Session-RPE). Results : Our main findings showed significant contributions of the Player Load (r = .62, p < .001; 42.3%) and Anaerobic Threshold (r = - .199, p = .05, 17%) for the predictive model of Session-RPE. Conclusions : Physical measures and external load have a significant influence on the internal load in elite soccer players. Our findings suggest that sport scientists can use the Session-RPE as a low-cost method for prescribing and monitoring training loads, by the influence of physical measures and external load on the match-based internal load, in order to optimize athletes' performance.

This study examined the effects of slow and fast music tempi on effort-related thoughts, rating of perceived exertion (RPE), affect, heart rate, and performance during isometric strength exercises. Participants were randomly assigned to one of three conditions (no-music control, fast-tempo music, and slow-tempo music) and performed two isometric strength exercises (wall-sit and plank). RPE, attention allocation, and affect were measured during each exercise task. Participants in both the fast- and slow-tempo music conditions maintained a dissociative state for longer than those in the no-music control condition during the wall-sit exercise; however, this effect did not manifest during the plank exercise. Neither music condition influenced HR, RPE, time to volitional exhaustion, or affect. Within the first few minutes of exercise, participants exhibited an increase in HR and perceived exertion, as well as a corresponding shift towards associative attention and a high arousal state. The results are discussed with reference to potential underlying mechanisms and current theories pertaining to RPE, attention allocation, and affect.

Purpose : This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods : Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results : Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition ( p < .05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band ( p < .05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion : Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

Background: Core affect is defined as the most general affective construct consciously accessible that is experienced constantly. It can be experienced as free-floating (mood) or related to prototypical emotional episodes. The aim of this study was to examine the influence of pleasant and unpleasant core affect on cyclo-ergometer endurance performance. Specifically, we considered the influence of pleasant and unpleasant core affect on performance outcomes (i.e., time to task completion) and rate of perceived exertion (RPE; Borg Scale, category ratio-10) collected during the task., Methods: Thirty-one participants aged 20-28 years were recruited. Core affect was randomly elicited by 2 sets of pleasant and unpleasant pictures chosen from the international affective picture system. Pictures were displayed to participants during a cyclo-ergometer performance in 2 days in a counterbalanced order. RPE was collected every minute to detect volunteers' exhaustion., Results: The study sample was split into 2 groups. Group 1 comprised participants who performed better with pleasant core affect, whereas Group 2 included participants who performed better with unpleasant core affect. Mixed between-within subjects analysis of variance revealed a significant 2 (group) × 2 (condition) × 5 (isotime) interaction (p = 0.002, η p 2  = 0.158). Post hoc comparisons showed that participants who obtained better performance with pleasant core affect (pleasant pictures; Group 1) reported lower RPE values at 75% of time to exhaustion in a pleasant core affect condition compared to an unpleasant core affect condition. On the other hand, participants who obtained better performance with unpleasant core affect (unpleasant pictures; Group 2) reported lower RPE values at 75% and 100% of time to exhaustion in an unpleasant core affect condition., Conclusion: Findings suggest differential effects of pleasant and unpleasant core affect on performance. Moreover, core affect was found to influence perceived exertion and performance according to participants' preferences for pleasant or unpleasant core affect., (Copyright © 2020. Production and hosting by Elsevier B.V.)

Background: Citrulline is one of the non-essential amino acids that is thought to improve exercise performance and reduce post-exercise muscle soreness. We conducted a systematic review and meta-analysis to determine the effect of citrulline supplements on the post-exercise rating of perceived exertion (RPE), muscle soreness, and blood lactate levels., Methods: A random effects model was used to calculate the effect sizes due to the high variability in the study design and study populations of the articles included. A systematic search of PubMed, Web of Science, and ClinicalTrials.gov was performed. Eligibility for study inclusion was limited to studies that were randomized controlled trials involving healthy individuals and that investigated the acute effect of citrulline supplements on RPE, muscle soreness, and blood lactate levels. The supplementation time frame was limited to 2 h before exercise. The types and number of participants, types of exercise tests performed, supplementation protocols for L-citrulline or citrulline malate, and primary (RPE and muscle soreness) and secondary (blood lactate level) study outcomes were extracted from the identified studies., Results: The analysis included 13 eligible articles including a total of 206 participants. The most frequent dosage used in the studies was 8 g of citrulline malate. Citrulline supplementation significantly reduced RPE (n = 7, p = 0.03) and muscle soreness 24-h and 48-h after post-exercise (n = 7, p = 0.04; n = 6, p = 0.25, respectively). However, citrulline supplementation did not significantly reduce muscle soreness 72-h post-exercise (n = 4, p = 0.62) or lower blood lactate levels (n = 8, p = 0.17)., Conclusion: Citrulline supplements significantly reduced post-exercise RPE and muscle soreness without affecting blood lactate levels., (Copyright © 2020. Production and hosting by Elsevier B.V.)

