Consumption of An Anthocyanin-Rich Antioxidant Juice Accelerates Recovery of Running Economy and Indirect Markers of Exercise-Induced Muscle Damage Following Downhill Running

Abstract

This study examined the effects of anthocyanin-rich antioxidant juice (AJ) on the recovery of exercise-induced muscle damage (EIMD) and the running economy (RE) following downhill running (DHR). Thirty healthy young men were randomly divided into two blinded groups and consumed either AJ or placebo (PLA) for nine days (240 mL twice-a-day). On day 5, the participants from both groups ran downhill (-15%) for 30 min at 70% of their maximal oxygen uptake (VO₂max) speeds. The changes in RE (oxygen uptake (VO₂) and perceived effort (PE) during 5-min runs at 80%VO₂max) and EIMD (isometric peak torque (IPT), muscle soreness (SOR) and serum creatine kinase activity (CK)) were compared over time and between the groups on the 4 days following DHR. VO₂ and PE increased (p < 0.05) immediately following DHR for both groups and remained elevated for PLA until 48h post-DHR while fully recovering 24 h post-DHR for AJ. SOR was greater (p < 0.05) for PLA throughout the study. CK increased for both groups and was greater (p < 0.05) for PLA at 96 h post-DHR. IPT decreased for both groups but recovered faster for AJ (72 h) compared to PLA (no full recovery). AJ accelerated recovery of RE and EIMD and should be used in specific contexts, but not chronically.

Keywords: anthocyanins; antioxidant supplementation; exercise-induced muscle damage; muscle soreness; recovery; running economy.

Figure 1

The experimental design of the study. The biggest dash represents downhill running. AJ: antioxidant juice; PLA: placebo; CK: creatine kinase.

Figure 2

The absolute changes in oxygen uptake (A) and perceived effort (B) over time following downhill running. * p < 0.05 compared to the baseline values in the same group. ^‡ p < 0.05 compared to the experimental group at the same time-point. CON: control group; EXP: experimental group.

Figure 3

The relative changes in isometric peak torque over time following downhill running. * p <0.05 compared to the baseline values in the same group. CON: control group; EXP: experimental group.

Figure 4

The changes in knee extensor muscle soreness (A) and serum creatine kinase (CK) activity (B) over time following downhill running. * p <0.05 compared to baseline values in the same group; ^‡ p <0.05 compared to the experimental group at the same time-point. CON: control group; EXP: experimental group.