Abstract
Purpose:
To evaluate the effects of exercise velocity (60, 150, 240 deg·s-1) and muscle mass (arm vs leg) on changes in gas exchange and arterio-venous oxygen content difference (avDO2) following high-intensity concentric-eccentric isokinetic exercise.
Methods:
Fourteen subjects (26.9±3.1 years) performed a 3x20-repetition isokinetic exercise protocol. Recovery beat-to-beat cardiac output (CO) and breath-by-breath gas exchange were recorded to determine post-exercise half-time (t1/2) for oxygen uptake (V’O2pulm), carbon dioxide output (V’CO2pulm), and ventilation (V’E).
Results:
Significant differences of the t1/2 values were identified between 60 and 150 deg·s-1. Significant differences in the t1/2 values were observed between V’O2pulm and V’CO2pulm and between V’CO2pulm and V’E. The time to attain the first avDO2-peak showed significant differences between arm and leg exercise.
Conclusions:
The present study illustrates, that V’O2pulm kinetics are distorted due to non-linear CO dynamics. Therefore, it has to be taken into account, that V’O2pulm may not be a valuable surrogate for muscular oxygen uptake kinetics in the recovery phases.
To evaluate the effects of exercise velocity (60, 150, 240 deg·s-1) and muscle mass (arm vs leg) on changes in gas exchange and arterio-venous oxygen content difference (avDO2) following high-intensity concentric-eccentric isokinetic exercise.
Methods:
Fourteen subjects (26.9±3.1 years) performed a 3x20-repetition isokinetic exercise protocol. Recovery beat-to-beat cardiac output (CO) and breath-by-breath gas exchange were recorded to determine post-exercise half-time (t1/2) for oxygen uptake (V’O2pulm), carbon dioxide output (V’CO2pulm), and ventilation (V’E).
Results:
Significant differences of the t1/2 values were identified between 60 and 150 deg·s-1. Significant differences in the t1/2 values were observed between V’O2pulm and V’CO2pulm and between V’CO2pulm and V’E. The time to attain the first avDO2-peak showed significant differences between arm and leg exercise.
Conclusions:
The present study illustrates, that V’O2pulm kinetics are distorted due to non-linear CO dynamics. Therefore, it has to be taken into account, that V’O2pulm may not be a valuable surrogate for muscular oxygen uptake kinetics in the recovery phases.
| Original language | English |
|---|---|
| Journal | Respiratory Physiology & Neurobiology |
| Volume | 240 |
| Pages (from-to) | 53-60 |
| Number of pages | 8 |
| DOIs | |
| Publication status | Published - 2017 |