Purpose: The current study investigated the effect of attention on heaviness perception and its physiological and kinematic contributions. Method: Participants lifted objects that varied in mass and volume while their muscle activity and movement were recorded. Participants were instructed to pay attention to their arm (internal) or the object (external). Results: While heaviness perception did not change as a function of attention, whether muscle activity and movement combined for perception differed across attention conditions. Specifically, muscle activity and movement combined to significantly predict heaviness perception in the external condition, but not the internal condition. Additionally, movement was more salient for perception in both conditions compared to previous research investigating the contribution of muscle activity and movement to heaviness perception. Conclusion: It is suggested that these results support the constrained action hypothesis, which suggests that adopting an external focus of attention benefits motor task performance and learning, and should be further explored in the context of a theory of haptic perception that suggests that the medium for haptic perception is the multifractal tensegrity structure of the body.

Purpose : The aim of the study was to verify the agreement between preplanned and executed pacing during a 3-km race and determine whether adjustments are mediated by the rating of perceived exertion (RPE). Method : Thirteen young runners (eight males and five females, 17.5 ± 2.1 and 17.0 ± 1.6 years old, respectively) with national and international experience participated in the study. Before the simulated competition, the athletes informed of their preplanned pacing for the distance through a dashboard with the most common pacing profiles and were also asked to complete a questionnaire communicating their preplanned RPE for each lap of race. During 3-km, heart rate (HR), executed RPE and lap time were recorded. Results : Our results showed no significant association between preplanned and executed pacing ( p = .631). Moreover, no significant difference between preplanned and executed RPE was found, including the analysis by laps and phases. RPE and HR increased over time during the race ( p < .001). Conclusions : The athletes changed from their preplanned pacing, however, their RPE were similar in the preplanned and executed during the 3-km race. These findings indicate that the RPE could be responsible for adjustments in the pacing strategy.

Introduction: To explain motivational difficulties in schizophrenia (SZ), attention has focused on the reward system and effort-based decision-making deficits. However, according to motivational intensity theory (MIT), effort is not directly determined by reward but by task difficulty. Moreover, no studies have examined the effort perception in the SZ. Therefore, this cross-sectional study compared effort perception in SZ group with healthy controls. Method: Task difficulty was manipulated by increasing the distance covered (from 8 to 48 metres). Walking speed, perceptions of difficulty and effort were assessed for all difficulty levels. Clinical and bodyweight variables were recorded. Results: As postulated by MIT, perceived effort and difficulty increased with task difficulty in both groups. Perceived effort and difficulty were higher in the SZ group. Perceptions of effort were positively correlated with BMI in SZ, but not with clinical variables. Importantly, although SZ patients perceived the task as more effortful, walking speed was similar between groups. Conclusions: Taken together, these results suggested that individuals with SZ perceived more strongly the effort and the difficulty of the task but could mobilise more effort to complete it. This observation may explain in part the decrease in engaging in physical demanding activities in daily life in SZ.

Background: The rest interval between sets can affect the responses to resistance training. Thus, the purpose of this study was to compare the effects of different rest intervals (RI) on volume, density, and rating of perceived exertion (RPE) when adopting a crescent pyramid (CP) system., Methods: Twenty young women (21.1±2.6 years, 1.59±0.06 m, 58.5±9.3 kg) participated in this study. All participants performed three experimental sessions of the leg press exercise in 5 sets until voluntary muscular failure at 60%, 65%, 70%, 75%, and 80% of one-repetition maximum (1RM). A randomized and crossover design was used so that in each session one of three RI (RI-1 = 1 min, RI-2 = 2 min, and RI-3 = 3 min) was tested., Results: The participants performed a significantly larger volume in the RI-3 (12820±3134 kg) when compared to RI-1 (10367±3053 kg) condition (P<0.05). The volume did not differ between RI-2 and RI-3 (P>0.05). The density was higher (P<0.05) in RI-1 (43.1±12.7 kg/s) when compared RI-2 (25.6±5.8 kg/s) and RI-3 (17.7±4.3 kg/s). The RI-2 presented higher density compared to RI-3 condition (P<0.05). The RPE was not different between the three conditions (P>0.05)., Conclusions: The use of 2 minutes of rest between sets allowed the performance of a high volume-load and density of the session in young women. In addition, the three experimental sessions provided a high perception of effort.

