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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.

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.

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.

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.

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.

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

Purpose This study examined whether additional external load during the eccentric phase of lower limb strength training exercises led to greater adaptations in knee extensor strength, muscle architecture, and patellar tendon properties than traditional concentric–eccentric training in already-trained men. Methods Twenty-eight men accustomed to strength training were randomized to undertake 10 weeks of supervised traditional (TRAD) or accentuated eccentric loading (AEL) or continue their habitual unsupervised (CON) strength training. TRAD and AEL trained 2∙week−1 with a six-repetition maximum (RM) session and a ten-RM session. TRAD used the same external load in both concentric and eccentric phases, while AEL used 40% greater load during the eccentric than concentric phase. Tests were performed at pre- and post-training, including: maximum unilateral isokinetic (30°·s−1) concentric, eccentric and isometric torques by isokinetic dynamometry, unilateral isometric ramp contractions with muscle–tendon ultrasound imaging to measure tendon stiffness and hysteresis, and resting vastus lateralis and medialis fascicle angle and length measured by extended-field-of-view ultrasound. Results After training, both TRAD and AEL significantly increased maximum concentric and isometric torque (p Conclusion Both TRAD and AEL increased maximum knee extensor strength but only AEL increased VL and VM fascicle length. Neither training program promoted changes in fascicle angle or changes in patellar tendon properties in our already-trained men.

Purpose This cross-sectional study investigated dynamic force–time variables and vaulting performance in young female gymnasts of different maturity status. Methods 120 gymnasts aged 5–14 years were sub-divided into maturity groupings using percent of predicted adult height (%PAH) attained. Participants performed three jumping protocols, the squat jump (SJ), countermovement jump (CMJ) and drop jump (DJ), before completing straight jump vaults that were recorded using two-dimensional video. Results Jumping performance improved with biological maturity evidenced by the most mature gymnasts’ producing significantly more absolute force (P d > 0.78), impulse (P d > 0.75) and power (P d > 0.91) than the least mature group, resulting in the greater jump heights (P d > 0.70). While, no significant differences were observed in relative peak force across multiple tests, measures of relative peak power did significantly increase with maturity. Based upon regression analyses, maturation was found to influence vertical take-off velocity during vaulting, explaining 41% of the variance in each jumping protocol. Across all tests, the DJ was found to have the highest predictive ability of vaulting vertical take-off velocity, explaining 55% of the total variance. Conclusion Biological maturation impacts jump height and underpinning mechanical variables in young female gymnasts. Vaulting vertical take-off velocity appears to be influenced by maturation and various dynamic force–time variables, particularly those during DJ, which had the highest explained total variance.

Short-interval intracortical inhibition (SICI) is often assessed to investigate inhibitory responses in the primary motor cortex representation of the quadriceps. However, determining appropriate paired-pulse transcranial magnetic stimulation (TMS) parameters to optimise SICI measurement can be impractical and time-consuming. This study investigated the intensity required to elicit maximal and 50% of maximum inhibition, and the test-retest reliability of a time-efficient approach for SICI measurement in quadriceps. Nine men and six women (26.6 ± 4.4 years) underwent single and paired-pulse (3-ms interval) TMS during 10% maximal voluntary isometric contraction on two days. Responses were recorded from vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM). Test stimulus intensity was 140% of active motor threshold (AMT), and conditioning stimulus intensities (CSIs) ranged from 55% to 90% (eight intensities) of AMT (five test and five paired responses for each intensity). With CSI of 55% AMT, SICI was minimal (conditioned:test motor evoked potential [MEP]; 1.00, 0.96 and 0.95 for VL, RF and VM, respectively

The purpose of the present investigation was to examine the acute effects of whole body vibration (WBV) on isometric mid-thigh pull force&ndash, time curve (FTC) characteristics. Eleven recreationally trained subjects were randomly assigned to three treatment conditions: sham no vibration protocol (T1), vibration protocol 30 Hz 2&ndash, 4 mm amplitude (T2), and vibration protocol 30 Hz 2&ndash, 4 mm (T3). After completing a standardized warm-up, the subject stood on a vibration platform with the knee at a 120&deg, angle and performed one of the three interventions. Each treatment condition required the subject to stand on the platform for thirty-second treatments, each separated by thirty seconds of recovery. Five minutes after the completion of the treatment conditions, the subjects performed the isometric mid-thigh pull. All FTCs were analyzed with standardized procedures for peak force (PF) and peak rate of force development (PRFD). A 1 &times, 3 repeated measures analysis of variance (ANOVA) was used to compare the three treatments. Additionally, coefficients of variance (CV), as well as intraclass and interclass correlations, were performed. There were no significant differences (p &gt, 0.05) for any of the FTC analyses performed in this investigation. The CV and the 95% confidence interval (CI) indicate that the WBV protocol resulted in trivial changes in PF and beneficial changes in PRFD. A 30 Hz 2&ndash, 4 mm amplitude WBV does not result in a significant increase in isometric mid-thigh pull performance.

New Findings: What is the central question of this study? Although acute responses of the principal gonadosteroid and corticosteroid hormones to resistance exercise are well documented, there is no information regarding how the key lower-concentration intermediary hormones respond and potentially influence these hormonal pathways. What is the main finding and its importance? This study provides evidence for cascading conversions of some gonadosteroids, and the data suggest that the testosterone concentration increases independently of these hormones. These findings challenge future studies to determine the exact physiological roles of the lower-concentration gonadosteroids and corticosteroids during and immediately after resistance exercise. Abstract: Resistance training is a potent stimulus for muscle growth, and steroid hormones are known to play a role in this adaptation. However, very little is known about the acute exercise-induced gonadosteroid and corticosteroid hormone responses, including those of key lower-concentration intermediate hormones. The present study determined the acute responses of these steroid hormone families using quantitative ultra-high performance liquid chromatography tandem mass spectrometry after resistance exercise in strength-trained men. Venous and fingertip blood samples were obtained pre-, mid-, 5 min post- and 15 min post-resistance exercise, both before and after 10 weeks of supervised resistance training. The experimental resistance exercise sessions consisted of three sets of 10 repetitions of bilateral leg-press exercise and three sets of 10 repetitions of unilateral knee-extension exercise, with 2 and 1 min recovery between sets, respectively. Statistically significant (P < 0.05) increases in the concentration of hormones in the gonadosteroid [including dehydroepiandrosterone (DHEA), androstenedione, testosterone and estrone] and the corticosteroid (including cortisol, corticosterone and cortisone) families were demonstrated after both experimental resistance exercise sessions, irrespective of training status. Correlation analyses revealed relationships between the following hormones: (i) DHEA and androstenedione; (ii) DHEA and cortisol; (iii) androstenedione and estrone; and (iv) 11-deoxycortisol and cortisol. Testosterone appears to increase acutely and independently of other intermediary hormones after resistance exercise. In conclusion, lower-concentration intermediary gonadosteroids (e.g. estrone) and corticosteroids (e.g. corticosterone) respond robustly to resistance exercise in strength-trained men, although it seems that testosterone concentrations are regulated by factors other than the availability of precursor hormones and changes in plasma volume.

