{'fraction_non_alphanumeric': 0.01814300960512273, 'fraction_numerical': 0.007470651013874066, 'mean_word_length': 5.424657534246576, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effects of caffeine ingestion on thermoregulatory and myocardial function during endurance performance.

The effect of caffeine administration on thermoregulatory and myocardial function during endurance performance was studied. A caffeine solution (250 ml; 5 mg caffeine/kg body weight) ingested 1 hour prior to 2 hours of running by 5 subjects was shown to have no significant effect on sweat loss, water deficit, percentage change in plasma volume, final rectal temperature and serum electrolyte levels, as compared with a similar control group who were given a caffeine-free drink. The rectal temperatures in both groups did, however, reach levels known to be associated with heatstroke despite a recommended regimen of fluid replacement. No pathological electrocardiographic changes occurred in either group. It is therefore concluded that the use of caffeine for ergogenic purposes by young athletes is a relatively safe procedure.