Enhancing the efficacy of the 20 m multistage shuttle run test.

OBJECTIVE Maximal oxygen uptake (Vo(2max)) of 44 ml kg(-1) min(-1) is an accepted criterion (Vo(2CR)) below which health and fitness for young male adults may be compromised. New algorithms validated for Vo(2CR) screening using the 20 m multistage shuttle run test (20mMST) were developed. METHODS Vo(2max) was assessed in 110 males using a stationary gas analyser in a treadmill test (TT) and in 40 of these subjects using a portable gas analyser in the 20mMST. Vo(2max) predicted from the 20mMST in 70 subjects was used for cross validation. Two equations predicting Vo(2max) during 20mMST (EQ(MST)) and TT (EQ(TT)) were developed. RESULTS Significant energy cost variance (EC(V)) was detected between TT and 20mMST (p<0.001), correlated significantly with subject height, and was a significant predictor of Vo(2max) differences between TT and 20mMST. The r(2) of EQ(MST) was 0.92 (p<0.001). Predicted Vo(2max) values from EQ(MST) correlated with directly measured 20mMST Vo(2max) at r = 0.96 (p<0.001). ANOVA detected no mean difference (p>0.05) between predicted and measured values. Prevalence of low fitness based on Vo(2CR) was 0.37. McNemar chi(2) indicated significant differences in sensitivity (p<0.001) and specificity (p<0.05) between the original 20mMST equation (EQ(LEG)) and EQ(TT), regarding Vo(2CR) screening. Cohen's kappa demonstrated higher agreement with TT Vo(2max) for EQ(TT) (p<0.001) than EQ(LEG) (p<0.05). TT Vo(2max) correlated with the end result of both EQ(LEG) and EQ(TT) at r = 0.75 (p<0.001). Unlike EQ(TT) (p>0.05), mean predicted Vo(2max) from EQ(LEG) was significantly higher compared to TT Vo(2max) (p<0.001). CONCLUSION These algorithms increase the efficacy of 20mMST to accurately evaluate aspects of health and fitness.