Purpose: To examine the relationships between the isometric midthigh pull (IMTP), isometric squat (ISqT), and sprint acceleration performance in track-and-field sprinters and to determine whether there are differences between men and women. Methods: Fifteen male and 10 female sprinters performed 3 maximal-effort IMTPs, ISqTs, and 3 × 30-m sprints from blocks. Results: Among the men, the results showed significant negative correlations between IMTP and ISqT peak force; relative peak force; force at 100, 150, and 200 ms; rate of force development (0–150 and 0–200 ms); and impulse (0–200 ms) and 0- to 5-m time (r = −.517 to −.714; P B = −0.582, P = .023) and ISqT relative peak force (B = −0.606, P = .017) significantly predicted 0- to 5-m time. Among the women, no IMTP or ISqT variables significantly correlated with any sprint times. Men measured significantly higher than women for all IMTP measures except relative peak force. Men were significantly faster than women at all splits. When comparing measures of the ISqT, there were no significant differences between men and women. Conclusions: Variables measured during the IMTP and ISqT significantly correlated with 0- to 5-m sprint performance in male athletes. Isometric strength can have a sizable influence on 0- to 5-m time, but in some cases, the maximum effect could be very small.

Background Cluster sets (CSs) are a popular resistance training (RT) strategy categorised by short rest periods implemented between single or groups of repetitions. However, evidence supporting the effectiveness of CSs on acute intra-session neuromuscular performance is still equivocal. Objective The objective of this investigation was to determine the efficacy of a single session of CSs to attenuate losses in force, velocity and power compared to traditional set (TS) training. Methods Screening consisted of a systematic search of EMBASE, Google Scholar, PubMed, Scopus and SPORTDiscus. Inclusion criteria were (1) measured one or more of mean/peak force, velocity or power; (2) implemented CSs in comparison to TSs; (3) an acute design, or part thereof; and (4) published in an English-language, peer-reviewed journal. Raw data (mean ± standard deviation) were extracted from included studies and converted into standardised mean differences (SMDs) and ± 95% confidence intervals (CIs). Results Twenty-five studies were used to calculate SMD ± 95% CI. Peak (SMD = 0.815, 95% CI 0.105–1.524, p = 0.024) and mean (SMD = 0.863, 95% CI 0.319–1.406, p = 0.002) velocity, peak (SMD = 0.356, 95% CI 0.057–0.655, p = 0.019) and mean (SMD = 0.692, 95% CI 0.395–0.990, p p = 0.031) favoured CS. Subgroup analyses demonstrated an overall effect for CS across loads (SMD = 0.702, 95% CI 0.548–0.856, p p p p Conclusion CSs are a useful strategy to attenuate the loss in velocity, power and peak force during RT and should be used to maintain neuromuscular performance, especially when kinetic outcomes are emphasised. However, it remains unclear if the benefits translate to improved performance across all RT exercises, between sexes and across the lifespan.

Background Although performance of the Nordic hamstring exercise (NHE) has been shown to elicit adaptations that may reduce hamstring strain injury (HSI) risk and occurrence, compliance in NHE interventions in professional soccer teams is low despite a high occurrence of HSI in soccer. A possible reason for low compliance is the high dosages prescribed within the recommended interventions. The aim of this review was to investigate the effect of NHE-training volume on eccentric hamstring strength and biceps femoris fascicle length adaptations. Methods A literature search was conducted using the SPORTDiscus, Ovid, and PubMed databases. A total of 293 studies were identified prior to application of the following inclusion criteria: (1) a minimum of 4 weeks of NHE training was completed; (2) mean ± standard deviation (SD) pre- and post-intervention were provided for the measured variables to allow for secondary analysis; and (3) biceps femoris muscle architecture was measured, which resulted in 13 studies identified for further analysis. The TESTEX criteria were used to assess the quality of studies with risk of bias assessment assessed using a fail-safe N (Rosenthal method). Consistency of studies was analysed using I2 as a test of heterogeneity and secondary analysis of studies included Hedges’ g effect sizes for strength and muscle architecture variables to provide comparison within studies, between-study differences were estimated using a random-effects model. Results A range of scores (3–11 out of 15) from the TESTEX criteria were reported, showing variation in study quality. A ‘low risk of bias’ was observed in the randomized controlled trials included, with no study bias shown for both strength or architecture (N = 250 and 663, respectively; p I2 = 62.49%) and muscle architecture (I2 = 88.03%). Within-study differences showed that following interventions of ≥ 6 weeks, very large positive effect sizes were seen in eccentric strength following both high volume (g = 2.12) and low volume (g = 2.28) NHE interventions. Similar results were reported for changes in fascicle length (g ≥ 2.58) and a large-to-very large positive reduction in pennation angle (g ≥ 1.31). Between-study differences were estimated to be at a magnitude of 0.374 (p = 0.009) for strength and 0.793 (p Conclusions Reducing NHE volume prescription does not negatively affect adaptations in eccentric strength and muscle architecture when compared with high dose interventions. These findings suggest that lower volumes of NHE may be more appropriate for athletes, with an aim to increase intervention compliance, potentially reducing the risk of HSI.

This study explored the acute effects of strength-oriented resistance training sessions performed using three different set configurations on barbell velocity and the force–velocity (F–v) relationship of upper-body muscles in men and women. Thirteen men (age: 23.8 ± 2.5 years; 6-repetition maximum [6RM] load: 73.4 ± 15.6 kg) and 13 women (age: 21.5 ± 1.4 years; 6RM load: 32.8 ± 5.2 kg) performed 24 repetitions with a 6RM load during the bench press exercise using traditional (TR: 6 sets of 4 repetitions with 3 min of rest between sets), cluster (CL: 6 sets of 4 repetitions with 15 s of intra-set rest every two repetitions and 2 min and 45 s of rest between sets) and inter-repetition rest (IRR: 1 set of 24 repetitions with 39 s of rest between repetitions) set configurations. The F–v relationship parameters [maximum force (F0), maximum velocity (v0) and maximum power (Pmax)] were determined before and after each training session. The average training velocity did not differ between the three set configurations (p = 0.234), but the IRR set configuration generally provided higher velocities during the last repetition of each set. Significant decreases in F0 (p = 0.001) and Pmax (p = 0.024) but not in v0 (p = 0.669) were observed after the training sessions. Comparable velocity loss was observed for men and women (− 12.1% vs. − 11.3%; p = 0.699). The administration of very short intra-set rest periods does not allow for the attainment of higher velocities than traditional set configurations during strength-oriented resistance training sessions conducted with the bench press exercise when the work-to-rest ratio is equated.

