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Title

Nutrition during Tennis Competition and Training: Need for Fluid and Carbohydrates - in particular in the Heat

Abstract

We confirm experimental evidence for an improved endurance and explosiveness through carbohydrate substitution of competitive tennis players. Consequently we derive advice for optimal supplementation of carbohydrates and liquids during intensive tennis competitions/training. Children require especially in hot conditions specific intervention.

Keywords

Carbohydrate-Substitution, Fluid, improved Performance, Tennis Competition/Training

Summary

Fluid ingestion during tennis competition and training has the twin aims: Supplying water and electrolytes to minimize hyperthermia and cardiovascular stress as well as providing a source of carbohydrate fuel to supplement the body’s limited glycogen stores. Fluid ingestion attenuates the rise in heart rate and core temperature primarily by preventing the decline in blood volume that accompanies dehydration. As well as causing dehydration the loss of large volumes of sweat will lead to a loss of electrolytes from the body.
Glycogen depletion will result in fatigue and a reduction in the exercise intensity; therefore the beneficial effects of carbohydrate feeding on exercise performance have been well documented during running and cycling lasting at least 90 min.-In the heat there is an increased carbohydrate (CHO) oxidation, mainly caused by muscle glycogenolysis.
Well-controlled field studies about the effects of administration of carbohydrate- electrolytes (CHO-E) solutions are described rarely. The main problem is with the design of an adequately controlled trial. That applies extremely to team and racquet sports like soccer and tennis.
In soccer only two publications receive attention, but with remarkable results from well known scientists. In conclusion Saltin & Karlsson in agreement with Balsom et al. have shown, that the amount of pre-game muscle glycogen (GLY) influenced significantly the quantity of high intensity exercise (e.g. pressuring the opponent player as well as number and longitude of sprints).
In tennis, corresponding with Kovacs (2006) we can only report on five evidence based studies, partial with inconsistent results. Match play under typical heat conditions, no comparative study is available (invincible methodological difficulties).
According to the results of Bergeron et al.(2005) ad libitum consumption of CHO-E drink may be more effective than water minimizing fluid deficits and mean core temperature responses during tennis training. The blood glucose concentration (GLUC) has been shown to remain stable in tennis competition lasting less than 90 min, subsequently we found a remarkable decrease (Ferrauti & Weber 1997); with CHO-E we observed a significant increase of GLUC after 90 and 150 minutes match play.
In contrast to Mitchell et al. (1992), Vergauwen et al. (1998) reported CHO feedings improve stroke performance by reducing the fatigue-induced increase of error rate (backhand preferred) in defensive rallies at the end of 2 hours strenuous training; furthermore CHO feeding improved post-test shuttle run performance. The latter result was confirmed by Ferrauti & Weber with significant shortened time for multiple tennis specific sprints after tournament simulation, using CHO-E.
Especially the study of Vergauwen et al. demonstrates CHO supplementation to improve stroke quality towards final stages of prolonged tennis play. This effect predominantly occurs in situations with high demands on time pressure (e.g. repeated sprints in combination with precise tennis technique in individual highest quality).
Disturbances in fluid balance and temperature regulation have potentially more serious consequences than carbohydrate depletion, in particular for children when tennis matches are prolonged and undertaken in the heat.
Children produce considerable less sweat than adults and have a larger surface area per unit; therefore the capacity evaporate cooling is lower and the heat gain in hot climate is greater. In consequence in childhood the core temperature increases faster with the danger of harmful heat-stroke. Thus children need comprehensive fluid very early.
Considering evidence based literature in nutrition or in physiology/biochemistry as well as a result of long lasting experiences in sports medical advice for competitive tennis several guidelines for different situations on court will be described. Finally praxis-orientated recommendations are detailed for
1. Leisure-time tennis (≤ 90 min)
2. Prolonged match play/training (> 90 min)
3. Intensive match play in the heat or best-of-five.

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CV

Name

Karl

Surname

Weber

Curriculum vitae

Karl has been the Director of the Department of Sport Games at the German Sport University since 1985 and was recently appointed the Dean of the Faculty of Applied Movement Science. Karl holds a Master´s degree (1966) in Physical Education from the German Sport University (Cologne) and received the licence to practice medicine with doctorate (M.D.) at the University of Cologne (1974). He has conducted numerous research studies in the field of elite performance and health care in sports, focusing on tennis and soccer. Karl who has served as President (1999), Vice-President (1997-1999) and Head of the Scientific Committee (1989-1997) of the German Tennis Federation, and is a member of the ITF Sports Medical Commission. As a player, Karl held a German National ranking between Top 30 and Top 60 for more than ten years and was German Vice Champion (1998) with the Team Middle Rhine (Men 55).

History

Member for

2 years 39 weeks