The Effect of Muscle Mass during Priming Exercise on Pulmonary Oxygen Uptake and Cardiac Output Kinetics

The effective of additional muscle mass in a priming exercise on cardiac output (Q) and pulmonary oxygen uptake (VO2) kinetics (mean response time, s) were determined in cyclists. Outcomes were measured over four trials, each consisting of a 6-minute legs alone (UAL) or arms and legs (ULO) warm-up, 3 minute passive recovery, then 6 minutes leg cycling (PAL, PLO; respectively). Q was significantly higher preceding exercise onset with PAL compared to PLO or ULO (0.72 ± 0.13 vs. 0.58 ± 0.09, 0.43 ± 0.09 L∙min-1; respectively, P < 0.05). Q kinetics did not differ between unprimed (ULO: 38.9 ± 8.6) and primed exercise regardless of muscle mass (PLO: 38.6 ± 11.0; PAL: 40.7 ± 11.3). VO2 kinetics were faster (P < 0.05) with PAL (36.9 ± 6.0) compared to ULO (58.7 ± 10.5). Muscle mass employed during priming exercise had only slight effect on subsequent VO2 and Q responses.MAS