Background: Resistance training has been used to enhance a range of athletic abilities through correct manipulation of several variables such as training load, training volume, set configuration, and rest period. Objective: The aim of this systematic review and meta-analysis was to compare the acute and chronic responses of lower body cluster, contrast, complex, and traditional training across a range of athletic performance outcomes (1-repetition maximum squat strength, jump height, peak power, peak force, peak velocity, and sprint time).\ud Methods: A database search was completed (SPORTDiscus, Medline and CINAHL) followed by a quality scoring system, which concluded with 41 studies being used in the meta-analysis. Effect sizes were calculated for acute and training intervention changes compared to baseline. For acute cluster training, effect sizes were used to represent differences between equated traditional and cluster sets.\ud Results: Acutely, contrast and cluster training can be implemented to enhance and maintain velocity. Complex training does not acutely show a performance-enhancing effect on jump performance.\ud Conclusion: When looking to develop exercise-specific force, the exercise should be completed closer to set failure with fewer repetitions still able to be completed, which can be achieved using complex or high-volume contrast training to pre-fatigue the lighter exercise. When the objective is to improve velocity for the target exercise, it can be combined with a heavier contrast pair to create a postactivation performance enhancing effect. Alternatively, cluster set designs can be used to maintain high velocities and reduce drop-off. Finally, traditional training is most effective for increasing squat 1-repetition maximum.

Stone, MH, Hornsby, WG, Haff, GG, Fry, AC, Suarez, DG, Liu, J, Gonzalez-Rave, JM, and Pierce, KC. Periodization and block periodization in sports: emphasis on strength-power training-a provocative and challenging narrative. J Strength Cond Res 35(8): 2351-2371, 2021-Periodization can be defined as a logical sequential, phasic method of manipulating fitness and recovery phases to increase the potential for achieving specific performance goals while minimizing the potential for nonfunctional over-reaching, overtraining, and injury. Periodization deals with the micromanagement of timelines and fitness phases and is cyclic in nature. On the other hand, programming deals with the micromanagement of the training process and deals with exercise selection, volume, intensity, etc. Evidence indicates that a periodized training process coupled with appropriate programming can produce superior athletic enhancement compared with nonperiodized process. There are 2 models of periodization, traditional and block. Traditional can take different forms (i.e., reverse). Block periodization has 2 subtypes, single goal or factor (individual sports) and multiple goals or factors (team sports). Both models have strengths and weaknesses but can be "tailored" through creative programming to produce excellent results for specific sports.

Background If interplanetary travel is to be successful over the coming decades, it is essential that countermeasures to minimize deterioration of the musculoskeletal system are as effective as possible, given the increased duration of spaceflight associated with such missions. The aim of this review, therefore, is to determine the magnitude of deconditioning of the musculoskeletal system during prolonged spaceflight and recommend possible methods to enhance the existing countermeasures. Methods A literature search was conducted using PubMed, Ovid and Scopus databases. 5541 studies were identified prior to the removal of duplicates and the application of the following inclusion criteria: (1) group means and standard deviations for pre- and post-spaceflight for measures of strength, muscle mass or bone density were reported (or provided by the corresponding author when requested via e-mail), (2) exercise-based countermeasures were included, (3) the population of the studies were human, (4) muscle function was assessed and (5) spaceflight rather than simulated spaceflight was used. The methodological quality of the included studies was evaluated using a modified Physiotherapy Evidence Database (PEDro) scale for quality, with publication bias assessed using a failsafe N (Rosenthal method), and consistency of studies analysed using I2 as a test of heterogeneity. Secondary analysis of studies included Hedges’ g effect sizes, and between-study differences were estimated using a random-effects model. Results A total of 11 studies were included in the meta-analyses. Heterogeneity of the completed meta-analyses was conducted revealing homogeneity for bone mineral density (BMD) and spinal muscle size (Tau2 I2 = 0.00%, p > 0.05), although a high level of heterogeneity was noted for lower body force production (Tau2 = 1.546; I2 = 76.03%, p 2 = 1.386; I2 = 74.38%, p p ≤ 0.033), for BMD (− 0.48 to − 0.53, p p p g = − 0.49 [− 0.69 to – 0.28]), trochanter (Hedges g = − 0.53 [− 0.77 to – 0.29]), and lumbo-pelvic region (Hedges g = − 0.48 [− 0.73 to – 0.23]), but large decreases in lower limb force production (Hedges g = − 1.75 [− 2.50 to – 0.99]) and lower limb muscle size (Hedges g = − 1.98 [− 2.72 to – 1.23]). Conclusions Current exercise countermeasures result in small reductions in BMD during long-duration spaceflight. In contrast, such exercise protocols do not alleviate the reductions in muscle function or muscle size, which may be attributable to the low to moderate loads reported by crewmembers and the interference effect associated with concurrent training. It is recommended that higher-load resistance exercise and the use of high-intensity interval training should be investigated, to determine if such modifications to the reported training practices result in more effective countermeasures to the deleterious effect of long-duration spaceflight on the muscular system.

Background Providing accommodating resistance with the use of chains (CRT) is a programming technique that may enhance muscle size, strength, and power. However, there is a paucity of studies comparing the responses to CRT and traditional resistance training (TRT) approaches. This study aimed to examine the effects of 8 weeks of CRT and TRT on muscular adaptations in young recreationally-trained men. Methods Thirty men (26 ± 4 y) volunteered to participate in the present study and were randomly assigned to either CRT (n = 10), TRT (n = 10), or a non-exercise control group (CG, n = 10). A resistancetraining program (3-4 sets, ~8-12 repetitions at 65-80% of 1RM) was performed three times a week for 8 weeks. Percentage body fat, arm and thigh circumferences, 1RM and endurance (number of repetitions to failure 60% of 1RM) strength tests in the back squat and bench press exercises, and vertical jump power were assessed before and after the intervention. Results Following the intervention, both training groups demonstrated improvements in strength compared to CG, where greater gains were observed for CRT (e.g., bench press 1RM: CRT=28%; TRT=19% / back squat endurance: CRT=8%; TRT=2%). Conclusions The use of chains during resistance training may promote greater gains in strength in young men.

