Main Article Content

Physiological effects of the amphetamines during exercise


CH Wyndham
GG Rogers
AJS Benade
NB Strydom

Abstract

Oxygen consumption, heart rate, minute ventilation and blood lactate were measured on two champion cyclists at work rates from 45 to 362 W (2 000 - 16 000 ft-Ib / min) on a bicycle ergometer after administration of a placebo and after 10 mg of methamphetamine, without their knowledge of which was given. No differences could be detected due to the ingestion of the amphetamine in submaximum or maximum oxygen consumption, heart rate, minute ventilation or blood lactic acid. However, after the amphetamine the men were able to continue to cycle at maximum effort for a longer period and in a run to exhaustion at 90 - 95% maximum effort one man increased the time 61 % and the other 29% with marked increases in blood lactic acid. Thus the study shows that amphetamines do not increase the men's capacity for aerobic exercise. It does, however, allow them to continue to exercise at high levels of effort for a longer period and endure a higher level of anaerobic metabolism. In short-distance events this may not be dangerous but in events lasting for more than an hour the failure to be aware of 'danger signals' and to react to them couid be a threat to life as was seen in the death from 'heat-stroke' of a British champion cyclist in a 'Tour de France' some years ago.

SAMJ, 45(6): 247-252

Journal Identifiers


eISSN: 2078-5135
print ISSN: 0256-9574