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INTRODUCTION: Hydrotherapy strategies such as cold, hot and contrast water immersion are used by athletes on completion of, and in preparation for, training and competition. The current study investigated the acute (<36 h) effects of post-exercise hydrotherapy on lower-body performance following a whole-body resistance exercise session. METHODS: Junior, international, male, volleyball athletes (n=15, 19.8 ± 3.7 y, 192.5 ± 11.8 cm, 80.2 ± 8.4 kg) were assessed for squat jump (SJ), counter-movement jump (CMJ) and isometric mid-thigh pull (IMTP) performance before and after a single whole-body resistance exercise and post-exercise hydrotherapy session. Athletes completed one of four 15min recovery strategies (control [CON]: passive seated rest at 23.7 ± 0.4°C; cold water immersion [CWI]: 14.8 ± 0.2°C; contrast water therapy [CWT]: 7 x 2 min, alternating hot 39.1 ± 0.5°C and cold 14.8 ± 0.2°C; and hot water immersion [HWI]: 39.1 ± 0.5°C), in a randomised crossover design, with >96 h between trials. SJ, CMJ and IMTP performance was assessed pre (-8 h) and at 0, 2, 4, 12 and 36 h post-resistance exercise. Mean percent change (%Δ) was calculated using a post-exercise (0 h) baseline. Jump height and vertical velocity was determined for SJ (SJ-HT%Δ and SJ-VEL%Δ) and CMJ (CMJ-HT%Δ and CMJ-VEL%Δ). Absolute (IMTP-PF%Δ) and relative (IMTP-relPF%Δ) peak force was determined for IMTP. Eccentric Utilization Ratio (EUR) and Dynamic Strength Index (DSI_SJ:IMTP and DSI_CMJ:IMTP) was calculated. Repeated-measures ANOVA was used to analyse main and interaction effects with significance accepted at p<0.10. The magnitude of change is interpreted using partial eta squared (ƞ²) and Cohen d effect size statistics. RESULTS: No significant main interactions were observed for SJ and CMJ variables (SJ-HT%Δ: p=0.679, ƞ²=0.039; SJ-VEL%Δ: p=0.642, ƞ²=0.041; CMJ-HT%Δ: p=0.545, ƞ²=0.043; CMJ-VEL%Δ: p=0.527, ƞ²=0.045). A significant main interaction was observed for IMTP-relPF%Δ (p=0.095, ƞ²=0.086) with relative IMTP peak force significantly (p=0.09, d=0.41) lower 12 h post-exercise in CWI (367.0 ± 52.6 N.kg-1) vs HWI (388.4 ± 60.1 N.kg-1), however there was no significant main interaction in IMTP-PF%Δ (p=0.43, ƞ²=0.051). No significant main interactions were observed for EUR (p=0.777, ƞ²=0.03), DSI-SJ:IMTP (p=0.242, ƞ²=0.083) or DSI-CMJ:IMTP (p=0.224, ƞ²=0.065). DISCUSSION: Previous research is inconsistent on the application of CWI as a post-exercise recovery strategy, with negative and positive effects on subsequent muscular performance. This research suggests that hydrotherapy strategies such as CWI and CWT do not appear to substantially influence post-exercise changes in SJ, CMJ and IMTP for <36 h following a single bout of resistance exercise. However, HWI optimises maximum isometric strength when compared with CWI at 12 h post-resistance exercise. PRACTICAL APPLICATION: Choice of hydrotherapy strategy may influence muscular contractions for up to 36 h post-exercise with small to medium interaction effects observed in dynamic strength indices. On days where multiple, same day resistance exercise bouts are performed, this data suggests that hydrotherapy would not be beneficial in between sessions. However, when resistance exercise is performed on subsequent days (~12 h apart), practitioners should prescribe post-exercise HWI to maximise isometric strength performance, while being cognisant of the effects that diurnal variation may have on muscular performance. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Following resistance training the acute effects of cold water immersion (CWI), contrast water therapy (CWT) and hot water immersion (HWI) on performance and perceived muscle soreness are not well characterised. This study assessed the effects of an acute bout of hydrotherapy compared with passive seated rest for 15 min (CON) on recovery (<48h) after a single, whole-body resistance training session. METHODS: Male sub-elite volleyball players (n=19, 24.1±5.5y, 181.9±8.9m, 78.4±11.2kg) were assessed for perceived muscle soreness (DOMS) and countermovement jumps (CMJ) performance prior to and immediately following a resistance training session. Athletes completed one of four 15min hydrotherapy strategies (CWI: 15°C; CWT: 7x2min, alternating hot 38°C and cold; HWI: 38°C), in a randomised order with at least 96h between trials with DOMS and CMJ reassessed immediately (0), 2, 24 and 48h post-resistance training. Flight time to contraction time (FT:CT) and a modified Reactive Strength Index (RSImod) were calculated from each CMJ. Data are presented as mean percent (%) change x/÷ 90% confidence intervals (CI) factor with the magnitude interpreted using effect size (ES, partial eta squared) and a linear mixed model was used to analyse the main and interaction effects. RESULTS: Immediately post-intervention RSImod and FT:CT increased compared to baseline (<8.1% x/÷ 0.02, p=0.02, ES=0.35-0.46) in CON and small effects were observed for CWI and CWT (<7.7% x/÷ 0.06, ES=0.37-0.53). Performance decreased 2h post exercise in CWT and HWI conditions (-5% x/÷ 0.05, ES=0.20). During CON RSImod and FT:CT (8x/÷ 0.02, ES=0.31-0.36) were increased at 48h while other conditions returned to baseline. Large correlations were observed between FT:CT and RSImod across all time points (r=0.77-0.94); however, greater main effects were observed in FT:CT. No significant intervention x group interaction for FT:CT