AbstractTennis is a fast-paced explosive sport centred on physical prowess. It demands players to possess high levels of speed, agility, muscular power, and cardiovascular fitness to compete at a high level. To develop these physical components and master tennis-specific skills, young tennis players are exposed to high training and competition loads. Nutrition plays a critical role in optimising energy stores, reducing fatigue, supporting training adaptations, recovery from injury, and health status, and thus warrants attention. The overarching objective of this thesis was to investigate the dietary practices of elite and highly trained young tennis players and determine whether they align with and support the training and competition demands imposed on them. A systematic review was conducted to develop an understanding of the training and match-play demands on performance and recovery and identify gaps in literature. Findings confirmed high training volumes and significant psychophysiological stress imposed by training and match play. Declines in performance were also observed when players were exposed to multiple matches in a day. The review also highlighted the need to investigate the role of nutrition with such a paucity of research in this field.
The three experimental studies within this thesis highlighted sub-optimal dietary habits and nutrient intake amongst elite and highly trained young tennis players. The first experimental study used an online survey to assess nutrition and recovery habits, with varied dietary practices reported. Players tend to consume balanced meals on match day minus one (MD-1) and shift towards more carbohydrate dominant meals on MD. Liquid nutrition (e.g., protein shakes) is used by many players post-match, with several players consuming nothing at all. The second experimental study quantified dietary intake (via food diaries, remote food photography method [RFPM], and 24-hour recall) during a typical training and competition period. No differences in dietary intake were reported between type of day, meal, nor age group (with the exception of higher protein intake at lunch on training days versus competition days). Daily calorie intake indicative of under fuelling was consistently reported, with dietary carbohydrate below recommendations. However, total daily energy expenditure was not quantified. The third experimental study assessed training load, energy expenditure, dietary intake, and sleep during an 8-day tennis training camp in LaManga, Spain. Negative energy balance was observed in all players with mean deficits in excess of 1400 kcal.day-1. Least calories were consumed at
breakfast prior to the longest training period, with most calories attained at dinner. Players also failed to meet sleep recommendations, with sub-optimal total sleep time and poor sleep quality observed. An exploratory scoping review was also carried out to provide a summary of nutritional practices to date amongst young tennis players and identify research opportunities to extend the works established by this thesis. The review highlighted an overemphasis on research investigating ergogenic aids and recommended future research to focus on dietary intake and its impact on performance.
In conclusion, the data contained within this thesis provides novel information on the dietary practices of elite and highly trained young tennis players. It appears that this sporting population are failing to optimise nutritional intake with under fuelling a particular concern for performance, adaptation, recovery, and health. Further research is required to substantiate the findings from this thesis, helping to formulate specific nutritional strategies and guidelines for players and those working with them.
|Date of Award||19 Dec 2022|
|Supervisor||Robert Naughton (Main Supervisor) & Steve Lui (Co-Supervisor)|