Periodisation is widely accepted by coaches and sports scientists as a central concept underpinning the development of athletes. Careful inspection of these authors’ perspectives reveals several significant issues that have resulted in a misrepresentation of the classic literature and display a significant lack of knowledge about the constructs that underpin the actual processes associated with the development of periodised training. One of the major sources of confusion about periodisation is a misunderstanding of the classic literature on the topic and the terminology often used in contemporary literature. In order to understand periodisation, it is important to classify the primary goals of a periodised training plan. Specifically, all periodised training plans target the elevation of performance at pre-determined time points, or to maintain performance capacity for an individual athlete or team throughout the course of a sport’s competitive season.

Sport science and medicine practitioners are interested in the relationships between training load, injury, and illness. The extent to which training preparedness is associated with workload-related injury and illness risk is debated. Therefore, this study applied multi-level mixed effect logistic regression to investigate time-dependent (±7- and ±28-day) relationships between training preparedness (fatigue, mood, motivation, soreness, stress, sleep duration, and quality), training load, injury, and illness in 536 elite and pre-elite female netball athletes. Absolute risk (AR ± 95% CI) of sustaining an injury (0.98 ± 0.06%, n = 1122 injuries, N = 254 athletes) or illness (1.09 ± 0.10%, n = 2881, N = 432 athletes) was calculated. All training preparedness variables combined resulted in an absolute risk of 0.88%-5.88% and 0.87%-20% for injury and illness, respectively. Injury and illness had significant (P < .05) bidirectional (ie, both increased and decreased) associations with physical (soreness) and physiological (sleep duration and quality), while illness also had negative (mood, motivation) and positive (stress) associations with psychological training preparedness variables. Low sleep duration in the 48-h period prior was associated (P = .005) with increased injury risk (OR = 0.91 ± 0.03; AR = 4.00%), while “very poor” sleep quality (OR = 0.59 ± 0.02; AR = 7.83%) or extremes of too little (10 hours, OR = 1.01 ± 0.03; AR = 2.61%-10.98%) sleep had bidirectional associations (P < .001) with an increased illness risk. Changes in training preparedness variables demonstrated bidirectional associations with injury and illness. These outcomes suggest that sport science and medicine practitioners should monitor sleep, physical, and psychological recovery status, to aid early detection and intervention regarding injury and illness symptomology.

This study&rsquo, s purpose was to examine heart rate variability (HRV) and direct current potential (DC) measures&rsquo, sensitivity and correlations between changes in the acute recovery and stress scale (ARSS) and the previous day&rsquo, s training load. Training load, HRV, DC and ARSS data were collected from fourteen professional mixed martial arts athletes (32.6 &plusmn, 5.3 years, 174.8 &plusmn, 8.8 cm, 79.2 &plusmn, 17.5 kg) the following morning after hard, easy and rest days. Sensitivity was expressed as a signal-to-noise ratio (SNR, inter-day typical error (TE) or coefficient of variation (%CV) divided by intra-day TE or %CV). Correlations between HRV, DC and ARSS with training load were also examined. The SNRs for the various HRV and DC measures were acceptable to good (1.02&ndash, 2.85). There was a 23.1% CV average increase between measures taken between different locations versus the same location. Training load changes were not correlated with HRV/DC but were correlated with ARSS stress variables. Practitioners should be aware of HRV/DC variability, however the daily training signal was greater than the test-retest error in this investigation. Upon awakening, HRV/DC measures appear superior for standardization and planning. HRV and DC measures were less sensitive to the previous day&rsquo, s training load than ARSS measures.

In this editorial, we focus on recent problematic developments in sport science, and more specifically, problems related to periodization research. Primary areas discussed are (1) appreciation of history, (2) considerations for training studies, (3) the development of concepts, and (4) programming-driven training models.

Cytokine and hormone concentrations can be linked to the manipulation of training variables and to subsequent alterations in performance. Subjects: Nine D-1 collegiate throwers and 4 control subjects participated in this preliminary and exploratory report. Methods: Hormone (testosterone (T) and cortisol (C)) and adipokine (adiponectin, leptin, and resistin) measurements were taken at weeks 1, 7, and 11 for the throwers and weeks 1 and 11 for the control group. The throwers participated in an 11-week periodized resistance training and throws program during the fall preparatory period. Volume load was recorded throughout the study. Results: Hormone values did not exhibit statistically significant changes across time; however, there were notable changes for C, the testosterone to cortisol ratio (T:C), and adiponectin. Conclusions: T:C was increased as volume load decreased, and adiponectin increased in concert with decreases in C and increases in the T:C, possibly suggesting a lesser degree of obesity-related inflammation and a higher degree of “fitness” and preparedness.

Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and between-session reliability of the isometric midthigh pull in young female athletes. J Strength Cond Res 32(7): 1892-1901, 2018-To investigate the within- and between-session reliability of the isometric midthigh pull (IMTP) in pre- and post-peak height velocity (PHV) female athletes. Nineteen pre- and 19 post-PHV athletes performed bilateral IMTPs using a custom-designed isometric testing system. Participants attended 3 separate testing sessions and performed 3 trials within each session. Peak force, relative peak force, force at 30, 50, 90, 100, 150, 200, and 250 ms, rate of force development (RFD) within time-specific bands, time to peak force (TPF), and time to peak RFD were obtained for analysis. Within- and between-session reliability for each variable was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICCs), and coefficients of variation (CV) with 95% confidence intervals. Within- and between-session measures of absolute and relative peak force were found to be reliable for both pre-PHV (CV ≤ 9.4%, ICC ≥ 0.87) and post-PHV (CV ≤ 7.3%, ICC ≥ 0.92), but systematic bias was evident between sessions in the pre-PHV group, from session 1 to 2. Analyses of force at the specific time points revealed CVs between 19-37% and 5-24% for pre-PHV and post-PHV athletes, respectively. Greater variability was evident in TPF, and all RFD-related variables for pre-PHV (CV ≥ 38%) and post-PHV (CV ≥ 27%) athletes, respectively. The IMTP appears a reliable and safe method for evaluating peak force in young female athletes. Overall, post-PHV athletes were more reliable than pre-PHV athletes, with pre-PHV athletes needing additional familiarization to minimize the influence of systematic bias.

