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Purpose Following resistance exercise, uncertainty exists as to whether the regular application of cold water immersion attenuates lean muscle mass increases in athletes. The effects of repeated post-resistance exercise cold versus hot water immersion on body composition and neuromuscular jump performance responses in athletes were investigated. Methods Male, academy Super Rugby players (n = 18, 19.9 ± 1.5 y, 1.85 ± 0.06 m, 98.3 ± 10.7 kg) participated in a 12-week (4-week × 3-intervention, i.e., control [CON], cold [CWI] or hot [HWI] water immersion) resistance exercise programme, utilising a randomised cross-over pre–post-design. Body composition measures were collected using dual-energy X-ray absorptiometry prior to commencement and every fourth week thereafter. Neuromuscular squat (SJ) and counter-movement jump (CMJ) performance were measured weekly. Linear mixed-effects models were used to analyse main (treatment, time) and interaction effects. Results There were no changes in lean (p = 0.960) nor fat mass (p = 0.801) between interventions. CON (p = 0.004) and CWI (p = 0.003) increased (g = 0.08–0.19) SJ height, compared to HWI. There were no changes in CMJ height (p = 0.482) between interventions. Conclusion Repeated post-resistance exercise whole-body CWI or HWI does not attenuate (nor promote) increases in lean muscle mass in athletes. Post-resistance exercise CON or CWI results in trivial increases in SJ height, compared to HWI. During an in-season competition phase, our data support the continued use of post-resistance exercise whole-body CWI by athletes as a recovery strategy which does not attenuate body composition increases in lean muscle mass, while promoting trivial increases in neuromuscular concentric-only squat jump performance.

Eccentric contractions induce muscle damage, but less is known about the effects of preceding concentric contractions to eccentric contractions on muscle damage. We compared eccentric-only (ECC) and coupled concentric and eccentric contractions (CON-ECC) of the knee extensors for parameters of neuromuscular fatigue and muscle damage.Twenty participants (age, 19-36 yr) were randomly placed into an ECC or a CON-ECC group (n = 10 per group), without significant (P0.06) differences in baseline neuromuscular variables between groups. The ECC group performed six sets of eight ECC at 80% of ECC one-repetition maximum (1-RMecc), whereas the CON-ECC group performed six sets of eight alternating concentric (CON) and ECC (16 contractions per set) at 80% of CON 1-RM and 1-RMecc, respectively. Maximal voluntary isometric contraction force, rate of force development, resting twitch force, maximal M-wave (MMAX), voluntary activation, motor evoked potentials, corticospinal silent period, short interval intracortical inhibition, and muscle soreness were measured before, immediately after, and 1-3 d after exercise.No significant (P ≥ 0.09) differences between ECC and CON-ECC were observed for changes in any variables after exercise. However, maximal voluntary isometric contraction force decreased immediately after exercise (ECC: -20.7% ± 12.8%, CON-ECC: -23.6% ± 23.3%) and was still reduced 3 d after exercise (ECC: -13.6% ± 13.4%, CON-ECC: -3.3% ± 21.2%). Rate of force development at 0-30 ms reduced immediately after exercise (ECC: -38.3% ± 33.9%, CON-ECC: -30.7% ± 38.3%). Voluntary activation, resting twitch force, and motor evoked potential/MMAX decreased and corticospinal silent period increased after exercise (all P ≤ 0.03), but short interval intracortical inhibition and MMAX did not change. Muscle soreness developed (P0.001) similarly for both groups (peak, 38.5 ± 29.5 mm).CON-ECC did not exacerbate neuromuscular fatigue and muscle damage when compared with ECC, despite twice as many contractions performed. Thus, eccentric contractions (n = 48 in both groups) seemed to mainly mediate the neuromuscular responses observed.

