Oxidative Stress and Heart Rate Variability Following an Accute Bout of CrossFit

Abstract

The purpose of this Dissertation was to provide a better understanding of the physiological stress involved in the newly popular style of exercise named CrossFit, and compare these findings to a more ‘traditional’ mode of exercise, treadmill running. Heart Rate Variability (HRV), which is a marker of parasympathetic activity and cardiac autonomic control, and oxidative stress, which are biomarkers of cellular damage are both independent markers of physiological stress. This dissertation covers two studies. The first study examined the affects of CrossFit and an intensity-matched bout of treadmill running on markers of HRV in ten CrossFit trained participants. The results of this study showed that both markers of HRV (LnRMSSD, LnHF) significantly decreased following both CrossFit and treadmill running. Furthermore, both markers of HRV were significantly lower following the trial when compared to treadmill running. The second study examined biomarkers of oxidative-stress following a bout of CrossFit and intensity-matched bout of treadmill running. Ten CrossFit Trained male athletes participated in this study. Markers of oxidative stress can be divided into two categories: oxidative-damage (LOOH, PC), and antioxidant capacity (FRAP, TEAC). The results of this study were mixed, with biomarkers of oxidative-stress LOOH and FRAP becoming significantly elevated following both trials and an unexpected significant decrease in PC and TEAC. No biomarker showed a trial dependent difference.