Conlon, JA, Haff, GG, Tufano, JJ, and Newton, RU. Training load indices, perceived tolerance, and enjoyment among different models of resistance training in older adults. J Strength Cond Res 32(3): 867-875, 2018-The purpose of this study was to investigate the relationship between volume load (VL), training monotony, and strain, and perceived tolerance and enjoyment, across periodized and nonperiodized (NP) resistance training (RT) in older adults. Forty-one healthy, untrained apparently healthy older adults (women = 21, men = 20; 70.9 ± 5.1 years; 166.3 ± 8.2 cm; 72.9 ± 13.4 kg) were randomly stratified into a NP, block periodized (BP), or daily undulating periodized (DUP) group and completed a 22-week RT intervention at a frequency of 3 d·wk. All training was executed on RT machines and training volume was equalized between training groups based on total repetitions. Despite statistical differences in VL, training monotony, and strain between NP, BP, and DUP RT, perceived tolerance and enjoyment were similar across training models. Therefore, no meaningful relationships between training load indices (VL, monotony, and strain) and perceived tolerance and enjoyment were evident. Based on these results, periodization strategies do not appear to impact perceived tolerance or enjoyment of RT among the elderly, yet are recommended for better management of training load, potentially reducing the risk of illness and injury and promoting long-term adherence. Above all, practitioners should promote a friendly, supportive, and motivating training environment to increase program adherence and consequent training adaptations.

The purpose of this investigation was to determine whether the magnitude of adaptation to integrated ballistic training is influenced by initial strength level. Such information is needed to inform resistance training guidelines for both higher‐ and lower‐level athlete populations. To this end, two groups of distinctly different strength levels (stronger: one‐repetition‐maximum (1RM) squat = 2.01 ± 0.15 kg·BM−1; weaker: 1.20 ± 0.20 kg·BM−1) completed 10 weeks of resistance training incorporating weightlifting derivatives, plyometric actions, and ballistic exercises. Testing occurred at pre‐, mid‐, and post‐training. Measures included variables derived from the incremental‐load jump squat and the 1RM squat, alongside muscle activity (electromyography), and jump mechanics (force‐time comparisons throughout the entire movement). The primary outcome variable was peak velocity derived from the unloaded jump squat. It was revealed that the stronger group displayed a greater (P = .05) change in peak velocity at mid‐test (baseline: 2.65 ± 0.10 m/s, mid‐test: 2.80 ± 0.17 m/s) but not post‐test (2.85 ± 0.18 m/s) when compared to the weaker participants (baseline 2.43 ± 0.09, mid‐test. 2.47 ± 0.11, post‐test: 2.61 ± 0.10 m/s). Different changes occurred between groups in the force‐velocity relationship (P = .001‐.04) and jump mechanics (P ≤ .05), while only the stronger group displayed increases in muscle activation (P = .05). In conclusion, the magnitude of improvement in peak velocity was significantly influenced by pre‐existing strength level in the early stage of training. Changes in the mechanisms underpinning performance were less distinct.

The primary purpose of this investigation was to determine the impact of altering the set structure during an 8-week resistance training program on anthropometric, hormonal, and strength power characteristics. Thirty female volleyball players were recruited for participation and then randomly assigned to 1 of 3 resistance training groups: (i) cluster sets (CRT; n = 10), (ii) traditional sets (TRT; n = 10), or (iii) control (CON; n = 10). All athletes were evaluated for thigh and arm circumference, vertical jump, 20-m sprint, 4 × 9-m shuttle-run, 1-repetition maximum (1RM) back squat, bench press, military press, and deadlift prior to and after an 8-week periodized training intervention. Blood samples were taken before and after the 8-week training period to evaluate resting testosterone, cortisol, and insulin-like growth factor 1 responses to the training period. After 8 weeks of training the CRT group displayed a small but significant improvement in vertical jump (CRT: effect size (ES) = 038, 7.1%) performance when compared with the TRT group (ES = 0.34, 5.6%). Both the CRT and TRT training interventions resulted in very large increases in the 1RM squat (CRT: 8.4% ± 1.2%; TRT: 7.3% ± 0.6%), bench press (CRT: 8.3% ± 2.0%; TRT: 8.7% ± 1.9%), military press (CRT: 5.7% ± 1.2%; TRT: 5.5% ± 1.6%), and deadlift (CRT: 8.2% ± 1.6%; TRT: 8.3% ± 2.2%). There were no significant differences in 20-m sprint or 4 × 9-m shuttle run times between the CRT, TRT, and CON groups. These results suggest that cluster sets allow for greater improvements in vertical jump performance and equal improvements in strength gains to those seen with traditional sets.

Swimmers undertake dry-land resistance training as part of their overall training regime in order to increase lower body force output, impulse and swim turn performance. We investigated whether short-term ballistic training or maximal strength training is more effective in enhancing leg extensor force characteristics during the swim turn. Twelve elite swimmers (10 males and 2 females 19.4 ± 1.0 y) were assigned to either strength (n = 6) or ballistic leg extensor (n = 6) training based on their coaching group for a six-week period. All testing was conducted during the final training cycle towards the World Championships selection trials. Swimmers undertook dry-land testing of a squat jump on a portable force platform with bodyweight only and an additional 30 kg load for males and 20 kg load for females. On the same day, all swimmers performed a turn analysis using a fixed force platform within the pool wall. There were no substantial differences between the strength and ballistic groups after the six-week...

Physical performance is a key factor in most of the actions that determine success in soccer competitions. The present meta-analysis aimed to determine whether, and to what extent different conditioning programmes implemented in addition to regular soccer training are able to enhance the performance of high-velocity soccer-related tasks. Study groups were categorised according to type of performance measurement: (A) vertical jump ability, (B) linear sprint performance, (C), change of direction with ball, (D) change of direction without ball, (E) repeated sprint ability, and (F) kicking performance. Subgroup analyses were done with reference to the type of conditioning programme applied: (A) resistance training, (B) plyometric, (C) sprint and/or change of direction, and (D) combined methods. The standardised mean differences (SMD) along with 95% confidence intervals (95% CI) were calculated using the Review Manager 5.3 software. The application of a conditioning programme was associated with a significant improvement in vertical jump ability (SMD = 0.64 [95% CI: 0.50–0.77]), linear sprint (SMD = −0.79 [95% CI: −0.61 to −0.96]), change of direction with ball (SMD = −0.78 [95% CI: −0.42 to −1.15]), change of direction without ball (SMD = −0.83 [95% CI: −0.61 to −1.05]), repeated sprint ability (SMD = −0.51 [95% CI: −0.19 to −0.84]), and kicking performance (SMD = 0.78 [95% CI: 0.34–1.22]). No clear differences among the different conditioning programmes were observed. The implementation of a conditioning programme in addition to regular soccer training enhances the performance of high-velocity soccer-related tasks.