The primary aim of this narrative review was to outline the historical genesis of resistance training strategies that incorporate high-load, low-velocity exercises and low-load, high-velocity exercises in the same training session allowing for different "exercise sequences" to be simultaneously implemented. Discrepancies between scientific works and the terminology used within contemporary sport science publications are identified. Upon review of the literature, we propose "complex training" to be considered an umbrella term with 4 different implementations, generally used to indicate a method in which movement velocity or load is altered between sets and/or exercises within the same session with the aim of improving slow and fast force expression. We propose the following terminology for said implementations: contrast training-exercise sequence with alternating high-load and low-load (higher-velocity) exercises in a set-by-set fashion within the same session (corresponding with 'contrast pairs' and 'intra-contrast rest'); descending training-several sets of high-load (e.g., back squat) exercises completed before the execution of several sets of low-load, higher-velocity (e.g., vertical jump) exercises within the same session; ascending training-several sets of low-load, higher-velocity exercises completed before several sets of high-load exercises within the same session; and French contrast training-subset of contrast training in which a series of exercises are performed in sequence within a single session: heavy compound exercise, plyometric exercise, light-to-moderate load compound exercise that maximises movement speed (i.e., external power), and a plyometric exercise (often assisted). Finally, practical applications and training considerations are presented.

We examined whether the magnitude of muscle damage indicated by changes in maximal voluntary isometric contraction (MVIC) strength 1 to 3 d after unaccustomed eccentric exercise (ECC) was correlated with changes in central and peripheral neuromuscular parameters immediately post-ECC.Twenty participants (19-36 yr) performed six sets of eight eccentric contractions of the knee extensors. Rate of force development (RFD) during knee extensor MVIC, twitch force, rate of force development (RFDRT) and rate of relaxation (RRRT) of the resting twitch, maximal M-wave (MMAX), voluntary activation, silent period duration, motor-evoked potentials (MEP) and short-interval intracortical inhibition were assessed before, immediately after, and 1 to 3 d post-ECC. Relationships between changes in these variables immediately post-ECC and changes in MVIC strength at 1 to 3 d post-ECC were examined by Pearson product-moment (r) or Spearman correlations.Maximal voluntary isometric contraction strength decreased (-22.2% ± 18.4%) immediately postexercise, and remained below baseline at 1 (-16.3% ± 15.2%), 2 (-14.7% ± 13.2%) and 3 d post-ECC (-8.6% ± 15.7%). Immediately post-ECC, RFD (0-30-ms: -38.3% ± 31.4%), twitch force (-45.9% ± 22.4%), RFDRT (-32.5% ± 40.7%), RRRT (-38.0% ± 39.7%), voluntary activation (-21.4% ± 16.5%) and MEP/MMAX at rest (-42.5% ± 23.3%) also decreased, whereas the silent period duration at 10%-MVIC increased by 26.0% ± 12.2% (P0.05). Decreases in RFD at 0 to 30 ms, 0 to 50 ms, and 0 to 100 ms immediately post-ECC were correlated (P0.05) with changes in MVIC strength at 1 d (r = 0.56-0.60) and 2 d post-ECC (r = 0.53-0.63). Changes in MEP/MMAX at 10%-MVIC immediately post-ECC were correlated with changes in MVIC strength at 1 d (r = -0.53) and 2 d (r = -0.54) post-ECC (P0.05).The magnitude of decrease in MVIC strength at 1 to 3 d after ECC was associated with the magnitude of changes in RFD and MEP/MMAX immediately post-ECC. However, based on individual data, these markers were not sensitive for the practical detection of muscle damage.

The aim of this study was to assess the agreement of three different automated methods of identifying force-onset (40 N, 5 SDs, and 3 SDs) with manual identification, during the isometric mid-thigh pull (IMTP). Fourteen resistance-trained participants with >6 months experience training with the power clean volunteered to take part. After three familiarisation sessions, the participants performed five maximal IMTPs separated by 1 min of rest. Fixed bias was found between 40 N and manual identification for time at force-onset. No proportional bias was present between manual identification and any automated threshold. Fixed bias between manual identification and automated was present for force at onset and F150. Proportional but not fixed bias was found for F50 between manual identification and all automated thresholds. Small to moderate differences (Hedges g = −0.487- −0.692) were found for F90 between all automated thresholds and manual identification, while trivial to small differences (Hedges g = −0.122—−0.279) were found between methods for F200 and F250. Based on these results, strength and conditioning practitioners should not use a 40 N, 5 SDs, or 3 SDs threshold interchangeably with manual identification of force-onset when analysing IMTP force–time curve data.

