Pollock et al. 1997, 20-year follow-up of older track athletes

Longitudinal follow-up of older track athletes over 20 years: all groups declined in VO2max, but the high-intensity group least (8% and 15% at successive measurements), versus 13–14% for moderate and 18–34% for low. Maximal heart rate fell independently of training status. Shows sustained high-intensity training attenuates, but cannot halt, age-related aerobic decline. A small longitudinal cohort.