C-REACTIVE PROTEIN LEVELS BEFORE AND AFTER ULTRA ENDURANCE EXERCISE

Abstract

C-reactive protein (CRP) is released by the body in response to acute injury, infection or other inflammatory stimuli and is associated with risk of cardiovascular disease. PURPOSE To assess blood levels of highly sensitive CRP prior to and following the Hawaii Ironman triathlon (2.4 mile swim, 112 mile bike, 26.2 mile run). METHODS Twenty-seven athletes (10 females, 17 males) over 50 years old (average age:58, ± 7.5 yrs, range:50–79) participated in the study. All women were postmenopausal. Athletes reported for pre-race morning blood draw (choice of either) 72 or 48 hours prior to race start, and again immediately following race finish. Post-race CRP levels were collected on 22 athletes (5 athletes did not finish the race). RESULTS Average finish time for females was 14:23 (race average for > 50 y.o. female finishers:14:40), males 13:31 (race average for > 50 y.o. male finishers:13:06). CRP rose on average by 5.2 ± 5.4 mg/L (p < 0.001). Baseline CRP levels were reported in the following risk categories for cardiovascular disease:59% (n = 16) lowest risk (defined as:0.0–0.6 mg/L), 11% (n = 3) low-risk (0.7–1.1 mg/L), 19% (n = 5) moderate risk (1.2–1.9 mg/L), 4% (n = 1) high-risk (2.0–3.8 mg/L), 7% (n = 2) highest risk (3.9–15.0mg/L). Post-race CRP levels in 77% of the finishers (17/22) rose from a lowest, low or moderate risk category to a high or highest risk category (p < 0.001). 54.5% (12/22) of CRP levels were of a highest risk category following the race. CRP for two male athletes decreased from a highest risk to a high-risk category (by 3.1 and 1.2 mg/L, respectively) following the race. CONCLUSION At pre-race baseline, ultra-endurance athletes show low levels of CRP, a risk factor for heart disease, consistent with known low risk in this group. However, CRP levels measured immediately after prolonged exercise are elevated, suggesting inflammation. The duration of elevation and implications for long-term risk are unknown.