Horgan, BG, West, NP, Tee, N, Drinkwater, EJ, Halson, SL, Vider, J, Fonda, CJ, Haff, GG, and Chapman, DW. Acute inflammatory, anthropometric, and perceptual (muscle soreness) effects of postresistance exercise water immersion in junior international and subelite male volleyball athletes. J Strength Cond Res 36(12): 3473-3484, 2022-Athletes use water immersion strategies to recover from training and competition. This study investigated the acute effects of postexercise water immersion after resistance exercise. Eighteen elite and subelite male volleyball athletes participated in an intervention using a randomized cross-over design. On separate occasions after resistance exercise, subjects completed 1 of 4 15-minute interventions: control (CON), cold water immersion (CWI), contrast water therapy (CWT), or hot water immersion (HWI). Significance was accepted at p ≤ 0.05. Resistance exercise induced significant temporal changes (time effect) for inflammatory, anthropometric, perceptual, and performance measures. Serum creatine kinase was reduced ( g = 0.02-0.30) after CWI ( p = 0.007), CWT ( p = 0.006), or HWI ( p0.001) vs. CON, whereas it increased significantly ( g = 0.50) after CWI vs. HWI. Contrast water therapy resulted in significantly higher ( g = 0.56) interleukin-6 concentrations vs. HWI. Thigh girth increased ( g = 0.06-0.16) after CWI vs. CON ( p = 0.013) and HWI ( p0.001) and between CWT vs. HWI ( p = 0.050). Similarly, calf girth increased ( g = 0.01-0.12) after CWI vs. CON ( p = 0.039) and CWT ( p = 0.018), and HWI vs. CON ( p = 0.041) and CWT ( p = 0.018). Subject belief in a postexercise intervention strategy was associated with HSP72 ("believer""nonbeliever," p = 0.026), muscle soreness ("believer""nonbeliever," p = 0.002), and interleukin-4 ("nonbeliever""believer," p = 0.002). There were no significant treatment × time (interaction effect) pairwise comparisons. Choice of postexercise water immersion strategy (i.e., cold, contrast, or hot) combined with a belief in the efficacy of that strategy to enhance recovery or performance improves biological and perceptual markers of muscle damage and soreness. On same or subsequent days where resistance exercise bouts are performed, practitioners should consider athlete beliefs when prescribing postexercise water immersion, to reduce muscle soreness.

Purpose: To analyze the differences in the force–velocity (F–v) profile assessed under unconstrained (ie, using free weights) and constrained (ie, on a Smith machine) vertical jumps, as well as to determine the between-day reliability. Methods: A total of 23 trained participants (18 [1] y) performed an incremental load squat jump test (with ∼35%, 45%, 60%, and 70% of the subjects’ body mass) on 2 different days using free weights and a Smith machine. Nine of these participants repeated the tests on 2 other days for an exploratory analysis of between-day reliability. F–v variables (ie, maximum theoretical force [F0], velocity [v0], and power, and the imbalance between the actual and the theoretically optimal F–v profile) were computed from jump height. Results: A poor agreement was observed between the F–v variables assessed under constrained and unconstrained conditions (intraclass correlation coefficient [ICC] .70). The F–v variables computed under constrained conditions showed an overall good agreement (ICC = .75–.95 for all variables) and no significant differences between days (P > .05), but a high variability for v0, the imbalance between the actual and the theoretically optimal F–v profile, and maximal theoretical power (coefficient of variation = 17.0%–27.4%). No between-day differences were observed for any F–v variable assessed under unconstrained conditions (P > .05), but all of the variables presented a low between-day reliability (coefficient of variation > 10% and ICC Conclusions: F–v variables differed meaningfully when obtained from constrained and unconstrained loaded jumps, and most importantly seemed to present a low between-day reliability.

