Efficacy of tart cherry juice in reducing muscle pain during running: a randomized controlled trial

Nutritional interventions for exercise-induced muscle damage: an umbrella review of systematic reviews and meta-analyses of randomized trials

CONTEXT

Several meta-analyses have been conducted on the effect of nutritional interventions on various factors related to muscle damage. However, the strength of the evidence and its clinical significance are unclear.

OBJECTIVES

This umbrella review aimed to provide an evidence-based overview of nutritional interventions for exercise-induced muscle damage (EIMD).

DATA SOURCES

PubMed, Scopus, and ISI Web of Science were systematically searched up to May 2022.

DATA EXTRACTION

Systematic reviews and meta-analyses of randomized controlled trials investigating nutritional interventions' effects on recovery following EIMD were included. The certainty of the evidence was rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

Fifty-three randomized controlled trial meta-analyses were included, evaluating 24 nutritional interventions on 10 different outcomes. The results revealed a significant effect of hydroxymethylbutyrate (HMB) supplementation and l-carnitine supplementation for reducing postexercise creatine kinase; HMB supplementation for reducing lactate dehydrogenase; branched-chain amino acids and leaf extract supplementation for reducing the delayed onset of muscle soreness; and l-carnitine, curcumin, ginseng, polyphenols, and anthocyanins for reducing muscle soreness, all with moderate certainty of evidence.

CONCLUSIONS

Supplementation with HMB, l-carnitine, branched-chain amino acids, curcumin, ginseng, leaf extract, polyphenols, and anthocyanins showed favorable effects on some EIMD-related outcomes.

PROTOCOL REGISTRATION

PROSPERO registration no. CRD42022352565.

Plasma-Induced Changes in the Metabolome Following Vistula Tart Cherry Consumption

Evidence suggests that tart cherry (TC) supplementation has beneficial effects on health indices and recovery following strenuous exercise. However, little is known about the mechanisms and how TC might modulate the human metabolome. The aim of this study was to evaluate the influence of an acute high- and low-dose of Vistula TC supplementation on the metabolomic profile in humans. In a randomised, double-blind, placebo controlled, cross-over design, 12 healthy participants (nine male and three female; mean ± SD age, stature, and mass were 29 ± 7 years old, 1.75 ± 0.1 m, and 77.3 ± 10.5 kg, respectively) visited the laboratory on three separate occasions (high dose; HI, low dose; LO, or placebo), separated by at least seven days. After an overnight fast, a baseline venous blood sample was taken, followed by consumption of a standardised breakfast and dose conditions (HI, LO, or placebo). Subsequent blood draws were taken 1, 2, 3, 5, and 8 h post consumption. Following sample preparation, an untargeted metabolomics approach was adopted, and the extracts analysed by LCMS/MS. When all time points were collated, a principal component analysis showed a significant difference between the conditions (p < 0.05), such that the placebo trial had homogeneity, and HI showed greater heterogeneity. In a sub-group analysis, cyanidine-3-O-glucoside (C3G), cyanidine-3-O-rutinoside (C3R), and vanillic acid (VA) were detected in plasma and showed significant differences (p < 0.05) following acute consumption of Vistula TC, compared to the placebo group. These results provide evidence that phenolics are bioavailable in plasma and induce shifts in the metabolome following acute Vistula TC consumption. These data could be used to inform future intervention studies where changes in physiological outcomes could be influenced by metabolomic shifts following acute supplementation.

Effects of a Tart Cherry Supplement on Recovery from Exhaustive Exercise

The aim of this study was to investigate the effects of a tart cherry supplement on recovery from exercise-induced muscle damage. Seventeen recreationally active women (mean age ± SD = 22.2 ± 3.3 years, height = 162.0 ± 6.0 cm, body mass = 65.1 ± 11.1 kg, BMI = 24.7 ± 3.5 kg·m2) supplemented with 1000 mg of concentrated tart cherry or a placebo for eight consecutive days. An overload protocol of 8 sets of 10 repetitions of maximal effort concentric and eccentric muscle actions of the leg extensors at a velocity of 60°·s-1 was performed on the fourth day of supplementation. Testing sessions consisted of a muscle function test (MFT) to examine pre- and post-testing peak torque, peak power, total work, time-to-peak torque, mean power, muscle activation of the quadriceps, and muscle soreness at baseline and post-testing at 0 h, 24 h, 48 h, and 72 h. A second trial of testing was repeated two weeks later using the opposite supplement to the one assigned for the first trial. No significant interaction for time × condition × velocity (p = 0.916) and no significant main effect for condition (p = 0.557) were demonstrated for peak torque. However, there were main effects for time and velocity for concentric quadriceps peak torque (p < 0.001). For muscle soreness, there was no two-way interaction for time x condition (p > 0.05) and no main effect for condition (p > 0.05), but there was a main effect for time (p < 0.001). In conclusion, a tart cherry supplement did not attenuate losses in isokinetic muscle peak torque, peak power, total work, time-to-peak torque, muscle soreness, or quadriceps muscle activation.

Pure Juice Supplementation: Its Effect on Muscle Recovery and Sports Performance

Strenuous exercise causes increased production of reactive oxygen species (ROS), creating an imbalance between ROS and antioxidants. The reduced antioxidant defence leads to defective elimination of ROS and consequently, delayed-onset muscle soreness (DOMS). DOMS due to exhaustive or prolonged exercise typically peaks between 24 h and 72 h after exercise results in soreness, inflammation, pain and decreased muscle function. As a result, muscle strength will be reduced progressively and this situation might be detrimental to one's athletic performance, especially amidst competition season. Therefore, supplementation to improve muscle recovery and sports performance has become a common practice among athletes. However, it is suggested to consume natural-based fruit-derived antioxidants as a more effective and safe nutritional strategy. Fruits containing a high amount of polyphenol protect muscle cells from excessive and harmful ROS due to their anti-inflammatory and antioxidant characteristics. To date, there are several expended studies on the consumption of supplements from various antioxidant-rich fruits to provide evidence on their effectiveness, giving better solutions and wider choices of supplementation to the athletes. Therefore, this review aims to provide a comprehensive overview of nutritional standpoint from previous literature on the effect of fruit juices supplementation on muscle recovery and sports performance.

The effect of dietary anthocyanins on biochemical, physiological, and subjective exercise recovery: a systematic review and meta-analysis

Anthocyanins (ACN), the sub-class of (poly)phenols responsible for the red-blue-purple pigmentation of fruit and vegetables, have gained considerable interest in sport and exercise research due to their potential to facilitate exercise recovery. A systematic literature search was performed using PubMed, The Cochrane Library, MEDLINE, SPORTDiscus and CINAHL. Thirty nine studies were included and the standardized mean difference (Hedges g) for creatine kinase (CK), anti-oxidative and inflammatory markers, strength, power and delayed onset muscle soreness (DOMS) indices were pooled in separate meta-analyses; meta-regression was also performed on reported ACN dose. Immediately post-exercise there was an increase in antioxidant capacity (g: 0.56) and reduced C reactive protein (g: -0.24) and tumor necrosis factor α (g: -40); p ≤ 0.02. Strength was improved with ACN at all time points (g: 0.45-0.67). DOMS (g: -0.23) was lower 24 hours post-exercise and power was improved 24 hours (g: 0.62) and 48 hours (g: 0.57) post exercise. The CK was lower 48 hours post-exercise (g: -0.31) and there was a trend for a positive association with ACN dose (p = 0.057). This systematic review provides new data showing ACN-rich foods promote functional and subjective recovery likely due to the antioxidant and anti-inflammatory properties of ACN.

CHERRY EXTRACT ON POST-EXERCISE MUSCLE DAMAGE

ABSTRACT Introduction: Cherry extract has a high amount of anthocyanins and flavonoids containing antioxidant effects. Its high antioxidant characteristics have been shown to reduce markers of delayed muscle soreness (DOMS) and exercise-induced muscle damage (EIMD) to improve recovery after exercise. Objective: Verify the effects of the cherry extract on post-exercise muscle damage. Methods: Google scholar, Medline, and Scopus were systematically searched until February 2022. The Cochrane Collaboration tool was applied to determine the risks of bias. Results: The results showed that cherry extract administration did not have a decreasing impact on creatine kinase levels overall: (WMD = 12.85 IU. L-1, 95% CI: −35.94, 61.64; P = 0.606). Considerable heterogeneity was observed among the articles (Cochran's Q-test = 990.80, P = 0.000, I2 = 96.7 %). However, there is a significant reducing effect on pain sensation by the consumption of cherry extract (WMD = −6.105 mm; 95% CI: −11.193 −1.017; p = 0.019). Conclusion: Cherry extract consumption effectively reduced late-onset muscle pain among participants in the overall and subgroup analysis. Thus, the cherry extract may be a complementary alternative in recovery after exercise. Level of evidence II; Therapeutic studies - Manuscript review.

