title: An Investigation into the Energy Demands of Elite and World Class Tennis Players
Creators: name: Ellis, D
Publisher: name: Liverpool John Moores University
Year: 2024

description: Professional tennis is a unique sport in which players travel thousands of miles every year in a continual pursuit of ranking points to increases, stabilise, or improved their world ranking position. The accumulation of points leads to a higher ranking, which in turn grants entry into higher level tournaments offering higher points and increased prize money. In a cyclical manner, a player travels, competes until elimination, then travels to the next tournament. During which the player experiences a variety of playing surfaces, environments, and opposition playing styles. Depending on tournament progression, these periods are interspersed with training blocks of varying duration. Despite literature outlining the technical aspects and performance analysis of tennis, the acute physiological impact of point play and physiological characteristics of players, the nutritional requirements are not well understood. No research has investigated the habitual physical demands experienced by the professional player using field-based measurement tools. The first study examined the energy expenditure of two world class tennis players (one male, one female) competing at the highest level, the Wimbledon Championships, following a week playing at the Eastbourne International tournament. For the first time, in using the gold standard method in doubly labelled water, the total daily energy expenditure (TDEE) of elite tennis was reported. During analysis, the TDEE for the female player was 3383 kcald-1 during the first week and 3824 kcald-1 during the second. Likewise, the male TDEE was 3712 kcald-1 for the first week and 5520 kcald-1 for the second. During energy expenditure measurement, corresponding match data (points played, shot count, distance covered) show the characteristics of match play were reflective of that previously reported at Grand slam level. The study reported that elite tennis played at the highest level is a high energy demanding sport. In study 2, the player group was broadened to create a wider understanding of the energy demands highlighted in study 1. In doing so, the doubly labelled water technique was once again employed with female players ranked between 100-200 during WTA grass court tournaments, a junior player during International Tennis Federation J1 and Wimbledon Juniors, and a male doubles player during Wimbledon Championships. The TDEE for the male doubles player was 4586 kcal·d-1 and lower than that of the male singles player measured during study 1. Although less matches were played by the doubles player, a similar amount of points were played between the two players. One female player was injured on day 1. Data collection continued as an opportunity to investigate the energy requirements of injury and early stages of recuperation from surgery showing Total Daily Energy Expenditure of 2583 kcal·d-1. Non-injured adult female participants TDEE were 3396 and 3948 kcal·d-1, with the junior player TDEE was 3988 kcal·d-1. Even with a lower match count than that reported in study 1, energy expenditure was similar for the uninjured female players as that of the female player in study 1. The energy expenditure data of a wider group of players reflected study 1, finding elite tennis to be a highly energetically demanding sport. In study 3 the player focus was moved to understanding the energy demands and physiological profile of wheelchair tennis. Wheelchair tennis is reliant solely on the upper body for movement of the chair around the court and simultaneous shot execution, requiring high levels of skill in chair handling and tennis ability. In using the doubly labelled water technique with the world number 1 wheelchair player, energy expenditure was captured during a competitive period of the highest level that included Wimbledon Championships and the British Open. During Wimbledon, TDEE was 3118 kcald-1 and during the British Open was 3368 kcal·d-1. During training, TDEE was 3177 kcal·d-1. The physiological profile of the player was also investigated to understand this calibre of athlete. In doing so the aerobic capacity, body composition, sprint capability, and the energy requirements of the world number 1 tennis player were reported. Study 4 focussed on the emerging need to understand the energy demands during the habitual training of elite tennis players. When considering the high energetic demands of competition, it was clear that a need existed to understand further the chronic energy needs of this population. Therefore, the day-to-day training of the elite player was investigated with no adjustment from established routines. A group of 27 (n = 10 male; n = 17 female) elite tennis players were assessed for resting metabolic rate via gas analysis, total daily energy expenditure, and acute tennis training energy expenditure. Using Actiheart wearable technology, players were analysed over a 2-to-5-day period. Results reflected the outcomes experienced during competition, confirming elite tennis as a high energy demand sport. The measured male TDEE was 4708 ± 583 kcal·d-1 and female was 3639 ± 305 kcal·d-1. While a significant difference between male and female players was reported, a relationship between energy expenditure and resting metabolic rate was seen. Nonetheless, a broad spectrum of variability was documented. This thesis serves to inform the energy demands of elite and world class tennis for the first time. During competition played at the highest level, the technique of doubly labelled water was employed, whereas during training the Actiheart activity monitor method was employed. The presented data now characterises elite tennis as a highly demanding sport in terms of energy expenditure (60 - 90 kcalkg-1 FFM). Additionally, a theme emerged that showed the need for individual analysis.