Age-related changes in physical and perceptual markers of recovery following high-intensity interval cycle exercise.

BACKGROUND: The purpose of this study was to compare physical performance, perceptual and haematological markers of recovery in well-trained masters and young cyclists across 48 h following a bout of repeated high-intensity interval exercise. METHODS: Nine masters (mean ± SD; age = 55.6 ± 5.0 years) and eight young (age = 25.9 ± 3.0 years) cyclists performed a high-intensity interval exercise session consisting of 6 × 30 s intervals at 175% peak power output with 4.5 min rest between efforts. Maximal voluntary contraction (MVC), 10 s sprint (10SST), 30-min time trial (30TT) performance, creatine kinase concentration (CK) and perceptual measures of motivation, total recovery, fatigue and muscle soreness were collected at baseline and at standardised time points across the 48 h recovery period. RESULTS: No significant group-time interactions were observed for performance of MVC, 10SST, 30TT and CK (P > 0.05). A significant reduction in 10SST peak power was found in both masters (P = 0.002) and young (P = 0.003) cyclists at 1 h post exercise, however, both groups physically recovered at similar rates. Neither group showed significant (P > 0.05) or practically meaningful increases in CK (%∆ < 10%). A significant age-related difference was found for perceptual fatigue (P = 0.01) and analysis of effect size (ES) showed that perceptual recovery was delayed with masters cyclists reporting lower motivation (ES ±90%CI = 0.69 ± 0.77, moderate), greater fatigue (ES = 0.75 ± 0.93, moderate) and muscle soreness (ES = 0.61 ± 0.70, moderate) after 48 h of recovery. CONCLUSION: The delay in perceived recovery may have negative effects on long-term participation to systematic training.

Autonomic cardiovascular modulation in masters and young cyclists following high-intensity interval training.

PURPOSE: This study aimed at examining the autonomic cardiovascular modulation in well-trained masters and young cyclists following high-intensity interval training (HIT). METHODS: Nine masters (age 55.6 ± 5.0 years) and eight young cyclists (age 25.9 ± 3.0 years) completed a HIT protocol of 6 x 30 sec at 175% of peak power output, with 4.5-min' rest between efforts. Immediately following HIT, heart rate and R-R intervals were monitored for 30-min during passive supine recovery. Autonomic modulation was examined by i) heart rate recovery in the first 60-sec of recovery (HRR60); ii) the time constant of the 30-min heart rate recovery curve (HRRτ); iii) the time course of the root mean square for successive 30-sec R-R interval (RMSSD30); and iv) time and frequency domain analyses of subsequent 5-min R-R interval segments. RESULTS: No significant between-group differences were observed for HRR60 (P = 0.096) or HRRτ (P = 0.617). However, a significant interaction effect was found for RMSSD30 (P = 0.021), with the master cyclists showing higher RMSSD30 values following HIT. Similar results were observed in the time and frequency domain analyses with significant interaction effects found for the natural logarithm of the RMSSD (P = 0.008), normalised low-frequency power (P = 0.016) and natural logarithm of high-frequency power (P = 0.012). CONCLUSION: Following high-intensity interval training, master cyclists demonstrated greater post-exercise parasympathetic reactivation compared to young cyclists, indicating that physical training at older ages has significant effects on autonomic function.

Resistance Training Priming Activity Improves Upper-Body Power Output in Rugby Players: Implications for Game Day Performance.

Mason, BRJ, Argus, CK, Norcott, B, and Ball, NB. Resistance training priming activity improves upper-body power output in rugby players: implications for game day performance. J Strength Cond Res 31(4): 913-920, 2017-"Priming" or preactivation strategies performed in the hours leading into competition have been suggested to improve game day performance. Therefore, this study assessed the effectiveness of a resistance training priming activity on eliciting changes in lower- and upper-body power output, along with perceptual measures. To assess these changes, 13 state-level rugby players (aged 18.5 ± 0.5 years) completed a test-retest protocol using a counterbalanced crossover design. Perceptual (readiness to perform questionnaire) and performance measures (20-kg countermovement jump [CMJ], 20-kg bench throw) were completed before either a control (rest) or priming activity (4 sets of 3 banded back squats and banded bench press). After a 1-hour and 45-minute recovery period, perceptual and performance measures were repeated. Readiness to perform showed no meaningful differences pre- and postintervention. Bench throw peak power (8.5 ± 5.8%, 90% confidence limit; p ≤ 0.05) improved after the priming activity when compared with the control trial. Countermovement jump peak power (3.4 ± 4.9%; p > 0.05) had a small decrease after the priming activity when compared with the control trial. Therefore, completing a priming activity 1 hour and 45 minutes before competition is recommended to improve upper-body power output. However, further research into lower-body priming protocols should be conducted before implementing a lower-body priming activity before competition.