Comprehensive effects of various nutrients on sleep

Sleep problems have become common among people today. Sleep disorders are closely associated with physiological and psychological diseases. Among the ways of improving objective or subjective sleep quality, controlling elements associated with food intake can be more efficient than other methods in terms of time and cost. Therefore, the purpose of this study was to understand the effects of nutrients and natural products on sleep. An extensive literature search was conducted, and related articles were identified through online databases, such as Elsevier, Google Scholar, PubMed, Springer, and Web of Science. Expert opinion, conference abstracts, unpublished studies, and studies published in languages other than English were excluded from this review. The effects of macronutrients and diet adjustment on sleep differed. Although not all nutrients independently affect sleep, they comprehensively affect it through tryptophan metabolism. Furthermore, natural foods related to GABA have an effect on sleep similar to that of sleeping pills. Taken together, our results suggest that humans can control both their objective and subjective sleep quality based on their lifestyle and food consumption. However, until now, direct studies on the relationship between human sleep and nutrition, such as clinical trials, have been insufficient. As both objective and subjective sleep quality are the factors determining the quality of life of individuals, further studies on those are needed to improve it.

Effects of Short-Term Intake of Montmorency Tart Cherry Juice on Sleep Quality after Intermittent Exercise in Elite Female Field Hockey Players: A Randomized Controlled Trial

The purpose of this study was to investigate the effect of short-term consumption of tart cherry juice on levels of cortisol and melatonin and sleep quality after intermittent exhaustion exercise in female elite field hockey players. A total of 19 field hockey players participated in the present study for 5 days. The individuals were divided into the placebo group (PLA, n = 9) and the tart cherry juice group (TCJ, n = 10), respectively. Actigraphy devices were distributed to analyze sleep quality and participants were required to wear the device while sleeping until the study was completed. Participants consumed tart cherry juice or placebo drinks five times in a total of 48 h while double-blinded after intermittent exhaustion exercise. A significant interaction effect (group × time) between PLA and TCJ groups was not observed in the levels of melatonin and cortisol. The variables of sleep quality showed significant interaction effects with regards to the total time in bed (TTB; p = 0.015), wake after sleep onset (WASO; p = 0.044), and movement index (MI; p = 0.031) variables. As a result, our study confirmed the possibility that the short-term intake of tart cherry juice could not change the levels of melatonin and cortisol in elite female hockey players but could help improve their sleep quality.

The beneficial effect of tart cherry on plasma levels of inflammatory mediators (not recovery after exercise): A systematic review and meta-analysis on randomized clinical trials

BACKGROUND

Chronic inflammation has been classified as one of the most important threats to health. Scientists suggested that tart cherry (TC) can reduce plasma levels of inflammatory mediators. Therefore, the aim of this study was to summarize the effect of TC on circulating C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among adult participants in non-exercise randomized clinical trials (RCTs).

METHODS AND MATERIALS

The eligible English-language RCTs were found by searching databases including PubMed, Web of Science, Cochrane Library, Scopus, and clinical Trials.gov up to May 2022, with no time limit. We used the mean change from baseline and its standard deviation for both intervention and comparison groups to calculate the effect size. The random-effects model proposed by DerSimonian and Laird was used to estimate the overall summary effect and the heterogeneity. We used PRISMA 2020 guidelines to report this study.

RESULTS

Ten RCTs were included in this study. The results demonstrated that TC had a significant decreasing effect on plasma CRP level compared with the comparison group (weighted mean differences (WMD) = -0.55 mg/L; 95% confidence interval (CI): - 1.03, - 0.06; p = 0.029), but had no significant effect on plasma IL-6 compared with comparison group (WMD = 0.08 pg/mL; 95% CI: -0.02, 0.17; p = 0.10). The effect of TC consumption on plasma TNF-α level was evaluated in only three studies that showed no significant effects (p>0.05).

CONCLUSION

Our results confirmed a significant decreasing effect of TC on CRP. Regarding IL-6 and TNF-α, our study did not present any significant effect of TC.

Montmorency Cherry Juice Consumption does not Improve Muscle Soreness or Inhibit Pro-inflammatory Monocyte Responses Following an Acute Bout of Whole-body Resistance Training

Montmorency Cherry Juice (MCJ) may improve acute exercise recovery by attenuating inflammation and oxidative stress. However, the anti-inflammatory effects of MCJ on monocyte responses following resistance exercise have not been explored. Seven resistance-trained males (age: 22.9 ± 4.1 yrs; height: 1.8 ± 0.1 m; weight: 81.7 ± 13.2 kg) participated in this study. Participants completed a placebo-controlled crossover design, drinking either MCJ or placebo beverages, 7 days prior to completing an acute bout of unilateral resistance exercise. Statistical significance was assessed using a withinsubjects repeated measures ANOVA; alpha level p ≤ 0.05. Main effects for time were observed for changes in classical and intermediate monocytes (p ≤ 0.05), but no significant treatment effects were observed for monocyte subtypes p > 0.05. Classical monocytes (CD14⁺ CD16^-) increased and peaked 24 hr post-exercise (placebo 1.14 ± 0.04 and MCJ 1.06 ± 0.06-fold). Intermediate monocytes peaked 48 hr post-exercise increasing 1.82 ± 0.41 and 2.01 ± 0.80- fold. Nonclassical monocytes peaked post-exercise (placebo 1.17 ± 0.31 and MCJ 1.02 ± 0.20-fold). Peak pain visual analog scale (VAS) occurred post-exercise for MCJ (3.63 ± 2.01-fold) and 72 hr post-exercise for placebo (4.26 ± 3.46- fold). IL-6 and pressure pain threshold (PPT) peaked 24 hr post-exercise (IL-6 placebo 3.83 ± 1.01- and MCJ 6.43 ± 3.43-fold) and (PPT placebo 86.37 ± 3.95% and MCJ 82.81 ± 2.90% of pressure needed at pre-exercise). Our data suggests MCJ consumption does not decrease muscle soreness, IL-6, or monocyte subset responses following a high-intensity resistance exercise protocol in resistance-trained males.

Effects of Functional Phenolics Dietary Supplementation on Athletes' Performance and Recovery: A Review

In recent years, many efforts have been made to identify micronutrients or nutritional strategies capable of preventing, or at least, attenuating, exercise-induced muscle damage and oxidative stress, and improving athlete performance. The reason is that most exercises induce various changes in mitochondria and cellular cytosol that lead to the generation of reactive species and free radicals whose accumulation can be harmful to human health. Among them, supplementation with phenolic compounds seems to be a promising approach since their chemical structure, composed of catechol, pyrogallol, and methoxy groups, gives them remarkable health-promoting properties, such as the ability to suppress inflammatory processes, counteract oxidative damage, boost the immune system, and thus, reduce muscle soreness and accelerate recovery. Phenolic compounds have also already been shown to be effective in improving temporal performance and reducing psychological stress and fatigue. Therefore, the aim of this review is to summarize and discuss the current knowledge on the effects of dietary phenolics on physical performance and recovery in athletes and sports practitioners. Overall, the reports show that phenolics exert important benefits on exercise-induced muscle damage as well as play a biological/physiological role in improving physical performance.

