Menstrual Cycle Affects Arterial Stiffness After High-intensity Resistance Exercise

Abstract

Acute high -intensity resistance exercise increases arterial stiffness, which is one potential mechanism of the increased arterial stiffness resulting from resistance exercise training. Estrogen concentrations in women may also influence arterial stiffness. Therefore, changes in arterial stiffness after high-intensity resistance exercise might differ according to the menstrual cycle. PURPOSE: The purpose of this study was to determine the effects of menstrual cycle phase on arterial stiffness after high-intensity resistance exercise. METHODS: Nine eumenorrheic females participated in this study (age 21.3 ± 0.8 years). None of the participants were taking oral contraceptives. Menstrual cycles were categorized according to serum estrogen and progesterone concentrations. Maximal muscle strength was assessed using one repetition maximum (1RM) strength tests 1 week before starting this study. The participants performed five sets of five repetitions using 80% of the 1RM bench press and five sets of ten repetitions using 70% of the 1RM biceps curl with an inter-set rest periods of 2 min at each of the menstrual, ovulatory, and luteal phases. Brachial-ankle pulse wave velocity (baPWV; an index of arterial stiffness), blood pressure, and heart rate were measured before (baseline) and at 30 and 60 min after completing the resistance exercise. RESULTS: Serum estrogen concentrations were significantly higher at the ovulatory and luteal phases than at the menstrual phase (ovulatory and luteal phases vs. menstrual phase; 192 ± 58, 170 ± 32 vs. 40 ± 7 pg/ml, P<0.05). The baPWV at the menstrual phase was significantly increased from baseline at 30 min (baseline vs. after 30 min; 952 ± 16 vs. 1061 ± 29 cm/sec, P<0.05) after the resistance exercise and persisted for 60 min (baseline vs. after 60 min; 952 ± 16 vs. 1044 ± 23 cm/sec, P<0.05), whereas the ovulatory and luteal phases did not significantly differ before and after the resistance exercise. Blood pressure and heart rate did not significantly differ before and after high-intensity resistance exercise during any phase. CONCLUSION: These results suggest that arterial stiffness induced by high-intensity resistance exercise changes according to phases of the menstrual cycle.