HETEROGENEITY OF RESPONSE TO AEROBIC TRAINING

PURPOSE Bouchard & Rankinen (2001) have described a dramatic range of response to a standard 20 week program of aerobic training. The purpose of the present study was to evaluate the potential contribution of experimental error to the magnitude of these inter-individual differences. METHODS The 2-week CV of individual VO2max readings was 5.1% (Skinner et al., 1999). Training response was estimated from paired measurements of VO2max taken before and after training in ˜ 52% of subjects (i.e., a CV of 3.6%), but if paired VO2max values differed by > 5%, the highest value was accepted (˜ 48% of subjects, CV 5.1%). RESULTS The weighted CV of VO2max for all subjects, as thus determined, was 4.3%. Assuming the 20-week CV matched the 2-week figure, the CV for test/retest data would be 6.1%, or (for an initial VO2max of 2159 ml/min) an SD of 132 ml/min. The previously reported inter-individual SD of training responses was 202 ml/min, age, gender and baseline values accounting for 11% of the total variance. The inter-individual SD after adjustment for these covariates was 191 ml/min. After allowing also for the likely measurement error of 132 ml/min (48% of residual variance), the SD due to inter-individual differences in training response decreased to 138 ml/min. CONCLUSION The likely explanation of the substantial residual inter-individual difference is a familial aggregation of training response. REFERENCES Bouchard C et al. J Appl Physiol 1999; 87: 1003–1008. Bouchard C, Rankinen T. Med Sci Sports Exerc 2001; 33: S446-S451. Skinner JS et al. Med Sci Sports Exerc 1999; 31: 1623–1628.