Hopper, A, Haff, EE, Barley, OR, Joyce, C, Lloyd, RS, and Haff, GG. Neuromuscular training improves movement competency and physical performance measures in 11-13-year-old female netball athletes. J Strength Cond Res 31(5): 1165-1176, 2017-The purpose of this study was to examine the effects of a neuromuscular training (NMT) program on movement competency and measures of physical performance in youth female netball players. It was hypothesized that significant improvements would be found in movement competency and physical performance measures after the intervention. Twenty-three junior female netball players (age, 12.17 ± 0.94 years; height, 1.63 ± 0.08 m; weight, 51.81 ± 8.45 kg) completed a test battery before and after a 6-week training intervention. Thirteen of these athletes underwent 6 weeks of NMT, which incorporated plyometrics and resistance training. Trained athletes showed significant improvements in 20-m sprint time, 505 agility time, countermovement jump height, and peak power (p ≤ 0.05, g0.8). In addition, trained athletes significantly improved their score in the Netball Movement Screening Tool (NMST) (p0.05, g-1.30); while the athletes also demonstrated increased reach in the anterior and posteromedial directions for the right leg and left leg, and in the posterolateral direction for the left leg only in the Star Excursion Balance Test (SEBT) (p0.05, g-0.03). Control subjects did not exhibit any significant changes during the 6-week period. Significant negative correlations were found between improved score on the NMST and decreased 5-, 10-, and 20-m sprint time, and 505 change of direction time (r0.4, p ≤ 0.05). Results of the study affirm the hypothesis that a 6-week NMT intervention can improve performance and movement competency in youth netball players.

Background: Surfing is a high skill sport that requires a considerable amount of time in a variety of ocean conditions to help develop the fundamental techniques. Objective: The purpose of this study was to investigate the effect of four weeks of detraining on strength, power, and sensorimotor ability in adolescent surfers. Methods: Nineteen adolescent surfers (13.8 A 1.7 y, 53.6 A 10.8 kg and 165.1 A 8.9 cm) participated in four weeks of detraining (surfing participation maintained but resistance training ceased) following seven weeks of periodized resistance training. Maximal isometric strength, power, and sensorimotor ability pre-test results were determined from the conclusion (post-test) of the first seven-week training block while post-test results were measured at the start (pre-test) of a second seven-week training block. Results: Four weeks of detraining significantly decreased the following variables: Vertical jump height by -5.26%, (p=0.037, d= 0.40), vertical jump peak velocity by -3.73% (p=0.001, d= 0.51), isometric strength by -5.5%, (p=0.012, d= 0.22), and relative isometric strength by -7.27% (p=0.003, d= 0.47). Furthermore, sensorimotor ability worsened, with a significant increase of 61.36% (p=0.004, d= 1.01), indicating that athletes took longer to stabilize from a dynamic landing task. Conclusions: This demonstrates that surfing, in the absence of resistance training, is not a sufficient training stimulus to maintain physical characteristics. Adolescent surfers with a relatively low training age should avoid cessation of resistance training and strive to maintain consistent resistance training in conjunction with surf training in order to avoid negative decrements in physical characteristics that are associated with surfing performance.

This study compared the effect of periodised versus non-periodised (NP) resistance training on neuromuscular adaptions in older adults. Forty-one apparently healthy untrained older adults (female = 21, male = 20; 70.9 ± 5.1 years; 166.3 ± 8.2 cm; 72.9 ± 13.4 kg) were recruited and randomly stratified to an NP, block periodised (BP), or daily undulating periodised (DUP) training group. Outcome measures were assessed at baseline and following a 22-week resistance training intervention (3 day week−1), including: muscle cross-sectional area (CSA), vertical jump performance, isometric and isokinetic peak torque, isometric rate of force development (RFD), and muscle activation. Thirty-three participants satisfied all study requirements and were included in analyses (female = 17, male = 16; 71.3 ± 5.4 years; 166.3 ± 8.5 cm; 72.5 ± 13.7 kg). Block periodisation, DUP, and NP resistance training induced statistically significant improvements in muscle CSA, vertical jump peak velocity, peak power and jump height, and peak isometric and isokinetic torque of the knee extensors at 60 and 180° s−1, with no between-group differences. Muscle activity and absolute RFD measures were statistically unchanged following resistance training across the entire cohort. Periodised resistance training, specifically BP and DUP, and NP resistance training are equally effective for promoting increases in muscular hypertrophy, strength, and power among untrained older adults. Consequently, periodisation strategies are not essential for optimising neuromuscular adaptations during the initial stages of resistance training in the aging population.

Resistance training is often recommended for combined increases in traditional and alternative hamstrings-to-quadriceps (H:Q) ratios in order to reduce knee strength imbalance and associated hamstrings and knee ligament injury risk. The aim of this study was to investigate the effect of different concentric and eccentric resistance training programs on traditional and alternative H:Q ratios. Forty male volunteers were assigned to one of 4 groups: concentric quadriceps and concentric hamstrings (CON/CON, n = 10), eccentric quadriceps and eccentric hamstrings (ECC/ECC, n = 10), concentric quadriceps and eccentric hamstrings (CON/ECC, n = 10), or no training (control (CNTRL), n = 10). Traditional conventional (CR) and functional (FR), alternative rate of torque development (RTD), muscle size (MS), and muscle activation (MA) H:Q ratios were measured before and after six weeks of unilateral nondominant knee extension&ndash, flexion resistance training performed on an isokinetic dynamometer. The ECC/ECC training significantly increased FR (pre = 0.75 &plusmn, 0.11, post = 0.85 &plusmn, 0.15), whereas the lack of training (CNTRL) decreased the RTD H:Q ratio (pre = 1.10 &plusmn, 0.67, post = 0.73 &plusmn, 0.33). There were no differences between groups for the other traditional and alternative ratios following resistance training protocols. These findings suggest eccentric exercise for quadriceps and hamstrings as the most beneficial training program for inducing increases in the traditional FR. However, different resistance training strategies may be needed to also elicit increases in the alternative RTD, MS, and MA H:Q ratios for fully restoring muscle balance and reducing potential hamstrings and knee ligament injury risk.

