Comparative Cross-Sectional Analysis of Body Composition, Energy Status, and Triad-Related Symptoms in Japanese and American Female Distance Runners
Restricted (Penn State Only)
- Author:
- Vijaya Krishnan, Maha Lakshmi
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Mary Jane De Souza, Thesis Supervisor
Stephen Wade Schaeffer, Thesis Honors Advisor - Keywords:
- Female Athlete Triad
Racial differences
Ethnic differences
Female Athlete Triad
Cultural differences
Body Composition
Energy Availability
Energy Deficiency
Menstrual Function
Bone Mineral Density
Female Athlete - Abstract:
- To date, few studies have investigated the effects of cultural differences in the presentations of the Female Athlete Triad (Triad) symptoms among different athlete populations. Understanding Triad-related differences between American and Japanese athletes may help to formulate more culturally sensitive and effective Triad prevention, management, and intervention strategies for athletes. Purpose: To compare the body composition, energy status, and Triad-related symptoms between Japanese and American female distance runners. Methods: This observational study utilized data from American and Japanese female distance runners (n=77). Dual-energy X-ray absorptiometry assessed body composition and bone mineral density (BMD). Diet and exercise logs were used to assess energy intake (EI), energy availability (EA), weekly exercise energy expenditure (EEE), and exercise time, and blood samples were obtained to measure serum total triiodothyronine (TT3) and insulin-like growth factor 1 (IGF-1) concentrations. Self-reported menstrual status was assessed to determine the prevalence of menstrual disturbances. T-tests, Mann-Whitney tests, and chi-square were used to compare the two groups. Data are presented as mean±standard error of the mean or median (interquartile range), for normally and non-normally distributed variables, respectively. Results: Japanese distance runners were significantly older (20(2) vs. 19(2) years, p=0.043), had lower height (161.7±0.8 vs. 164.8±1.0 cm, p=0.014), body weight (50.2(7.5) vs. 54.4(10.3) kg, p=0.006), fat mass (8.7(2.5) vs. 12.2(4.8) kg, p<0.001), and percent body fat (17.5±0.4 vs. 22.7±4.6 %, p<0.001), compared to the American distance runners. Japanese runners had a significantly higher EI in kcal per kg of body weight (43.1±1.4 vs. 37.6±2.0 kcal/kg BW, p=0.023), carbohydrate intake in grams (302.0±10.7 vs. 267.7±12.8 g, p=0.043), energy from carbohydrates in kcal (1208.1±43.0 vs. 1071.0±51.0 kcal, p=0.043), energy from carbohydrates as a percent of total diet kilocalories (55.9(5.2) vs. 52.9(10.3)%, p=0.041), exercise energy expenditure (665.1(449.5) vs. 463.2(461.7) kcal/day, p=0.017), and daily exercise time (78.9±41.8 vs. 44.6±33.6 min/day, p<0.001), as well as lower energy from fats (27.9±0.7 vs. 30.9±1.4%, p=0.034). No significant differences in EA were found between the two groups (p>0.05). IGF-1 concentrations were lower in the Japanese runners (222.8±10.1 vs. 267.0±16.1 ng/mL, p=0.020) compared to their American counterparts, but no differences were observed in TT3 (91.5(25.8) vs. 95.5(22.8), p=0.752). No significant differences were found in menstrual disturbances between the two groups (p>0.05). Japanese runners also had a lower lumbar spine (L1-L4) BMD (0.921±0.016 vs. 1.115±0.020 g/cm2, p<0.001) and total hip BMD (0.960±0.016 vs. 1.075±0.020 g/cm2, p<0.001), but no differences were observed in BMD z-scores (p>0.05). Conclusion: American runners were found to present significantly higher body weight, primarily due to a greater fat mass. The greater EI relative to BW in Japanese was not coupled with greater percent body fat, body weight, or BMI, likely due to a greater EEE than American runners. Differences in macronutrient intake suggest the need for coaches and physicians to consider cultural dietary preferences in meal planning, as the Japanese versus American runners consumed more carbohydrates and more fat, respectively. It is important to consider z-scores rather than absolute BMD values when comparing bone health across different populations to account for body size differences. These findings call for prevention, management, and treatment approaches that address the complex interplay between physiological, nutritional, cultural, and environmental factors of different athlete populations affected by the Triad.