Abstract

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 r² 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 χ² indicated significant differences in sensitivity (p<0.001) and specificity (p<0.05) between the original 20mMST equation (EQ_LÉG) and EQ_TT, regarding Vo_2CR screening. Cohen’s κ demonstrated higher agreement with TT Vo_2max for EQ_TT (p<0.001) than EQ_LÉG (p<0.05). TT Vo_2max correlated with the end result of both EQ_LÉG and EQ_TT at r = 0.75 (p<0.001). Unlike EQ_TT (p>0.05), mean predicted Vo_2max from EQ_LÉG 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.