Blanco, P, Nimphius, S, Seitz, LB, Spiteri, T, and Haff, GG. Countermovement jump and drop jump performances are related to grand jeté leap performance in dancers with different skill levels. J Strength Cond Res 35(12): 3386-3393, 2021-Thirty-five classical ballet dancers were chosen to investigate relationships between the grand jeté leap, countermovement jump (CMJ), and drop jump (DJ) and establish whether the magnitude of the relationship between these tests differed across 3 skill levels. Subjects (male: n = 11 and female: n = 24) were divided into 3 groups: novice (n = 12; age: 16.6 ± 1.5 years; height: 1.7 ± 0.1 m; body mass: 58.0 ± 13.0 kg), semiprofessional (n = 13; age: 20.0 ± 1.6 years; height: 1.7 ± 0.1 m; body mass: 64.1 ± 10.5 kg), and professional (n = 10; age: 23.8 ± 3.5 years; height: 1.8 ± 1.2 m; body mass: 63.3 ± 14.7 kg). Grand jeté leap height, followed by CMJ and DJ vertical displacement, was assessed. Significant relationships were found between the grand jeté, CMJ (r = 0.77, p = 0.001) and DJ (r = 0.76, p = 0.001). After a Fisher's r-z transformation, professional dancers and novice dancers showed greater r-value differences in CMJ (r2 - r1 = 0.27) compared with novice (r2 - r1 = 0.17) and semiprofessional dancers (r2 - r1 = 0.11), indicating larger strength of CMJ to grand jeté relationship in professionals. The grand jeté leap showed large to very large correlations with CMJ and DJ within groups. These common performance tests were determined to be practical and efficient methods for assessing the jumping ability of dancers. As dance skill increased, larger correlations were observed, suggesting that dancers with superior ballet skills may be more likely to use their underpinning physical capacities to jump higher within the context of ballet-specific jumping.

Weightlifting is a competitive sport in which the main goal is to lift the heaviest possible load in the snatch and clean and jerk. As a sport, weightlifting requires athletes to demonstrate high levels of muscular strength, rates of force development and the ability to produce high power outputs. Due to the very unique force and power characteristics of the weightlifting movements, many strength and conditioning programmes, for a variety of sports, utilise the sports training methods to enhance sports performance. One of the key aspects of weightlifting is the unique muscle coactivation strategy that leads to enhanced jumping performance, as well as reducing knee injury risk. Even though there are many benefits to weightlifting training there is a false perception that young athletes should not participate in or use weightlifting movements in their training. This chapter seeks to present current information on the sport of weightlifting and its benefits for young athletes. Particular attention is paid to the safety of the sport as well as how to develop training programmes that can capitalise on the benefits of this unique training modality.

Delgado, J, Drinkwater, EJ, Banyard, HG, Haff, GG, and Nosaka, K. Comparison between back squat, Romanian deadlift, and barbell hip thrust for leg and hip muscle activities during hip extension. J Strength Cond Res 33(10): 2595-2601, 2019-This study compared muscle activities of vastus lateralis (VL), biceps femoris (BF), and gluteus maximus (GM) during the back squat (SQ), Romanian deadlift (RDL), and barbell hip thrust (BHT) exercises performed with the same load (60 kg) and at one repetition maximum (1RM). Eight men with a minimum of 1 year's lower-body strength training experience performed the exercises in randomized order. Before each exercise, surface electromyography (EMG) was recorded during a maximal voluntary isometric contraction (MVIC) and then used to normalize to each muscle's EMG during each trial. Barbell hip thrust showed higher GM activity than the SQ (effect size [ES] = 1.39, p = 0.038) but was not significantly different from RDL (ES = 0.49, p = 0.285) at 1RM. Vastus lateralis activity at 1RM during the SQ was significantly greater than RDL (ES = 1.36, p = 0.002) and BHT (ES = 2.27, p = 0.009). Gluteus maximus activity was higher during MVIC when compared with the 60 kg load for the SQ (ES = 1.29, p = 0.002) and RDL (ES = 1.16, p = 0.006) but was similar for the BHT (ES = 0.22, p = 0.523). There were no significant differences in GM (ES = 0.35, p = 0.215) and BF activities (ES = 0.16, p = 0.791) between 1RM and MVIC for the SQ. These findings show that the RDL was equally as effective as the BHT for isolating the hip extensors, while the SQ simultaneously activated the hip and knee extensors.

Guppy, SN, Brady, CJ, Kotani, Y, Stone, MH, Medic, N, and Haff, GG. Effect of altering body posture and barbell position on the within-session reliability and magnitude of force-time curve characteristics in the isometric midthigh pull. J Strength Cond Res 33(12): 3252-3262, 2019-A large degree of variation in the position used during isometric midthigh pull (IMTP) testing and conflicting results of the effects of these changes can be found in the literature. This study investigated the effect of altering body posture and barbell position on the reliability and magnitude of force-time characteristics generated during the IMTP. Seventeen strength-power athletes (n = 11 males, height: 177.5 ± 7.0 cm, body mass: 90.0 ± 14.1 kg, age: 30.6 ± 10.4 years; n = 6 females, height: 165.8 ± 11.4 cm; body mass: 66.4 ± 13.9 kg, age: 30.8 ± 8.7 years) with greater than 6 months of training experience in the clean (1 repetition maximum: 118.5 ± 20.6 kg, 77.5 ± 10.4 kg) volunteered to undertake the experimental protocol. Subjects performed the IMTP using 4 combinations of hip and knee angles, and 2 different barbell positions. The first barbell position corresponded to the second pull of the clean, while the second rested at the midpoint between the iliac crest and the patella. Peak force (PF), time-specific force (F50, F90, F150, F200, and F250), peak rate of force development (pRFD), and impulse (IMP) time bands were reliable in all 4 testing positions examined. Statistically greater PF, F50, F90, F150, F200, F250, pRFD, and IMP0-50, IMP0-90, IMP0-150, and IMP0-200 were generated in a testing position corresponding to the second pull of the clean when compared with a bent over torso angle, regardless of the barbell position used. Moderate to large effect sizes favoring a testing position corresponding to the second pull were also found. Overall, when performing the IMTP, an upright torso and a barbell position that matches the second pull of the clean should be used.

The purpose of this review is to provide strength and conditioning practitioners with recommendations on how best to implement tempo eccentric training (TEMPO), flywheel inertial training (FIT), accentuated eccentric loading (AEL), and plyometric training (PT) into resistance training programs that seek to improve an athlete’s hypertrophy, strength, and power output. Based on the existing literature, TEMPO may be best implemented with weaker athletes to benefit positional strength and hypertrophy due to the time under tension. FIT may provide an effective hypertrophy, strength, and power stimulus for untrained and weaker individuals; however, stronger individuals may not receive the same eccentric (ECC) overload stimulus. Although AEL may be implemented throughout the training year to benefit hypertrophy, strength, and power output, this strategy is better suited for stronger individuals. When weaker and stronger individuals are exposed to PT, they are exposed to an ECC overload stimulus as a result of increases in the ECC force and ECC rate of force development. In conclusion, when choosing to utilize ECC training methods, the practitioner must integrate these methods into a holistic training program that is designed to improve the athlete’s performance capacity.

