Effects of Two Different Post-Exercise Stretching Modalities on Delayed Onset Muscular Soreness in Adults

Abstract

Until recently, it was believed that post-exercise stretching could reduce delayed onset muscular soreness (DOMS), but recent reviews of studies on the topic have concluded that post-exercise stretching has no effect on DOMS. However, the effect of proprioceptive neuromuscular facilitation (PNF) post-exercise stretching on preventing DOMS has not been adequately studied. PURPOSE: To determine the effect of post-exercise PNF stretching on DOMS. METHODS: Participants (N =57) were randomly assigned to a PNF stretching group (n =19), static stretching group (n =20), and to a no-stretching control group (n=18). All participants completed exercise designed to induce DOMS prior to post-exercise experimental stretching protocols. They then rated their soreness level on a pain scale 24 and 48 hours afterwards. RESULTS: A 3 × 2 (group × time) mixed ANOVA showed no main effect for stretching type on DOMS (F [2, 54] = 86, p = NS), or interaction between group and time (F [2, 54] =.93, p = NS). However, there was an effect for time (F [1, 54] = 8.67, p <.01). Post hoc testing showed that DOMS pain significantly decreased (p <.05) from 24 to 48 hours post-exercise for the PNF and control groups, but not for the static stretching group. Other analyses revealed a significant correlation (r =.61, p <.01) between the pre and post-exercise stretch scores and the 48 hour post-exercise pain score for the PNS group. CONCLUSION: As with the results of previous research on post-exercise static stretching, these results indicate that post-exercise PNF stretching also does not prevent DOMS. However, the correlation analysis suggests that it is possible that the pre-stretch muscle contractions of the post-exercise PNF protocol may have placed a load on an already damaged muscle causing more DOMS for some subjects. Further research is necessary to support or disprove that possibility.