and RSImod was observed. DOMS increased in all conditions at 24 and 48h (p<0.03, ES=0.80-1.61) with the large effects observed in CWT and HWI (ES=1.40-1.61). DISCUSSION: Hydrotherapy does not appear to influence CMJ performance following a resistance training bout, but may substantially effect the perception of recovery. Although a large correlation was observed between jumping variables across time, an increased number of effects were observed for FT:CT. Suggesting, that in a semi-elite male habituated jumping cohort, FT:CT has a greater sensitivity to fatigue post-resistance training than RSImod. PRACTICAL APPLICATIONS: When monitoring neuromuscular fatigue using CMJ, FT:CT may provide a more sensitive measure. CON may be more effective for recovery post-resistance training at 48h than CWI, CWT and HWI on jumping performance. HWI and CWT may have detrimental effects on jump performance 2h post resistance-training and therefore, should be used with caution if prescribed as an intervention between successive training sessions performed on the same day. [ABSTRACT FROM AUTHOR]

INTRODUCTION: International long haul (>5h) air travel is a necessity for many highly trained athletes as part of their training or competition schedules. Negative effects associated with long haul travel may impair an athlete's neuromuscular function. Countermovement jumps (CMJ) are frequently used to assess an athlete's lower body neuromuscular status. This study assessed the impact of westbound trans-meridian travel and intensified training on changes in CMJ performance. METHODS: Highly trained rowers (n=21, 23.7±1.4y, 190.9±7.5cm, 86.9±9.9kg) completed a single set of 6 loaded CMJ's weekly with performance measured using a digital optical encoder attached to a 20kg barbell. Each CMJ was assessed for mean concentric velocity (MV), jump height (JH) and dip. Data collection occurred four weeks prior to (T-4), week of (T-1), week post (T+1) and up to four weeks post (T+3 and T+4) travel. Athletes undertook a westbound flight incurring 22h flight time with 30h total travel time across nine time zones. Descriptive data is reported as mean (SD) with changes between time points reported as Cohen's d (90% CL) using criteria of <0.2=trivial, 0.2-0.6=small, 0.6-1.2=moderate and >1.2=large. RESULTS: Small changes were observed in JH and MV following westbound trans-meridian travel, and continued small changes were observed in these variables and dip up to 4 weeks post travel (Table 1). Trivial changes were observed for all variables between the T+3 and T+4 time periods. DISCUSSION: Westbound travel results in small differences in JH and MV. We hypothesise that this small change is due to athletes' retaining a high training load prior to travel, while the travel time worked as a forced rest period. Greater changes in JH and MV post travel may have been stifled by athletes being in a fatigued state prior to travel, small reductions in dip and MV during the pre-travel period support this, while only trivial reductions in JH were observed. Previous research indicates changes in dip may be a better indicator of fatigue. During intensified training there were small changes in JH, MV and dip, with a trivial reduction in JH and MV T+3 to T+4. A trivial increase in dip occurred concurrently, suggesting that despite an intensified training period athletes were able to maintain performance. This may be characteristic of this athlete cohort, which regularly undertake large training volumes and are potentially training in a compromised state. Analysis suggests westbound trans-meridian travel may have a greater impact on this athlete cohort than changes in training intensity (trivial changes T+3 to T+4 during the period of greatest load of the intensified training period). PRACTICAL APPLICATIONS: Reductions in CMJ performance are likely following westbound trans-meridian travel, however this may also be impacted by training fatigue prior to travel. Athletes may be able to maintain velocity and displacement based variables during periods of intensified training. [ABSTRACT FROM AUTHOR]

In combat sports, athletes are divided into categories based on gender and body mass. Athletes attempt to compete against a lighter opponent by losing body mass prior to being weighed (i.e., 'weight-cutting'). The purpose of this narrative review was to explore the current body of literature on weight-cutting and outline gaps for further research. Methods of weight-loss include energy intake restriction, total body fluid reduction and pseudo extreme/abusive medical practice (e.g., diuretics). The influence of weight-cutting on performance is unclear, with studies suggesting a negative or no effect. However, larger weight-cuts (~5% of body mass in <24 h) do impair repeat-effort performance. It is unclear if the benefit from competing against a smaller opponent outweighs the observed reduction in physical capacity. Many mechanisms have been proposed for the observed reductions in performance, ranging from reduced glycogen availability to increased perceptions of fatigue. Athletes undertaking weight-cutting may be able to utilise strategies around glycogen, total body water and electrolyte replenishment to prepare for competition. Despite substantial discussion on managing weight-cutting in combat sports, no clear solution has been offered. Given the prevalence of weight-cutting, it is important to develop a deeper understanding of such practices so appropriate advice can be given.