Abstract

Tennis ball machine tests permit the concurrent measurement of physiological function and groundstroke performance in a sport specific manner. The purpose of this study was to understand further the demands of groundstroke performance during a test with progressively increasing ball frequency, by determining the running speed between strokes, upper and lower limb acceleration and pulmonary gas exchange throughout. Sixteen tennis players (n=8, male; n=8, female; all right handed) completed three 4 min stages of hitting against a ball feed frequency of 15, 20, 25 ball/min interspersed by 8 min of rest. Stepwise multiple regression analysis identified a predictive model of VO2 containing the variables of left arm acceleration and right ankle acceleration but not running speed (p<0.0001; adjusted r2=0.93; left wrist acceleration Beta=1.04; right ankle acceleration Beta=- 0.12; S. E. E.=2.61 ml/g x min. Regression analysis found that the strongest predictors of stroke performance (ball speed [m/s] x stroke accuracy [%]) were right wrist acceleration and stroke economy (p<0.0001; adjusted r2=0.28; right wrist acceleration Beta=- 0.59; movement economy Beta=- 0.28). The findings of this study highlight the contribution of limb acceleration and not running speed to the oxygen cost of tennis groundstroke performance.