چکیده:
The main objective of the present research is to evaluate the interaction effect of daily rhythm and the menstrual cycle on cardio-respiratory functions. To this end, body temperature, maximal oxygen consumption, heart rate, and blood pressure were measured before and after activity. 20 female physical education students from Isfahan University were selected to participate in the study (age 21.5±2.5 years, height 1.64±1.03 meters, weight 57.2±4.8 kg). All subjects had a natural and regular menstrual cycle with a period of 26-30 days, and none of them had consumed any hormonal or sexual drugs, including contraceptives, for at least 4 months prior to participating in the test, and they had not suffered any injuries before participating in the test. Before performing the main test, all subjects performed 2 familiarization sessions, executed in the laboratory exactly like the main test, to minimize learning effects and increase measurement reliability. The main test was performed at 06:00 and 18:00 during the follicular and luteal phases of the menstrual cycle. Body temperature was measured in a standard state 30 minutes before performing other tests. Cardio-respiratory indices included heart rate and blood pressure before and after activity, as well as maximal oxygen consumption measured by performing the Bruce incremental protocol. To evaluate the effect of daily rhythm, the menstrual cycle, and the interaction of the two daily and monthly rhythms on the variables of interest, two-way analysis of variance (ANOVA) was used for statistical analysis. Body temperature significantly increased from 06:00 to 18:00 by 0.8 degrees Celsius. The daily rhythm had a significant effect on maximal oxygen consumption, showing an increase of 2.6 ml/min at 18:00 compared to 06:00. The daily rhythm also had a significant effect on heart rate before and after activity, being 8 and 4 beats per minute higher at 18:00 compared to 06:00, respectively. A daily rhythm was also observed for systolic blood pressure before and after activity, such that at 18:00 it was 6 and 4.8 mmHg higher than at 06:00, respectively. The menstrual cycle was significant in temperature, heart rate before and after activity with higher values in the luteal phase compared to the follicular phase, and in maximal oxygen consumption, systolic blood pressure before and after activity with higher values in the follicular phase compared to the luteal phase. No significant effect of daily rhythm and menstrual cycle was observed in diastolic blood pressure before and after activity. The interaction between daily rhythm and the menstrual cycle was only significant in temperature. The results obtained show that maximal oxygen consumption, heart rate, and blood pressure before and after activity are under the influence of daily rhythm and the menstrual cycle. Therefore, when measuring body temperature and cardio-respiratory indices, the effect of daily changes and the menstrual cycle must be considered. Thus, in studies conducted on women, the effect of daily rhythm and the menstrual cycle is an undeniable necessity and must be carefully controlled.
خلاصه ماشینی:
Heart rate before and after activity increased by 8 and 4 beats per minute from morning to afternoon, respectively, which indicated a significant daily rhythm and was consistent with the findings of Fang-Gu (2003) and Eichner (1988).
Maximum oxygen consumption showed a significant difference with a decrease of 2 ml/min from the follicular to the luteal phase, which was consistent with the findings of Nicholas et al.
No significant difference was observed between the mean diastolic blood pressures during the follicular phase (X 75-12/1-51 mmHg) and the luteal phase (X 73-2/1-33 mmHg) of the menstrual cycle (P 0-148 and F 2-27).
The interaction between the daily rhythm and the menstrual cycle did not show a significant effect on diastolic blood pressure after activity (P 0-199 and F 1-77) (Figure 8 and Table 1).
No significant interaction was observed between the daily rhythm and the menstrual cycle on systolic blood pressure before activity (P 0-073 and F 3/59) (Figure 5 and Table 1).
No significant interaction was observed between the daily rhythm and the menstrual cycle on systolic blood pressure before activity (P 0-073 and F 3/59) (Figure 5 and Table 1).
The menstrual cycle showed significant differences in temperature, heart rate before and after activity with higher values in the luteal phase compared to the follicular phase, and in maximal oxygen consumption, systolic blood pressure before and after activity with higher values in the follicular phase compared to the luteal phase.
No significant daily rhythm or menstrual cycle effect was observed in diastolic blood pressure before and after activity.
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