Lean body mass and maximal strength changes during physique contest preparation and recovery: A case series

This study aimed to investigate changes in lean body mass (LBM) and maximal strength during preparation for a physique contest season and one month post-season. Three drug-free male physique athletes were observed. Laboratory tests were conducted at various intervals: immediately before starting weight loss, 2 months, 1 month, and 1 week before their first contest, 1 week before their last contest, and 1 month post-season. Body composition was assessed using Dual-energy X-ray absorptiometry (DXA), bioimpedance (BIA), and skinfold (SK) measurements. Muscle thickness (MT) of the elbow flexors and muscle cross-sectional area (CSA) of the vastus lateralis were evaluated via ultrasound. Strength assessments (isometric and isokinetic peak torque) were measured using a dynamometer. Blood biomarkers and dietary intake were also tracked. During the preparation phase, LBM decreased in all athletes: 1.7–5.3 kg (DXA), 4.3–8.5 kg (BIA), and 7.0–9.5 kg (SK). One month into recovery, LBM rapidly increased: 2.5–3.4 kg (DXA), 4.1–4.6 kg (BIA), and 3.4–5.5 kg (SK). Both MT and CSA decreased during preparation but increased during recovery. Maximal strength performance remained within expected day-to-day variation for isometric peak torque and isokinetic peak torque at 60°/s, but isokinetic peak torque at 240°/s exceeded expected variation, only partially restored post-contest. Testosterone levels decreased and sex-hormone binding globulin increased during preparation, with varying recovery. Reductions in LBM, MT, and CSA during caloric restriction were followed by rapid increases post-contest, resulting in negligible net changes from baseline. This provides evidence that highly trained individuals are able to retain contractile tissue during substantial weight loss following a daily caloric deficit of 500 kcal.