Aim:
This study’s aim was to determine the effect of a fruit, vegetable, and berry juice powder concentrate (FVB) on oxidative stress, muscle soreness, and muscle function after resistance training.
Methods:
A total of 41 healthy young men and women (aged 18-35) were randomly assigned to take either a fruit, vegetable and berry juice powder concentrate (Juice Plus+®; 2 capsules per day each of the Fruit, Vegetable, and Berry Blends) or placebo for 28 days. On the 29th day, both groups completed a round of eccentric or resistance exercises (4 sets of 12 repetitions of elbow flexion of the non-dominant arm). Blood samples were analyzed for levels of several markers of oxidative stress, including protein carbonyls (PC) and malondialdehyde (MDA), before and at various time points after the exercise was performed (2, 6, 24, 48, and 72 hours postexercise). Range of motion, muscle soreness, and maximal isometric force were also obtained at these time points.
Results:
Following completion of the exercise, PC and MDA steadily increased in the placebo group, as would be expected. However, they did not significantly change in the FVB group. The researchers concluded that due to the array of antioxidants it contains, FVB “was effective in attenuating the increase in several markers of oxidative stress within the blood.”
Range of motion, muscle soreness, and maximal isometric force were similar in both the supplementation and placebo groups after completion of the exercise, indicating that muscle force loss or muscle soreness are unrelated to blood markers of oxidative stress with eccentric exercise.
Conclusion:
This study reports that pretreatment with an FVB for 4 wk before and continued for 3 d after an eccentric protocol can attenuate blood oxidative stress markers but had no significant impact on the changes in functional measures and MS associated with this muscle-damaging procedure. In addition, the results suggest that blood oxidative stress may not be a good indicator of muscle damage and force declines manifested by this protocol.”
PubMed link: