Heat and cold responses in young women in relation to physical training and/or the menstrual cycle

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Seven experiments were performed to examine the heat and cold responses of young women in relation to physical training and/or the menstrual cycle. (1) The results of the 1st experiment using the foot bath method suggest that in young women physical training improves sweating and vasodilation functions, and affecting both central and peripheral mechanisms in the sweating function and the central rather than peripheral mechanism in the vasodilation function. The improvement of the central mechanism in both functions by physical training was more marked in the mid-luteal than the mid-follicular phase (due to the marked group difference of the female hormones in the luteal phase). (2) The results of the 2nd experiment suggest that physical training improves cutaneous vasodilation both centrally and peripherally during exercise as well as at rest mentioned above (the 1st experiment). (3) The results of the 3rd experiment indicate that the superior cutaneous vasodilation observed in the phy … More sically trained women (compared to untrained women) may be due to a greater withdrawal of vasoconstrictor tone, but not due to a greater active vasodilation. (4) The results of the 4th experiment showed that arterial blood is preferentially redistributed to active muscle and skin rather than inactive muscle in only untrained women exercising at 65%VO2max, and suggested that such redistribution occurs at higher intensity of exercise in trained women. (5) The results of the 5th experiment suggest that, compared to men, women depend on insulation by thicker subcutaneous fat rather than by greater cutaneous vasoconstriction during a mild cold stress. The central mechanism contributing to vasoconstriction is modified by the menstrual cycle, while the peripheral mechanism is affected by sex and menstrual cycle. (6) The results of the 6th experiment suggest that women complaining of unusual coldness suffer a deterioration of cutaneous vasodilation during a rise of environmental temperature after cold stimulus. The deterioration was more marked on upper limbs. (7) The results of the 7th experiment indicate that the cold-induced vasodilation is inferior in women rather than men, and particularly so in women complaining of unusual coldness. Less