Objective: To assess the efficacy of two different passive back-support exoskeleton (BSE) designs, in terms of trunk muscle activity, perceived low-back exertion, and task performance., Background: BSEs have the potential to be an effective intervention for reducing low-back physical demands, yet little is known about the impacts of different designs in work scenarios requiring varying degrees of symmetric and asymmetric trunk bending during manual assembly tasks., Method: Eighteen participants (gender balanced) completed lab-based simulations of a precision manual assembly task using a "grooved pegboard." This was done in 26 different conditions (20 unsupported; 6 supported, via a chair), which differed in vertical height, horizontal distance, and orientation., Results: Using both BSEs reduced metrics of trunk muscle activity in many task conditions (≤47% reductions when using BackX™ and ≤24% reductions when using Laevo™). Such reductions, though, were more pronounced in the conditions closer to the mid-sagittal plane and differed between the two BSEs tested. Minimal effects on task completion times or ratings of perceived exertion were found for both BSEs., Conclusion: Our findings suggest that using passive BSEs can be beneficial for quasi-static manual assembly tasks, yet their beneficial effects can be task specific and specific to BSE design approaches. Further work is needed, though, to better characterize this task specificity and to assess the generalizability of different BSE design approaches in terms of physical demands, perceived exertion, and task performance., Application: These results can help guide the choice and application of passive BSE designs for diverse work scenarios involving nonneutral trunk postures.

Purpose: To systematically quantify the external and internal workloads reported during games-based drills in basketball and identify the effects of different modifiable factors on the workloads encountered., Methods: PubMed, Scopus, MEDLINE, and SPORTDiscus databases were searched for original research published up until January 2, 2019. The search included terms relevant to workload, games-based drills, and basketball. Studies were screened using predefined selection criteria, and methodological quality was assessed prior to data extraction., Results: The electronic search yielded 8,284 studies with 3,411 duplicates. A total of 17 studies met the inclusion criteria for this review, with quality scores ranging from 9 to 10 out of 11. Factors regularly modified during games-based drills among the included studies were team size, playing area, playing and rest time, and game alterations. Games-based drills containing smaller team sizes elicited greater external and internal workloads compared to larger team sizes. Furthermore, full-court games-based drills elicited greater external and internal workloads compared to half-court drills, while continuous games-based drills elicited greater internal workloads compared to intermittent drills., Conclusions: This review provides a comprehensive collation of data indicating the external and internal workloads reported during different games-based drills in various samples of basketball players. Furthermore, evidence is provided for basketball coaches to consider when prescribing games-based drills and modifying factors during drills across the season. Current literature suggests that smaller team sizes and full-court playing areas elicit greater external and internal workloads than larger team sizes and half-court drills, respectively. Furthermore, continuous games-based drills elicit greater internal workloads than intermittent drills.

Purpose: To determine whether daily perceived recovery is explained from a multifactorial single-session classification of recovery (ie, faster vs slower) or other circumstantial factors (ie, previous training load, self-reported sleep, or phase of the microcycle)., Methods: Nineteen elite male futsal players were initially allocated to a recovery-classification group (faster recovery, slower physiological, or slower perceptual) based on previous research using a multifactorial cluster-analysis technique. During 4 ensuing weeks of preseason, training loads were monitored via player load, training impulse, and session rating of perceived exertion. Before each day's training, players reported their perception of recovery (Total Quality of Recovery scale [TQR]) and the number of hours and perceived quality of sleep the night prior. A hierarchical linear mixed model was used to analyze the effect of the different recovery profiles, training load, sleep, and phase of the microcycle (ie, start, middle, end) on daily TQR., Results: The recovery classification of players (P = .20), training load (training impulse, P = .32; player load, P = .23; session rating of perceived exertion, P = .46), and self-reported hours slept the night before (P = .45) did not significantly influence TQR. However, perceived sleep quality (P < .01) and phase of the microcycle (P < .01) were significantly associated with TQR (r2 = .41)., Conclusions: Neither recovery classification nor prior training load influenced perceived recovery during the preseason. However, higher TQR was evident with better self-reported sleep quality, whereas lower values were associated with phases of the training week.

