Impact of exercise changes on body composition during the college years - A five year randomized controlled study

Abstract

Background: Observational studies have consistently reported severe weight gains during the college years; information about the effect on body composition is scarce, however. Thus, the aim of the study was to determine the effect of exercise changes on body composition during 5 years at university. Methods: Sixty-one randomly selected male and female dental (DES; 21 ± 3 years., 22 ± 2 kg/m2) and 53 sport (physical education) students (SPS; 20 ± 2 years., 22 ± 3 kg/m2) were accompanied over their 5-year study program. Body mass and body composition as determined via Dual-Energy x-ray-absorptiometry (DXA) at baseline and follow-up were selected as primary study endpoints. Confounding parameters (i.e., nutritional intake, diseases, medication) that may affect study endpoints were determined every two years. Endpoints were log-transformed to stabilize variance and achieve normal distributed values. Paired t-tests and unpaired Welch-t-tests were used to check intra and inter-group differences. Results: Exercise volume decreased significantly by 33 % (p < 0.001) with no changes of total fat mass (0.6 %, -5.0-6.5 %, p = 0.823), while DES gained total FM and LBM in a proportion of 2:1. Corresponding changes were determined for appendicular skeletal muscle mass and abdominal body-fat. Maximum aerobic capacity increased (p =.076) in the SPS (1.6 %, -0.2-3.3 %) and significantly decreased (p =.004) in the DES (-3.3 %, -5.4 to -1.2 %). Group differences were significant (p