Publications by authors named "Vanhelder W"

To test how leukocyte responses to endurance exercise were modified by clamping body temperature, nine men (27.3 +/- 6.0 yr) completed four 80-min immersions to midchest at water temperatures of 23 or 39 degrees C; two tests included 40-min of cycle ergometer exercise at 65% of aerobic power.

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The use of androgenic-anabolic steroids (AAS) for enhancing athletic performance and body image is widespread. An increasing number of elite and recreational athletes of varying ages and athletic pursuits are using AAS. Sophisticated patterns of AAS use are supported by unethical and illegal distribution channels.

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The purpose of the present study was to investigate the effect of a range of water temperatures (Tw from 15 to 36 degrees C) on the tissue temperature profile of the resting human forearm at thermal stability. Tissue temperature (Tti) was continuously monitored by a calibrated multicouple probe during 3 h of immersion of the forearm. The probe was implanted approximately 9 cm distal from the olecranon process along the ulnar ridge.

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The purpose of the present study was to investigate the intramuscular temperature fluctuations in the human forearm immersed in water at 15 degrees C. Tissue temperature (Tt) was continuously monitored by a calibrated multicouple probe during 3 h immersion of the forearm. The probe was implanted approximately 90 mm distal from the olecranon process along the ulnar ridge.

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Five normal men performed seven sets of seven squats at a load equal to 80% of their seven repetition maximum. Plasma growth hormone (GH) and lactate levels increased during and after the completion of the exercise. A significant (r = 0.

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Five normal men, aged 23 to 35 years, participated in two bouts of continuous aerobic cycling separated by five days. The first type of exercise (EI) was cycling at a pedalling frequency of 50 rev X min-1 with a load which produced a steady state O2 uptake of approximately 40% of the subjects' VO2max. The second type of exercise (EII) was cycling at a pedalling frequency of 90 rev X min-1 with a load such that an equal steady state VO2 was reached and maintained.

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Five normal men, aged 20-30 years, participated in three types of exercise (I, II, III) of equal duration (20 min) and total external work output (120-180 kJ) separated by ten days of rest. Exercises consisted of seven sets of squats with barbells on the shoulders (I; Maximal Power Output Wmax = 600-900 W), continuous cycling at 50 rev X min-1 (II; Wmax = 100-150 W) and seven bouts of intermittent cycling at 70 rev X min-1 (III; Wmax = 300-450 W). Plasma cortisol, glucagon and lactate increased significantly (P less than 0.

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Five normal male volunteers performed two intermittent weight lifting exercises of equal total external work output and duration (20 min) with identical work-rest intervals but different load and frequency of movements. Exercise I consisted of seven sets of seven vertical leg lifts at 85% of the subject's Seven Repetition Maximum (SRM) and, 5 days later, seven sets of 21 vertical leg lifts with one-third of the previously used load (Exercise II). Blood was sampled throughout the exercise and recovery periods for growth hormone, lactate, and glucose analysis.

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Growth hormone (GH) and lactic acid levels were measured in five normal males before, during and after two different types of exercise of nearly equal total duration and work expenditure. Exercise I (aerobic) consisted of continuous cycling at 100 W for 20 min. Exercise II (anaerobic) was intermittent cycling for one minute at 285 W followed by two minutes of rest, this cycle being repeated seven times.

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Sampling portal blood every 15 min by means of indwelling cannulae, we have found evidence that basal insulin secretion in nonanesthetized dogs takes place in six or seven major secretory episodes over a 24-h period. Reproducible patterns were obtained in four experiments conducted on three normal animals. When frequency of peaks was plotted against the log of insulin concentration, a normal distribution was obtained (lognormal distribution).

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