Vascular Occlusion and Sequential Compression for Recovery After Resistance Exercise.

The purpose of this study was to evaluate vascular occlusion (OCC) and sequential intermittent pneumatic compression (SIPC) as recovery strategies after fatiguing resistance exercise. Twelve strength-trained male participants (age: 24.0 ± 6.3 years, height: 180.4 ± 9.7 cm, and weight: 84.8 ± 9.6 kg) participated in a randomized cross-over study. Participants performed a fatiguing resistance exercise bout consisting of 10 sets with 10 repetitions of back squats at 70% 1 repetition maximum with 3-minute rest between sets. Outcome measures of perceived recovery status, muscle soreness, concentric peak isokinetic torque of the quadriceps, squat jump (SJ) height, and countermovement jump (CMJ) height were taken before the fatiguing resistance exercise bout and repeated immediately post, 1 hour, and 24 hours later. Immediately after the postexercise measures, participants undertook 1 of the 3 recovery strategies: OCC, SIPC, and a passive control (CON). Concentric peak isokinetic torque of the quadriceps was decreased significantly immediately post and 1 hour after the fatiguing resistance exercise bout compared with baseline values (p ≤ 0.05). Mean SJ and CMJ jump height decreased significantly immediately post and 1 hour compared with baseline measures, but only the SJ was significantly decreased at 24 hours. There were no significant differences between conditions for any of the postexercise measures (p > 0.05). In conclusion, this study indicates that OCC and SIPC are not effective for attenuating muscle performance loss after a fatiguing resistance exercise bout relative to passive recovery.

Assessing the variation in the load that produces maximal upper-body power.

Substantial variation in the load that produces maximal power has been reported. It has been suggested that the variation observed may be due to differences in subjects' physical characteristics. Therefore, the aim of this study was to determine the extent in which anthropometric measures correlate with the load that produces maximal power. Anthropometric measures (upper-arm length, forearm length, total arm length, and upper-arm girth) and bench press strength were assessed in 26 professional rugby union players. Peak power was then determined in the bench press throw exercise using loads of 20-60% of one repetition maximum (1RM) in the bench press exercise. Maximal power occurred at 30 ± 14% 1RM (mean ± SD). Upper-arm length had the highest correlation with the load maximizing power: -0.61 (90% confidence limits -0.35 to -0.78), implying loads of 22 vs. 38% 1RM maximize power for players with typically long vs. short upper-arm length. Correlations for forearm length, total arm length, and upper-arm girth to the load that maximized power were -0.29 (0.04 to -0.57), -0.56 (-0.28 to -0.75), and -0.29 (0.04 to -0.57), respectively. The relationship between 1RM and the load that produced maximal power was r = -0.23 (0.10 to -0.52). The between-subject variation in the load that maximized power observed (SD = ±14% of 1RM) may have been due to differences in anthropometric characteristics, and absolute strength and power outputs. Indeed, athletes with longer limbs and larger girths and greater maximal strength and power outputs used a lower percentage of 1RM loads to achieve maximum power. Therefore, we recommend individual assessment of the load that maximizes power output.

Routine, Routine, Routine: Sleep Regularity and its Association with Sleep Metrics in Professional Rugby Union Athletes.

