Downhill Running Followed by Foam Rolling Has No Effect on the Cost of Running

Abstract

PURPOSE: Downhill running (DHR) causes muscle soreness that may affect running performance. Foam rolling (FR) is a potential recovery tool for reducing soreness and attenuating performance decrements. Running economy (RE), which quantifies the efficiency of running, is a key factor in distance running ability. It is unclear whether DHR affects RE in trained runners and whether FR is an effective recovery method for DHR-induced soreness. Furthermore, RE may be assessed in several ways, including O2 cost (VO2) and energy cost (EC, kcal*kg-1*min-1). These measures may be more accurate with allometric scaling of body weight (alloVO2 and alloEC; body weight in kg0.66). Thus, our purpose was to evaluate changes in RE with DHR and FR or placebo using 4 definitions of RE. METHODS: Subjects did submaximal running to assess RE 2-4 days before (SUBMAX1) and 48 hours after (SUBMAX2) DHR. Immediately after DHR, they performed FR or placebo (sham compression tights [T]). In a randomized crossover design, subjects repeated these tests 2-4 weeks later. RE during SUBMAX was calculated as VO2, alloVO2, EC, and alloEC. Muscle soreness was measured on a 0-10 verbal scale before DHR and SUBMAX2. RESULTS: Eight trained runners completed the study (VO2max 57±7 ml*kg-1*min-1, age 30.6±7 years, 4 females). Soreness at SUBMAX2 was greater than at SUBMAX1, showing that DHR induced soreness in all subjects (p = 0.012). Subjects had lower soreness at SUBMAX2 with FR than T (p = 0.025). However, there were no significant effects of time or treatment on VO2, alloVO2, EC, or alloEC (p > 0.05 for all comparisons). CONCLUSION: Downhill running causes muscle soreness but does not affect running performance as evaluated through RE. FR reduces DHR-induced soreness compared to a placebo. While allometric scaling and energy cost definitions of RE may be better indicators of running performance than the traditional VO2, none of the measures of RE are affected by DHR-induced muscle soreness.