PURPOSE The purpose of this review was to summarize the current knowledge on the trends in athletes’ health problems (and their preventive strategies) caused by low energy availability (LEA) and relative energy deficiency in sports (RED-S). METHODS In this narrative review, we summarized previous studies by searching the literature in the PubMed, Google Scholar, and Science Direct databases. RESULTS Energy availability (EA) refers to the amount of energy from caloric intake used for exercise, and a LEA is considered as a surrogate marker of RED-S. In several previous studies, chronic low energy availability in female athletes has been reported to cause health problems such as endocrine dysfunctions, immunosuppression, and psychological disorders, and to also affect the hypothalamic-pituitary-gonadal (HPC) axis and bone health. Moreover, it has been suggested that an increase in injury risk and a decrease in exercise performance may occur. CONCLUSIONS Since it can be difficult to recover from the health deteriorations caused by RED-S, early detection (of related signs and symptoms) and prevention are very important. Therefore, athletes, coaches, and parents need to develop educational programs that ease the recognition of the problems caused by various symptoms related to RED-S and promote educational interventions.
PURPOSE Using GPS data from actual field hockey matches, this study examined the effects of position and substitution time on the physical performance of elite female players. METHODS From 25 matches played in 2023, data involving 26 players were collected. Players’ positions were classified as forwards (FW), midfielders (MF), and defenders (DF). Substitution times were segmented into 5, 10, and 15 minutes, respectively. A two-way ANOVA was employed to analyze movement patterns across different exercise intensities as influenced by player position and substitution time, followed by Bonferroni post-hoc tests for further detailed analysis. RESULTS Analysis revealed that both position and substitution time significantly affected exercise intensity. Notably, at a substitution time of 5 minutes, substantial differences were observed in high-intensity movements, including the distance covered at high-intensity and the frequency of high-intensity efforts. Furthermore, the substitution time’s impact was particularly pronounced among forwards and midfielders. CONCLUSIONS Findings suggest that shorter substitution times can enhance players’ active movement, thereby supporting maintenance of tactical adjustments and positively influencing overall performance. Implementing shorter substitution times could be particularly beneficial for optimizing team performance, especially for players in forward positions.
The purpose of this study was to examine whether β-alanine ingestion for 8 weeks can regulate isokinetic knee strength, and 3km record in middle-long distance woman cyclists. Fourteen middle-long woman cyclists participated in this study and were divided into two groups; training group with beta-alanine ingestion and training group with placebo ingestion. All subjects took in beta-alanine or placebo supplement three times per a day for 8 weeks. Physical activity was evaluated by measuring the isokinetic muscular strength and 3km record before and after intervention for 8 weeks. As a results, in isokinetic test, there were significant interrelationships in peak torque of the right and left flexors at 60°/sec, peak torque of the right and left extensors at 180°/sec, peak torque of the right flexors at 180°/sec. In 3km record, result showed a significant interrelationship by groups and time. The results of present study provide evidence that beta-alanine supplement may be effective to increase physical activity and competition record in middle-long woman cyclists.
