Case Study: Energy Availability and Endocrine Markers in Elite Male Track Cyclists

in International Journal of Sports Physiology and Performance
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Aim: To highlight energy availability status, resting metabolic rate measures, dietary protein intake, and testosterone concentration in 4 elite male track cycling athletes (mean [SD]: age: 20.8 [1.5] y, body mass: 76.3 [3.6] kg, height: 181.8 [2.9] cm). Method: A cross-sectional observation included measures of energy availability (energy intake minus exercise energy expenditure, divided by fat-free mass), resting metabolic rate from indirect calorimetry, dietary protein intake from food records, blood analysis to assess sex hormone status, and performance markers. Results: Midrange testosterone (16.9–19.8 nmol/L), lowered resting metabolic rate ratio (0.76–0.98), varied luteinizing hormone (4–10 U/L), and suboptimal energy availability (26–41 kcal/kg fat-free mass/d, range) were observed in the male track cyclists. Protein intakes ranged from 2.0 g to 2.8 g protein/kg/d. Conclusion: The current cohort may have within-day energy deficiency, putting them in a catabolic state.

Schofield and Thorpe are with the Te Huataki Waiora School of Health, University of Waikato, Hamilton, New Zealand. Sims is with the Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand.

Schofield (katie.schofield.study@gmail.com) is corresponding author.
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