Soriano, MA, Jiménez-Ormeño, E, Amaro-Gahete, FJ, Haff, GG, and Comfort, P. How does lower-body and upper-body strength relate to maximum split jerk performance? J Strength Cond Res 36(8): 2102-2107, 2022-The aims of this study were to (I) determine the relationships between the maximum dynamic strength of the upper and lower body, measured by overhead press and back squat 1 repetition maximum (1RM) performances, and the split jerk (SJ) performance in trained weightlifters and (II) explore the magnitude of these relationships for men and women to establish sex-specific prediction equations. Twenty men (age: 28.9 ± 6.6 years; height: 1.8 ± 0.1 m; body mass [BM]: 82.5 ± 10.2 kg; weightlifting training experience: 4.2 ± 2.4 years) and 13 women (age: 27.7 ± 4.4 years; height: 1.7 ± 0.1 m; BM: 61.8 ± 5.2 kg; weightlifting training experience: 2.7 ± 1.7 years) competitive weightlifters participated. The 1RM performances of the overhead press, back squat, and SJ were assessed for all subjects. A very strong correlation exists between the back squat and overhead press, with maximum SJ performance for all subjects (r = 0.97; p0.001). Similarly, very strong correlations were found for men (r = 0.90, p0.001) and women (r = 0.90, p = 0.0002), separately. The coefficient of determination indicates that the prediction equation for the maximum SJ performance is quite accurate (R2 = 0.94) for all subjects and men (R2 = 0.83) and women (R2 = 0.81), separately. These results provide evidence that the maximum strength of the upper and lower body are major contributors to SJ performance. In addition, SJ performance can accurately be predicted from the back squat and overhead press performances.

Kotani, Y, Lake, J, Guppy, SN, Poon, W, Nosaka, K, Hori, N, and Haff, GG. The reliability of the squat jump force-velocity and load-velocity profiles. J Strength Cond Res XX(X): 000-000, 2021-The purpose of this study was to investigate the between-session reliability of the squat jump force-velocity (FV) and load-velocity (LV) profiles. Eighteen subjects (age = 28.1 ± 4.8 years; height = 1.7 ± 9.7; body mass = 74.7 ± 12.8) who could back squat >1.5 times body mass participated in this study. Each subject completed a familiarization session, followed by 2 experimental sessions each separated by 72 hours. Subjects performed a series of squat jumps on a force plate against external loads between 0 and 100% of their body mass in a quasi-randomized block order. Intraclass correlation coefficient (ICC) and coefficient of variation (CV) were used to examine the between-session reliability. Peak velocity (PV) and mean velocity (MV) at each load were highly reliable (ICC >0.80, CV%

Background In-season competition and tournaments for team sports can be both long and congested, with some sports competing up to three times per week. During these periods of time, athletes need to prepare technically, tactically and physically for the next fixture and the short duration between fixtures means that, in some cases, physical preparation ceases, or training focus moves to recovery as opposed to progressing adaptations. Objective The aim of this review was to investigate the effect of training frequency on muscular strength to determine if a potential method to accommodate in-season resistance training, during busy training schedules, could be achieved by utilizing shorter more frequent training sessions across a training week. Methods A literature search was conducted using the SPORTDiscus, Ovid, PubMed and Scopus databases. 2134 studies were identified prior to application of the following inclusion criteria: (1) maximal strength was assessed, (2) a minimum of two different training frequency groups were included, (3) participants were well trained, and finally (4) compound exercises were included within the training programmes. A Cochrane risk of bias assessment was applied to studies that performed randomized controlled trials and consistency of studies was analysed using I2 as a test of heterogeneity. Secondary analysis of studies included Hedges’ g effect sizes (g) and between-study differences were estimated using a random-effects model. Results Inconsistency of effects between pre- and post-intervention was low within-group (I2 = 0%), and moderate between-group (I2 ≤ 73.95%). Risk of bias was also low based upon the Cochrane risk of bias assessment. Significant increases were observed overall for both upper (p ≤ 0.022) and lower (p ≤ 0.008) body strength, pre- to post-intervention, when all frequencies were assessed. A small effect was observed between training frequencies for upper (g ≤ 0.58) and lower body (g ≤ 0.45). Conclusion Over a 6–12-week period, there are no clear differences in maximal strength development between training frequencies, in well-trained populations. Such observations may permit the potential for training to be manipulated around competition schedules and volume to be distributed across shorter, but more frequent training sessions within a micro-cycle rather than being condensed into 1–2 sessions per week, in effect, allowing for a micro-dosing of the strength stimuli.

