Yin and yang, or peas in a pod? Individual-sport versus team-sport athletes and altitude training

Three sessions of repeated sprint training in normobaric hypoxia improves sprinting performance

The objective of the present study was to evaluate the impacts of three-session repeated sprint training conducted in normobaric hypoxia with 48-h intervals on sprint performance, arterial oxygen saturation (SpO2), and rating of perceived exertion (RPE) scores. A total of 27 moderately trained male university students voluntarily took part in this study. In this single-blind placebo-controlled study, subjects were assigned into normobaric hypoxia (FiO2: 13.6%; HYP), normobaric normoxia (FiO2: 20.9%; PLA), and control group (CON). The HYP and PLA groups underwent three repeated sprint training sessions (a total of four sets of five times 5-s sprints with a 5-min rest between sets and a 30-s rest between each sprint) on a cycle ergometer in normobaric hypoxia or normoxia conditions. Pre- and post-tests were performed 72 h before and after the training period. Three participants were excluded from the study, and the data from twenty-four participants were analyzed. Contrary to what was observed in the pre and post tests, no time and condition interactions were observed in the relative peak power output (PPO), mean power output (MPO), percentage of sprint decrement score (Sdec%), and RPE parameters. Time effect was found in all observed variables respectively; relative PPO (F = 5.784, p = 0.045, η2 = 0.74), relative MPO (F = 3.927, p = 0.042, η2 = 0.66) and large time effect found for Sdec% (F = 11.430, p = 0.046, 0.83), and RPE (F = 14.990, p = 0.008, η2 = 0.96). A notable increase in relative peak power output (PPO) and mean power output (MPO) was observed in the post-test in comparison to the pre-test values, indicating statistical significance. The increase in PPO was in HYP 13.44% (p = 0.006), in PLA 7.48% (p = 0.264) and in CON 2.66% (p = 0.088). The decrease in Sdec% was in HYP -13.34%% (p = 0.048), PLA -10.54 (p = 0.577) and CON -4.83 (p = 0.644) at post-test. The results show that although there were no statistical differences between the groups, notable differences in performance-related variables were observed in the HYP group after 3 sessions of repetitive sprint training in hypoxia.

SPORTS INJURIES IN HIGH-LEVEL AEROBIC GYMNASTICS ATHLETES

ABSTRACT Introduction: With the rapid development of aerobic gymnastics worldwide, research is required to constantly increase. Objective: Analyze the main causes of sports injuries, proposing measures for prevention, treatment, and rehabilitation, as well as providing a theoretical basis for reducing the risk of sports injuries and actively seeking ways and measures to prevent and treat sports injuries in aerobic gymnastics athletes. Methods: Statistical-mathematical analysis was used, mainly including the coefficient of variation method, correlation matrix method, and factor analysis. The common variable of the trend of sports injuries was found. Results: The research shows that the scientific awareness, self-protection, and injury prevention of aerobic gymnastics training strengthen the ideological education and theoretical guidance of athletes, improve athletes' awareness of sports injuries, regulate technical specifications, strengthen fitness training and improve Chinese competitive aerobics. Conclusion: In the healthy period before injuries, we should take various measures to improve physical fitness and skills, enabling good health work in the acute period after injuries and understanding the working principle of early diagnosis and treatment to better use treatment time. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Primum non nocere; It's time to consider altitude training as the medical intervention it actually is!

Sleep is one of the most important aspects of recovery, and is known to be severely affected by hypoxia. The present position paper focuses on sleep as a strong moderator of the altitude training-response. Indeed, the response to altitude training is highly variable, it is not a fixed and classifiable trait, rather it is a state that is determined by multiple factors (e.g., iron status, altitude dose, pre-intervention hemoglobin mass, training load, and recovery). We present an overview of evidence showing that sleep, and more specifically the prolonged negative impact of altitude on the nocturnal breathing pattern, affecting mainly deep sleep and thus the core of physiological recovery during sleep, could play an important role in intra- and interindividual variability in the altitude training-associated responses in professional and recreational athletes. We conclude our paper with a set of suggested recommendations to customize the application of altitude training to the specific needs and vulnerabilities of each athlete (i.e., primum non nocere). Several factors have been identified (e.g., sex, polymorphisms in the TASK2/KCNK5, NOTCH4 and CAT genes and pre-term birth) to predict individual vulnerabilities to hypoxia-related sleep-disordered breathing. Currently, polysomnography should be the first choice to evaluate an individual's predisposition to a decrease in deep sleep related to hypoxia. Further interventions, both pharmacological and non-pharmacological, might alleviate the effects of nocturnal hypoxia in those athletes that show most vulnerable.

Plyometric jump training effects on the physical fitness of individual-sport athletes: a systematic review with meta-analysis

Background

The aim of this study is to conduct a systematic review with meta-analysis to explore the effects of plyometric jump training (PJT) on the physical fitness of individual sport athletes (ISA).

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched through PubMed, Web of Science, and SCOPUS electronic databases. We included controlled studies that incorporated a PJT intervention among ISA (with no restriction for age or sex), that included a pre-to-post intervention assessment of physical fitness (e.g., sprint; jump). From the included studies, relevant data (e.g., PJT and participants characteristics) was extracted. We assessed the methodological quality of the included studies using the PEDro scale. Using a random-effects model, meta-analyses for a given outcome was conducted. Means and standard deviations for a measure of pre-post-intervention physical fitness from the PJT and control groups were converted to Hedges' g effect size (ES). Heterogeneity was assessed using the I ² statistic. The risk of bias was explored using the extended Egger's test. The statistical significance threshold was set at p < 0.05. Moderator analyses were conducted according to the sex, age and sport background of the athletes.

Results

Twenty-six studies of moderate-high methodological quality were included (total participants, n = 667). Compared to controls, PJT improved vertical jump (ES = 0.49; p < 0.001; I = 0.0%), linear sprint (ES = 0.23; p = 0.032; I ² = 10.9%), maximal strength (ES = 0.50; p < 0.001; I² = 0.0%) and endurance performance (ES = 0.30; p = 0.028; I² = 11.1%). No significant effect was noted for sprint with change of direction (ES = 0.34; p = 0.205; I² = 70.9%). Athlete's sex, age and sport background had no modulator role on the effect of PJT on vertical jump, linear sprint, maximal strength and endurance performance. Among the included studies, none reported adverse effects related to the PJT intervention.

Conclusions

PJT induces small improvements on ISA physical fitness, including jumping, sprinting speed, strength and endurance.