Written By: Trenton Voss, UH Dietetic Intern, Memorial Hermann Rockets Sports Medicine Institute
Edited By: Meredith Parmley, MS, RD, CSSD, LD, Memorial Hermann Rockets Sports Medicine Institute
Introduction
Athletes are constantly pushing the limits of their body. They strive to reach peak athletic performance and seek out every advantage of recovery. Among the many factors that impact athletic performance, one crucial yet often overlooked component is sleep. Insufficient sleep has been associated with impaired cognition, hindered learning and memory processes, heightened pain perception, compromised immunity, and increased inflammation [1-2]. Athletes may experience lower sleep quality and quantity during intensified training, which can have far-reaching consequences [1]. In the pursuit of better sleep and enhanced athletic performance, athletes may experiment with natural remedies, such as tart cherry juice.
Sleep
While you sleep, your body undergoes a process of physical and mental rejuvenation, while also regulating hormones responsible for growth, development, stress management, and facilitating restful sleep [3]. However, it has been revealed that approximately one-third of the general population grapples with insomnia, which is defined as difficulties in both falling asleep and staying asleep [12] [13]. Furthermore, between 4% - 26% of individuals experience excessive sleepiness throughout the day [12].
The National Sleep Foundation categorizes sleep quality into four key aspects [14] :
1. Sleep Latency, which assesses the time it takes to fall asleep (ideally less than 30 minutes).
2. Sleep Waking, measuring how often you awaken during the night (preferably no more than once per night).
3. Wakefulness, examining the duration of wakefulness after awakening in the middle of the night (preferably less than 20 minutes).
4. Sleep Efficiency, quantifying the proportion of time spent asleep while in bed; it represents the ratio of actual sleeping time to the time spent in bed (ideally greater than 85%) [15].
Total sleep duration is measured from the moment eyes close to initiate sleep. The two key terms to keep in mind are sleep onset and sleep latency. Sleep onset is the starting point of trying to sleep, whereas sleep latency is the duration of time it takes from trying to sleep (closing the eyes) to actually falling asleep [15].
To enhance athletic performance, it's advisable for adults to target 7 to 8 hours of sleep per night, while teenagers and children should aim for 7 to 9 hours [3-4]. It's worth noting that many adolescent and teenage athletes often fall short of these recommended sleep durations due to their commitments to sports, academics, and extracurricular activities.
Emphasizing both the quality and quantity of sleep is crucial, as it not only supports better muscle recovery but also leads to improved cognitive function, emotional stability, enhanced mental well-being, and a reduced risk of sports-related injuries [1] [4-5] [16].
A study conducted with adolescent teens showed the strongest predictor of injury was getting less than 8 hours of sleep, and those athletes who slept for less than 8 hours per night were at 1.7 times greater risk for injury [16].
Tart Cherry Juice
Tart cherries, often referred to as sour cherries, are aptly named due to their pronounced flavor, which differs significantly from sweet cherries. Varieties such as Richmond, Montmorency, and English morello fall into this category, and they are available in their whole fruit form, supplement, concentrate and as tart cherry juice [1][7].
Antioxidants
Montmorency cherries hold one of the highest antioxidant capacities for fruit, rich in polyphenols and anthocyanins [1] [8]. Many athletes utilize tart cherry juice for its antioxidant properties due to potential improvements in muscle recovery and soreness, however research is mixed. However, the benefits of tart cherry juice may reach beyond its impact on soreness and muscle recovery [17][21].
Melatonin & Tryptophan
Tart Cherry juice is a natural source of the hormone melatonin, which is renowned for its sleep-promoting properties [2] [9]. The melatonin in tart cherries not only facilitates faster sleep onset, but the presence of tryptophan may also assist with staying asleep through the night [10]. Tryptophan is a crucial precursor in melatonin production [18]. This study among others suggests that even low doses of tryptophan, similar to dosages found in tart cherry juice, improve sleep latency and quality [2][18].
The roots of this positive effect on sleep can be traced back to one of the most pivotal study involving 15 participants, aged 65 or older, who experienced insomnia but were otherwise healthy and not taking any sleep-inducing medications [5]. They consumed either a tart cherry juice blend or a placebo over four 2-week periods in a randomized, double-blind, crossover trial [5]. The primary outcomes measured improvements in insomnia severity and sleep continuity [5].
The researchers found that participants who consumed the tart cherry juice blend reported significant improvements in these outcomes compared to those who received the placebo, suggesting that the juice may be a beneficial natural remedy for insomnia in older adults [5].
