Endurance Training Does Not Alter Serum C-reactive Protein Concentrations In Apparently Healthy, Inactive Males

Abstract

Regular aerobic exercise may reduce cardiovascular disease (CVD) risk in part by lowering the concentration of inflammatory markers such as C-reactive protein (CRP). While studies in diseased populations have shown significant decreases in serum CRP concentrations with regular aerobic training, little has been conclusively determined regarding the effects of exercise training on serum CRP concentrations in apparently healthy, untrained populations that may "fall through the cracks" of traditional CVD risk screening. PURPOSE: To examine the effects of a 17-week half marathon training program on serum CRP concentrations, blood lipids, aerobic fitness, and body fat percentage (BF) in apparently healthy, untrained men. METHODS: Seventeen male subjects (29.5 ± 4.6 yr, 36.8 ± 7.2 ml/kg/min VO2peak, 28.6 ± 8.7% BF) became active (ACT) in a 17-week half marathon training program. An additional 20 male subjects (28.4 ± 6.6 yr, 38.7 ± 5.1 ml/kg/min VO2peak, 27.5 ± 6.8% BF) served as controls (CON). Aerobic testing (graded maximal exercise test), BF (DEXA), and fasting blood samples were collected prior to and at the completion of the training program. Blood samples were analyzed for high sensitivity CRP (hs-CRP) concentrations as well as complete lipid profiles. RESULTS: No significant changes in serum hs-CRP concentrations (p=.10), blood lipids or BF (p=.078) were seen in ACT as a result of the half marathon training program while aerobic capacity (42.1 ± 9.1 ml/kg/min VO2peak, p<.0001) improved significantly. No significant changes in serum CRP concentrations, blood lipids, aerobic fitness, or BF were detected in CON over time. CONCLUSION: Serum CRP concentration is not influenced by regular aerobic training in apparently healthy, untrained men and may not serve as a useful CVD risk marker for this population.