Purpose: To investigate whether providing global positioning system feedback to players between bouts of small-sided games (SSGs) can alter locomotor, physiological, and perceptual responses., Methods: Using a reverse counterbalanced design, 20 male university rugby players received either feedback or no feedback during "off-side" touch rugby SSGs. Eight 5v5, 6 × 4-minute SSGs were played over 4 d. Teams were assigned to a feedback or no-feedback condition (control) each day, with feedback provided during the 2-min between-bouts rest interval. Locomotor, heart rate, and differential rating of perceived exertion of breathlessness and leg-muscle exertion were measured and analyzed using a linear mixed model. Outcomes were reported using effect sizes (ES) and 90% confidence intervals (CI), and then interpreted via magnitude-based decisions., Results: Very likely trivial to unclear differences at all time points were observed in heart rate and differential rating of perceived exertion measures. Possibly to very likely trivial effects were observed between conditions, including total distance (ES = 0.15; 90 CI, -0.03 to 0.34), high-speed distance (ES = -0.07; 90 CI, -0.27 to 0.13), and maximal sprint speed (ES = 0.11; 90% CI, -0.11 to 0.34). All within-bout comparisons showed very likely to unclear differences, apart from possible increases in low-speed distance in bout 2 (ES = 0.23; 90% CI, 0.01 to 0.46) and maximal sprint speed in bout 4 (ES = 0.21; 90% CI, -0.04 to 0.45)., Conclusions: In this study, verbal feedback did not alter locomotor, physiological, or perceptual responses in rugby players during SSGs. This may be due to contextual factors (eg, opposition) or the type (ie, distance) or low frequency of feedback provided.

Purpose: Session RPE (sRPE) is used to track internal training/competition load in athletes using a metric known as the acute to chronic workload ratio (ACWR). Research that reported on team sports has determined that if the acute load is higher than the chronic load, athletes are likely to sustain injury. No studies, however, have attempted to investigate internal load and injury in a tennis population despite the rigorous training loads. Therefore, the purpose of this study was to investigate if sRPE ACWR is associated with injury in junior tennis players over a 7-month time period., Methods: Forty-two junior tennis players were recruited to participate, 26 were included in the final analysis. Players provided a rating of RPE as an estimate of training intensity every day after training/match sessions. sRPE, a measure of internal and external training load was calculated by multiplying the training/match sRPE by the session duration in minutes. Players self-reported all injuries. The ACWR was the primary independent variable. Acute load was determined as the total sRPE for 1 wk, whereas a 4-wk rolling average sRPE represented chronic load., Results: Seventeen players sustained injuries. The model indicated that ACWR from the previous week (P < 0.001) and previous injury history (P = 0.003) were significant predictors of injury the following week. In the week preceding injury, the average ACWR was 1.57 (SD, 0.90)., Conclusion: Injured players had on average 1.5 times more training load in the past week compared with the previous 4 wk. A majority of players who went on to sustain an injury were not prepared for the load endured. These results were similar to previous studies investigating ACWR where an acute increase in load was associated with increased injury risk.

Identifying the external training load variables which influence subjective internal response will help reduce the mismatch between coach-intended and athlete-perceived training intensity. Therefore, this study aimed to reduce external training load measures into distinct principal components (PCs), plot internal training response (quantified via session Rating of Perceived Exertion [sRPE]) against the identified PCs and investigate how the prescription of PCs influences subjective internal training response. Twenty-nine school to international level youth athletes wore microtechnology units for field-based training sessions. SRPE was collected post-session and assigned to the microtechnology unit data for the corresponding training session. 198 rugby union, 145 field hockey and 142 soccer observations were analysed. The external training variables were reduced to two PCs for each sport cumulatively explaining 91%, 96% and 91% of sRPE variance in rugby union, field hockey and soccer, respectively. However, when internal response was plotted against the PCs, the lack of separation between low-, moderate- and high-intensity training sessions precluded further analysis as the prescription of the PCs do not appear to distinguish subjective session intensity. A coach may therefore wish to consider the multitude of physiological, psychological and environmental factors which influence sRPE alongside external training load prescription.

