Effect of Short-Term Training Cessation on Performance Measures in Distance Runners

Abstract

This study examined if measures associated with distance running performance were affected by short-term (14 d) training cessation in 12 distance runners. V̇O₂max decreased by ≈ 3 ml · kg^-1 · min^-1 (mean ± SE, 61.6 ± 2.0 vs 58.7 ± 1.8 ml · kg^-1 · min^-1, p < 0.05) with training cessation. Time to exhaustion (TTE) during the incremental V̇O₂max test decreased by 1.2 min (13.0 ± 0.5 vs 11.8 ± 0.5 min, p < 0.001) and maximal heart rate increased (p < 0.001) by 9 beats per minute (BPM). No changes in running economy (75 and 90% V̇O₂max) were evident, although submaximal heart rate increased by 11 BPM (p < 0.001) at both running speeds. Other evidence for detraining were decreases in estimated resting plasma volume (-5.1 ± 1.9%) and muscle citrate synthase activity (-25.3 ± 2.6%, p < 0.05). Muscular atrophy (muscle fiber cross-sectional area) was not evident. TTE and submaximal heart rate exhibited relatively large percent changes (-9 and +6%, respectively) compared to V̇O₂max (-4%). These findings indicate that the reduction in V̇O₂max with short-term training cessation is relatively small. TTE and submaximal heart rate may be easily measured, yet more sensitive indicators of decrements in distance running performance.

Key words

Detraining - endurance performance - athletes