Cherries and Recovery in Training (#61)

Cherries are gaining attention in the sports world as a promising aid for recovery. But what does research indicate about their effects on inflammation, muscle damage, and performance? Can a natural food truly help you recover more quickly between tough sessions or competitions? The reality is, cherries appear to reduce exercise-induced stress in the body and enhance recovery, especially during intense training periods. While they don't substitute for sleep, strategic planning, and a balanced diet, they can be a valuable addition when the demands are high.

Research on "functional foods" and their bioactive substances continues — and it's quite exciting for those of us looking to fine-tune our athletic performance. We've previously explored this topic through our articles on natural performance enhancers, beet juice, and blackcurrant powder. This time, we dive into the research on Montmorency tart cherries and their potentially remarkable effects on recovery.

When it comes to cherries, and particularly Montmorency cherries (Prunus cerasus), they are rich in specific flavonoids, notably the powerful antioxidant anthocyanin. We've discussed this in our article on blackcurrant powder, and the levels are even higher in these specific cherries, mainly in the skin if we're being precise. Anthocyanin is an antioxidant with strong potential to improve your recovery through several mechanisms:

1. Reduced oxidative cell damage
2. Decreased inflammation
3. Less muscle damage
4. Reduced perceived pain

All these factors contribute to what's commonly referred to as less muscle soreness and a more efficient recovery. The research has primarily focused on recovery, although there are studies that have also examined acute performance in events like half marathons (see below).

We know from previous research that antioxidants inhibit some of the training effects and physiological adaptation that your body initiates. Taking high doses of vitamins/antioxidants as supplements in conjunction with training is a big no-no! HOWEVER, there are occasions when better and faster recovery is more important than maximal training adaptation. Example: race season with only a week between races, or the final sessions before a competition where you want to ensure that you are fully recovered when the starting gun goes off.

Throughout the entire year, the benefit is greatest during the competition season, as well as in particularly grueling sessions and short high-intensity training blocks that focus on oxygen uptake, threshold, and the like. Here, you risk missing a few sessions due to muscle soreness (DOMS) — something we can sometimes reduce with cherry supplements.

In 2014, a review article was published summarizing eight studies that investigated the effects of cherries on recovery. One study was on horses and another on rats, but the remaining six were conducted on athletes (both males and women).

In the review, it is emphasized that cherries do not magically remove mechanical muscle soreness—the mechanical damage remains as long as you stress your muscles. Where cherries, and especially anthocyanins, show an effect is in the subsequent reactions leading to pain sensation. By reducing acute oxidative stress and subsequent inflammation, you recover faster. In cases of oxidative damage, several functions in the muscle, including glucose uptake, are impaired. Some oxidative damage is beneficial for adaptation, but under really tough strain, a supplement of cherries can provide a positive net effect despite some hindrance to adaptation.

Regarding inflammation, a research team in 2010 showed that the amount of inflammatory markers after a marathon was 49% lower in the group that consumed cherry juice five days before and two days after the competition.

In terms of pain, researchers already in 2004 demonstrated that the intake of cherries reduced inflammation-induced pain in rats. Several studies on humans show similar results: lower pain after intense training compared to a control group. Since pain is largely a symptom of exercise-induced inflammation, it's not surprising that muscle soreness decreases when cherries have an anti-inflammatory effect.

Following the review, an additional 3–4 studies have been published. For example, this one recently published focuses more on performance-enhancing effects rather than solely recovery. The researchers examined how a 10-day regimen with 0.5 g of cherry powder per day affects performance in a half-marathon involving 27 runners and triathletes (18 males, 9 women). To summarize, participants in the cherry group achieved a 13% faster half-marathon time compared to the placebo group. Both groups were around two hours (average 1:52), so the difference amounted to roughly 10–15 minutes—which seems almost too good to be true, yet the effect is evident, and several previous studies report similar findings. We remain somewhat skeptical, particularly since the study is not entirely free from conflicts of interest.

“This study was funded by Anderson Global Group, LLC (Irvine, CA, USA) and Shoreline Fruit, LLC (Traverse City, MI, USA) through an unrestricted research grant to Texas A&M University. All researchers involved independently collected, analyzed, and interpreted the results from this study and have no financial interests concerning the outcome of this investigation. The results from this study do not constitute endorsement by the authors and/or the institution concerning the nutrients investigated.”

The researchers also measured several physiological markers for recovery, with results confirming earlier research. 24 and 48 hours after the race, the cherry group showed 47% lower muscle inflammation and 34% less perceived pain (soreness). In summary, it is mainly in recovery where Montmorency cherries demonstrate a well-supported, physiologically proven effect.

daily intake of Anthocyanin

A good rule of thumb is to consume cherries every day as instructed for 3–5 days before and then continue after your sessions until the soreness disappears.

If we convert the juice amount to whole cherries or dried powder, 2 x 30 ml juice concentrate is roughly equivalent to 50–60 cherries (yes, you can of course eat them whole — that might be best, even though some nutrients are lost during the drying process) or about 2 g of powder per day.

Anthocyanin is likely the main active substance, but researchers point out that it's just one of several active compounds — so-called polyphenols — in cherries. Anthocyanins make up ~7% of all polyphenols in cherries and are found almost exclusively in the skin. Since the proportion is so small, we can’t say that anthocyanin alone is decisive.

Also note that the bioavailability, or absorption of anthocyanin, seems to decrease as the dose increases — the body absorbs everything up to a certain level, and then the proportional absorption drops. The review indicates that the upper daily dose should not exceed 320 mg of anthocyanin. Larger doses are not dangerous, but above that level, it’s likely just wasteful.

If we convert 320 mg of anthocyanin to grams of cherries, the performance study states that the anthocyanin content in cherry powder is about 14%. This means you need to consume about 2–2.5 g of cherry powder or roughly 100 cherries per day to reach 320 mg of anthocyanin. No study has reported negative effects regardless of form (dried, juice, or whole berries), so we suspect it’s not harmful if you happen to eat a bit extra — other than your gut might protest in the end.

As a note, we can say that daily intake of anthocyanin (at least in the USA) is 12.5 mg/day — so if you eat your cherries or currants, you're getting a decent antioxidant dose.

For the average male, the best option is still to eat the cherries as they are (sour cherries are listed by the Swedish Food Agency as regular food) – but that's a lot of cherries, and they might go bad. Then you're left with half a cherry tree in your kitchen, pondering your next move. Or the fibers in your gut become a bit too noticeable in the final days leading up to a race. A powder offers practical advantages in many ways.

• 2 grams of cherry powder/day for 5 days before the race and 3 days after the race!

If you've read our previous article on blackcurrant powder and have your cupboard at home filled, we suspect it works just as well, but it's only a strong suspicion. Backed by science, we recommend Montmorency cherry powder for improved recovery until the research expands further.