Effects of randomization versus pre-orientation of subjects for the prediction of maximum oxygen uptake using the twelve minutes run test

Aim: To compare the results from twelve minutes run test (12-MRT) when subjects run singly with those obtained when subjects run in randomized groups and in pre oriented groups. Methods: 33 subjects performed the 12-MRT in four variants: Achieving alone the 12-MRT on a 400 m track (Alone); Achieving in randomised groups of three the 12-MRT on a 400 m track (Group); Achieving in preoriented groups of three the 12-MRT on a 400 m track (PO-Group); Completing alone the 12-MRT on a 200 m tract (Half-Track). At the end of each test, the rate of perceived exertion was determined. Results: No significant difference (p>0.05) was found in predicted VO2max between tests. RPE was significantly higher during PO-Group compared to Alone. Underperforming athletes elicited an underestimation of predicted VO2max in Alone more important to POGroup (12.1%) compared to Group (8%). No change of predicted VO2max was observed in the middle athletes between Alone, Group and PO-Group. For the fastest athletes, predicted VO2max was significantly lower (p<0.05) for PO-Group compared to Alone where as for the Group, predicted VO2max was higher (p<0.05) compared to Alone. Conclusion: These results suggest that prediction of VO2max using the 12-MRT is influenced by peer relationship and the training status of athletes