Low Energy Availability, Plasma Lipids, and Hormonal Profiles of Recreational Athletes

Abstract

Black, K, Slater, J, Brown, RC, and Cooke, R. Low energy availability, plasma lipids, and hormonal profiles of recreational athletes. J Strength Cond Res 32(10): 2816-2824, 2018-It has been postulated that low energy availability (LEA) impacts bone health, hormonal concentrations, and cardiovascular function. This study describes the lipid levels, hormonal profiles, and nutrient intakes of recreationally active adults at risk of LEA compared with those not at risk. Thirty-eight women who meet or exceed the New Zealand guidelines for physical activity participated. Each participant completed an online questionnaire including the Low Energy Availability in Females questionnaire (LEAF-Q), demographic questions, and daily exercise to determine energy expenditure. Participants also provided a weighed 3-day diet record, a blood sample analyzed for total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and cortisol, and a saliva sample analyzed for testosterone. Body composition was assessed using bioelectrical impedance. Those classed as at risk of LEA according to the LEAF-Q showed very likely lower energy availability (at risk: mean, 36.3 [95% confidence interval, 30.8-41.7] kcal·kg·FFMd vs. not at risk: mean, 47.5 [95% CI, 39.5-55.4] kcal·kg·FFMd) and lower calcium intakes (mean, 847 [95% CI, 695-998] mg, vs. mean, 1488 [95% CI, 690-2,286] mg). Those at risk also had a likely small lower T3 concentration of 1.78 (SD: 0.36) nmol·L compared with 2.01 (SD: 0.53) nmol·L for those not at risk. These data suggest that recreationally active female subjects classed as at risk of LEA according to the LEAF-Q also have lower energy availability as determined by diet records and exercise diaries. The results also suggests that those at risk of LEA have reductions in T3, and their low energy intake, in addition to a low calcium intake, could put them at an increased risk of poor bone health.