Arterial stiffness results from eccentrically biased downhill running exercise

Objectives: There is increasing evidence that select forms of exercise are associated with vascular changes that are in opposition to the well-accepted beneficial effects of moderate intensity aerobic exercise. To determine if alterations in arterial stiffness occur following eccentrically accentuated aerobic exercise, and if changes are associated with measures of muscle soreness. Design: Repeated measures experimental cohort. Methods: Twelve (m = 8/f= 4) moderately trained (VO(2)max= 52.2 +/- 7.4 ml kg(-1) min(-1)) participants performed a downhill run at 12 grade using a speed that elicited 60% VO(2)max for 40 min. Cardiovascular and muscle soreness measures were collected at baseline and up to 72 h post-running. Results: Muscle soreness peaked at 48 h (p = <0.001). Arterial stiffness similarly peaked at 48 h (p = 0.04) and remained significantly elevated above baseline through 72 h. Conclusions: Eccentrically accentuated downhill running is associated with arterial stiffening in the absence of an extremely prolonged duration or fast pace. The timing of alterations coincides with the well-documented inflammatory response that occurs from the muscular insult of downhill running, but whether the observed changes are a result of either systemic or local inflammation is yet unclear. These findings may help to explain evidence of arterial stiffening in long-term runners and following prolonged duration races wherein cumulative eccentric loading is high. (C) 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.