. All physical performance measures improved from baseline. Reactive strength index improved by 5%, isometric pull strength improved by 4%, and power increased by 1%. Linear speed, on-court speed, and repeated speed all improved by 1%, 6%, and 6%, respectively. Increases in blood serum from baseline
Rachel A. Hildebrand, Bridget Miller, Aric Warren, Deana Hildebrand and Brenda J. Smith
Increasing evidence indicates that compromised vitamin D status, as indicated by serum 25-hydroxyvitamin D (25-OH D), is associated with decreased muscle function. The purpose of this study was to determine the vitamin D status of collegiate athletes residing in the southern U.S. and its effects on muscular strength and anaerobic power. Collegiate athletes (n = 103) from three separate NCAA athletic programs were recruited for the study. Anthropometrics, vitamin D and calcium intake, and sun exposure data were collected along with serum 25-OH D and physical performance measures (Vertical Jump Test, Shuttle Run Test, Triple Hop for Distance Test and the 1 Repetition Maximum Squat Test) to determine the influence of vitamin D status on muscular strength and anaerobic power. Approximately 68% of the study participants were vitamin D adequate (>75 nmol/L), whereas 23% were insufficient (75–50 nmol/L) and 9%, predominantly non-Caucasian athletes, were deficient (<50 nmol/L). Athletes who had lower vitamin D status had reduced performance scores (p < .01) with odds ratios of 0.85 on the Vertical Jump Test, 0.82 on the Shuttle Run Test, 0.28 on the Triple Hop for Distance Test, and 0.23 on the 1 RM Squat Test. These findings demonstrate that even NCAA athletes living in the southern US are at risk for vitamin D insufficiency and deficiency and that maintaining adequate vitamin D status may be important for these athletes to optimize their muscular strength and power.
Brendan R. Scott, Robert G. Lockie, Timothy J. Knight, Andrew C. Clark and Xanne A.K. Janse de Jonge
To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer.
Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 individual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA; <14.4 km/h], high-speed running [HSR; >14.4 km/h], very high-speed running [VHSR; >19.8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product–moment correlations.
Physical measures of TD, LSA volume, and player load provided large, significant (r = .71−.84; P < .01) correlations with the HR-based and sRPE-based methods. Volume of HSR and VHSR provided moderate to large, significant (r = .40−.67; P < .01) correlations with measures of internal TL.
While the volume of HSR and VHSR provided significant relationships with internal TL, physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.
Lee Taylor, Christopher J. Stevens, Heidi R. Thornton, Nick Poulos and Bryna C.R. Chrismas
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 (T c; 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 ΔT c (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 T c 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 (T c) and perceptual (TS, TC, and RPE) warm-up responses, without compromising the utilized warm-up characteristics or physical-performance measures.
Shane Ball, Mark Halaki, Tristan Sharp and Rhonda Orr
rugby union, body-composition and physical-performance measures are likely to vary between positions. For example, forwards are more likely to be involved in more high-intensity contact events than backs, while backs tend to be involved in high-intensity running, both types of activity requiring
Helmi Chaabene, Yassine Negra, Jason Moran, Olaf Prieske, Senda Sammoud, Rodrigo Ramirez-Campillo and Urs Granacher
improve a wide variety of physical performance measures (ie, speed, jumping, CoD, and RSA). Of note, the NHE training intervention lasted no more than 10 minutes, making it a time-efficient training method that can be routinely carried out in a sporting environment with few resources required. Further
João Ribeiro, Luís Teixeira, Rui Lemos, Anderson S. Teixeira, Vitor Moreira, Pedro Silva and Fábio Y. Nakamura
CMJ height, in which no substantial effect (trivial ES: −0.03; 90% CI, −0.38 to 0.31) was detected, all other physical performance measures were slightly impaired throughout the control period (9 wk). There were very likely and likely harmful changes for SJ height (small ES: −0.51; 90% CI, −0.82 to −0
Jonathan P. Norris, Jamie Highton and Craig Twist
with physical contact were also reliable, with a lower variation between trials than that observed between competitive matches. Accordingly, we present an ecologically valid model that is capable of detecting changes in key physical performance measures of rugby league interchange players that might be
Shannon O’Donnell, Christopher M. Beaven and Matthew Driller
20 m sprint times following a similar time period of 30-minute nap compared to a NN condition. Although this study differs in the type of physical performance measures used (CMJs vs sprint time), we contend that these are both neuromuscular power tests. Therefore, results are comparable between the 2
Reid Reale, Gary Slater, Gregory R. Cox, Ian C. Dunican and Louise M. Burke
composition was assessed by a trained technician using dual-energy X-ray absorptiometry (iDEXA; GE Healthcare, Madison, WI), according to the standardized protocol developed at the Australian Institute of Sport ( Nana et al., 2016 ). Physical Performance Testing Physical performance measures included maximal