Purpose: To quantify the sleep/wake behaviors of adolescent, female basketball players and to examine the impact of daily training load on sleep/wake behaviors during a 14-day training camp., Methods: Elite, adolescent, female basketball players (N = 11) had their sleep/wake behaviors monitored using self-report sleep diaries and wrist-worn activity monitors during a 14-day training camp. Each day, players completed 1 to 5 training sessions (session duration: 114 [54] min). Training load was determined using the session rating of perceived exertion model in arbitrary units. Daily training loads were summated across sessions on each day and split into tertiles corresponding to low, moderate, and high training load categories, with rest days included as a separate category. Separate linear mixed models and effect size analyses were conducted to assess differences in sleep/wake behaviors among daily training load categories., Results: Sleep onset and offset times were delayed (P < .05) on rest days compared with training days. Time in bed and total sleep time were longer (P < .05) on rest days compared with training days. Players did not obtain the recommended 8 to 10 hours of sleep per night on training days. A moderate increase in sleep efficiency was evident during days with high training loads compared with low., Conclusions: Elite, adolescent, female basketball players did not consistently meet the sleep duration recommendations of 8 to 10 hours per night during a 14-day training camp. Rest days delayed sleep onset and offset times, resulting in longer sleep durations compared with training days. Sleep/wake behaviors were not impacted by variations in the training load administered to players.

During 20 m shuttle tests, obese adolescents may have difficulty achieving maximum cardiorespiratory performance due to the presence of braking-relaunch phases (BRP). Nineteen obese adolescents aged 15.2 ± 1.5 years (body mass index [BMI] = 39.7 ± 5.9 kg.m -2 ) performed three graded walking exercises on a 50 m track at speeds between 3 and 6 km/h: a continuous-straight-line protocol (C), a continuous protocol that required turning back every 30 sec (C-BRP) and an intermittent protocol that consisted of successively walking then resting for 15 sec (15-15). Oxygen uptake (VO 2 ), aerobic cost of walking (Cw), ventilation (VE) and rating of perceived exertion (RPE) were measured at each stage during the protocols. During C-BRP, the responses were not significantly higher compared with C (p > 0.30). During 15-15, the VO 2 , Cw and VE were ~ 15 to 25% lower than during C beginning at 4 km/h (p < 0.05). In obese adolescents, the respiratory impact of sudden directional changes during the 20 m shuttle-type test appeared to be minor at walking speeds. During the 15-15 test, the intensity increases more progressively, and this design may encourage obese adolescents to walk further than during a continuous test.

Purpose: Due to age-related changes in the psychobiological state of masters athletes, this brief report aimed to compare training load responses using heart rate (HR) and ratings of perceived exertion (RPE) during standardized training sessions between masters and young cyclists., Methods: Masters (n = 10; 55.6 [5.0] y) and young (n = 8; 25.9 [3.0] y) cyclists performed separate endurance and high-intensity interval training sessions. Endurance intensity was set at 95% of ventilatory threshold 2 for 1 hour. High-intensity interval training consisted of 6 × 30-second intervals at 175% peak power output with 4.5-minute rest between intervals. HR was monitored continuously and RPE collected at standardized time periods during each session. Banister training impulse and summated-HR-zones training loads were also calculated., Results: Despite a significantly lower mean HR in masters cyclists during endurance (P = .04; d = 1.06 [±0.8], moderate) and high-intensity interval training (P = .01; d = 1.34 [±0.8], large), no significant differences were noted (P > .05) when responses were determined relative to maximum HR or converted to training impulse and summated-HR-zone loads. Furthermore, no interaction or between-group differences were evident for RPE across either session (P > .05)., Conclusions: HR and RPE values were comparable between masters and young cyclists when relative HR responses and HR training load models are used. This finding suggests HR and RPE methods used to monitor or prescribe training load can be used interchangeably between masters and young athletes irrespective of chronological age.

