Reduced Training Volume and Intensity Maintain Aerobic Capacity but not Performance in Distance Runners

Abstract

It has recently been shown that a 70% reduction in training volume, while maintaining training intensity, results in the maintenance of V̇O₂max and 5 km running performance in distance runners. The purpose of this study was to examine the effects of a 4 wk reduction in training volume and intensity in distance runners. Ten well-conditioned males (V̇O₂max = 63.4 ± 1.3 ml · kg^-1 · min^-1) underwent 4 wks of base training (BT) at their accustomed training distance (71.8 ± 3.6 km · wk^-1) and intensity (76% of total distance >70% V̇O₂max). Training volume (-66%), frequency (-50%), and intensity (all running <70% V̇O₂max) were then decreased for a 4 wk reduced training period (RT). Treadmill V̇O₂max was unchanged with RT (p > 0.05) as were resting plasma volume, estimated from haemoglobin and haematocrit levels, and resting heart rate (HR). Submaximal treadmill exercise V̇O₂ (1·min^-1), ventilation and HR were also unchanged, however, submaximal exercise RER and blood lactate accumulation following 4 mins at 95% V̇O₂max (8.39 vs 9.89 mmol ·1^-1) were significantly elevated by RT (p < 0.05). Estimated percent body fat also increased (10.4% vs 11.8%) (p < 0.05). Five km race completion time significantly increased from 16.6 ± 0.3 mins at week 4 of BT to 16.8 ± 0.3 mins (12 seconds) at week 4 of RT. Nine of the 10 subjects were slower after RT. It is concluded that aerobic capacity was maintained in these runners, despite the combined reduction in training volume and intensity. However, it appears that training intensity during RT is important for the maintenance of 5 km running performance.

Key words

Intensity - performance - submaximal exercise - lactic acid