"Precovery" Versus Recovery: Understanding the role of cherry juice in exercise recovery

Cherry juice has become a standard component of athlete recovery strategies. This review covers the history of cherry juice as a recovery drink to give context to its current use. Fifteen studies were identified that included a measure of muscle function, soreness, or inflammation on the days following exercise and had an exercise insult sufficient to assess the effectiveness of the tart cherry intervention. Eight studies used a concentrated juice, three used a juice from fresh‐frozen cherries, two used a tart cherry concentrate gel, and two used a tart cherry powder. The effective juice dose was specific to the type of drink (fresh‐frozen versus concentrate) but dose‐response studies are lacking, and thus, the optimal dose for any specific type of cherry juice is not known. Timing of the dosing regimen is a critical factor. Studies have uniformly shown that muscle function will recover faster on the days after exercise if juice is provided for several days prior to exercise. Effects on soreness or systemic inflammation are more equivocal. The available evidence does not support a regimen that begins on the day of exercise or post‐exercise. Tart cherry powder did not enhance any metric of recovery on the days after exercise. In conclusion, the term recovery implies an intervention that is introduced after an exercise insult. The term “precovery” may be preferable to describe interventions that should be introduced on the days prior to exercise to facilitate recovery on the days after exercise. The evidence supports cherry juice as a precovery intervention across a range of athletic activities.

Effect of Polyphenol-Rich Foods, Juices, and Concentrates on Recovery from Exercise Induced Muscle Damage: A Systematic Review and Meta-Analysis

Objectives. To determine the effects of consuming polyphenol-rich foods, juices and concentrates on recovery from exercise-induced muscle damage (EIMD). Method. Eligibility criteria. Randomised and quasi-randomised placebo-controlled trials with a parallel or cross-over design evaluating the effects of consuming polyphenol-rich foods, juices and concentrates on recovery from EIMD in humans. Eligible studies included at least one of the primary outcome measures: maximal isometric voluntary contraction; MIVC, delayed onset muscle soreness; DOMS, or countermovement jump; CMJ. Information sources. AMED, Cochrane Central Register of Controlled Trials, International Clinical Trials Registry Platform, PUBMED, SCOPUS (Elsevier), SPORTDiscus (EBSCO), and the UK Clinical Trials Gateway were searched from inception to September 2020. Risk of bias and quality of evidence. Risk of bias was assessed using Cochrane Risk of Bias 2 tool. Quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation framework. Synthesis of results. Random effects models were used to determine the effect of polyphenol supplementation on recovery from EIMD. Data are presented as standardised mean differences (SMD) with 95% confidence intervals (CI). Results. Included studies. Twenty-five studies were included; 15 had a parallel, and 10 had a cross-over design. A total of 527 participants (male: n = 425; female: n = 102) were included in the meta-analysis. Synthesis of results. Consumption of polyphenol-rich foods, juices and concentrates accelerated recovery of MIVC immediately post-exercise (SMD = 0.23, 95% CI 0.04, 0.42; p = 0.02; low-quality evidence), 24 h (SMD = 0.39, 95% CI 0.15, 0.62; p = 0.001; low-quality evidence), 48 h (SMD = 0.48, 95% CI 0.28, 0.67; p < 0.001; moderate-quality evidence), 72 h (SMD = 0.29, 95% CI 0.11, 0.46; p = 0.001; low-quality evidence) and 96 h post-exercise (SMD = 0.50, 95% CI 0.16, 0.83; p = 0.004; very low-quality evidence). DOMS was reduced at 24 h (SMD = −0.29, 95% CI −0.47, −0.11; p = 0.002; low-quality evidence), 48 h (SMD = −0.28, 95% CI −0.46, −0.09; p = 0.003; low-quality evidence) and 72 h post-exercise (SMD = −0.46, 95% CI −0.69, −0.24; p < 0.001; very low-quality evidence). CMJ height was greater immediately post-exercise (SMD = 0.27, 95% CI 0.01, 0.53; p = 0.04; low-quality evidence), at 24 h (SMD = 0.47, 95% CI 0.11, 0.83; p = 0.01; very low-quality evidence), 48 h (SMD = 0.58, 95% CI 0.24, 0.91; p < 0.001; very low-quality evidence) and 72 h post-exercise (SMD = 0.57, 95% CI 0.03, 1.10; p = 0.04; very low-quality evidence). Polyphenol supplementation did not alter creatine kinase, c-reactive protein, and interleukin−6 at any time points. At 72 h post-exercise, protein carbonyls (SMD = −0.64, 95% CI −1.14, −0.14; p = 0.01) were reduced. Discussion. Limitations of evidence. Risk of bias was high for 10 studies and moderate for 15. Sensitivity analyses excluding the high risk of bias studies reduced the SMDs for MIVC and DOMS, and for CMJ effects at 24 and 48 h were no longer statistically significant. Interpretation. Consuming polyphenol-rich foods, juices and concentrates accelerated recovery of muscle function while reducing muscle soreness in humans. Maximal benefit occurred 48–72 h post-exercise, however, the certainty of the evidence was moderate to very low. Supplementation could be useful when there is limited time between competitive events and impaired recovery could negatively impact performance.

Effect of Tart Cherry on Aromatase Inhibitor-Induced Arthralgia (AIA) in Nonmetastatic Hormone-Positive Breast Cancer Patients: A Randomized Double-Blind Placebo-Controlled Trial

BACKGROUND

Aromatase Inhibitor induced Arthralgia (AIA) can cause noncompliance leading to decreased breast-cancer survival. Effective interventions for AIA are limited. Tart cherry (TC) showed beneficial effect on musculoskeletal pain. 48 patients (Pts) randomized to TC versus placebo over 6 weeks, TC (23pts) had 34.7% mean pain decrease versus 1.4% in Placebo (25pts). TC can improve AIA in nonmetastatic breast-cancer patients.

METHODS

Randomized, placebo-controlled, double-blind trial. Eligible patients with NMHPBC on AI for at least 4 weeks were randomized to TC concentrate [50 tart cherries] vs. placebo (P) [syrup] in 1:1 model. Patients instructed to consume 1 Oz of concentrate in 8 Oz water daily for 6 weeks, and document their pain intensity at baseline, weekly and at study completion in a diary using Visual Analog Scale (VAS), with 0 mm indicating no pain, and 100 mm indicating highest pain.

RESULTS

Sixty patients were enrolled. Two patients did not complete the study due to diarrhea, and 10 patients were noncompliant. Forty-eight patients were included in the final analysis. TC group (23 pts) had 34.7% mean decrease in pain compared to 1.4% in P group (25 pts). This difference was statistically significant (Mann-Whitney U Test, P = .034).

CONCLUSIONS

Tart cherry can significantly improve AIA in nonmetastatic breast cancer patient.

Broad Spectrum Polyphenol Supplementation from Tart Cherry Extract on Markers of Recovery from Intense Resistance Exercise

BACKGROUND

Tart cherry supplementation has been shown to enhance recovery from strenuous exercise due to its antioxidant properties. The majority of these studies used tart cherry juice, with a significant calorie content. The primary purpose of this study was to assess whether powdered tart cherry extract with minimal calorie content reduces oxidative stress and enhances recovery following intense resistance exercise.

METHODS

Thirteen men (mean age: 26.2 ± 5.3 years; height: 184.3 ± 8.2 cm; weight: 92.9 ± 15.6 kg) performed a demanding resistance exercise protocol consisting of 6 sets of 10 repetitions of barbell back squat with 80% 1RM. The protocol was performed once following 7 days of 500 mg of tart cherry extract and once following placebo. Serum protein carbonyl (PC) content, creatine kinase activity (CK) and creatine kinase myocardial band content (CK-MB) were used to assess oxidative stress, skeletal and cardiac muscle damage respectively. Muscle soreness was assessed by visual analog scale. Physical performance was measured by countermovement jump power and handgrip dynamometer strength.

RESULTS

There was a significant increase in PC in the placebo (PL) condition when compared to the Tart Cherry (TC) condition at Immediate Post (IP) (PL: 0.4 ± 0.3 vs. TC: - 0.4 ± 0.2 nmol∙mg^- 1; p < 0.001), 1 h (PL: 0.3 ± 0.3 vs. TC: - 0.7 ± 0.3 nmol∙mg^- 1; p < 0.001) and 24 h (PL: 0.1 ± 0.4 vs. TC: - 0.3 ± 0.5 nmol∙mg^- 1; p = 0.010). There was a significant increase in CK activity in PL when compared to the TC at IP (PL: 491.1 ± 280 vs. TC: 296.3 ± 178 U∙L^- 1; p = 0.008) and 3 h (PL: - 87 ± 123 vs. TC: 43.1 ± 105.3 U∙L^- 1; p = 0.006). There was a significant (p = 0.003) increase in CKMB concentration in PL when compared to the TC (PL: 21.6 ± 12.4 vs. TC: - 0.3 ± 11.8 ng∙ml^- 1; p = 0.006) at 1 h post. There was a significant increase in handgrip strength in TC when compared to PL (PL: - 2 ± 5.1 vs. TC: 1.7 ± 3 kg; p = 0.017) at 24 h post.

