Acute Effects Of Maximal Exercise On Inflammatory Markers And Heart Rate Variability

Abstract

BACKGROUND: It has been suggested that vagal input may influence inflammatory responses on a millisecond timescale akin to heart rate. This study aimed to investigate the relations between vagally mediated markers of heart rate variability (HRV) and inflammatory profiles in response to maximal aerobic exercise. METHODS: Eight recreationally active males (26±3 yrs, 9.7±3.2 %BF) completed two trials separated by a minimum of eight weeks. Resting HRV was assessed during a 5-min seated period at both trials; the root mean square of successive differences (rMSSD) was used to assess vagal input. Maximal oxygen uptake (VO2max) was assessed via ramp protocol on the cycle ergometer (100W + 25W per minute) until volitional fatigue. A blood draw was collected immediately pre-, and immediately post-maximal oxygen uptake testing. Inflammatory markers were quantified in serum using a high sensitivity T-Cell multiplex (IFNy, IL-10, IL-2, IL-4, IL-6, and TNF-α). Principal component analysis (PCA) was used to form three components and a repeated measures multivariate analysis of covariance (MANCOVA) was used to examine differences in these components between the two trials and across time (pre vs post). RESULTS: After controlling for the difference in baseline rMSSD, inflammation between the two trials approached significance (p=.095). However, none of the 3 components were significantly different in response to maximal exercise (p=.824). CONCLUSIONS: Vagal input was assessed by seated resting HRV (rMSSD) which influenced baseline resting inflammatory status but did not influence the exercise-induced inflammatory response. This data suggests that when investigating inflammatory responses, resting vagal input should be considered.