SONY DSCBack in 2012, I wrote a blog post about how drinking tart cherry juice can be helpful for people doing endurance sports. This has proved to be one of my most popular articles on www.endurancesportsnutritionist.co.uk. Since then, several new research studies have been published looking at the effect that tart cherry juice, specifically from Montmorency cherries, has on different aspects of health and performance in endurance sports. New cherry juice products have also launched onto the market, although my personal preference is still for Cherry Active concentrate (http://www.cherryactive.co.uk/). I’m particularly pleased to see the introduction of single serving 30ml sachets which are perfect to take to races as part of your recovery nutrition plan.

In my original blog post, I looked at studies that showed how tart cherry juice promoted muscle recovery and improved sleep. 2014 and 2015 has seen publication of three further papers of specific interest to endurance athletes. In the first, 16 trained cyclists were divided into two equal groups and consumed either 30ml of Montmorency cherry juice concentrate or a placebo, twice a day for 7 days. 1 During this time they completed a 109 minute stimulated road cycling trial on days 5, 6 and 7. Various markers for inflammation and oxidative stress were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 & 7. The markers for lipid hydroperoxides (a measure of oxidative stress), IL-6 and hsCRP (markers for inflammation) were lower in the group taking the cherry juice than in those taking the placebo. There was no difference in other markers of inflammation (TNF-alpha, IL-1-beta and creatine kinase). The main takeaway from this study is that cherry juice may be helpful in reducing certain aspects of inflammation and oxidative stress during multi-day races.

The second study, published in 2015 by the same research group, looks further at the effect of tart cherry juice on muscle recovery.2 16 trained cyclists were divided into two groups and consumed either 30ml of Montmorency cherry juice concentrate or a placebo twice a day for eight days. On the 5th day only, they also completed a 109 minute cycling trial designed to replicate the demands of a road race. Functional performance and delayed onset muscle soreness were assessed at baseline, 24 hrs, 48 hrs and 72 hrs post-trial. This showed maximum voluntary isometric contraction did not decline at 72 hrs in the group taking the cherry supplement, compared with the group taking the placebo. It also showed improved cycling economy in the supplemented group at 24 hours. Blood samples were also collected at baseline, immediately pre- and post-trial, and at 1, 3, 5, 24, 48 and 72 hrs post-trial to assess indicators of inflammation. These showed that high sensitivity C-reactive protein (hsCRP – a marker of inflammation) was reduced in the group taking the cherry juice compared with the group taking the placebo, which was also seen in the first study. Other indictors of inflammation and muscle damage (tumour necrosis factor, oxidative stress, IL-1-beta, IL6 & IL8 and creative kinase) showed no differences between the groups. The researchers concluded that Montmorency cherry concentrate can be an efficacious functional food for accelerating recovery and reducing exercise-induced inflammation following strenuous exercise.

The third study was published in the Journal of the International Society for Sports Nutrition in 2015.3 It looked at the influence of Montmorency cherry juice on stress and symptoms of upper respiratory tract infections such as the common cold or sinusitis following marathon running. 20 recreational marathon runners consumed either tart cherry juice or a placebo before or after running a marathon race. Salivary markers for mucosal immunity (sIgA and IgG) and stress (cortisol), as well as serum CRP to assess inflammation, were measured before and after the race, as well as self-reported incidence and severity of upper respiratory tract infections (URTIs). The CRP increase at 24 and 48 hour post-marathon was lower in the group taking the cherry juice than in the group taking the placebo, suggesting a quicker recovery from hard exercise, but the immunity and stress markers showed no difference. However the most significant finding came with the incidence of URTIs: no URTIs were reported in the cherry juice group while 50% of runners in the placebo group developed symptoms.

While only a pilot, this third study does give support to the practice of taking cherry juice both before and after a race to help prevent the development of upper respiratory tract infections. Extending this to a few days before and a few days after a race might also have benefits for muscle recovery, according to the first and second studies, and particularly when racing occurs on consecutive days, as shown by the first study. Mix 30ml of tart cherry concentrate into 500ml of cold or hot water, or add it to a smoothie. Consume twice daily.

Jo Scott-Dalgleish BSc (Hons) is a BANT Registered Nutritionist, writing and giving talks about nutrition for endurance sportBased in London, she also works as a Registered Nutritional Therapist, conducting onetoone consultations with triathletes, distance runners and cyclists to help them eat well, be healthy and perform better through the creation of an individual nutritional plan. To learn more about these consultations, please visit www.nutritionforendurancesports.co.uk

 

References

 

1 Bell PG et al. Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days of high-intensity stochastic cycling. Nutrients. 2014. Feb 21; 6(2):829-43 http://www.ncbi.nlm.nih.gov/pubmed/24566440 http://www.ncbi.nlm.nih.gov/pubmed/24566440

2 Bell PG et al. Recovery facilitation with Montmorency cherries following high intensity, metabolically challenging exercise. Appl Physiol Nutr Metab. 2015 Apr; 40(4): 414-23 http://www.ncbi.nlm.nih.gov/pubmed/25794236

3 Dimitrou et al. Influence of a Montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon-running – a pilot investigation. JISSN. 2015 May 11: 12:22 http://www.ncbi.nlm.nih.gov/pubmed/25983669