Tart cherry concentrate may enhance endurance exercise performance via its low glycemic index, anti-inflammatory and anti-oxidative capacity, and blood flow enhancing effects, according to a meta-analysis of ten existing studies.
“The recovery benefits of tart cherry concentrate are well researched, yet evidence on performance enhancement is scarce and results have been mixed,” said Professor Philip Chilibeck, a researcher at the University of Saskatchewan.
“The results of this meta-analysis found that tart cherries did help improve performance, and we gained greater insight into the potential mechanism responsible for this benefit.”
Ten studies were included (totaling 127 males and 20 females) in the meta-analysis. Most of the participants were endurance-trained individuals, including cyclists, runners and triathletes.
Nine of the 10 studies involved longer-term tart cherry consumption (around two to seven days prior to exercise) and one involved same-day supplementation.
Tart cherry dosages varied across studies and included 200 to 500 mg/day in capsule or powder form, 60 to 90 mL/day of tart cherry juice concentrate diluted with 100 to 510 mL water and 300 to 473mL/day of tart cherry juice.
The total amount of anthocyanins consumed daily ranged from 66 to 2,760 mg.
Methods of measuring performance differed across studies, and included distance on a shuttle swimming test, time to exhaustion during high-intensity cycling, total work performed during cycling, cycling time trials and time to complete a full or half marathon.
Pooled results across these 10 studies indicated a significant improvement in endurance performance with tart cherry concentrate, with two of the 10 studies reporting significant performance-enhancing effects on their own.
While pooled results in the meta-analysis found significant benefits, eight of the 10 studies on recovery did not demonstrate a performance benefit when comparing tart cherry to placebo.
This could be related to participant demographics and fitness levels, diet and exercise control, supplementation protocol and measurements of performance.
Not all studies used well-trained athletes, and the meta-analysis found the lowest improvement when tart cherry juice was consumed by the lowest trained participants.
No dose-response relationship was found between tart cherry concentrate and performance, and further studies are warranted to find an optimal dosing strategy.
The findings were published on January 27, 2020 in the Journal of the American College of Nutrition.
Ruirui Gao & Philip D. Chilibeck. Effect of Tart Cherry Concentrate on Endurance Exercise Performance: A Meta-analysis. Journal of the American College of Nutrition, published online January 27, 2020; doi: 10.1080/07315724.2020.1713246