This study investigated the stability of three repetition maximum (3RM) strength during the deadlift. Eleven participants performed four testing sessions comprising a one repetition maximum test and 3RM tests separated by 48 h. Preparedness was assessed before each testing session using countermovement jumps and by measuring barbell velocity during each set of deadlifts. Trivial statistically significant differences were determined for the 3RM between T1 and both T2 ( p = 0.012; ES [95% CI] = −0.1 [−0.58, 0.41]) and T3 ( p = 0.027; ES [95% CI] = −0.09 [−0.57, −0.43]). No significant differences were noted between T2 and T3 ( p = 0.595; ES [95% CI] = 0.01 [−0.49, 0.50]). No significant differences in jump height ( p = 0.071), time-to-take-off ( p = 0.862), eccentric displacement ( p = 0.209), or mean force during any countermovement jump sub-phase were found between each session ( p = 0.529–0.913). Small differences in barbell mean velocity were found between both T1–T2 (effect size statistics (ES) = −0.21–0.27) and T2–T3 (ES = 0.31–0.48), while trivial differences were found at others. Therefore, 3RM deadlift strength appears stable enough over a microcycle to continue using traditionally recommended heavy/light programming strategies.

The primary aim of this study was to investigate the stability of the six-repetition maximum (6RM) deadlift over the length of a five-day microcycle and whether the fatigue induced by maximal effort testing detrimentally impacted preparedness. Twelve participants performed four testing sessions, comprising a one-repetition maximum test and three 6RM tests separated by 48 hours. Countermovement jumps were performed before each testing session, and barbell velocity was measured during each warm-up set to assess changes in preparedness. The 6RM deadlift was not statistically different between any of the testing sessions ( p = .056; ηp2 = 0.251). Similarly, there were no significant differences in jump height or other CMJ variables between sessions ( p > .05). There were small to moderate differences in mean barbell velocity between the first and second 6RM test ( g = 0.24–0.88), while there were only small differences in mean velocity (MV) between the second and third 6RM test at some of the warm-up loads (40% 6RM: g = 0.20; 80% 6RM: g = −0.47). Taken collectively, these data indicate that 6RM deadlift strength is stable over five days and does not appear to induce sufficient fatigue to impact vertical jump performance or rating of perceived exertion despite some changes in barbell velocity.

Coyne, JOC, Coutts, AJ, Newton, RU, and Haff, GG. The influence of mental fatigue on sessional ratings of perceived exertion in elite open and closed skill sports athletes. J Strength Cond Res 35(4): 963-969, 2021-The main purpose of this investigation was to examine influence of mental fatigue on sessional ratings of perceived exertion (sRPE) over a training week in elite athletes in open skill (OS, i.e., more unpredictable and externally paced sports) and closed skill (CS, i.e., more predictable and internally paced) sports. Visual analogue scales for mental fatigue, sRPE (CR-10 scale), and training duration were collected from an OS group (n = 27) of basketball and volleyball athletes and a CS group (n = 28) of weightlifting and track and field athletes during a typical training week 5 months before the 2016 Olympic Games. These variables were then examined using repeated measure correlations and linear mixed models with the level of significance set for the study at p < 0.05. There was a small significant correlation between mental fatigue and sRPE in the OS group (r = 0.23, p < 0.01), but not in the CS group (r = -0.07, p = 0.38). Mental fatigue had trivial influence on sRPE during individual sessions, but had a moderate effect on total sRPE over a week (p < 0.001, f2 = 0.265) when accounting for type of sport, training duration, and injury/illness burden. It seems mental fatigue may not significantly influence sRPE in individual training sessions, but may potentially have a cumulative effect that may affect the sRPE over a training week. This suggests monitoring mental fatigue independently of other training load (TL) measures may be worthwhile for strength and conditioning specialists and sports coaches to manage their athletes and researchers conducting studies into TL and performance.