CONCLUSIONS

This study demonstrated that tart cherry extract reduced oxidative stress and markers of muscle and cardiac damage following intense resistance exercise. This occurred along with a prevention of the decrease in handgrip strength seen following the intense exercise protocol, indicating a potential reduction in central fatigue. These benefits were seen with minimal energy intake.

Natural Antioxidant Application on Fat Accumulation: Preclinical Evidence

Obesity represents one of the most important challenges in the contemporary world that must be overcome. Different pathological consequences of these physical conditions have been studied for more than 30 years. The most nagging effects were found early in the cardiovascular system. However, later, its negative impact was also investigated in several other organs. Damage at cellular structures due to overexpression of reactive oxygen species together with mechanisms that cause under-production of antioxidants leads to the development of obesity-related complications. In this view, the negative results of oxidant molecules due to obesity were studied in various districts of the body. In the last ten years, scientific literature has reported reasonable evidence regarding natural and synthetic compounds' supplementation, which showed benefits in reducing oxidative stress and inflammatory processes in animal models of obesity. This article attempts to clarify the role of oxidative stress due to obesity and the opposing role of antioxidants to counter it, reported in preclinical studies. This analysis aims to clear-up different mechanisms that lead to the build-up of pro-oxidants during obesity and how various molecules of different origins hinder this phenomenon, behaving as antioxidants.

Tart cherry and pomegranate supplementations enhance recovery from exercise-induced muscle damage: a systematic review

Phenolic compounds have antioxidant and anti-inflammatory properties and may prevent inflammation and oxidative stress as well as help the athletes to recover from exercise-induced muscle damage (EIMD). Tart cherry (TC) and pomegranate (PG) are two fruits with high content of polyphenols. Their antioxidant and anti-inflammatory properties have recently attracted substantial interest for their potential to reduce strength loss and promote recovery from EIMD. The aims of this review are (1) to summarise the effects of tart cherry and pomegranate supplementation on oxidative stress, inflammation and recovery, and (2) to outline the differences found in supplementation with tart cherries or pomegranates. SPORTDiscus, PubMed, Web of Science and Scopus were searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis and 25 studies were included. The existing evidence suggests that both types of supplementation are good strategies to accelerate recovery of functional performance variables, perceptual variables and inflammation but PG supplementation shows better recovery of oxidative stress. However, positive effects are more likely: 1) when supplementation starts some days before muscle damage is induced and finishes some days after, for a total period of at least 8/10 days, 2) with pronounced muscle damage of the muscles involved, and 3) when total phenolic content is at least 1000 mg/day. This review may help to optimise TC or PG supplementation practice to improve post-exercise recovery.

Review of Analytical Methods and Reporting of the Polyphenol Content of Tart Cherry Supplements in Human Supplementation Studies Investigating Health and Exercise Performance Effects: Recommendations for Good Practice

Tart cherries (TC) are a rich source of polyphenols that elicit antioxidant and anti-inflammatory effects. As a consequence, the effects of TC derived supplements on markers of human health, exercise performance and sleep have been investigated. Supplementation protocols have been highly variable across studies and the dose of bioactive compounds used has often been poorly characterized. Specific and non-specific analytical methods were employed for measuring the total polyphenol and anthocyanin content in TC supplements. This review critically analyses the supplementation protocols and the analytical methods used for the characterization of TC supplements, culminating in recommendations for good practice in the analysis and reporting of the polyphenol content and profile of TC products. A literature search was conducted using PubMed/Medline and Web of Science up to May 4th, 2020, including studies published in all years prior. Only articles written in English that provided a TC dietary supplement as opposed to fresh whole TC were included in this review. Forty-three studies were identified as eligible and included for analysis in this review. The studies investigated the effects of TC supplementation on various aspects of human health, exercise recovery and performance and sleep. Twenty studies conducted an analysis of TC supplement and reported total polyphenol/anthocyanin content. Six studies did not report the polyphenol content of the TC supplement used. Seventeen studies reported the TC supplement polyphenol content but this was derived from previously published studies and presumably different supplement batches. The duration of the supplementation protocol ranged from acute supplementation to 84 days, meanwhile the total polyphenol and anthocyanin dose ranged from 143 to 2,140 mg/day and 15 to 547 mg/day, respectively. Due to the variety of specific and non-specific analytical methods used, the relative efficacy of different doses and polyphenol blends cannot reliably be extrapolated from critical analysis of the literature. Future studies should conduct an analysis of the study supplement batch. In addition to analysis and reporting of total polyphenol content, specific analytical methods such as HPLC UV/MS should be used to quantify total and individual anthocyanin contents.

Tart Cherry Supplementation and Recovery From Strenuous Exercise: A Systematic Review and Meta-Analysis

The aim of this study was to determine the efficacy of tart cherry (TC) supplementation on recovery following strenuous exercise. A systematic review and meta-analysis were conducted using studies investigating TC supplementation on measures of muscle soreness, muscular strength, muscular power, creatine kinase, C-reactive protein, Interleukin-6, and tumor necrosis factor alpha. A literature search ending in July 2020 was conducted in three databases (SPORTDiscus, Web of Science, and PubMed). Data from 14 studies were extracted and pooled for analysis. Tart cherry supplementation had a small beneficial effect in reducing muscle soreness (effect size [ES] = -0.44, 95% confidence interval [CI] [-0.87, -0.02]). A moderate beneficial effect was observed for recovery of muscular strength (ES = -0.78, 95% CI [-1.11, -0.46]). A moderate effect was observed for muscular power (ES = -0.53, 95% CI [-0.77, -0.29]); a further subgroup analysis on this variable indicated a large effect of TC supplementation on recovery of jump height (ES = -0.82, 95% CI [-1.18, -0.45]) and a small significant effect of supplementation on sprint time (ES = -0.32, 95% CI [-0.60, -0.04]). A small effect was observed for both C-reactive protein (ES = -0.46, 95% CI [-0.93, -0.00]) and Interleukin-6 (ES = -0.35, 95% CI [-0.68, -0.02]. No significant effects were observed for creatine kinase and tumor necrosis factor alpha. These results indicate that the consumption of a TC supplement can aid aspects of recovery from strenuous exercise.

Use, Practices and Attitudes of Sports Nutrition and Strength and Conditioning Practitioners towards Tart Cherry Supplementation

Tart cherry (TC) supplementation has been shown to accelerate post-exercise recovery, enhance endurance performance and improve sleep duration and quality. This study aimed to identify the use, practices and attitudes of sports nutrition and strength and conditioning practitioners towards tart cherry supplementation. Thirty-five practitioners anonymously completed an online survey investigating their use, practices and attitudes towards tart cherry supplements. Forty-six percent of the responders were currently recommending TC supplements, 11% had previously recommended TC supplements and 26% have not previously recommended TC supplements but were planning on doing so in the future. Of those recommending TC, 50% recommended or were planning on recommending TC supplements to enhance exercise recovery and 26% to improve sleep duration and quality. Acute supplementation and daily use during multi-day competition or demanding training blocks with a 2–3-day pre-load were the most reported supplementation recommendations (28% and 18%, respectively). Fifty-two percent of responders indicated uncertainty about the daily polyphenol dose to recommend as part of a TC supplementation protocol. Despite the high use and interest from sports nutrition and strength and conditioning practitioners in TC supplements, their practices did not align with the protocols found to be effective within the literature.

Ergogenic potential of foods for performance and recovery: a new alternative in sports supplementation? A systematic review

In recent years, there have been studies in the literature reporting the ergogenic effect of some different foods on sports performance. Given the reasonable number of studies in which some food has shown improvement in some physiological variables related to physical performance, a review is pertinent in order to produce a compilation of these studies, providing new elements for athletes and coaches which aim to optimize their performance. Thus, the objective of this work was to present a systematic review of the findings regarding the potential ergogenic effect of food for athletes. Researchers performed a double-blind research in Medline/PubMed considering articles published until January 2019 which resulted in 71 articles. Increased time until exhaustion, improved aerobic capacity and strength recovery were the most commonly reported physical effects. In general, food showed equal or superior ergogenic activity over supplements. Although the number of foods investigated is reasonable, there is still no body of evidence for each studied food, except beets. The current data support the possibility of certain foods being able to enhance athletic performance, as well as serving as an energy source. However, a larger volume of studies is needed to form a body of evidence on each of these foods.

