D-32 Free Communication/Poster - Renal

Abstract

Trained cyclists exercise for long durations in an unloaded position, particularly in the lumbar spine (LS), and this may lead to increased bone loss. USA Cycling Association reports almost 66% of their members are over 35 years old. It is important to understand the impact high-level training will have on bone health in this population. PURPOSE: To determine the effects of 12 weeks of calcium collagen chelate (CCC) supplementation on body composition and bone biomarkers in 18 (38.6±9.1 yrs) trained (57.9±4.2 ml/kg/min) male cyclists. METHODS: Trained cyclists were stratified and assigned to one of two groups: 1) 6 g/d CCC or 2) placebo (CON). Supplements were taken twice daily for 12 weeks during habitual training and racing. Body composition and BMD of the whole body, LS and both hips were measured using DXA. ELISA was used to measure bone alkaline phosphatase (BAP), tartrate resistant acid phosphatase-5b (TRAP5b) and sclerostin (SCL). One-way ANOVA was used to compare baseline variables between the CON and CCC. Pearson’s correlations were used to examine relationships between the dependent variables. Possible effects of the independent variable, CCC or CON supplementation, on the dependent variables, BMD (whole body, total hip, LS), fat mass, lean body mass, BAP, TRAP5b and SCL were evaluated by two-way (group x time) repeated measures ANOVA. Significance was accepted at p < 0.05. RESULTS: LS Z-scores identified 12 cyclists as osteopenic (-1.2 to -2.2) and three as osteoporotic (-2.5 to -2.9). There were no group differences in VO2max, body composition, BMD, BAP, TRAP5b or SCL. There were no (group x time) effects found for body composition, BMD, BAP, TRAP5b or SCL. Strong correlations were found at baseline between weekly training hours and TRAP5b (r = 0.53), VO2max and BAP (r = -0.56), and BAP/TRAP5b ratio and right and left hip BMD (r = -0.65, r = -0.65, respectively). CONCLUSION: Male cyclists riding ≥ 10 h/wk have reduced BMD, particularly at the LS. 12-week supplementation with CCC did not affect body composition, BMD, BAP, TRAP5b or SCL. Further research is needed to determine whether low BMD compromises bone strength in male cyclists and to identify successful interventions. Supported in part by the Institute of Sports Sciences and Medicine, The Graduate School and the College of Human Sciences at Florida State University.