Pilot study
muscle mass, FM
Participants in the pilot study had a mean age of 23.7 ±7.6 years, a BMI of 32.7 ±1.7 kg/mThe nonparametric Wilcoxon test for related samples revealed significant changes in body composition and muscular health (muscle mass and function) with very strong effect sizes (0.83 – 0.90) only for the HICT group. Specifically, %BF and FM were significantly reduced after three weeks of intervention (Z = - 2.207, The Mann-Whitney U test revealed a significant increase of WtHR in the HIIT group compared to controls (Effects of the pilot interventions on body composition, muscular health, and cardiorespiratory fitness.CON, control group; HIIT, high-intensity interval training; HICT, high-intensity circuit training; BW, Body weight; BMI, Body Mass Index; WtH, Waist to Hip; %BF, % body fat; FM, Fat mass; LBM, Lean body mass; LM, Lean Mass; FFM, Free Fat Mass; SMM, Total Body Skeletal Muscle; 1RM-LP, 1 Max Rep Leg Press; 1RM-BP, 1 Rep Max Bench Press; rVO*p < 0.05; ** p < 0.01.CON versus HIIT.HIIT versus HICT.CON versus HICT.Data reported as means and standard deviations.Baseline MR-derived CAT values (CON: 58.5 ± 1.2 mL; HIIT: 39.9 ± 1.6 mL; HICT: 68.7 ± 0.9 mL) and echocardiography-derived CAT values (CON: 5.9 ± 0.09 mm; HIIT: 4.2 ± 0.16 mm; HICT: 5.1 ± 0.04 mm) were similar at baseline. The Mann-Whitney U test did not show significant differences between groups on change in CAT thickness (echocardiography) or volume (MR). Change in CAT. CON – control group; HIIT – high intensity interval training group; HICT – high intensity circuit training group; CAT (mm) – cardiac adipose tissue derived from echocardiography analysis; CAT (mL) – cardiac adipose tissue derived from magnetic resonance analysis. Data reported as means and standard error of mean.Magnetic resonance images representing pre- to post-intervention changes in cardiac fat of three participants. Close-up of the cardiac fat for a single subject in: 