Influence of Complex Training Design on Acute Postactivation Performance Enhancement of Jump Squat and Ballistic Bench Throw Performance in Developing Team-Sport Athletes.

ABSTRACT: Poulos, N, Haff, GG, Nibali, M, Norris, D, and Newton, R. Influence of complex training design on acute postactivation performance enhancement of jump squat and ballistic bench throw performance in developing team-sport athletes. J Strength Cond Res 37(5): 969-979, 2023-The effect of complex training (CT) session design on acute postactivation performance enhancement (PAPE) of loaded jump squat(s) (JS) and ballistic bench throw(s) (BBT) was examined. This study further investigated whether relative strength is a moderating factor in PAPE in response to 3 distinct CT protocols. Fourteen Australian Football League (AFL) Academy athletes performed 3 different protocols comprising 85% 1 repetition maximum (1RM) back squats and bench press, and 30% 1RM loaded JS and BBT, differing in the sequencing of exercise order (i.e., complex pairs performed in isolation or with additional exercise interspersed within the intracomplex recovery period) and duration of the intracomplex recovery (2.5, 5, or 15 minutes). Differences in JS and BBT performance between CT protocols were trivial except for JS eccentric depth and eccentric impulse where small to moderate substantial differences were observed between protocols 2 and 3 in various sets; a small difference was observed between protocols 1 and 3 for eccentric depth. Small differences between protocols 1 and 2 were observed in set 1 in BBT peak velocity (ES = -0.26) and peak power (W·kg-1) (ES = -0.31). Small magnitudes of PAPE and decrements in performance were observed in some variables within protocols, yet effects across sets were inconsistent. Relative strength was negatively associated with JS performance (i.e., stronger athletes demonstrated a lower magnitude of PAPE) yet positively associated with PAPE of BBT peak force (N·kg-1) and peak power (W·kg-1). Alternating lower-body and upper-body complex sets and performance of ancillary exercise within the intracomplex recovery does not contribute to cumulative fatigue throughout the session and does not detrimentally affect subsequent JS and BBT performance. The manipulation of complex-set sequences offers practitioners a time-efficient means of providing both lower-body and upper-body heavy-resistance and ballistic training stimuli to achieve chronic training adaptations in maximal strength and power, with targeted improvements in specific kinetic and kinematic variables.

Comparison of the Potentiating Effect of Variable Load Jump Squats on Acute Drop Jump Performance in Rugby Sevens Athletes.

ABSTRACT: Poulos, N, Haff, GG, Nibali, M, Graham-Smith, P, and Newton, RU. Comparison of the potentiating effect of variable load jump squats on acute drop jump performance in rugby sevens athletes. J Strength Cond Res 37(1): 149-160, 2023-The effect of variable load jump squats (JSs) on acute drop jump (DJ) performance across multiple sets was examined. Seventeen elite rugby sevens athletes performed 3 DJs after 3 repetitions of a JS conditioning activity (CA) performed at 30 or 50% 1RM back squat loads. Acute postactivation performance enhancement (PAPE) in DJ kinetic and kinematic variables was assessed using a commercially available force platform (1,000 Hz). Postactivation performance enhancement was predominant after the 30% 1RM load with the greatest frequency of potentiation exhibited in set 3. The 50% 1RM CA resulted in substantial decrements in DJ performance with the exception of active stiffness, reactive strength index (flight:contact time), and contact time. Moderate differences were observed between the 50 and 30% 1RM loads for peak power (W), impulse (N·s), and force at zero velocity (N); active stiffness was the only variable where PAPE was greater in the 50% 1RM CA (ES: small). Active stiffness was the only variable to display favorable associations with relative strength in both the JS 30% 1RM (ES: 0.38 ± 0.20; moderate) and 50% 1RM (ES: 0.24 ± 0.23; small) CA loads. The JS 30% 1RM CA results in greater magnitude and frequency of PAPE of DJ kinetic and kinematic variables and is recommended if seeking to target PAPE in a range of DJ performance variables. Heavier JS loads may be appropriate if enhancement of muscle stiffness and stretch-shortening cycle efficiency is required. Consideration of targeted kinetic and kinematic variables when selecting CA intensity in complex training design is recommended.