BACKGROUND: Maintaining a consistent sleep and wake time is often reported as a key component of circadian rhythmicity and quality sleep. However, the impact of sleep onset and offset time variability on overall sleep outcomes are underreported in elite athlete populations. This study investigated the relationship between sleep onset and offset time variability using the sleep regularity index (SRI) and measures of sleep and well-being in professional rugby union athletes. Twenty-three professional male rugby union athletes (mean ± SD, age: 23 ± 3 y) underwent sleep monitoring via wrist actigraphy for three weeks during a pre-season phase of training and completed a daily wellness questionnaire. Median SRI was calculated and used to stratify the trainees into two quantile groups: >76.4 SRI (Regular, n = 11) and < 76.4 SRI (Irregular, n = 12). RESULTS: The regular sleep group showed significantly longer total sleep duration (p = 0.02, d = 0.97) compared to the irregular group (7:42 ± 0:29 vs. 7:18 ± 0:20 h: min per night, respectively). Furthermore, while not statistically significant, the regular sleep group showed greater sleep efficiency and less wake episodes compared to irregular sleepers, as demonstrated by moderate effect sizes (d = 0.71 and 0.69, respectively). CONCLUSIONS: The results from this study indicate that minimizing variability in sleep onset and offset time is beneficial for increasing sleep duration and may improve sleep efficiency during pre-season training in elite male rugby union athletes. This study provides evidence for the importance of including sleep-wake routines as a key component of sleep education interventions.

Daytime naps improve afternoon power and perceptual measures in elite rugby union athletes-a randomized cross-over trial.

Daytime naps are used by elite athletes in both training and match-day settings. Currently, there are limited interventional studies on the efficacy of napping on physical performance in elite team-sport athletes. Therefore, the objective was to investigate the effect of a daytime nap (<1 hour) on afternoon performance of peak power, reaction time, self-reported wellness, and aerobic performance in professional rugby union athletes. A randomized cross-over design was carried out among 15 professional rugby union athletes. Athletes performed nap (NAP) and no nap (CON) conditions on two occasions, separated by 1 week. Baseline testing of reaction time, self-reported wellness, and a 6-second peak power test on a cycle ergometer were completed in the morning, followed by 2 × 45-minute training sessions, after which athletes completed the NAP or CON condition at 1200 hours. Following the nap period, baseline measures were retested in addition to a 30-minute fixed-intensity interval cycle and a 4-minute maximal effort cycling test. A significant group × time interaction was determined for 6-second peak power output (+157.6 W, p < 0.01, d = 1.53), perceived fatigue (-0.2 AU, p = 0.01, d = 0.37), and muscle soreness (-0.1 AU, p = 0.04, d = 0.75) in favor of the NAP condition. A significantly lower perceived exertion rating (-1.2 AU, p < 0.01, d = 1.72) was recorded for the fixed-intensity session in favor of NAP. This study highlights that utilizing daytime naps between training sessions on the same day improved afternoon peak power and lowered perceptions of fatigue, soreness, and exertion during afternoon training in professional rugby union athletes.

Comparing Perceived Sleep Quality, Practices, and Behaviors of Male and Female Elite Rugby Union Athletes with the Use of Sleep Questionnaires.

Objective To evaluate the differences in subjective sleep quality, quantity, and behaviors among male and female elite rugby union athletes through two common sleep questionnaires. Materials and Methods A sample of 38 male and 27 female elite rugby union athletes filled out the Athlete Sleep Behavior Questionnaire (ASBQ) and the Pittsburgh Sleep Quality Index (PSQI). Global scores and individual items for each questionnaire were compared to assess differences between sexes. Results Male athletes reported significantly longer sleep duration (7 h 50 m ± 50 m versus 7h 12 m ± 58 m respectively; p ≤ 0.01; d = 0.70) and higher habitual sleep efficiency (88% versus 83% respectively; p < 0.05; d = 0.54) when compared with female athletes. Individual items of the ASBQ revealed significant differences between male and female athletes for five questions. Male athletes displayed higher instances of taking stimulants before training or competition and consuming alcohol within 4 hours of going to bed. Conversely, female athletes expressed greater thought or worry while in bed and a higher instance of training late at night. Discussion Male athletes displayed better self-reported sleep quality and quantity than female athletes; however, the present study highlighted that male and female elite rugby union athletes face specific challenges that differ. It appears that the differences observed between male and female elite rugby union athletes may be due to differing levels of professionalism or differences in training or competition schedules.

Characterization of the differences in strength and power between different levels of competition in rugby union athletes.