Although the results of that study were initially limited to elder populations with insomnia, a more recent study, focusing on healthy adult populations between 18 and 40, reaffirms the broad applicability of tart cherry juice as a natural remedy for sleep improvement [6].
Who Benefits from Tart Cherry Juice
The introduction of tart cherry juice to your daily regimen as a potential sleeping aid can be for a wide range of people. If you aren’t experiencing any sleeping disturbances or issues, tart cherry juice likely is not necessary. However, if you fall into any of these categories, tart cherry juice may be an appropriate, low-risk choice for you.
1. Athletes undergoing heavy periods of training
2. The traveling athlete who has varied schedules
3. Athletes with late night games
4. Athlete’s struggling to fall asleep or experiencing insomnia
Dosage
Dosage and form may be different according to people’s preferences; however, dosage would be similar across the board as that is what is seen in the current literature. The NIH suggests that there are no safety concerns with either drinking up to 16 ounces of tart cherry juice or taking 480 mg of tart cherry extract capsules daily [11]. Depending on an athlete’s body composition goals, they may want to choose the juice without added sugar.
The literature supports 30 mL (1 ounce) of concentrate, twice daily [2][9]. You can take the concentrate neat or dilute it with 100 – 200 mL (3 -6 oz) of water. Tart cherry capsules are another option, but it's important to note that the studies confirming its effectiveness primarily utilized the concentrated form. When it comes to whole fruits, you would need to consume 30 to 60 cherries daily, which is often an impractical quantity. Therefore, opting for the supplement or concentrated form may be the more feasible approach [8].
Timing
Timing doesn’t seem to matter if you get two doses of 30 mL daily. However, studies suggest that taking 30 mL in the morning with a meal and 30 mL one hour before bed enhanced sleep quality and recovery in athletes [8].
To further corroborate that suggestion, one small study investigated the effects of low-dose melatonin (0.3 mg to 1.0 mg) administered at different evening times (6:00 pm, 8:00 pm, and 9:00 pm). Melatonin taken at 6:00 pm and 8:00 pm significantly reduced sleep latency, while there were no significant changes observed at 9:00 pm. This suggests that consuming melatonin with an earlier evening meal could potentially have positive effects on sleep[20]. These findings could hypothetically transfer over to those utilizing tart cherry juice.
Sleep Hygiene
Quality sleep patterns depend on good sleep hygiene practices. Melatonin production is naturally higher at night, and while tart cherry juice can provide melatonin and tryptophan to support this production, exposure to light can hinder one’s ability to produce melatonin [16].
The American Academy of Sleep Medicine defines sleep hygiene as a set of healthy sleep habits aimed at enhancing your ability to both fall asleep and remain asleep. These habits will likely be more impactful than tart cherry juice and should be assessed before beginning to supplement. Some tips include [19]:
1. Limiting the use of electronics and bright lights close to bedtime.
2. Maintaining a consistent bedtime and wake-up time every day.
3. Establishing a calming bedtime routine.
4. Avoiding the consumption of caffeine in the late afternoon or evening.
Limitations
While promising, many of the studies in this space have limitations, including small sample sizes, and the specific population of one of the studies had been focused on elder adults suffering from insomnia. As such, the full sleep-enhancing effects of tart cherry juice on athletes remains under investigation.
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Practical Takeaways |
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Sleep :
Dosage:
Forms and Methods:
Timing:
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Have questions? Please feel free to talk to an Athlete Training and Health Performance Coach or Meredith Parmley, MS, RD, CSSD, LD, Sports Dietitian with the Memorial Hermann Rockets Sports Medicine Institute. Meredith can be reached at Meredith.Parmley@memorialhermann.org or can be found on Instagram at @meredithdarcienutrition.