Purpose: A simple and 2 different exponentially weighted moving average methods were used to investigate the relationships between internal training load and elite weightlifting performance. Methods: Training impulse data (sessional ratings of perceived exertion × training duration) were collected from 21 elite weightlifters (age = 26.0 [3.2] y, height = 162.2 [11.3] cm, body mass = 72.2 [23.8] kg, previous 12-mo personal best total 96.3% [2.7%] of world record total) during the 8 weeks prior to the 2016 Olympic Games qualifying competition. The amount of training modified or cancelled due to injury/illness was also collected. The training stress balance (TSB) and acute to chronic workload ratio (ACWR) were calculated with the 3 moving average methods. Along with the amount of modified training, TSB and ACWR across the moving average methods were then examined for their relationship to competitive performance. Results: There were no consistent associations between performance and training load on the day of competition. The volatility (SD) of the ACWR in the last 21 days preceding the competition was moderately correlated with performance across moving average methods (r = −.41 to .48, P = .03–.07). TSB and ACWR volatility in the last 21 days were also significantly lower for successful performers but only as a simple moving average (P = .03 and .03, g = 1.15 and 1.07, respectively). Conclusions: Practitioners should consider restricting change and volatility in an athlete’s TSB or ACWR in the last 21 days prior to a major competition. In addition, a simple moving average seemed to better explain elite weightlifting performance than the exponentially weighted moving averages in this investigation.

Hughes, S, Warmenhoven, J, Haff, GG, Chapman, DW, and Nimphius, S. Countermovement jump and squat jump force-time curve analysis in control and fatigue conditions. J Strength Cond Res 36(10): 2752-2761, 2022-This study aimed to reanalyze previously published discrete force data from countermovement jumps (CMJs) and squat jumps (SJs) using statistical parametric mapping (SPM), a statistical method that enables analysis of data in its native, complete state. Statistical parametric mapping analysis of 1-dimensional (1D) force-time curves was compared with previous zero-dimensional (0D) analysis of peak force to assess sensitivity of 1D analysis. Thirty-two subjects completed CMJs and SJs at baseline, 15 minutes, 1, 24, and 48 hours following fatigue and control conditions in a pseudo random cross-over design. Absolute (CMJ ABS /SJ ABS ) and time-normalized (CMJ NORM /SJ NORM ) force-time data were analyzed using SPM 2-way repeated measures analysis of variance with significance accepted at α = 0.05. The SPM indicated a magnitude of difference between force-time data with main effects for time ( p0.001) and interaction ( p0.001) observed in CMJ ABS , SJ ABS, and SJ NORM, whereas previously published 0D analysis reported no 2-way interaction in CMJ and SJ peak force. This exploratory research demonstrates the strength of SPM to identify changes between entire movement force-time curves. Continued development and use of SPM analysis techniques could present the opportunity for refined assessment of athlete fatigue and readiness with the analysis of complete force-time curves.

This study aimed to investigate the influence of chronological age and maturation status on sprint acceleration characteristics in junior Australian football (AF) players. Biological maturity of 109 subjects was assessed and subjects were grouped according to predicted years from peak height velocity (PHV) (pre-, mid-, and post-PHV) and chronological age (13 years, 14 years, and 15 years). A one-way multivariate analysis of variance and magnitude-based decisions were used to determine between-group differences. Instantaneous velocity was measured during two maximal 30m sprints via radar gun with the velocity-time data used to derive the force, velocity, and power characteristics. Chronologically, the greatest differences were observed between the 13 and 14 year old groups with the latter group producing likely greater relative maximum power (Pmax) (ES[effect size]=0.44) and theoretical maximal velocity (V0) (ES=0.49). The post-PHV group likely demonstrated a greater ability to apply force at faster velocity (V0; ES=0.59) and orient the force in a horizontal direction (Drf%; ES=-0.49) than the mid-PHV group. No differences in relative theoretical maximal force (F0) were observed between groups. Considering the findings, practitioners should aim to improve relative lower limb strength through heavy sled push or sled pulls and traditional strength training exercises to improve relative F0.

