R. A. Binkhorst

Physiological responses to asynchronous and synchronous arm-cranking exercise

The purpose of this study was to examine mechanical efficiency (ME) and physiological responses during asynchronous (the pedal arms oriented in opposing directions) arm-cranking exercise (AACE) and compare these responses to those obtained during synchronous (the pedal arms oriented in the same direction) arm-cranking exercise (SACE). Ten male subjects participated in the study and performed two exercise tests, one AACE and the other SACE in counter-balanced order. Each test consisted of submaximal (30, 60 and 90 W) and maximal exercise. At 30 W, gross ME was significantly lower during SACE compared to AACF, whereas at 60 W and 90 W no differences between the two types of exercise could be observed. We found that at lower power output levels the flywheel mass and its moment of inertia may have induced more body movements for compensation, which may have been more pronounced during SACE than during AACE. At higher levels of power output this flywheel mass-effect was less, which explained the lack of differences in ME at these levels. Physiological responses to maximal AACE or SACE exercise were not significantly different. The results indicated that there were no differences in physiological responses to AACE and SACE exercise at higher exercise intensities. However, at lower levels of power output ME seemed to decrease, most likely as a result of the flywheel-mass effect, which was more pronounced during SACE.

Reproducibility of incremental maximal cycle ergometer tests in patients with mild to moderate obstructive lung diseases

AbstractThis study was designed to examine the reproducibility and the learning effects of incremental maximal cycle ergometer testing in patients with obstructive lung diseases who are untrained and have never done such a test before.Eleven patients were studied on 2 consecutive days with an interval of 24 h. The reproducibility (expressed in relative duplicate error) of most of the parameters tested was good: workload (watt) 4.5%, maximal oxygen consumption (

Metabolic capacity, fibre type area and capillarization of rat plantaris muscle. Effects of age, overload and training and relationship with fatigue resistance

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Specific force of the rat plantaris muscle changes with age, but not with overload

O2max 3.5%, gas exchange ratio (R) 3.4%, and heart rate 3.7%. Moderate reproducibility was found in maximal ventilation (

Ventilatory response to CO2 at rest and during positive and negative work in normoxia and hyperoxia.

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Reliability of the cardiac output measurement with the indirect Fick-principle for CO2 during exercise

Emax) 6.6%, carbon dioxide production (