Dietary Interventions in the Management of Fibromyalgia: A Systematic Review and Best-Evidence Synthesis

Fibromyalgia syndrome (FMS) is characterised by chronic widespread pain alongside fatigue, poor sleep quality and numerous comorbidities. It is estimated to have a worldwide prevalence of 1.78%, with a predominance in females. Treatment interventions for fibromyalgia have limited success, leading to many patients seeking alternative forms of treatment, including modifications to their diet and lifestyle. The effectiveness of dietary changes in fibromyalgia has not been widely researched or evaluated. This systematic review identified twenty-two studies, including 18 randomised control trials (RCTs) and four cohort studies which were eligible for inclusion. In total these studies investigated 17 different nutritional interventions. Significant improvements in reported pain were observed for those following a vegan diet, as well as with the low fermentable oligo di-mono-saccharides and polyols (FODMAP) diets. Supplementation with Chlorella green algae, coenzyme Q10, acetyl-l-carnitine or a combination of vitamin C and E significantly improved measures of pain. Interpretation of these studies was limited due to the frequent poor quality of the study design, the wide heterogeneity between studies, the small sample size and a high degree of bias. Therefore, there is insufficient evidence to recommend any one particular nutritional intervention for the management of fibromyalgia and further research is needed.

Nutritional interventions for reducing the signs and symptoms of exercise-induced muscle damage and accelerate recovery in athletes: current knowledge, practical application and future perspectives

PURPOSE

This review provides an overview of the current knowledge of the nutritional strategies to treat the signs and symptoms related to EIMD. These strategies have been organized into the following sections based upon the quality and quantity of the scientific support available: (1) interventions with a good level of evidence; (2) interventions with some evidence and require more research; and (3) potential nutritional interventions with little to-no-evidence to support efficacy.

METHOD

Pubmed, EMBASE, Scopus and Web of Science were used. The search terms 'EIMD' and 'exercise-induced muscle damage' were individually concatenated with 'supplementation', 'athletes', 'recovery', 'adaptation', 'nutritional strategies', hormesis'.

RESULT

Supplementation with tart cherries, beetroot, pomegranate, creatine monohydrate and vitamin D appear to provide a prophylactic effect in reducing EIMD. β-hydroxy β-methylbutyrate, and the ingestion of protein, BCAA and milk could represent promising strategies to manage EIMD. Other nutritional interventions were identified but offered limited effect in the treatment of EIMD; however, inconsistencies in the dose and frequency of interventions might account for the lack of consensus regarding their efficacy.

CONCLUSION

There are clearly varying levels of evidence and practitioners should be mindful to refer to this evidence-base when prescribing to clients and athletes. One concern is the potential for these interventions to interfere with the exercise-recovery-adaptation continuum. Whilst there is no evidence that these interventions will blunt adaptation, it seems pragmatic to use a periodised approach to administering these strategies until data are in place to provide and evidence base on any interference effect on adaptation.

Fruit-Derived Polyphenol Supplementation for Athlete Recovery and Performance

Polyphenols are characterised structurally by two or more hydroxyl groups attached to one or more benzene rings, and provide the taste and colour characteristics of fruits and vegetables. They are radical scavengers and metal chelators, but due to their low concentration in biological fluids in vivo their antioxidant properties seem to be related to enhanced endogenous antioxidant capacity induced via signalling through the Nrf2 pathway. Polyphenols also seem to possess anti-inflammatory properties and have been shown to enhance vascular function via nitric oxide-mediated mechanisms. As a consequence, there is a rationale for supplementation with fruit-derived polyphenols both to enhance exercise performance, since excess reactive oxygen species generation has been implicated in fatigue development, and to enhance recovery from muscle damage induced by intensive exercise due to the involvement of inflammation and oxidative damage within muscle. Current evidence would suggest that acute supplementation with ~ 300 mg polyphenols 1–2 h prior to exercise may enhance exercise capacity and/or performance during endurance and repeated sprint exercise via antioxidant and vascular mechanisms. However, only a small number of studies have been performed to date, some with methodological limitations, and more research is needed to confirm these findings. A larger body of evidence suggests that supplementation with > 1000 mg polyphenols per day for 3 or more days prior to and following exercise will enhance recovery following muscle damage via antioxidant and anti-inflammatory mechanisms. The many remaining unanswered questions within the field of polyphenol research and exercise performance and recovery are highlighted within this review article.

Cherry intake as a dietary strategy in sport and diseases: a review of clinical applicability and mechanisms of action

Cherries are fruits rich in phytochemical compounds, particularly anthocyanins. Thus, consumption of cherries has gained attention in both clinical and sport-related fields for their antioxidant and anti-inflammatory properties. Mechanistically, anthocyanins from the intake of cherries may help to attenuate pain and decrease blood concentrations of biomarkers linked to skeletal muscle degradation, which in turn may provide ergogenic effects. In addition, the ability of anthocyanins to balance the redox state represents a conceivable target for rheumatic disorders (e.g. gout and arthritis). Moreover, cherry anthocyanins are emerging as a potential non-pharmacological remedy for cardiometabolic diseases (hypertension and dyslipidemia). Herein, we summarize the effects of cherry intake in sport and diseases, and discuss their purported mechanisms of action to provide insights into practical application.

The Efficacy of Tart Cherry Juice in Aiding Recovery After Intermittent Exercise

PURPOSE

To investigate the effects of supplementation with tart cherry juice (TCJ) on markers of recovery after intermittent exercise under habitual dietary conditions.

METHODS

Using a randomized, single-blind, placebo (PLA)-controlled, independent-groups design, 20 team-sport players (8 male and 12 female; age 26 [4] y, height 175.4 [9.6] cm, body mass 70.2 [12.6] kg) were divided equally into 2 groups and consumed either TCJ or PLA twice per day for 8 consecutive days while following their normal dietary habits. Participants completed an adapted version of the Loughborough Intermittent Shuttle Test (LIST) on day 6 of supplementation. Countermovement jump, 20-m sprint, maximal voluntary isometric contraction, and delayed onset muscle soreness were assessed at baseline and 1, 24, and 48 hours post-LIST. Blood markers of muscle damage (creatine kinase) and inflammation (C-reactive protein) were taken presupplementation, immediately pre-LIST, and 1, 24, and 48 hours post-LIST. Data were analyzed using a repeated-measures analysis of variance.

RESULTS

Countermovement jump, 20-m sprint, and maximal voluntary isometric contraction showed significantly faster recovery with TCJ (P < .05) at 24 and 48 hours post-LIST. A significant interaction effect (P < .05) was observed for muscle soreness; however, Bonferroni post hoc analysis could not identify when the significant differences between TCJ and PLA occurred. There were no significant differences throughout recovery between TCJ and PLA for C-reactive protein and creatine kinase (P < .05).

CONCLUSION

The results suggest that TCJ, in addition to habitual diet, can accelerate recovery after intermittent exercise and therefore extend the efficacy of TCJ in accelerating recovery in team sports.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Effect of Tart Cherry Concentrate on Endurance Exercise Performance: A Meta-analysis

Objective: Tart cherry concentrate has been shown to improve muscle function, and reduce muscle damage, oxidative stress/inflammation, and muscle soreness in athletes; however, evidence for acute endurance performance benefits is scarce. The purpose of this review was to evaluate the effect of tart cherry juice on endurance exercise performance with a meta-analysis.Method: Data sources included Medline, Embase, Web of Science, and Google Scholar. Eligibility criteria were randomized controlled trials with endurance exercise performance tests. Participants were healthy individuals. Interventions included tart cherry supplementation and placebo ingested before, and/or on the day of exercise. Ten studies were included (totaling 127 males and 20 females). Standardized mean differences (SMD) with 95% confidence intervals were calculated for each study and pooled effects were assessed.Results: Tart cherry concentrate in juice or powdered form, ingested for 7 days to 1.5 hours before exercise performance testing significantly improved endurance exercise performance (SMD: 0.36; 95% CI: 0.07 to 0.64; p = 0.01; I² = 0%) upon pooling of the ten studies.Conclusions: Tart cherry concentrate has a significant benefit for endurance exercise performance. Key teaching pointsTart cherry concentrate has a significant benefit for endurance exercise performance.Tart cherry concentrate may enhance endurance exercise performance via its low glycemic index, anti-inflammatory and anti-oxidative capacity, and blood flow enhancing effects.