Introduction: An increased perception of effort and subjective fatigue are thought to be central to decreased exercise performance observed after disrupted sleep. However, there is limited understanding of mechanisms that underpin these phenomena. We investigated the role of interleukin-6 (IL-6), the soluble IL-6 receptor, and neuroendocrine factors (cortisol, adrenaline, noradrenaline, and brain-derived neurotropic factor) in mediating these responses at rest and during exercise., Methods: In a randomized order, 10 healthy active men completed three experimental trials following different sleep conditions: a single night of sleep deprivation, partial sleep deprivation equivalent to 4 h of sleep, and normal sleep. The experimental sessions consisted of physiological and perceptual measurements of exercise intensity throughout 45-min moderate intensity and 15-min maximal effort cycling. Cytokine and neuroendocrine factors were assessed at rest and in response to exercise., Results: Sleep deprivation resulted in increased resting IL-6, lower blood glucose, increased perceived fatigue and perception of effort, lower free-living energy expenditure, and reduced maximal exercise performance. In contrast, sleep deprivation did not alter physiological, cytokine, or neuroendocrine responses to exercise. Variations in the resting concentration of IL-6 were associated with lowered blood glucose, an increased perception of effort, and impaired exercise performance. Resting concentrations of cortisol, adrenaline, noradrenaline, and BNDF showed subtle interactions with specific aspects of mood status and performance but were not affected by sleep deprivation. There were minimal effects of partial sleep deprivation., Conclusions: These findings demonstrate that cytokine and neuroendocrine responses to exercise are not altered by sleep deprivation but that changes in the resting concentration of IL-6 may play a role in altered perception of effort in this context.

The purpose of the study was to examine the concurrent and construct validity of a new perceptual scale to control the exercise intensity using elastic bands (Resistance Intensity Scale for Exercise; RISE) in the elderly. Twenty-six participants underwent two sessions consisting of 4 exercises. The participants performed three sets of 15 repetitions per exercise of either low, medium, or high intensity. The criterion variables were heart rate and applied force (mean and peak). Following the final repetition of each set, active muscle (AM) and overall body (OB) ratings of perceived exertion (RPE) were collected from RISE and the OMNI-Resistance Exercise Scale of perceived exertion with elastic bands (OMNI-RES EB). Construct validity was established by correlating the perceptual score obtained from both scales, RISE and OMNI-RES EB. Significant ( p ≤ 0.05) and positive linear relationships between both scales were found (RPE-AM R 2 = 0.90; RPE-OB R 2 = 0.77). Significant differences in heart rate, applied force, and RISE scores were observed between the sets of the three intensities. For all 4 analyzed exercises, high-intensity sets elicited higher heart rate, applied force, and perceptual scores compared with the medium- and low-intensity sets. Furthermore, the medium-intensity sets produced higher perceptual, physiologic, and performance responses than the low-intensity sets. Intersession reliability was 0.88 for heart rate, 0.94 and 0.95 for applied force, 0.88 for the RPE-AM, and 0.80 for the RPE-OB. Conclusion : The RISE scale can be considered a valid method for assessing the perceived exertion during resistance exercises performed with elastic bands in the elderly., (© Journal of Sports Science and Medicine.)

Purpose: Dietary supplementation with inorganic nitrate (NO3-) can enhance high-intensity exercise performance by improving skeletal muscle contractility and metabolism, but the extent to which this might be linked to altered psychophysiological processes is presently unclear. The purpose of this study was to assess the effects of NO3--rich beetroot juice (BJ) supplementation on profile of mood states, ratings of perceived exertion (RPE), and performance in a 30-second Wingate cycle test., Methods: In a double-blind, randomized, cross-over study, 15 subjects completed 2 laboratory sessions after ingesting NO3--rich or NO3--depleted (placebo) BJ. Participants initially completed the profile of mood states questionnaire. Subsequently, participants completed a warm-up followed by a 30-second all-out Wingate cycling test. After the Wingate test, participants immediately indicated the RPE of their leg muscles (RPEmuscular), cardiovascular system (RPEcardio), and general RPE (RPEgeneral)., Results: Compared with the placebo condition, supplementation with BJ increased peak power output (Wpeak) (+4.4%, 11.5 [0.7] vs 11.1 [1.0] W·kg-1; P = .039) and lowered the time taken to reach Wpeak (7.3 [0.9] vs 8.7 [1.5] s; P = .002) during the Wingate test. The profile of mood states score linked to tension was increased prior to the Wingate test (4.8 [3.0] vs 3.4 [2.4]; P = .040), and RPEmuscular was lowered immediately following the Wingate test (17.7 [1.6] vs 18.3 [1.0]; P = .031), after BJ compared with placebo ingestion., Conclusions: Acute BJ supplementation improved pre-exercise tension, 30-second Wingate test performance, and lowered postexercise RPEmuscular.