References
1. Ruirui Gao & Philip D. Chilibeck (2020): Effect of Tart Cherry Concentrate on Endurance Exercise Performance: A Meta-analysis, Journal of the American College of Nutrition, DOI: 10.1080/07315724.2020.1713246
2. Doherty, R., Madigan, S., Warrington, G., & Ellis, J. (2019). Sleep and Nutrition Interactions: Implications for Athletes. Nutrients, 11(4), 822. https://doi.org/10.3390/nu11040822
3. Suni, E., & Callendar, E. (2009, December 22). What Happens When You Sleep: The Science of Sleep | Sleep Foundation. Sleep Foundation. https://www.sleepfoundation.org/how-sleep-works/what-happens-when-you-sleep
4. Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C., Bruni, O., DonCarlos, L., Hazen, N., Herman, J., Adams Hillard, P. J., Katz, E. S., Kheirandish-Gozal, L., Neubauer, D. N., O'Donnell, A. E., Ohayon, M., Peever, J., Rawding, R., Sachdeva, R. C., Setters, B., Vitiello, M. V., & Ware, J. C. (2015). National Sleep Foundation's updated sleep duration recommendations: final report. Sleep health, 1(4), 233–243. https://doi.org/10.1016/j.sleh.2015.10.004
5. Pigeon, W. R., Carr, M., Gorman, C., & Perlis, M. L. (2010). Effects of a tart cherry juice beverage on the sleep of older adults with insomnia: a pilot study. Journal of medicinal food, 13(3), 579–583. https://doi.org/10.1089/jmf.2009.0096
6. Howatson, G., Bell, P. G., Tallent, J., Middleton, B., McHugh, M. P., & Ellis, J. (2011). Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. European journal of nutrition, 51(8), 909–916. https://doi.org/10.1007/s00394-011-0263-7
7. Suni, E., & Vyas, N. (2017, January 11). The Best Foods To Help You Sleep | Sleep Foundation. Sleep Foundation. https://www.sleepfoundation.org/nutrition/food-and-drink-promote-good-nights-sleep
8. Howatsen, G., & Jeukendrup, A. (2016, November 6). How to use tart cherry juice. Mysportscience.Com. https://www.mysportscience.com/post/how-to-use-tart-cherry-juice
9. Howatson, G. (2016, November 5). Bitter-sweet application of Montmorency cherries in recovery. Mysportscience.Com. https://www.mysportscience.com/post/2016/11/05/bitter-sweet-application-of-montmorency-cherries-in-recovery
10. Losso, J. N., Finley, J. W., Karki, N., Liu, A. G., Prudente, A., Tipton, R., Yu, Y., & Greenway, F. L. (2018). Pilot Study of the Tart Cherry Juice for the Treatment of Insomnia and Investigation of Mechanisms. American journal of therapeutics, 25(2), e194–e201. https://doi.org/10.1097/MJT.0000000000000584
11. Suni, E., & Rosen, D. (2021, September 8). Does Tart Cherry Juice Promote Better Sleep? | Sleep Foundation. Sleep Foundation. https://www.sleepfoundation.org/nutrition/tart-cherry-juice
12. Scott, A. J., Webb, T. L., Martyn-St James, M., Rowse, G., & Weich, S. (2021). Improving sleep quality leads to better mental health: A meta-analysis of randomized controlled trials. Sleep medicine reviews, 60, 101556. https://doi.org/10.1016/j.smrv.2021.101556
13. Kerkhof G. A. (2017). Epidemiology of sleep and sleep disorders in The Netherlands. Sleep medicine, 30, 229–239. https://doi.org/10.1016/j.sleep.2016.09.015
14. National Sleep Foundation. (2020). What Is Sleep Quality? National Sleep Foundation. https://www.thensf.org/what-is-sleep-quality/
15. Institute for Quality and Efficiency in Health Care (IQWiG); InformedHealth.org. (2016). What is “normal” sleep? Cologne, Germany: (IQWiG). https://www.ncbi.nlm.nih.gov/books/NBK279322/
16. Milewski, Matthew D. MD*; Skaggs, David L. MD, MMM†; Bishop, Gregory A. MS‡; Pace, J. Lee MD†; Ibrahim, David A. MD†; Wren, Tishya A.L. PhD†; Barzdukas, Audrius MEd‡. Chronic Lack of Sleep is Associated With Increased Sports Injuries in Adolescent Athletes. Journal of Pediatric Orthopaedics 34(2):p 129-133, March 2014. | DOI: 10.1097/BPO.0000000000000151
17. Brown, Meghan A., Emma J. Stevenson & Glyn Howatson (2018): Montmorency tart cherry (Prunus cerasus L.) supplementation accelerates recovery from exercise-induced muscle damage in females, European Journal of Sport Science, DOI: 10.1080/17461391.2018.1502360
18. Silber, B. Y., & Schmitt, J. A. (2010). Effects of tryptophan loading on human cognition, mood, and sleep. Neuroscience and biobehavioral reviews, 34(3), 387–407. https://doi.org/10.1016/j.neubiorev.2009.08.005