The acute responses to cluster set resistance training (RT) have been demonstrated. However, as compared to traditional sets, the effect of cluster sets on muscular and neuromuscular adaptations remains unclear. To compare the effects of RT programs implementing cluster and traditional set configurations on muscular and neuromuscular adaptations. Systematic searches of Embase, Scopus, Medline and SPORTDiscus were conducted. Inclusion criteria were: (1) randomized or non-randomized comparative studies; (2) publication in English; (3) participants of all age groups; (4) participants free of any medical condition or injury; (5) cluster set intervention; (6) comparison intervention utilizing a traditional set configuration; (7) intervention length ≥ three weeks and (8) at least one measure of changes in strength/force/torque, power, velocity, hypertrophy or muscular endurance. Raw data (mean ± SD or range) were extracted from included studies. Hedges’ g effect sizes (ES) ± standard error of the mean (SEM) and 95% confidence intervals (95% CI) were calculated. Twenty-nine studies were included in the meta-analysis. No differences between cluster and traditional set configurations were found for strength (ES = − 0.05 ± 0.10, 95% CI − 0.21 to 0.11, p = 0.56), power output (ES = 0.02 ± 0.10, 95% CI − 0.17 to 0.20, p = 0.86), velocity (ES = 0.15 ± 0.13, 95% CI − 0.10 to 0.41, p = 0.24), hypertrophy (ES = − 0.05 ± 0.14, 95% CI − 0.32 to 0.23, p = 0.73) or endurance (ES = − 0.07 ± 0.18, 95% CI − 0.43 to 0.29, p = 0.70) adaptations. Moreover, no differences were observed when training volume, cluster set model, training status, body parts trained or exercise type were considered. Collectively, both cluster and traditional set configurations demonstrate equal effectiveness to positively induce muscular and neuromuscular adaptation(s). However, cluster set configurations may achieve such adaptations with less fatigue development during RT which may be an important consideration across various exercise settings and stages of periodized RT programs.

Force plates are commonly used when assessing vertical jumping performance but are not always affordable or practical tools for all testing situations. Twenty-four participants volunteered to take part in a study investigating the agreement between bilateral force plates and a new commercially available contact mat that records jump height, flight-time (FT), and FT of individual limbs during both countermovement (CMJ) and squat (SJ) jumps. Each participant performed six jumps of each type while standing on a contact mat placed upon a pair of in-ground force plates. When compared to the force plate via ordinary least products regression, the contact mat agreed with force plate CMJ and SJ jump height, individual limb FT during CMJs, and left-leg FT during SJs. The bilateral contact mat provided valid assessment of individual limb FT during CMJs, but not SJs. Practitioners can therefore use a bilateral contact mat interchangeably with bilateral force plates to measure SJ and CMJ performance.

Guppy, SN, Kotani, Y, Brady, CJ, Connolly, S, Comfort, P, and Haff, GG. Title: The reliability and magnitude of time-dependent force-time characteristics during the isometric mid-thigh pull are impacted by both testing protocol and analysis choices. J Strength Cond Res 36(5): 1191-1199, 2022-This study aimed to investigate whether the use of short-duration (SHORT) isometric midthigh pull (IMTP) trials resulted in greater reliability and magnitude of time-dependent force-time characteristics than traditionally performed IMTP trials (TRAD). Fourteen subjects with6 months' training experience with the power clean volunteered to take part in the study. Subjects performed five ∼1-second IMTP trials (SHORT) and five 5-second IMTP trials (TRAD). SHORT resulted in substantially more reliable rate of force development (RFD) measures (intraclass correlation coefficient [ICC] = 0.97-0.99; coefficient of variation [CV] = 2.6-7.0%), particularly during time bands from force-onset to 150 ms, compared with TRAD when trials were selected for analysis based on peak force (ICC = 0.66-0.83; CV = 14.1-38.5%). Selecting TRAD trials based on RFD0-200 resulted in similar reliability compared with SHORT of those same epochs (ICC = 0.97-0.99; CV = 2.5-7.8%). Furthermore, SHORT resulted in significantly greater force at specific time points, RFD, and impulse compared with TRAD trials (p = 0.001-0.033; g = -0.16 to -0.66). Based on these results, strength and conditioning professionals should use specific testing protocols (i.e., TRAD and SHORT) depending on the component of an athlete's force-generating capacity that they wish to assess and remain aware of the effect analysis choices they have on the reliability of IMTP force-time characteristics.