The purpose of this review was to provide a physiological rationale for the use of eccentric resistance training and to provide an overview of the most commonly prescribed eccentric training methods. Based on the existing literature, there is a strong physiological rationale for the incorporation of eccentric training into a training program for an individual seeking to maximize muscle size, strength, and power. Specific adaptations may include an increase in muscle cross-sectional area, force output, and fiber shortening velocities, all of which have the potential to benefit power production characteristics. Tempo eccentric training, flywheel inertial training, accentuated eccentric loading, and plyometric training are commonly implemented in applied contexts. These methods tend to involve different force absorption characteristics and thus, overload the muscle or musculotendinous unit in different ways during lengthening actions. For this reason, they may produce different magnitudes of improvement in hypertrophy, strength, and power. The constraints to which they are implemented can have a marked effect on the characteristics of force absorption and therefore, could affect the nature of the adaptive response. However, the versatility of the constraints when prescribing these methods mean that they can be effectively implemented to induce these adaptations within a variety of populations.

Resistance exercise increases blood flow, induces osmotic and hydrostatic fluid shifts during and immediately after exercise, and may trigger inflammatory responses for several days in the working muscle. The resultant muscle swelling can subsequently affect muscle size and quality assessments. However, the effects of muscle swelling on x-ray attenuation of adipose estimate errors are unknown.Peripheral quantitative computed tomography (pQCT) and ultrasonography were used to assess muscle and adipose tissue properties of both upper arms before, 24, 48, and 72 h after unilateral resistance exercise. Recreationally active participants (n = 17) completed the exercise while their contralateral limb served as a control.Resistance exercise resulted in a significant increase in pQCT-derived muscle cross-sectional area (includes intermuscular adipose tissue [IMAT] area), muscle area (excludes IMAT area) and IMAT area, and ultrasound-derived muscle thickness at 24, 48, and 72 h. A significant decrease in pQCT-derived muscle density was also detected as well as an increase in ultrasound-derived echo intensity at 48 and 72 h. The changes in muscle area, IMAT area, and muscle density were significantly correlated with changes in echo intensity, whereas the changes in muscle cross-sectional area and IMAT area were significantly correlated with changes in muscle thickness.Unaccustomed resistance exercise can cause errors in pQCT- and ultrasound-based muscle and adipose estimates for at least 72 h. These errors are the result of muscle swelling likely caused by muscle blood flow and inflammation-dependent fluid shifts in muscle. These findings may have implications for measurements in other inflammatory conditions.

The hamstrings-to-quadriceps muscle strength ratio calculated by peak torque has been used as an important tool to detect muscle imbalance, monitor knee joint stability, describe muscle strength properties and functionality, and for lower extremity injury prevention and rehabilitation. However, this ratio does not consider other neuromuscular variables that can also influence the antagonist to agonist muscle relationship, such as torque produced at multiple angles of range of motion, explosive strength, muscle size, muscle fatigue, or muscle activation. The aim of this study was to comprehensively review alternative methods of determining the hamstrings-to-quadriceps ratio. These include ratios calculated by angle-specific torque, rate of torque development, muscle size, fatigue index, and muscle activation (measured by electromyography). Collectively, the literature demonstrates that utilizing alternative methods of determining the hamstrings-to-quadriceps ratio can be functionally relevant for a better understanding of the neuromuscular mechanisms underpinning the interaction of strength between hamstrings and quadriceps. However, there is insufficient evidence to recommend any of the alternative methods as sensitive clinical tools for predicting injury risk and monitoring knee joint integrity. Future longitudinal studies, along with injury incidence, are needed to further investigate all alternative methods of determining the hamstrings-to-quadriceps ratio. These have potential to offer insight into how athletes and the general population should be trained for performance enhancement and injury reduction, and may be used along with traditional methods for a thorough assessment of an individual’s H:Q muscle balance.

Harden, M, Wolf, A, Haff, GG, Hicks, KM, and Howatson, G. Repeatability and specificity of eccentric force output and the implications for eccentric training load prescription. J Strength Cond Res 33(3): 676-683, 2019-Prescribing supramaximal eccentric (ECC) loads based on repetition maximum, isometric (ISO), or concentric-only (CON) strength overlooks the possibility that individuals have a different tolerance for ECC exercise. To inform the prescription of ECC training regimes, this study implemented a test battery that included maximal accentuated-eccentric (ECC+), traditional coupled eccentric-concentric (TRAD), and 2 ISO conditions (90 and 120° knee-joint angle [ISO90 and ISO120, respectively]). The study aimed to determine the repeatability and specificity of ECC+ force output and assess the methodological accuracy when using nonspecific measures of strength to prescribe ECC+ training loads. Results show that the test battery was repeatable (p > 0.05, intraclass correlation coefficient >0.95, coefficient of variation: 0.05), estimations were associated with up to a 7% error. This investigation confirms that force output is task-specific; therefore, prescribing ECC loads based on strength during another task will likely lead to discrepancies in intended and actual ECC exercise intensity. Consequently, using an ECC-specific approach to assess ECC strength qualities will provide a more accurate platform to prescribe individualized ECC training programs and a more definitive evaluation of ECC strength.

Purpose This study compared the effect of periodized versus nonperiodized (NP) resistance training (RT) on physical function and health outcomes in older adults. Methods Forty-one apparently healthy untrained older adults (women = 21, men = 20; 70.9 ± 5.1 yr; 166.3 ± 8.2 cm; 72.9 ± 13.4 kg) were recruited and randomly stratified to a NP, block periodized, or daily undulating periodized training group. Outcome measures were assessed at baseline and after a 22-wk × 3 d·wk RT intervention, including; anthropometrics, body composition, blood pressure and biomarkers, maximal strength, functional capacity, balance confidence, and quality of life. Results Thirty-three subjects satisfied all study requirements and were included in analyses (women = 17, men = 16; 71.3 ± 5.4 yr; 166.3 ± 8.5 cm; 72.5 ± 13.7 kg). The main finding was that all three RT models produced significant improvements in several physical function and physiological health outcomes, including; systolic blood pressure, blood biomarkers, body composition, maximal strength, functional capacity and balance confidence, with no between-group differences. Conclusions Periodized RT, specifically block periodization and daily undulating periodized, and NP RT are equally effective for promoting significant improvements in physical function and health outcomes among apparently healthy untrained older adults. Therefore, periodization strategies do not appear to be necessary during the initial stages of RT in this population. Practitioners should work toward increasing RT participation in the age via feasible and efficacious interventions targeting long-term adherence in minimally supervised settings.