Changes in ultrasound and bioelectrical-derived body composition parameters in response to training load during pre-season in professional male road cyclists

Purpose: The pre-season is commonly a period during which cyclists implement interventions to optimize performance, training, and body composition. Ultrasonography and bioelectrical impedance vector analysis (BIVA) can serve as efficient methods to track changes in body fat and lean soft tissue. This study aimed to longitudinally monitor changes in subcutaneous adipose tissue thickness and fluids during the pre-season in response to training load. Methods: Twelve professional male cyclists participated in the study. Body composition and field performance data were collected on three occasions over three months during the pre-season: December (T1), January (T2), and February (T3). Results: Significant reductions in total subcutaneous adipose tissue thickness (p = 0.001; ES = 0.45) and fat mass percentage (p = 0.005; ES = 0.38) were observed. Phase angle increased (p < 0.001; ES = 0.68), while the impedance vector decreased (p < 0.001; ES = 0.66). Training metrics, including distance, elevation gain, and workload, increased. Improvements were recorded in 5-min, 20-min, and 60-min mean maximal power outputs. Conclusions: Professional road cyclists exhibited reduced adiposity, particularly in the lower limbs, alongside increases in soft tissue and extracellular fluids during the pre-season. Monitoring body composition during the pre-season using ultrasonography and BIVA can provide valuable insights for coaches, sports scientists, and medical staff, enabling them to tailor training loads and optimize cyclists' readiness for the competitive season.