Limiting the Rise in Core Temperature During a Rugby Sevens Warm-Up With an Ice Vest.

PURPOSE: To determine how a cooling vest worn during a warm-up could influence selected performance (countermovement jump [CMJ]), physical (global positioning system [GPS] metrics), and psychophysiological (body temperature and perceptual) variables. METHODS: In a randomized, crossover design, 12 elite male World Rugby Sevens Series athletes completed an outdoor (wet bulb globe temperature 23-27°C) match-specific externally valid 30-min warm-up wearing a phase-change cooling vest (VEST) and without (CONTROL), on separate occasions 7 d apart. CMJ was assessed before and after the warm-up, with GPS indices and heart rate monitored during the warm-ups, while core temperature (Tc; ingestible telemetric pill; n = 6) was recorded throughout the experimental period. Measures of thermal sensation (TS) and thermal comfort (TC) was obtained pre-warm-up and post-warm-up, with rating of perceived exertion (RPE) taken post-warm-ups. RESULTS: Athletes in VEST had a lower ΔTc (mean [SD]: VEST = 1.3°C [0.1°C]; CONTROL = 2.0°C [0.2°C]) from pre-warm-up to post-warm-up (effect size; ±90% confidence limit: -1.54; ±0.62) and Tc peak (mean [SD]: VEST = 37.8°C [0.3°C]; CONTROL = 38.5°C [0.3°C]) at the end of the warm-up (-1.59; ±0.64) compared with CONTROL. Athletes in VEST demonstrated a decrease in ΔTS (-1.59; ±0.72) and ΔTC (-1.63; ±0.73) pre-warm-up to post-warm-up, with a lower RPE post-warm-up (-1.01; ±0.46) than CONTROL. Changes in CMJ and GPS indices were trivial between conditions (effect size < 0.2). CONCLUSIONS: Wearing the vest prior to and during a warm-up can elicit favorable alterations in physiological (Tc) and perceptual (TS, TC, and RPE) warm-up responses, without compromising the utilized warm-up characteristics or physical-performance measures.

Individual Factors Affecting Rugby Sevens Match Performance.

Purpose: To examine the collective independent influence of a range of individual characteristics on physical and technical match performance during international rugby sevens matches. Methods: Data were collected from 20 international rugby sevens players from 1 team across 1 season. Activity profiles were measured using wearable microtechnology devices, and technical performance measures were collected from match video analysis. Subjective well-being measures were collected using a well-being questionnaire completed on the morning of main training days, and groin-squeeze assessments at 0° and 60° knee flexion were also conducted using a sphygmomanometer. Assessments of aerobic fitness were completed periodically across the season, including time to complete a 2-km run and final velocity during the 30:15 Intermittent Fitness Test (VIFT). A principal-components analysis was conducted to reduce the dimensionality of the physical and technical variables into single-factor values. Linear mixed models were then constructed to examine the collective influence of a range of individual contextual variables on physical and technical performance factors. Results: Increased muscle soreness, stress, and VIFT were associated with trivial to small increases in physical and technical performance values, whereas trivial to small decreases were associated with higher perceived recovery, body weight, and groin squeeze (0° knee flexion). Conclusions: A range of well-being metrics are required to account for a significant portion of the variance in physical and technical performance. These factors may be manipulated by coaches or practitioners to achieve favorable physiological readiness that may lead to improved match performance.

A novel sleep optimisation programme to improve athletes' well-being and performance.

