Risk of Red-S Syndrome among Individuals Who Regularly Engage in Physical Activity

Abstract Introduction. Regular physical activity increases energy expenditure and requires adequate energy intake to maintain physiological homeostasis. Inadequate energy intake can lead to low energy availability (LEA), which is a key factor in the development of relative energy deficiency in sport (RED-S), a syndrome affecting multiple systems in the human body. The aim of this study was to assess the risk of RED-S. The study was conducted among physically active young adults in Poland and involved the identification of dietary and behavioral factors associated with an increased risk of RED-S. Material and methods. A total of 151 participants (72 women, 79 men) aged 22.09 ± 2.2 years completed an online questionnaire assessing dietary habits, hydration, physical activity, and energy intake. Basal metabolic rate was calculated using the Mifflin-St. Jeor equation, and lean body mass was calculated using the James (1976) formula. Total energy expenditure was compared to the intake to estimate energy deficits. Results. Approximately 70% of participants had a negative energy balance, and most consumed four or fewer meals per day. Logistic regression showed that a negative energy balance significantly increased the risk of RED-S in both women (OR = 3.82) and men (OR = 8.50). In men, inadequate hydration and low meal frequency were also significant predictors. Conclusions. The results indicate that physically active young adults, especially men, may be at increased risk of RED-S due to poor eating habits. Better nutrition education and energy balance monitoring are recommended.