Abstract

This study examined if measures associated with distance running performance were affected by short-term (14d) training cessation in 12 distance runners. VO2max decreased by ca. 3 ml/kg/min (mean +/- SE, 61.6+/-2.0 vs 58.7+/-1.8 ml/kg/min, p<0.05) with training cessation. Time to exhaustion (TTE) during the incremental VO2max 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 VO2max) 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 VO2max (-4). These findings indicate that the reduction in VO2max 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. Verf.-Referat