Effects of Post-Race Nutritional Intervention on Delayed-Onset Muscle Soreness and Return to Activity in Ironman Triathletes

The purpose of this study is to examine the effect of a post-race nutritional intervention on DOMS and ability of triathletes to return to activity. Thirty-six triathletes participated in this study. Subjects were randomly assigned to either an intervention or control group by finish time. The intervention group received recovery shakes (540 kcal, 90g carbohydrate, 40g protein, 16g fat) both 1-hour and 3-hours post-race. DOMS was measured with a 100mm-visual analogue scale (VAS) and 11-point global rating of change (GRC) in standing position (static) and sitting-to-standing motion (active). DOMS was evaluated at 11 time points (pre-race, 1h, 3h, 12h post-race, and everyday for up to 7 days (1-7d) post-race) using paper-based and online surveys. Return to activity questionnaires were used to assess days returning to activity, length, intensity, and composition of activities. Activity intensity was measured with a 15-point rated perceived exertion (RPE) scale. Subjects completed return to activity questionnaires via online survey for 2 weeks post-race. Energy intake on the race day was monitored using diet log. Two-way ANOVA (group x time) was used to compare outcomes between groups over time and independent t-tests were utilized for group comparisons. DOMS increased dramatically in response to the race and gradually subsided by 4 days post-race regardless of treatment group. Within the context of this study, the post-race nutritional intervention did not result in differences on DOMS and return to activity compared to control despite it has changed composition of post-race macronutrient intake.