Anti-Inflammatory Effect of Cherry Extract Loaded in Polymeric Nanoparticles: Relevance of Particle Internalization in Endothelial Cells

This study aimed at evaluating the anti-inflammatory effect of natural cherry extract (CE), either free or encapsulated in nanoparticles (NPs) based on chitosan derivatives (Ch-der) or poly(lactic-co-glycolic acid) (PLGA), on human umbilical vein endothelial cells (HUVEC). CE from Prunus avium L. was characterized for total polyphenols, flavonoids, and anthocyanins content. CE and CE-loaded NP cytotoxicity and protective effect on lipopolysaccharide (LPS)-stressed HUVEC were tested by water-soluble tetrazolium salt (WST-1) assay. Pro- and anti-inflammatory cytokines (TNF-α, IL-6, IL-10, and PGE2) released by HUVEC were quantified by enzyme-linked immunosorbent assay (ELISA). All NP types were internalized into HUVEC after 2 h incubation and promoted the anti-inflammatory effect of free CE at the concentration of 2 µg gallic acid equivalents (GAE)/mL. CE-loaded Ch-der NPs showed the highest in vitro uptake and anti-inflammatory activity, blunting the secretion of IL-6, TNF-α, and PGE2 cytokines. Moreover, all NPs reduced the production of nitric oxide and NLRP3 inflammasome, and had a stronger anti-inflammatory effect than the major corticosteroid dexamethasone. In particular, the results demonstrate that natural CE protects endothelial cells from inflammatory stress when encapsulated in NPs based on quaternary ammonium chitosan. The CE beneficial effects were directly related with in vitro internalization of CE-loaded NPs.

Consumption of An Anthocyanin-Rich Antioxidant Juice Accelerates Recovery of Running Economy and Indirect Markers of Exercise-Induced Muscle Damage Following Downhill Running

This study examined the effects of anthocyanin-rich antioxidant juice (AJ) on the recovery of exercise-induced muscle damage (EIMD) and the running economy (RE) following downhill running (DHR). Thirty healthy young men were randomly divided into two blinded groups and consumed either AJ or placebo (PLA) for nine days (240 mL twice-a-day). On day 5, the participants from both groups ran downhill (-15%) for 30 min at 70% of their maximal oxygen uptake (VO₂max) speeds. The changes in RE (oxygen uptake (VO₂) and perceived effort (PE) during 5-min runs at 80%VO₂max) and EIMD (isometric peak torque (IPT), muscle soreness (SOR) and serum creatine kinase activity (CK)) were compared over time and between the groups on the 4 days following DHR. VO₂ and PE increased (p < 0.05) immediately following DHR for both groups and remained elevated for PLA until 48h post-DHR while fully recovering 24 h post-DHR for AJ. SOR was greater (p < 0.05) for PLA throughout the study. CK increased for both groups and was greater (p < 0.05) for PLA at 96 h post-DHR. IPT decreased for both groups but recovered faster for AJ (72 h) compared to PLA (no full recovery). AJ accelerated recovery of RE and EIMD and should be used in specific contexts, but not chronically.

No Effect of Tart Cherry Juice or Pomegranate Juice on Recovery from Exercise-Induced Muscle Damage in Non-Resistance Trained Men

Tart cherry juice (TC) and pomegranate juice (POM) have been demonstrated to reduce symptoms of exercise-induced muscle damage (EIMD), but their effectiveness has not been compared. This randomized, double-blind, parallel study compared the effects of TC and POM on markers of EIMD. Thirty-six non-resistance trained men (age 24.0 (Interquartile Range (IQR) 22.0, 33.0) years, body mass index (BMI) 25.6 ± 4.0 kg·m^-2) were randomly allocated to consume 2 × 250 mL of: TC, POM, or an energy-matched fruit-flavored placebo drink twice daily for nine days. On day 5, participants undertook eccentric exercise of the elbow flexors of their non-dominant arm. Pre-exercise, immediately post-exercise, and at 24 h, 48 h, 72 h and 96 h post-exercise, maximal isometric voluntary contraction (MIVC), delayed onset muscle soreness (DOMS), creatine kinase (CK), and range of motion (ROM) were measured. The exercise protocol induced significant decreases in MIVC (p < 0.001; max decrease of 26.8%, 24 h post-exercise) and ROM (p = 0.001; max decrease of 6.8%, 72 h post-exercise) and significant increases in CK (p = 0.03; max increase 1385 U·L^-1, 96 h post-exercise) and DOMS (p < 0.001; max increase of 26.9 mm, 48 h post-exercise). However, there were no statistically significant differences between treatment groups (main effect of group p > 0.05 or group x time interaction p > 0.05). These data suggest that in non-resistance trained men, neither TC nor POM enhance recovery from high-force eccentric exercise of the elbow flexors.

Cherry Gel Supplementation Does Not Attenuate Subjective Muscle Soreness or Alter Wellbeing Following a Match in a Team of Professional Rugby Union players: A Pilot Study

This study examined the effects of sour tart cherry juice (TC) on muscle soreness (MS) and wellbeing following a rugby union match in professional players. In a crossover design, 10 players from a senior squad in the top tier of England consumed either 2 × 30 mL servings of TC or an isocaloric cherry-flavoured control gel (CON) two days before, the day of, and two days following an 80 min match. Subjective wellbeing and MS were measured before the match (Pre), and for three days following the match (M+1, M+2, and M+3, respectively). MS was elevated from Pre at M+1 (CON, 111 ± 37 mm vs. TC 94 ± 41 mm) and M+2 (CON, 81 ± 35 mm vs. TC 72 ± 36 mm) (time effect; p = 0.0001; ηp² = 0.821) but there were no differences between TC and CON at either time point post-exercise (p = 0.807; ηp² = 0.035). Wellness scores were ~15% lower at M+1 (p = 0.023; ηp² = 0.638) but there were no differences between the two conditions at any time point (p = 0.647; ηp² = 0.160). In conclusion, tart cherry juice did not attenuate soreness or alter wellbeing in a team of professional rugby union players following a competitive match.

Nutritional and Supplementation Strategies to Prevent and Attenuate Exercise-Induced Muscle Damage: a Brief Review

Exercise-induced muscle damage (EIMD) is typically caused by unaccustomed exercise and results in pain, soreness, inflammation, and reduced muscle function. These negative outcomes may cause discomfort and impair subsequent athletic performance or training quality, particularly in individuals who have limited time to recover between training sessions or competitions. In recent years, a multitude of techniques including massage, cryotherapy, and stretching have been employed to combat the signs and symptoms of EIMD, with mixed results. Likewise, many varied nutritional and supplementation interventions intended to treat EIMD-related outcomes have gained prominence in the literature. To date, several review articles have been published that explore the many recovery strategies purported to minimize indirect markers of muscle damage. However, these articles are very limited from a nutritional standpoint. Thus, the purpose of this review is to briefly and comprehensively summarize many of these strategies that have been shown to positively influence the recovery process after damaging exercise. These strategies have been organized into the following sections based on nutrient source: fruits and fruit-derived supplements, vegetables and plant-derived supplements, herbs and herbal supplements, amino acid and protein supplements, vitamin supplements, and other supplements.

Flavanol-Rich Cacao Mucilage Juice Enhances Recovery of Power but Not Strength from Intensive Exercise in Healthy, Young Men

(1) Background: Mucilage within cacao pods contains high levels of polyphenols. We investigated whether consumption of cacao juice enhances the recovery of muscle function following intensive knee extension exercise. (2) Methods: Ten recreationally active males completed two trials of 10 sets of 10 single leg knee extensions at ~80% one repetition maximum. Participants consumed each supplement (ZumoCacao^® juice, CJ or a dextrose drink, PL) for 7 days prior to and 48 h post exercise. Knee extension maximum voluntary contraction (MVC) and a counter movement jump (CMJ) were performed at baseline, immediately, 24 h, and 48 h post-exercise. Venous blood samples were collected at each time point and analyzed for indices of inflammation, oxidative damage, and muscle damage. (3) Results: CMJ height recovered faster with CJ at 24 h and 48 h post-exercise (p < 0.05), but there was no effect of CJ on recovery of MVC (both p > 0.05). There was also no effect of the trial on any blood markers (all p > 0.05). (4) Conclusions: Supplementation with CJ for 7 days prior to and 2 days after intensive knee extensor exercise improved functional recovery as shown by an improved recovery of CMJ up to 48 h post-exercise. However, the precise mechanism of action is unclear and requires further investigation.

