Using the 20m-Shuttle Run Test to Predict VO2max in Female National Level Field Hockey Players

Abstract

PURPOSE: Field hockey is an intense eleven player sport requiring both a highly developed aerobic and anaerobic system. The 20 meter shuttle run test (MSRT) is a field test commonly used to assess the fitness of national level players at various phases of their competitive cycle. Maximum oxygen consumption (VO2max) can be estimated from the MSRT using predictive equations and tables, or can be directly measured using a metabolic cart. While the relationship between the MSRT and VO2max has been investigated in international-level male athletes, it has not been evaluated in elite female athletes. METHODS: Seventeen national level female field hockey players (Age: 19-30 years) were studied using a progressive treadmill VO2max test and the MSRT. Athletes were randomly assigned to each test to avoid an order effect. Tests were conducted one week apart. An initial treadmill speed of 4.0 mph was increased by 0.5 mph every minute until volitional fatigue. The MSRT was conducted outdoors on a soft playing surface with cones placed 20 meters apart. Paired t-tests were used to compare the measured VO2max with the predicted VO2max. Linear regression was used to determine a predictive equation for VO2max from the total number of shuttles completed. RESULTS: The median VO2max was 53.6 (Range: 48.8-63.1 ml/kg/min) while the median number of shuttles completed was 102 (Range: 83 to 122). The predictive equation for VO2max is Y (VO2 in ml/kg/min)=[(0.29 x total number of shuttles completed) + 24.63] (R=0.75; R2=0.56; SEE=2.6 ml/kg/min; p<0.001). CONCLUSION: We have generated a new gender- and sport-specific equation for predicting VO2max in elite female field hockey players. Our results differ from previously published data. Care should be taken when drawing conclusions from the MSRT, especially when gender- and sport-specific equations are unavailable.