Purpose: Although the session rating of perceived exertion (sRPE) is primarily a marker of internal training load (TL), it may be sensitive to external TL determining factors, such as duration and volume. Thus, sRPE could provide further information on accumulated fatigue not available from markers of internal TL. Therefore, the purpose of this study was to investigate sRPE during heavy training bouts at relatively constant intensity., Methods: Eleven university swimmers performed a high-volume training session consisting of 4 × 10 × 100-yd (4 × 10 × 91.4 m). Repetition lap time and heart rate were measured for each repetition and averaged for each set. Blood lactate concentration was measured after each set. At the end of each set, a 10-minute rest period was allowed, during which sRPE values were obtained, as if the training bout had ended., Results: There were no differences between sets for lap time (P = .096), heart rate (P = .717), and blood lactate concentration (P = .466), suggesting that the subjects were working at the same external and internal intensity. There was an increase (P = .0002) in sRPE between sets (first 4 [1.2], second 5 [1.3], third 7 [1.3], and fourth 8 [1.5]), suggesting that even when maintaining the same intensity, the perception of the entire workload increased with duration., Conclusions: Increases in duration, although performed with a consistent internal and external intensity, influences sRPE. These findings support the concept that sRPE may provide additional information on accumulated fatigue not available from other markers of TL.

Purpose: To investigate within-player effect, between-player effect, and individual response of external training load from player tracking devices on session rating of perceived exertion training load (sRPE-TL) in elite football players., Methods: The authors collected sRPE-TL from 18 outfield players in 21 training sessions. Total distance, high-speed running distance (>14.4 m/s), very high-speed running distance (>19.8 m/s), PlayerLoad™, PlayerLoad2D™, and high-intensity events (HIE > 1.5, HIE > 2.5, and HIE > 3.5 m/s) were extracted from the tracking devices. The authors modeled within-player and between-player effects of single external load variables on sRPE-TL, and multiple levels of variability, using a linear mixed model. The effect of 2 SDs of external load on sRPE-TL was evaluated with magnitude-based inferences., Results: Total distance, PlayerLoad™, PlayerLoad2D™, and HIE > 1.5 had most likely substantial within-player effects on sRPE-TL (100%-106%, very large effect sizes). Moreover, the authors observed likely substantial between-player effects (12%-19%, small to moderate effect sizes) from the majority of the external load variables and likely to very likely substantial individual responses of PlayerLoad™, high-speed running distance, very high-speed running distance, and HIE > 1.5 (19%-30% coefficient of variation, moderate to large effect sizes). Finally, sRPE-TL showed large to very large between-session variability with all external load variables., Conclusions: External load variables with low intensity-thresholds had the strongest relationship with sRPE-TL. Furthermore, the between-player effect of external load and the individual response to external load advocate for monitoring sRPE-TL in addition to external load. Finally, the large between-session variability in sRPE-TL demonstrates that substantial amounts of sRPE-TL in training sessions are not explained by single external load variables.

Purpose: The aim of this study was to compare the concentration of blood lactate [bLa-] and the subjective perception of exertion of trained men in a moderate repetition protocol (MRP) versus a high repetition protocol (HRP) equated for time under tension., Methods: A sample of 40 healthy young men (aged, 23.2 ± 4.0 years; height, 177.3 ± 7.0 cm; BMI, 24.3 ± 2.2) performed two sessions of 8 sets of bicep curls with a one-week recovery interval between the trials. In the HRP protocol, 20 repetitions were performed with a cadence of 2 seconds of eccentric and 1 second of concentric, while in the MRP protocol 10 repetitions were performed with 4 seconds of eccentric and 2 seconds of concentric. Cadences were controlled by a metronome. At the beginning and end of each of the sessions, blood lactate was taken at 2, 15, and 30 minutes, and rating of perceived exertion (OMNI-RES) was assessed immediately after completion of each session., Results: There were [bLa-] differences between protocols in the MRP 2 min, (5.2 ±1.4); 15 min, (3.2 ±1.2); 30 min, (1.9 ±0.6); p< 0.05, and the HRP 2 min, (6.1 ±1.6); 15 min, (3.7 ±1.1); 30 min, (2.2 ±0.6); p<0.01. OMNI-RES was higher in HRP, (8.8 ±0.7) than in MRP, (7.7 ±0.9). Additionally, a correlation was found between the RPE and [bLa-] values in the HRP protocol (rs = 0.35, p < 0.01)., Conclusions: Training protocols with high times under tension promote substantial increases in metabolic stress, however, our findings indicate that HRP generates more [bLa-] than MRP. In addition, there were higher RPE values in the HRP protocol compared to MRP in single-joint exercises., Competing Interests: The authors have declared that no competing interests exist.