Physical fitness metrics and their relationship to locomotor activity profiles among female international field hockey players across an Olympic cycle.

OBJECTIVES: The study explored the correlations between physical fitness metrics and match locomotor activity profiles. Furthermore exploring the transformations of both fitness tests as well as match locomotor activities over an Olympic cycle. DESIGN: Observational descriptive study. METHODS: Fitness testing (n = 24) and match locomotor activity (n = 102) profiles were collected. A Pearson's product-moment correlation and 95 % confidence intervals were calculated to determine relationships between metrics for each year. A mixed-effects model was used for repeated measures to identify differences in the physical fitness tests and match locomotor activity profiles between years. RESULTS: The YoYo intermittent reocvery testest level 1 changed significantly (p < 0.0001) and accounted for 29 % of the variance in average speed (p < 0.001, rrm (59) = 0.54) Upper and lower body muscular strength, also improved, evidenced by the 3RM bench press (p < 0.0001), and a 28 % (2017-2019) increase in 3RM squat (p < 0.0001). Also pull-ups increased from 4.2 ± 2.8 pull-ups (2017) to 10.0 ± 3.1 pull-ups (2020) (p < 0.0001) and. countermovement jump height increased over the study duration (p < 0.0001). Match total distances remained unchanged, while average speed increased significantly (p < 0.0001). High-speed running distance (p < 0.0003) and sprint counts (p < 0.0001), showed significant improvements over the study period. CONCLUSIONS: The study underscores noteworthy improvements in physical attributes and performance metrics over an Olympic cycle. Contributing valuable insights for enhancing athletic performance in hockey players competing in the Olympics.

Changes in countermovement jump performance and subjective readiness-to-train scores following a simulated soccer match.

The study investigated whether countermovement jump (CMJ) metrics and subjective responses to a readiness-to-train questionnaire (RTT-Q) tracked simulated match-induced acute fatigue. This was a randomized cross-over repeated measures study. Participants were assigned into one of two groups; CONTROL or LIST. The LIST group performed the Loughborough Intermittent Shuttle Run (LIST), which was designed to simulate the demands of a soccer match. The CONTROL performed light physical activity at an intensity of <65% of maximal heart rate. Each group performed three CMJ's and completed an RTT-Q before (PRE), and again at 24 and 48 h after the LIST and/or CONTROL interventions. At 24 h there were significant differences in RTT-Q answers between the Pre and 24 h for the LIST group for questions; "Do you feel physically strong today?" and "Do you have muscle soreness today?" (p = 0.02 and 0.0008, respectively). The questions "Do you feel mentally strong today?" and "Do you have muscle soreness today?" (p = 0.02 and p = 0.0001 respectively) were the only questions that had a significant difference between Pre and 48 h for the LIST group. None of the CMJ metrics (LIST or CONTROL) changed significantly at any stage of the experiment. Although fatigue was detected by changes in the RTT-Q at 24 and 48 h after the LIST, none of the CMJ metrics changed. These findings suggest that subjective measures are more sensitive to low-level fatigue than objective measures, thus effective monitoring should include both.

Effects of foam rolling on performance and recovery: A systematic review of the literature to guide practitioners on the use of foam rolling.

BACKGROUND: Foam Rolling (FR) is currently used by athletes at all levels. It is not known whether FR is more effective being used as a warm up to aid performance or more effectively used as a cool-down for recovery. Therefore, the purpose of this systematic review was to determine the effects of FR on performance and recovery. METHODS: A customized search strategy was conducted to search seven electronic databases: Google Scholar; Science Direct; Pubmed Central; Pubmed; ISI Web of Science; Medline and Scopus. The database search was limited to journals published in English between January 2006 and June 2019. Any study design, for example, cross-over, repeated measures, randomized-control trials, was considered, as long as one of the interventions was using a FR. Studies that tested FR combined with other techniques were also considered, as long as one of the conditions was FR only. RESULTS: A total of 49 articles met the inclusion criteria. CONCLUSION: FR may reduce muscle stiffness and increase ROM and should be used in combination with dynamic stretching and active warm-up before a training session. Furthermore, the optimum dosage to achieve these flexibility benefits seems to be a total 90s-120s of FR. FR reduced DOMS and increased PPT, and therefore may optimize recovery from training. Future studies on the effects of FR should include true controls or sham groups, and consider the FR experience of the athlete. SYSTEMATIC REVIEW REGISTRATION: PROSPERO - CRD42017064976.

Changes in body size and physical characteristics of South African under-20 rugby union players over a 13-year period.

This study compared changes in the body size and physical characteristics of South African under-20 rugby union players over a 13-year period. A total of 453 South African under-20 players (forwards: n = 256 and backs: n = 197) underwent measurements of body mass, stature, muscular strength, endurance, and 10- and 40-m sprint times. A 2-way analysis of variance was used to determine significant differences for the main effects of position (forwards vs. backs) and time (1998-2010). The pooled data showed that forwards were significantly heavier (22%), taller (5%), and stronger (18%) than the backs. However, when 1 repetition maximum strength scores were adjusted for body mass, backs were stronger per kg body mass. Stature did not change over the 13-year period for both groups. There were, however, significant increases in muscular strength (50%), body mass (20%), and muscular endurance (50%). Furthermore, an improvement in sprint times over 40 (4%) and 10 m (7%) was evident over the period of the study. In conclusion, the players became heavier, stronger, taller, and improved their upper-body muscular endurance over the 13 years of the study. Furthermore, sprint times over 10 and 40 m improved over the same time period despite the increase in body mass. It can be speculated that the changes in physical characteristics of the players over time are possibly a consequence of (a) adaptations to the changing demands of the game and (b) advancements in training methods.