Edwards, T, Piggott, B, Banyard, HG, Haff, GG, and Joyce, C. The effect of a heavy resisted sled-pull mesocycle on sprint performance in junior Australian football players. J Strength Cond Res XX(X): 000-000, 2022-This study assessed the effect of heavy resisted sled-pull training on sprint times and force, velocity, and power characteristics in junior Australian football players. Twenty-six athletes completed a 6-week resisted sled-pull training intervention which included 10 training sessions and 1-week taper. Instantaneous velocity during 2 maximal 30 m sprints was recorded 1 week before and 1 week after the intervention with a radar gun. Velocity-time data were used to derive sprint performance and force, velocity, and power characteristics. A paired t-test assessed the within-group differences between preintervention and postintervention testing. Statistical significance was accepted at p ≤ 0.05. Hedges' g effect sizes (ESs) were used to determine the magnitude of change in dependent variables. Maximum velocity (ES = 1.33) and sprint times at all distances (ES range 0.80-1.41) significantly improved after heavy resisted sled-pull training. This was reflected in sprint force, velocity, and power characteristics with significant improvements in relative theoretical force (ES = 0.63), theoretical velocity (ES = 0.99), relative maximum power (ES = 1.04), and ratio of horizontal to vertical force (ES = 0.99). Despite the multifactorial nature of training and competing physical demands associated with preseason training, these findings imply that a short, resisted sled-pull training mesocycle may improve sprint performance and underlying force, velocity, and power characteristics in junior athletes.

This article addresses several key issues that have been raised related to subjective training load (TL) monitoring. These key issues include how TL is calculated if subjective TL can be used to model sports performance and where subjective TL monitoring fits into an overall decision-making framework for practitioners. Regarding how TL is calculated, there is conjecture over the most appropriate (1) acute and chronic period lengths, (2) smoothing methods for TL data and (3) change in TL measures (e.g., training stress balance (TSB), differential load, acute-to-chronic workload ratio). Variable selection procedures with measures of model-fit, like the Akaike Information Criterion, are suggested as a potential answer to these calculation issues with examples provided using datasets from two different groups of elite athletes prior to and during competition at the 2016 Olympic Games. Regarding using subjective TL to model sports performance, further examples using linear mixed models and the previously mentioned datasets are provided to illustrate possible practical interpretations of model results for coaches (e.g., ensuring TSB increases during a taper for improved performance). An overall decision-making framework for determining training interventions is also provided with context given to where subjective TL measures may fit within this framework and the determination if subjective measures are needed with TL monitoring for different sporting situations. Lastly, relevant practical recommendations (e.g., using validated scales and training coaches and athletes in their use) are provided to ensure subjective TL monitoring is used as effectively as possible along with recommendations for future research.

This narrative review deals with the topic of strength training in swimming, which has been a controversial issue for decades. It is not only about the importance for the performance at start, turn and swim speed, but also about the question of how to design a strength training program. Different approaches are discussed in the literature, with two aspects in the foreground. On the one hand is the discussion about the optimal intensity in strength training and, on the other hand, is the question of how specific strength training should be designed. In addition to a summary of the current state of research regarding the importance of strength training for swimming, the article shows which physiological adaptations should be achieved in order to be able to increase performance in the long term. Furthermore, an attempt is made to explain why some training contents seem to be rather unsuitable when it comes to increasing strength as a basis for higher performance in the start, turn and clean swimming. Practical training consequences are then derived from this. Regardless of the athlete’s performance development, preventive aspects should also be considered in the discussion. The article provides a critical overview of the abovementioned key issues. The most important points when designing a strength training program for swimming are a sufficiently high-load intensity to increase maximum strength, which in turn is the basis for power, year-round strength training, parallel to swim training and working on the transfer of acquired strength skills in swim training, and not through supposedly specific strength training exercises on land or in the water.

Article published in Strength and Conditioning Journal available at https://doi.org/10.1519/SSC.0000000000000608