Tart Cherry Reduces Inflammation in Adipose Tissue of Zucker Fatty Rats and Cultured 3T3-L1 Adipocytes

Obesity increases adipose tissue inflammation and secretion of pro-inflammatory adipokines, which have systemic effects on the organism's health status. Our objective was to dissect mechanisms of anti-inflammatory effects of tart cherry (TC) in adipose tissue of Zucker fatty rats, and cultured 3T3-L1 adipocytes. Rats were fed either a control diet, or 4% TC powder diets for eight weeks. Body and epididymal fat pad weights were not significantly different between control and TC groups. However, rats fed the TC diet had significantly reduced adipose tissue inflammation (p < 0.05), as determined by reduced mRNA levels of pro-inflammatory markers including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), interleukin-1beta (IL-1β), monocyte chemoattractant protein 1 (MCP-1), inducible nitric oxide synthase (iNOS), and CD-11b, and increased mRNA levels of type-1 arginase (Arg-1) anti-inflammatory marker. Consistent with these in vivo results, TC significantly decreased expression of IL-6 mRNA and protein levels in lipopolysaccharide (LPS) stimulated adipocytes compared to those stimulated with LPS, but no TC. Moreover, both in vivo (rat adipose tissue) and in vitro (3T3-L1 adipocytes), phosphorylation of p65-NF-κB subunit was significantly reduced by TC. Additionally, TC decreased mRNA expression of fatty acid synthase (FASN), and increased expression of peroxisome proliferator-activated receptor alpha (PPARα), master regulator of lipid oxidation, and anti-oxidant markers nuclear factor erythroid-derived 2-related factor (NRFs) in both models. In conclusion, our findings indicate that TC downregulates inflammation in part via the nuclear factor kappa B (NF-κB) pathway in adipose tissue. Thus, TC may serve as a potential intervention to reduce obesity-associated inflammation.

Impact of tart cherry juice on systolic blood pressure and low-density lipoprotein cholesterol in older adults: a randomized controlled trial

Hypertension and dyslipidemia are major risk factors for cardiovascular disease (CVD). Common treatments for high blood pressure (BP) and dyslipidemia include medications, but there is question as to whether natural sources may be adequate to reduce CVD risk factors. We examined the effects of tart cherry juice on lipid profiles, BP, glucose, insulin, and homeostatic model assessment-insulin resistance (HOMA-IR) in older adults. In this randomized-controlled clinical trial, 17 men and 20 women between the ages of 65-80 years were randomly assigned to consume 480 ml of tart cherry juice or control drink daily for 12 weeks. Control beverages were matched for energy and sugar content. Outcome variables were assessed at baseline and after 12 weeks of tart cherry juice or control drink. Systolic BP and low-density lipoprotein cholesterol (LDL) exhibited treatment × time interaction effects. At the end of the study, participants in the tart cherry group had lower levels of LDL cholesterol (difference of -20.6 with P = 0.001) and total cholesterol (difference of -19.11 with P = 0.01), and higher levels of glucose (difference of 7.94 with P = 0.001), triglycerides (difference of 6.66 with P = 0.01) and BMI (difference of 1.06 with P = 0.02) than in the control group. Neither tart cherry juice nor control significantly altered body weight, high-density lipoprotein cholesterol, diastolic BP, insulin and HOMA-IR. Our findings show that tart cherry juice can lower the levels of systolic BP and LDL cholesterol. However, larger and longer follow-up studies are needed to further assess cardio-protective effects of tart cherry juice.

Sour Cherry By-products: Compositions, Functional Properties and Recovery Potentials - A Review

Sour (tart) cherry is an industrial fruit where a considerable amount of by-products remain after processing. Sour cherry by-products consist of pomace (skin and flesh) and seeds (pit, stone) which remain after the fruit juice and IQF processes. Sour cherry pomace is characterized with a high content of phenolic compounds and the seed constitutes a high oil yield with beneficial effects on human health because of their antioxidant, antimicrobial, and anti-inflammatory properties. There has been a great interest in sour cherry by-products due to the increasing production rate of sour cherry worldwide and the increasing efforts on seeking bioactive compounds from natural sources as functional food. Thus, there have been a number of studies regarding the sour cherry pomace and sour cherry seed, especially in the last five years. The present review summarizes the chemical, biological, functional, and technological properties of the sour cherry pomace and sour cherry seed with their current and potential applications.

Exercise-induced muscle damage: What is it, what causes it and what are the nutritional solutions?

Exercise-induced muscle damage (EIMD) is characterized by symptoms that present both immediately and for up to 14 days after the initial exercise bout. The main consequence of EIMD for the athlete is the loss of skeletal muscle function and soreness. As such, numerous nutrients and functional foods have been examined for their potential to ameliorate the effects of EIMD and accelerate recovery, which is the purpose of many nutritional strategies for the athlete. However, the trade-off between recovery and adaptation is rarely considered. For example, many nutritional interventions described in this review target oxidative stress and inflammation, both thought to contribute to EIMD but are also crucial for the recovery and adaptation process. This calls into question whether long term administration of supplements and functional foods used to target EIMD is indeed best practice. This rapidly growing area of sports nutrition will benefit from careful consideration of the potential hormetic effect of long term use of nutritional aids that ameliorate muscle damage. This review provides a concise overview of what EIMD is, its causes and consequences and critically evaluates potential nutritional strategies to ameliorate EIMD. We present a pragmatic practical summary that can be adopted by practitioners and direct future research, with the purpose of pushing the field to better consider the fine balance between recovery and adaptation and the potential that nutritional interventions have in modulating this balance.

Montmorency tart cherry (Prunus cerasus L.) supplementation accelerates recovery from exercise-induced muscle damage in females

Tart Montmorency cherry concentrate (MC) has been reported to attenuate the symptoms of exercise-induced muscle damage (EIMD) and to accelerate exercise recovery, which has been attributed to its high anti-inflammatory and antioxidant properties. Although these data are promising, there are no data regarding exclusively female populations. Therefore, the aim of this investigation was to examine the efficacy of MC on recovery following EIMD in females. In a randomised, double-blind, placebo-controlled study, twenty physically active females (mean ± SD age 19 ± 1 y; stature 167 ± 6 cm; body mass 61.4 ± 5.7 kg) consumed MC or a placebo (PL) for eight days (30 mL twice per day). Following four days of supplementation, participants completed a repeated-sprint protocol and measures of muscle soreness (DOMS), pain pressure threshold (PPT), limb girth, flexibility, muscle function, and systemic indices of muscle damage and inflammation were collected pre, immediately post (0 h) and 24, 48 and 72 h post-exercise. Time effects were observed for all dependent variables (p < 0.05) except limb girth and high sensitivity C-reactive protein. Recovery of countermovement jump height was improved in the MC group compared to PL (p = 0.016). There was also a trend for lower DOMS (p = 0.070) and for higher PPT at the rectus femoris (p = 0.071) in the MC group. The data demonstrate that MC supplementation may be a practical nutritional intervention to help attenuate the symptoms of muscle damage and improve recovery on subsequent days in females.

Antioxidants for preventing and reducing muscle soreness after exercise: a Cochrane systematic review

OBJECTIVE

To determine whether antioxidant supplements and antioxidant-enriched foods can prevent or reduce delayed-onset muscle soreness after exercise.

METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, SPORTDiscus, trial registers, reference lists of articles and conference proceedings up to February 2017.

