Microvascular Perfusion Changes in the Contralateral Gastrocnemius Following Unilateral Eccentric Exercise

Abstract

Context: Eccentric exercise increases local blood flow and volume as a result of increased metabolic demand. It is not known how eccentric exercise affects microvascular perfusion in the musculature of the opposite limb over this 48 hour period. Objective: To quantify microvascular perfusion immediately after eccentric exercise to the gastrocnemius in the opposite limb and over 48 hours following the exercise. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: Six healthy participants volunteered (1M, 5F; Age: 22.4 ± 2.1 years; Height: 165.2 ± 16.6 cm; Weight: 64.5 ± 25.1 Kg). Intervention(s): A unilateral, eccentric exercise was performed to a randomized leg. Each subject performed 100 calf-lowering repetitions in the sequence of 50 repetitions, 5 min rest and 50 repetitions. Main outcome measure: Micro vascular perfusion measurements (blood volume (dB), blood flow (dB/sec), and blood flow velocity (1/sec)) of the contralateral gastrocnemius were taken using contrast-enhanced ultrasound (CEU) at baseline, immediately after exercise, and 48 hours after exercise. Pain using a visual analog scale was also recorded baseline, 24, and 48 hours after exercise to determine the onset of delayed onset muscle soreness (DOMS). Results: There was a significant increase in blood volume immediately after exercise (9.77 ± 3.19 dB) from baseline (6.18 ± 2.05 dB) (p=.023). There was a significant increase in blood flow immediately after exercise (3.53 ± 0.86 dB/sec) from baseline (2.40 ± 0.69 dB/sec) (p=.010). There was no change in blood flow velocity (p=0.487). Blood flow (p=0.003) and volume (p=0.002) remained significantly higher at 48 hours from baseline, with no change in blood flow velocity (p=0.316). Pain significantly increased. Conclusion: Micro vascular perfusion increased immediately after exercise in the contralateral gastrocnemius. This increase was maintained following a single bout of eccentric exercise over a 48 hour period in the presence of DOMS.