عنوان مقاله [English]
نویسنده [English]چکیده [English]
Aim: The purpose of this study was to examine whether physical fitness components (flexibility, handgrip, agility, cardiovascular endurance and body composition) are affected by hormonal fluctuation within a monophasic oral contraceptive (OC) cycle.
Method: Twenty eumenorrheic nonprofessional athletic females (Mean ± SD; age: 25.7±5.7 yr, body mass: 56 ±6.65 kg, height: 1.60±0.04 m, BMI: 22.4±2.8 kg/m2) using pill (at least from 18 months before entering in the present study) were tested at two different times of a single OC cycle, during High Hormone Phase (HP: days 19-21) and Low Hormone Phase (LP: days 4-6). Handgrip was measured three times by dynamometer and the best performance was recorded for statistical analysis. The percentage of total body fat was measured by taking the girth measurements at abdomen, right thigh and right forearm with a measuring tape. Agility, flexibility and cardiovascular endurance were measured by the Illinois agility run test, sit and reach test and multistage fitness test, respectively.
Results: There was a significant difference between phases for VO2max which at LP (27.9±2.9 ml/kg/min) was 2.1% higher than HP (27.3±2.9 ml/kg/min) (p<0.05). Body mass was significantly (1.9%) higher at HP compared to LP (p<0.05). Body composition was affected significantly by the OC cycle. Body fat percentage and lean body fat was significantly higher at HP than LP by 0.8% and 1.1%, respectively (p<0.05).
Conclusion: It can be concluded that nonprofessional athletic females may experience significant variation in VO2max, body mass and body composition throughout an OC cycle that could be detrimental to performance.
Key words: Oral contraceptive, Physical fitness, Female