P3A355: Effect of Gender on Exercise Related Cardiovascular Conditioning in High School Students

Background: Regular physical activity has been associated with improved cardiovascular conditioning. Effects of gender on cardiovascular conditioning due to regular physical activity in high school students were not well studied.

Methods: We performed an observational cohort study of single high-school 121 female and 108 male students, 15.4+/-1.1 years old. Students were grouped according to the self-reported consistent participation in physical activity at least 3 times per week. Cardiovascular conditioning was evaluated with a five-minute YMCA exercise step test by analyzing resting heart rate (HR), lowest HR during voluntary breath-holding, immediate post-exercise, and 3-minute post-exercise HR.

Results: Heart rates in females were significantly higher at rest (89.0±15.9 vs. 84.5±15.1 bpm in males, p=0.023), post-peak exercise (138.4±30.9 vs. 123.2±25.5 bpm in males, p< 0.001), and during recovery (103.8±20.5 vs. 93.3±18.3 bpm in males, p< 0.001) but not during breath holding (81.9±15.3 in females vs. 81.1±15.0 bpm in males, p=0.667). In addition to that, students who reported consistent participation in physical activity were found to have significantly lower heart rates at rest (83.3±14.9 vs. 90.4±15.5 bpm, p< 0.001), with breath-holding (78.7±13.2 vs. 84.9±16.5 bpm, p=0.001), immediately after peak exercise (121.3±27.6 vs. 140.5±27.3 bpm, p< 0.001), and during recovery (92.3±18.9 vs. 104.9±19.1 bpm in the rest of the cohort, p< 0.001). In multivariate analysis, in all tested parameters, except for HR during breath holding (p=0.854), direction and magnitude of gender effects remained highly significant (p < 0.05 for each tested effect).

Conclusion: High-school students who are consistently physically active manifest significantly lower resting, breath holding, peak exercise, and recovery heart rates suggestive of better cardiovascular conditioning. Female high-school students experience consistently higher heart rates, indicative of attenuated effects of conditioning, except for during breath holding. Higher baseline heart rates and lack of differences in heart rates during breath holding suggest augmented cardioinhibitory response to breath holding in females.