It is unclear whether physiological measures monitored in an incremental treadmill test during a training season provide useful diagnostic information about changes in distance running performance.
To quantify the relationship between changes in physiological measures and performance (peak running speed) over a training season.
Well-trained distance runners (34 males; VO2max 64 ± 6 mL⋅kg-1⋅min-1, mean ± SD) completed four incremental treadmill tests over 17 wk. The tests provided values of peak running speed, VO2max, running economy, and lactate threshold (as speed and %VO2max). The physiological measures were included in simple and multiple linear regression models to quantify the relationship between changes in these measures and changes in peak speed.
The typical within-subject variation in peak speed from test to test was 2.5%, whereas those for physiological measures were VO2max (mL⋅min-1⋅kg-1) 3.0%, economy (m⋅kg⋅mL–1) 3.6%, lactate threshold (%VO2max) 8.7%, and body mass 1.8%. In simple models these typical changes predicted the following changes in performance: VO2max 1.4%, economy 0.8%, lactate threshold –0.3%, and body mass –0.2% (90% confidence limits ~±0.7%); the corresponding correlations with performance were 0.57, 0.33, –0.05, and –0.13 respectively (~±0.20). In a multiple linear regression model, the contribution of each physiological variable to performance changed little after adjustment for the other variables.
Change in VO2max in an incremental test during a running season is a good predictor of change in peak running speed, change in running economy is a moderate predictor, and lactate threshold and body mass provide little additional information.
Saunders, Cox, and Pyne are with the Australian Institute of Sport, Canberra, Australia. Hopkins is with the Auckland University of Technology, Auckland, New Zealand.