Tomoyuki Shiojiri

Kinetics of oxygen uptake and cardiac output at onset of arm exercise

Pulmonary oxygen uptake (V O2) kinetics at onset of exercise is reported to be slower for arm than for leg exercise. This could be attributed to reduced cardiac output (Q) or reduced arteriovenous O2 content difference or both. To test this, V O2 mean tissue oxygen consumption (V O2T) and Q kinetics in arm cranking were compared with corresponding values found in leg cycling. The increase in V O2 during phase 1 (abrupt increase after onset of exercise) was less in arm than in leg exercise, suggesting that immediate Q adjustments to arm exercise were less pronounced. Mean response times (MRT, the relative rates at which a steady state was attained) for V O2, V O2T, and Q were prolonged during arm exercise. The MRT of VO 2 in arm exercise at a given blood lactate increase was higher than in leg exercise. The delayed V O2 kinetics in arm exercise might be due to delayed Q kinetics and higher anaerobic glycolysis occurring early during arm exercise.

Sweating responses to passive and active limb movements

The changes in esophageal and mean skin temperatures did not show a marked difference between active limb movement (ALM) and passive limb movement (PLM). Increase in heart rate was significantly greater during ALM than PLM at 30 and 60 rpm (P < 0.05). Sweating rate on the chest and forearm were significantly greater during ALM than PLM at each pedalling frequency (P < 0.05). The result suggests that the greater increase in sweating rate during ALM relative to PLM may in part be of a consequence of non-thermal factors.

The effect of diurnal variation on the regional differences in sweating and skin blood flow during exercise

AbstractThe aim of the present study was to examine changes in the control of heat-dissipation responses to exercise associated with the diurnal variation in core temperature from the viewpoint of the regional response patterns. We studied seven men during exercise on a cycle ergometer at 100 W for 40 min at 25°C at 0630 (morning) 1630 (evening) hours on 2 separate days. Oesophageal temperature (Toes), local skin temperature, local sweating rate (

Comparison of oxygen uptake kinetics during knee extension and cycle exercise.

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The relationship between muscle deoxygenation and activation in different muscles of the quadriceps during cycle ramp exercise

) on the forehead, back, forearm and thigh, and skin blood flow by laser Doppler flowmeter (LDF) on the back and forearm were measured continuously. TheToes at rest was significantly higher in the evening than in the morning, the difference averaging approximately 0.4°C (P < 0.05). TheToes thresholds for each site in

Effect of muscle mass on V˙o2kinetics at the onset of work

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