Heavy-intensity warm-up exercise accelerated pulmonary O2 uptake kinetics in older adults (30 vs 38 s; P<0.05) but not in young adults, suggesting O2 delivery limitations in older adults.
Does heavy-intensity warm-up exercise improve pulmonary O2 uptake and muscle deoxygenation kinetics during moderate-intensity cycling in young and older adults?
Heavy-intensity warm-up exercise speeds pulmonary O2 uptake kinetics in older adults, suggesting their baseline kinetics may be limited by slow adaptation of muscle blood flow and O2 delivery.
Absolute Event Rate: 30% vs 38%
p-value: p=<0.05
Pulmonary O2 uptake (VO2p) and muscle deoxygenation kinetics were examined during moderate-intensity cycling (80% lactate threshold) without warm-up and after heavy-intensity warm-up exercise in young (n = 6; 25 +/- 3 yr) and older (n = 5; 68 +/- 3 yr) adults. We hypothesized that heavy warm-up would speed VO2p kinetics in older adults consequent to an improved intramuscular oxygenation. Subjects performed step transitions (n = 4; 6 min) from 20 W to moderate-intensity exercise preceded by either no warm-up or heavy-intensity warm-up (6 min). VO2p was measured breath by breath. Oxy-, deoxy-(HHb), and total hemoglobin and myoglobin (Hb(tot)) of the vastus lateralis muscle were measured continuously by near-infrared spectroscopy (NIRS). VO2p (phase 2; tau) and HHb data were fit with a monoexponential model. After heavy-intensity warm-up, oxyhemoglobin (older subjects: 13 +/- 9 microM; young subjects: 9 +/- 8 microM) and Hb(tot) (older subjects: 12 +/- 8 microM; young subjects: 14 +/- 10 microM) were elevated (P < 0.05) relative to the no warm-up pretransition baseline. In older adults, tauVO2p adapted at a faster rate (P < 0.05) after heavy warm-up (30 +/- 7 s) than no warm-up (38 +/- 5 s), whereas in young subjects, tauVO2p was similar in no warm-up (26 +/- 7 s) and heavy warm-up (25 +/- 5 s). HHb adapted at a similar rate in older and young adults after no warm-up; however, in older adults after heavy warm-up, the adaptation of HHb was slower (P < 0.01) compared with young and no warm-up. These data suggest that, in older adults, VO2p kinetics may be limited by a slow adaptation of muscle blood flow and O2 delivery.
DeLorey et al. (Tue,) reported a other. Heavy-intensity warm-up exercise vs. No warm-up was evaluated on Pulmonary O2 uptake (VO2p) kinetics (tau) in older adults (p=<0.05). Heavy-intensity warm-up exercise accelerated pulmonary O2 uptake kinetics in older adults (30 vs 38 s; P<0.05) but not in young adults, suggesting O2 delivery limitations in older adults.