Nutrition and hydration implications for trained athletes
2014-10-31T11:18:05Z (GMT) by
Lifestyle choices threaten to compromise health and performance of trained athletes. This thesis presents a series of studies which broadly investigated the impact of nutritional and physical challenges to human health and performance. The potential causes and effects of fluid imbalances on physical health, immune function and athletic performance were investigated. Certain populations experience chronic low-level hypohydration and athletes often fail to rehydrate sufficiently between exercise sessions. The long-term implications of hypohydration are not fully understood, but are suggested to be associated with chronic disease. In this thesis, maintenance of fluid balance was observed in healthy males, despite a caffeine intervention thought to cause diuresis. Furthermore, when mild hypohydration was induced by 24-h fluid restriction, there was little impact on mucosal immunity during endurance exercise compared with euhydration. The impact of intensified training (IT) on the physical, mental, hormonal and immunological status of well-trained athletes was investigated. A performance-specific nutritional intervention was implemented to investigate the effects of nutrient availability during prolonged exercise training sessions. Phases of IT are a regular feature of a periodised training programme. However, an imbalance between training and recovery can have significant implications for long-term athletic performance and general wellbeing. Changes in neuroendocrine, neurobiological and mucosal immune function were observed during IT and some potential markers of overreaching and were identified. Further research is required before practical application of these markers can be used effectively in the field. A relatively short period of IT resulted in significant disruptions to mood state and sleep quality. Minor changes in exercise performance were observed. Markers of overreaching were highly individual, as were responses to training.