Levels of strength and power have been used to effectively discriminate between different levels of competition; however, there is limited literature in rugby union athletes. To assess the difference in strength and power between levels of competition, 112 rugby union players, including 43 professionals, 19 semiprofessionals, 32 academy level, and 18 high school level athletes, were assessed for bench press and box squat strength, and bench throw, and jump squat power. High school athletes were not assessed for jump squat power. Raw data along with data normalized to body mass with a derived power exponent were log transformed and analyzed. With the exception of box squat and bench press strength between professional and semiprofessional athletes, higher level athletes produced greater absolute and relative strength and power outputs than did lower level athletes (4-51%; small to very large effect sizes). Lower level athletes should strive to attain greater levels of strength and power in an attempt to reach or to be physically prepared for the next level of competition. Furthermore, the ability to produce high levels of power, rather than strength, may be a better determinate of playing ability between professional and semiprofessional athletes.

Kinetic and training comparisons between assisted, resisted, and free countermovement jumps.

Elastic band assisted and resisted jump training may be a novel way to develop lower-body power. The purpose of this investigation was to (a) determine the kinetic differences between assisted, free, and resisted countermovement jumps and (b), investigate the effects of contrast training using either assisted, free, or resisted countermovement jump training on vertical jump performance in well-trained athletes. In part 1, 8 recreationally trained men were assessed for force output, relative peak power (PP·kg(-1)) and peak velocity during the 3 types of jump. The highest peak force was achieved in the resisted jump method, while PP·kg(-1) and peak velocity were greatest in the assisted jump. Each type of jump produced a different pattern of maximal values of the variables measured, which may have implications for developing separate components of muscular power. In part 2, 28 professional rugby players were assessed for vertical jump height before and after 4 weeks of either assisted (n = 9), resisted (n = 11), or free (n = 8) countermovement jump training. Relative to changes in the control group (1.3 ± 9.2%, mean ± SD), there were clear small improvements in jump height in the assisted (6.7 ± 9.6%) and the resisted jump training group (4.0 ± 8.8%). Elastic band assisted and resisted jump training are both effective methods for improving jump height and can be easily implemented into current training programs via contrast training methods or as a part of plyometric training sessions. Assisted and resisted jump training is recommended for athletes in whom explosive lower-body movements such as jumping and sprinting are performed as part of competition.

Assessing lower-body peak power in elite rugby-union players.

Resistance training at the load that maximizes peak power (Pmax) may produce greater increases in peak power than other loads. Pmax for lower-body lifts can occur with no loading but whether Pmax can be increased further with negative loading is unclear. The purpose of this investigation was therefore to determine lower-body Pmax (jump squat) using a spectrum of loads. Box squat 1 repetition maximum (1RM) was measured in 18 elite rugby-union players. Pmax was then determined using loads of -28 to 60%1RM. Elastic bands were used to unload body weight for negative loads. Jump squat Pmax occurred with no loading (body weight: 8,880 ± 2,186 W) in all but 2 subjects. There was a discontinuity in the power-load relationship for the jump squat, possibly because of the increased countermovement in the body weight jump. The self-selected depth (dip) before the propulsive phase of the jump was greater by 24 ± 11 to 40 ± 16% (moderate to large effect size) than all positive loads. These findings highlight methodological issues that need to be taken into consideration when comparing power outputs of loaded and unloaded jumps.

Acute effects of verbal feedback on upper-body performance in elite athletes.

Argus, CK, Gill, ND, Keogh, JWL, and Hopkins, WG. Acute effects of verbal feedback on upper-body performance in elite athletes. J Strength Cond Res 25(12): 3282-3287, 2011-Improved training quality has the potential to enhance training adaptations. Previous research suggests that receiving feedback improves single-effort maximal strength and power tasks, but whether quality of a training session with repeated efforts can be improved remains unclear. The purpose of this investigation was to determine the effects of verbal feedback on upper-body performance in a resistance training session consisting of multiple sets and repetitions in well-trained athletes. Nine elite rugby union athletes were assessed using the bench throw exercise on 4 separate occasions each separated by 7 days. Each athlete completed 2 sessions consisting of 3 sets of 4 repetitions of the bench throw with feedback provided after each repetition and 2 identical sessions where no feedback was provided after each repetition. When feedback was received, there was a small increase of 1.8% (90% confidence limits, ±2.7%) and 1.3% (±0.7%) in mean peak power and velocity when averaged over the 3 sets. When individual sets were compared, there was a tendency toward the improvements in mean peak power being greater in the second and third sets. These results indicate that providing verbal feedback produced acute improvements in upper-body power output of well-trained athletes. The benefits of feedback may be greatest in the latter sets of training and could improve training quality and result in greater long-term adaptation.

