{'fraction_non_alphanumeric': 0.04849201655824956, 'fraction_numerical': 0.03784742755765819, 'mean_word_length': 4.755102040816326, '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}}
Heart rates, cardiac arrhythmia, lactate levels and catecholamine excretions in CHD patients during cross-country skiing.

We examined cross-country skiing-related strain in 10 less experienced postinfarction patients, performing a skiing test, covering a distance of approximately 7 km in 90 min. Heart rates, cardiac arrhythmia, lactic acid levels and catecholamine excretions were determined as strain indicators. The patients' exercise capacity, estimated during graded ergometric cycling, was 2.1 +/- 0.4 watts.kg-1, indicating a nearly age-appropriate submaximum performance ability. They had suffered myocardial infarction 2.8 +/- 0.7 years previously, participated regularly in a rehabilitation program for at least one year, and they did not show coronary insufficiency or significant cardiac dysrhythmias during laboratory testing under their usual medications. They went cross-country skiing during a 4-day instruction period and subsequently performed a cross-country skiing test on the 5th day. Mean skiing-related heart rates (124 +/- 9 bpm) and adrenaline excretions (124 +/- 88 pmol.min-1) corresponded on average to an exercise level of 1.85-2.0 watts.kg-1 during laboratory testing, and mean noradrenaline excretions (586-343 pmol.kg-1) and lactate concentrations (3.83 +/- 2.18 mmol.l-1) to a level of 1.48-1.73 watts.kg-1. Cardiac dysrhythmias were observed in a moderate number of 6-8 SVES, 9 to 12 VES and 4 to 7 couplets of VES per 1000 beats during cross-country skiing. The present results point to a comparatively high cardiovascular strain in less experienced postinfarction patients during a cross-country skiing test at an intensity level thought to be moderate.