Editorial: Highlights in sport and exercise nutrition 2021/22

Abstract

Editorial on the Research Topic Highlights in sport and exercise nutrition 2021/22This Research Topic features emerging research findings authored by leaders in the field of sport and exercise nutrition. The five papers in this Research Topic focused on hydration-related research, factors influencing dietary intake in rugby players, caffeine and athletic endeavor, and the influence of physical activity on chronic disease mortality rates.The article "Estrogen to progesterone ratio and fluid regulatory responses to varying degrees and methods of dehydration" summarized data from a study investigating the relationship between fluid volume regulatory biomarkers and the estrogen to progesterone ratio (E:P) in response to dehydration in 10 women (Giersch et al.). One of these biomarkers was copeptin, which is a stable surrogate marker for arginine vasopressin (AVP) (1). AVP is a posterior pituitary hormone that has a direct antidiuretic action on the kidney. Copeptin and AVP are typically increased with fluid restriction and exercise. The data from this study showed that the relationships between copeptin concentration, estrogen, progesterone, and E:P following dehydrating exercise in the heat are weak and inconsistent. More information is needed on the role of E:P in body fluid regulation but these results do not show an impact of high estrogen with or without high progesterone on the copeptin response. The authors concluded that E:P hormonal fluctuations do not meaningfully regulate fluid responses during exercise in the heat and that women are not at a particular "disadvantage" during any phase of the menstrual cycle.Another article, "Barriers, attitudes, and influences towards dietary intake amongst elite rugby union players", focused on barriers that influenced optimal nutritional intake in a cross-sectional study of 30 high-level male rugby players (Sharples et al.). Childhood upbringing emerged as an important factor that influenced body composition and healthy eating habits. Body composition acted as both a barrier to and an enabler of optimal dietary intake. High-level rugby players relied on the team nutritionist, while those at lower performance levels were more influenced by the media and teammates. The authors concluded that there needs to be more nutrition education, with an emphasis on affordable food choices, meal planning, and skills for evaluating nutrition information obtained from the internet.Caffeine use as an ergogenic aid is widespread. Most systematic reviews support the notion that, when used properly, caffeine from supplements and beverages improves endurance performance (2, 3). The paper "Caffeine supplementation strategies among endurance athletes" explored the findings from a cross-sectional study of 254 endurance athletes regarding the prevalence of caffeine use, dosing regimens, and perceived effects during TYPE