Die fisieke werkvermoë (W170) van aktiewe en onaktiewe Blanke dames tydens sekere dae van die menstruale siklus

Abstract

The ability of the cardio-vascular system to supply the body tissues with oxygen determines the physical working capacity of an individual. Several physiological parameters such as oxygen ventilation rate, pulse rate and haemoblobin concentration etc. can influence this ability. Exercise can also influence the physical working capacity of a person. During the natural process of menstruation these physiological parameters change to a certain extend. Up to the present various researchers differ about whether this change in the various physiological parameters changes the physical working capacity during menstruation. There is also uncertainty about whether these changes are the same in different groups of various intensities. An increasingly large number of women nowadays are engaged full time in sporting and other vocational activities. It is therefore important to determine whether women can maintain the same physical working capacity during menstruation. METHOD OF RESEARCH The following physiological parameters were recorded after a rest period of thirty minutes; body temperature, basal metabolic rate, pulse rate, bloodpressure, oxygen ventilation equivalent and haemoglobin concentration. The necessary

precauttons for the various tests were taken, As a test for the physical working capacity (PWC 170 ) walking on the treadmill at a constant speed was used. The different work levels on the treadmill were 0, ½, 2½ and 3 degrees. Women of the same age group, belonging to three different activity groups were tested. The first group was completely inactive while the second (moderately active) group regularly took part in various activities from 1,35 hours per week up to 4,8 hours per week. The activities of the third group ranged from 5,25 to 7,0 hours per week, Each of these women took part in an individual intensive training program. All the persons were tested on the second and eighth day of their respective menstrual cycles, for at least four successive menstrual cycles. All available menstrual information was recorded. A controll group of eight male persons was used to test the reliability of the test procedures. CONCLUSIONS 1. There was a marked decrease both in the length of the menstrual cycle and the duration of flow with the increase in physical activities. 2. The lenght of the menstrual cycle can be stabilized by regularly taking part in physical activities, 3. Dysmenorea and other menstrual symptoms occured the least amongst the moderately active group.

4, More women in the moderately active group took part in physical activities on the first day of fl ow than those in the active. group. 5. There was no significant difference in the PWC 170 of the active group between the two test days of the menstrual cycle. The moderately active group showed a higher PWC170 on the second day than on the 8th day of the menstrual cycle. No significant change in PWC170 was found on the two test days of the menstrual cycle for the inactive group. Their resting pulse rate, diastolic blood pressure and basal metabolic rate however were higher on the 2nd day of the cycle. The active group showed a significantly higher systolic blood pressure as well as basal metabolic rate on the 2nd day of menstruation, while the basal metabolic rate of the moderately active group was the only parameter that showed a marked increase in the 2nd day. 6. There was a marked decrease in mean resting pulse rate, oxygen ventilation equivalent and body temperature with an inc:-ease in physical activities, 7. Training resulted in an increase in pwc170 of the two activity groups.