Sleep and Performance during a Preseason in Elite Rugby Union Athletes.

BACKGROUND: Preseason training optimises adaptations in the physical qualities required in rugby union athletes. Sleep can be compromised during periods of intensified training. Therefore, we investigated the relationship between sleep quantity and changes in physical performance over a preseason phase in professional rugby union athletes. METHODS: Twenty-nine professional rugby union athletes (Mean ± SD, age: 23 ± 3 years) had their sleep duration monitored for 3 weeks using wrist actigraphy. Strength and speed were assessed at baseline and at week 3. Aerobic capacity and body composition were assessed at baseline, at week 3 and at week 5. Participants were stratified into 2 groups for analysis: <7 h 30 min sleep per night (LOW, n = 15) and >7 h 30 min sleep per night (HIGH, n = 14). RESULTS: A significant group x time interaction was determined for aerobic capacity (p = 0.02, d = 1.25) at week 3 and for skinfolds at week 3 (p < 0.01, d = 0.58) and at week 5 (p = 0.02, d = 0.92), in favour of the HIGH sleep group. No differences were evident between groups for strength or speed measures (p ≥ 0.05). CONCLUSION: This study highlights that longer sleep duration during the preseason may assist in enhancing physical qualities including aerobic capacity and body composition in elite rugby union athletes.

Effects of a short-term pre-season training programme on the body composition and anaerobic performance of professional rugby union players.

Pre-season rugby training develops the physical requisites for competition and consists of a high volume of resistance training and anaerobic and aerobic conditioning. However, the effects of a rugby union pre-season in professional athletes are currently unknown. Therefore, the purpose of this investigation was to determine the effects of a 4-week pre-season on 33 professional rugby union players. Bench press and box squat increased moderately (13.6 kg, 90% confidence limits +/-2.9 kg and 17.6 +/- 8.0 kg, respectively) over the training phase. Small decreases in bench throw (70.6 +/- 53.5 W), jump squat (280.1 +/- 232.4 W), and fat mass (1.4 +/- 0.4 kg) were observed. In addition, small increases were seen in fat-free mass (2.0 +/- 0.6 kg) and flexed upper-arm girth (0.6 +/- 0.2 cm), while moderate increases were observed in mid-thigh girth (1.9 +/- 0.5 cm) and perception of fatigue (0.6 +/- 0.4 units). Increases in strength and body composition were observed in elite rugby union players after 4 weeks of intensive pre-season training, but this may have been the result of a return to fitness levels prior to the off-season. Decreases in power may reflect high training volumes and increases in perceived of fatigue.

Changes in strength, power, and steroid hormones during a professional rugby union competition.

The purpose of this investigation was to assess changes in strength, power, and levels of testosterone and cortisol over a 13-week elite competitive rugby union season. Thirty-two professional rugby union athletes from a Super 14 rugby team (age, 24.4 +/- 2.7 years; height, 184.7 +/- 6.2 cm; mass, 104.0 +/- 11.2 kg; mean +/- SD) were assessed for upper-body and lower-body strength (bench press and box squat, respectively) and power (bench throw and jump squat, respectively) up to 5 times throughout the competitive season. Salivary testosterone and cortisol samples, along with ratings of perceived soreness and tiredness, were also obtained before each power assessment. An effect size of 0.2 was interpreted as the smallest worthwhile change. A small increase in lower-body strength was observed over the study period (8.5%; 90% confidence limits +/-7.2%), whereas upper-body strength was maintained (-1.2%; +/-2.7%). Decreases in lower-body power (-3.3%; +/-5.5%) and upper-body power (-3.4; +/-4.9%) were small and trivial. There were moderate increases in testosterone (54%; +/-27%) and cortisol (97%; +/-51%) over the competitive season, and the testosterone to cortisol ratio showed a small decline (22%; +/-25%), whereas changes in perceived soreness and tiredness were trivial. Individual differences over the competitive season for all measures were mostly trivial or inestimable. Some small to moderate relationships were observed between strength and power; however, relationships between hormonal concentrations and performance were mainly trivial but unclear. Positive adaptation in strength and power may be primarily affected by cumulative training volume and stimulus over a competitive season. Greater than 2 resistance sessions per week may be needed to improve strength and power in elite rugby union athletes during a competitive season.

Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training.

We determined the effects of cold water immersion (CWI) on long-term adaptations and post-exercise molecular responses in skeletal muscle before and after resistance training. Sixteen men (22.9 ± 4.6 y; 85.1 ± 17.9 kg; mean ± SD) performed resistance training (3 day/wk) for 7 wk, with each session followed by either CWI [15 min at 10°C, CWI (COLD) group, n = 8] or passive recovery (15 min at 23°C, control group, n = 8). Exercise performance [one-repetition maximum (1-RM) leg press and bench press, countermovement jump, squat jump, and ballistic push-up], body composition (dual X-ray absorptiometry), and post-exercise (i.e., +1 and +48 h) molecular responses were assessed before and after training. Improvements in 1-RM leg press were similar between groups [130 ± 69 kg, pooled effect size (ES): 1.53 ± 90% confidence interval (CI) 0.49], whereas increases in type II muscle fiber cross-sectional area were attenuated with CWI (-1,959 ± 1,675 µM2 ; ES: -1.37 ± 0.99). Post-exercise mechanistic target of rapamycin complex 1 signaling (rps6 phosphorylation) was blunted for COLD at post-training (POST) +1 h (-0.4-fold, ES: -0.69 ± 0.86) and POST +48 h (-0.2-fold, ES: -1.33 ± 0.82), whereas basal protein degradation markers (FOX-O1 protein content) were increased (1.3-fold, ES: 2.17 ± 2.22). Training-induced increases in heat shock protein (HSP) 27 protein content were attenuated for COLD (-0.8-fold, ES: -0.94 ± 0.82), which also reduced total HSP72 protein content (-0.7-fold, ES: -0.79 ± 0.57). CWI blunted resistance training-induced muscle fiber hypertrophy, but not maximal strength, potentially via reduced skeletal muscle protein anabolism and increased catabolism. Post-exercise CWI should therefore be avoided if muscle hypertrophy is desired.NEW & NOTEWORTHY This study adds to existing evidence that post-exercise cold water immersion attenuates muscle fiber growth with resistance training, which is potentially mediated by attenuated post-exercise increases in markers of skeletal muscle anabolism coupled with increased catabolism and suggests that blunted muscle fiber growth with cold water immersion does not necessarily translate to impaired strength development.

Cold-Water Immersion and Contrast Water Therapy: No Improvement of Short-Term Recovery After Resistance Training.

CONTEXT: An athlete's ability to recover quickly is important when there is limited time between training and competition. As such, recovery strategies are commonly used to expedite the recovery process. PURPOSE: To determine the effectiveness of both cold-water immersion (CWI) and contrast water therapy (CWT) compared with control on short-term recovery (<4 h) after a single full-body resistance-training session. METHODS: Thirteen men (age 26 ± 5 y, weight 79 ± 7 kg, height 177 ± 5 cm) were assessed for perceptual (fatigue and soreness) and performance measures (maximal voluntary isometric contraction [MVC] of the knee extensors, weighted and unweighted countermovement jumps) before and immediately after the training session. Subjects then completed 1 of three 14-min recovery strategies (CWI, CWT, or passive sitting [CON]), with the perceptual and performance measures reassessed immediately, 2 h, and 4 h postrecovery. RESULTS: Peak torque during MVC and jump performance were significantly decreased (P < .05) after the resistance-training session and remained depressed for at least 4 h postrecovery in all conditions. Neither CWI nor CWT had any effect on perceptual or performance measures over the 4-h recovery period. CONCLUSIONS: CWI and CWT did not improve short-term (<4-h) recovery after a conventional resistance-training session.

The Effect of Initial Knee Angle on Concentric-Only Squat Jump Performance.

PURPOSE: There is uncertainty as to which knee angle during a squat jump (SJ) produces maximal jump performance. Importantly, understanding this information will aid in determining appropriate ratios for assessment and monitoring of the explosive characteristics of athletes. METHOD: This study compared SJ performance across different knee angles-90º, 100º, 110º, 120º, 130º, and a self-selected depth-for jump height and other kinetic characteristics. For comparison between SJ and an unconstrained dynamic movement, participants also performed a countermovement jump from a self-selected depth. Thirteen participants (Mage = 25.4 ± 3.5 years, Mheight = 1.8 ± 0.06 m, Mweight = 79.8 ± 9.5 kg) were recruited and tested for their SJ performance. RESULTS: In the SJ, maximal jump height (35.4 ± 4.6 cm) was produced using a self-selected knee angle (98.7 ± 11.2°). Differences between 90°, 100°, and self-selected knee angles for jump height were trivial (ES ± 90% CL = 90°-100° 0.23 ± 0.12, 90°-SS -0.04 ± 0.12, 100°-SS -0.27 ± 0.20; 0.5-2.4 cm) and not statistically different. Differences between all other knee angles for jump height ranged from 3.8 ± 2.0 cm (mean ± 90% CL) to 16.6 ± 2.2 cm. A similar outcome to jump height was observed for velocity, force relative to body weight, and impulse for the assessed knee angles. CONCLUSIONS: For young physically active adult men, the use of a self-selected depth in the SJ results in optimal performance and has only a trivial difference to a constrained knee angle of either 90° or 100°.

Reliability of a 2-bout exercise test on a wattbike cycle ergometer.

PURPOSE: To determine the intraday and interday reliability of a 2 × 4-min performance test on a cycle ergometer (Wattbike) separated by 30 min of passive recovery (2 × 4MMP). METHODS: Twelve highly trained cyclists (mean ± SD; age = 20 ± 2 y, predicted VO2max = 59.0 ± 3.6 mL · kg-1 · min-1) completed six 2 × 4MMP cycling tests on a Wattbike ergometer separated by 7 d. Mean power was measured to determine intraday (test 1 [T1] to test 2 [T2]) and interday reliability (weeks 1-6) over the repeated trials. RESULTS: The mean intraday reliabilities of the 2 × 4MMP test, as expressed by the typical error of measurement (TEM, W) and coefficient of variation (CV, %) over the 6 wk, were 10.0 W (95% confidence limits [CL] 8.2-11.8), and 2.6% (95%CL 2.1-3.1), respectively. The mean interday reliability TEM and CV for T1 over the 6 wk were 10.4 W (95%CL 8.7-13.3) and 2.7% (95%CL 2.3-3.5), respectively, and 11.7 W (95%CL 9.8-15.1) and 3.0% (95%CL 2.5-3.9) for T2. CONCLUSION: The testing protocol performed on a Wattbike cycle ergometer in the current study is reproducible in highly trained cyclists. The high intraday and interday reliability make it a reliable method for monitoring cycling performance and for investigating factors that affect performance in cycling events.

Does hydrotherapy help or hinder adaptation to training in competitive cyclists?

PURPOSE: Cold water immersion (CWI) may be beneficial for acute recovery from exercise, but it may impair long-term performance by attenuating the stimuli responsible for adaptation to training. We compared effects of CWI and passive rest on cycling performance during a simulated cycling grand tour. METHODS: Thirty-four male endurance-trained competitive cyclists were randomized to CWI for four times per week for 15 min at 15°C or control (passive recovery) groups for 7 d of baseline training, 21 d of intensified training, and an 11-d taper. Criteria for completion of training and testing were satisfied by 10 cyclists in the CWI group (maximal aerobic power, 5.13 ± 0.21 W·kg; mean ± SD) and 11 in the control group (5.01 ± 0.41 W·kg). Each week, cyclists completed a high-intensity interval cycling test and two 4-min bouts separated by 30 min. CWI was performed four times per week for 15 min at 15°C. RESULTS: Between baseline and taper, cyclists in the CWI group had an unclear change in overall 4-min power relative to control (2.7% ± 5.7%), although mean power in the second effort relative to the first was likely higher for the CWI group relative to control (3.0% ± 3.8%). The change in 1-s maximum mean sprint power in the CWI group was likely beneficial compared with control (4.4% ± 4.2%). Differences between groups for the 10-min time trial were unclear (-0.4% ± 4.3%). CONCLUSION: Although some effects of CWI on performance were unclear, data from this study do not support recent speculation that CWI is detrimental to performance after increased training load in competitive cyclists.