OBJECTIVES: To improve well-being and performance indicators in a group of Australian Football League (AFL) players via a six-week sleep optimisation programme. DESIGN: Prospective intervention study following observations suggestive of reduced sleep and excessive daytime sleepiness in an AFL group. METHODS: Athletes from the Adelaide Football Club were invited to participate if they had played AFL senior-level football for 1-5 years, or if they had excessive daytime sleepiness (Epworth Sleepiness Scale [ESS] >10), measured via ESS. An initial education session explained normal sleep needs, and how to achieve increased sleep duration and quality. Participants (n = 25) received ongoing feedback on their sleep, and a mid-programme education and feedback session. Sleep duration, quality and related outcomes were measured during week one and at the conclusion of the six-week intervention period using sleep diaries, actigraphy, ESS, Pittsburgh Sleep Quality Index, Profile of Mood States, Training Distress Scale, Perceived Stress Scale and the Psychomotor Vigilance Task. RESULTS: Sleep diaries demonstrated an increase in total sleep time of approximately 20 min (498.8 ± 53.8 to 518.7 ± 34.3; p < .05) and a 2% increase in sleep efficiency (p < 0.05). There was a corresponding increase in vigour (p < 0.001) and decrease in fatigue (p < 0.05). CONCLUSIONS: Improvements in measures of sleep efficiency, fatigue and vigour indicate that a sleep optimisation programme may improve athletes' well-being. More research is required into the effects of sleep optimisation on athletic performance.

Physiological, psychometric, and performance effects of the Christmas break in Australian football.

PURPOSE: The aim of the current study was to quantify the physiological, psychometric, and performance effects of a 2-wk Christmas break in a professional Australian Football League club. METHODS: A series of physiological (eg, heart-rate [HR] response to a 5-min submaximal run and skinfold thicknesses), psychometric (rating-of-perceived-exertion [RPE] responses and wellness variables), and performance (running activity during standardized handball games, isometric midthigh pull [IMTP] peak force, and countermovement jump [CMJ]) measures were conducted in the weeks before and after the break. RESULTS: There was a possible and small increase in the sum of 7 skinfolds, while body mass and fat-free mass remained possible and likely unchanged, respectively. Sleep and stress scores remained likely to almost certainly unchanged, but there were some small, possible to likely decreases in fatigue and soreness scores. HR and RPE responses to the 5-min submaximal run were likely slightly lower (ie, improved) after the break. High-intensity running and acceleration distance during a standard handball game were very likely slightly greater, while HR and RPE responses to the game were possibly to very likely unchanged. HR responses to a high-intensity training session remained very likely unchanged. There was also a likely small increase in IMTP peak force but likely to very likely no change in CMJ variables. CONCLUSIONS: The results show that players returned from a 2-wk break during preseason well recovered, with preserved to improved levels of strength and cardiorespiratory fitness, despite small increases in skinfold thickness.

Volume, intensity, and timing of muscle power potentiation are variable.

Whereas muscle potentiation is consistently demonstrated with evoked contractile properties, the potentiation of functional and physiological measures is inconsistent. The objective was to compare a variety of conditioning stimuli volumes and intensities over a 15-min recovery period. Twelve volleyball players were subjected to conditioning stimuli that included 10 repetitions of half squats with 70% of 1-repetition maximum (RM) (10 × 70), 5 × 70, 5 × 85, 3 × 85, 3 × 90, 1 × 90, and control. Jump height, power, velocity, and force were measured at baseline, 1, 3, 5, 10, and 15 min. Data were analysed with a 2-way repeated measure ANOVA and magnitude-based inferences. The ANOVA indicated significant decreases in jump height, power, and velocity during recovery. This should not be interpreted that no potentiation occurred. Each dependent variable reached a peak at a slightly different time: peak jump height (2.8 ± 2.3 min), mean power (3.6 ± 3.01 min), peak power (2.5 ± 1.8 min), and peak velocity (2.5 ± 1.8 min). Magnitude-based inference revealed that both the 5 × 70 and 3 × 85 protocol elicited changes that exceeded 75% likelihood of exceeding the smallest worthwhile change (SWC) for peak power and velocity. The 10 × 70 and the 5 × 70 had a substantial likelihood of potentiating peak velocity and mean power above the SWC, respectively. Magnitude-based inferences revealed that while no protocol had a substantial likelihood of potentiating the peak vertical jump, the 5 × 70 had the most consistent substantial likelihood of increasing the peak of most dependent variables. We were unable to consistently predict if these peaks occurred at 1, 3, or 5 min poststimulation, though declines after 5 min seems probable.