If you have ever become sore after an intense exercise session, then you have probably experienced what is known as exercise-induced muscle damage (EIMD). What happens is that for a short period of time the muscle or muscle groups that you stimulated in your workout become damaged and inflamed, as well as accompanied by oxidative stress. This is only temporary, as your body will eventually heal itself. Although the exact methodology has not been discovered, it has been proven antioxidants can play a beneficial role in promoting recovery following EIMD. A recent study done in New Zealand revealed blueberries demonstrate both antioxidant and anti-inflammatory properties that aid in recovery.1
There are various chemicals in blueberries that display antioxidant properties. Blueberries contain pterostilbene, anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins, which inhibit mechanisms of cancer cell development and inflammation.2
This study used a blueberry beverage that contained 200 grams of frozen New Zealand blueberries, a banana, and 200 mL concentrated apple juice. The control beverage omitted the blueberries and replaced it with dextrose. Those subjects given this beverage consumed it at breakfast, as well as post exercise. Another beverage was given 12 hours and 36 hours post training. Over the duration of the entire trial, participants consumed a total of 1kg of New Zealand blueberries.3
The muscle-damaging exercise that was used in the study was similar to what is known as a leg extension. Subjects performed 3 sets of 100 eccentric repetitions, which were performed at the same angle and velocity. Each set had a 5-minute rest period before starting another set. There was a test done on each subject to test average peak torque/tension, which was used for determining muscle function. Ratings of perceived muscle soreness were then monitored, as well as oxidative stress and inflammatory biomarkers.
Blood tests were done to check for muscle damage indicators such as creatine kinase. These were collected before, and then 12, 36, and 60 hours post muscle damage. Plasma protein carbonyls, plasma radical oxygen species (ROS)-generating potential, plasma interleukin (IL)-6, and plasma antioxidant capacity were also measured from the blood tests that were performed.4
The subjects who had the blueberry beverage had accelerated recovery of muscle peak isometric strength. All of the other tests did not display much difference between the control and the blueberry beverage group. However, there was enough evidence to support the claim that blueberry consumption induces cellular adaptive events that help accelerate muscle repair and also muscle isometric strength. The main focus of a follow-up study will probably be one that focuses on identifying specific dietary changes that synergistically coincide with exercise-induced short term as well as adaptive responses following various exercise strategies.5
While the mechanisms are still vague as to just how the antioxidants in blueberries help aid in recovery from EIMD, there was enough evidence that supported the claim that blueberries are in fact beneficial in recovery. People have been praising the benefits of blueberries for a long time, and the list of praises just may have gotten a bit longer.6