RESULTS

In total, 50 studies were included in this review which included a total of 1089 participants (961 were male and 128 were female) with an age range of 16-55 years. All studies used an antioxidant dosage higher than the recommended daily amount. The majority of trials (47) had design features that carried a high risk of bias due to selective reporting and poorly described allocation concealment, potentially limiting the reliability of their findings. We rescaled to a 0-10 cm scale in order to quantify the actual difference between groups and we found that the 95% CIs for all five follow-up times were all well below the minimal important difference of 1.4 cm: up to 6 hours (MD -0.52, 95% CI -0.95 to -0.08); at 24 hours (MD -0.17, 95% CI -0.42 to 0.07); at 48 hours (mean difference (MD) -0.41, 95% CI -0.69 to -0.12); at 72 hours (MD -0.29, 95% CI -0.59 to 0.02); and at 96 hours (MD -0.03, 95% CI -0.43 to 0.37). Thus, the effect sizes suggesting less muscle soreness with antioxidant supplementation were very unlikely to equate to meaningful or important differences in practice.

CONCLUSIONS

There is moderate to low-quality evidence that high-dose antioxidant supplementation does not result in a clinically relevant reduction of muscle soreness after exercise of up to 6 hours or at 24, 48, 72 and 96 hours after exercise. There is no evidence available on subjective recovery and only limited evidence on the adverse effects of taking antioxidant supplements.

Immunomodulatory Protein Hydrolysates and Their Application

Immunomodulatory protein hydrolysate consumption may delay or prevent western immune-related diseases. In order to purposively develop protein hydrolysates with an optimal and reproducible immunomodulatory effect, knowledge is needed on which components in protein hydrolysates are responsible for the immune effects. Important advances have been made on this aspect. Also, knowledge on mechanisms underlying the immune modulating effects is indispensable. In this review, we discuss the most promising application possibilities for immunomodulatory protein hydrolysates. In order to do so, an overview is provided on reported in vivo immune effects of protein hydrolysates in both local intestinal and systemic organs, and the current insights in the underlying mechanisms of these effects. Furthermore, we discuss current knowledge and physicochemical approaches to identify the immune active protein sequence(s). We conclude that multiple hydrolysate compositions show specific immune effects. This knowledge can improve the efficacy of existing hydrolysate-containing products such as sports nutrition, clinical nutrition, and infant formula. We also provide arguments for why immunomodulatory protein hydrolysates could be applied to manage the immune response in the increasing number of individuals with a higher risk of immune dysfunction due to, for example, increasing age or stress.

Effect of bilberry juice on indices of muscle damage and inflammation in runners completing a half-marathon: a randomised, placebo-controlled trial

Background

Emerging evidence indicates that fruits rich in polyphenols may attenuate exercise-induced muscle damage and associated markers of inflammation and soreness. This study was conducted to determine whether bilberry juice (BJ), which is particularly rich in polyphenols, reduces markers of muscle damage in runners completing a half marathon.

Methods

A total of 21 recreationally trained runners (age 30.9 ± 10.4 y; mass 71.6 ± 11.0 kg; M = 16; F = 5) were recruited to a single blind, randomised, placebo-controlled, parallel study. Participants were block randomised to consume 2 × 200 ml of BJ or energy-matched control drink (PLA) for 5 d before the Sheffield Half Marathon, on race day, and for 2 days post-race. Measurements of delayed onset muscle soreness (DOMS), muscle damage (creatine kinase; CK) and inflammation (c-reactive protein; CRP) were taken at baseline, pre-race, post-race, 24 h post-race and 48 h post-race. The effect of treatment on outcome measures was analysed using magnitude-based inferences based on data from 19 participants; 2 participants were excluded from the analyses because they did not provide samples for all time points.

Results

The half marathon caused elevations in DOMS, CRP and CK. BJ had a possibly harmful effect on DOMS from pre-race to immediately post-race (11.6%, 90% CI ± 14.7%), a likely harmful effect on CRP from pre-race to 24 h post-race (mean difference ES 0.56, 90% CI ± 0.72) and a possibly harmful effect on CRP from pre-race to 48 h post-race (ES 0.12, 90% CI ± 0.69). At other time points, the differences between the BJ and PLA groups in DOMS and CRP were unclear, possibly trivial or likely trivial. Differences in the changes in CK between BJ and PLA were unclear at every time point other than from baseline to pre-race, where BJ had a possibly harmful effect on reducing muscle damage (ES 0.23, 90% CI ± 0.57).

Conclusion

Despite being a rich source of antioxidant and anti-inflammatory phytochemicals, BJ evoked small to moderate increases in exercise-induced DOMS and CRP. Further larger studies are required to confirm these unexpected preliminary results.

A Review of the Health Benefits of Cherries

Increased oxidative stress contributes to development and progression of several human chronic inflammatory diseases. Cherries are a rich source of polyphenols and vitamin C which have anti-oxidant and anti-inflammatory properties. Our aim is to summarize results from human studies regarding health benefits of both sweet and tart cherries, including products made from them (juice, powder, concentrate, capsules); all referred to as cherries here. We found 29 (tart 20, sweet 7, unspecified 2) published human studies which examined health benefits of consuming cherries. Most of these studies were less than 2 weeks of duration (range 5 h to 3 months) and served the equivalent of 45 to 270 cherries/day (anthocyanins 55–720 mg/day) in single or split doses. Two-thirds of these studies were randomized and placebo controlled. Consumption of cherries decreased markers for oxidative stress in 8/10 studies; inflammation in 11/16; exercise-induced muscle soreness and loss of strength in 8/9; blood pressure in 5/7; arthritis in 5/5, and improved sleep in 4/4. Cherries also decreased hemoglobin A1C (HbA1C), Very-low-density lipoprotein (VLDL) and triglycerides/high-density lipoprotein (TG/HDL) in diabetic women, and VLDL and TG/HDL in obese participants. These results suggest that consumption of sweet or tart cherries can promote health by preventing or decreasing oxidative stress and inflammation.

Bioactive and functional properties of sour cherry juice (Prunus cerasus)

Sour cherry juice (Prunus cerasus) is consumed as a nutritional supplement claiming health effects. The aim of the study was to evaluate the different properties of sour cherry juice in terms of antioxidant activity and inhibition of target enzymes in the central nervous system and diabetes. The content of polyphenols and anthocyanins was quantified. Different experiments were carried out to determine the radical scavenging properties of the juice. The activity of sour cherry juice was also tested in physiological relevant enzymes of the central nervous system (acetylcholinesterase, monoamine oxidase A, tyrosinase) and others involved in type 2 diabetes (α-glucosidase, dipeptidyl peptidase-4). Sour cherry juice showed significant antioxidant effects but the activity of the lyophilized juice was not superior to compounds such as ascorbic, gallic or chlorogenic acid. Furthermore, sour cherry juice and one of its main polyphenols known as chlorogenic acid were also able to inhibit monoamine oxidase A and tyrosinase as well as enzymes involved in diabetes. This is the first time that sour cherry juice is reported to inhibit monoamine oxidase A, α-glucosidase and dipeptidyl peptidase-4 in a dose dependent manner, which may be of interest for human health and the prevention of certain diseases.

Antioxidants for preventing and reducing muscle soreness after exercise

BACKGROUND

Muscle soreness typically occurs after intense exercise, unaccustomed exercise or actions that involve eccentric contractions where the muscle lengthens while under tension. It peaks between 24 and 72 hours after the initial bout of exercise. Many people take antioxidant supplements or antioxidant-enriched foods before and after exercise in the belief that these will prevent or reduce muscle soreness after exercise.

OBJECTIVES

To assess the effects (benefits and harms) of antioxidant supplements and antioxidant-enriched foods for preventing and reducing the severity and duration of delayed onset muscle soreness following exercise.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, SPORTDiscus, trial registers, reference lists of articles and conference proceedings up to February 2017.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials investigating the effects of all forms of antioxidant supplementation including specific antioxidant supplements (e.g. tablets, powders, concentrates) and antioxidant-enriched foods or diets on preventing or reducing delayed onset muscle soreness (DOMS). We excluded studies where antioxidant supplementation was combined with another supplement.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, assessed risk of bias and extracted data from included trials using a pre-piloted form. Where appropriate, we pooled results of comparable trials, generally using the random-effects model. The outcomes selected for presentation in the 'Summary of findings' table were muscle soreness, collected at times up to 6 hours, 24, 48, 72 and 96 hours post-exercise, subjective recovery and adverse effects. We assessed the quality of the evidence using GRADE.

MAIN RESULTS

Fifty randomised, placebo-controlled trials were included, 12 of which used a cross-over design. Of the 1089 participants, 961 (88.2%) were male and 128 (11.8%) were female. The age range for participants was between 16 and 55 years and training status varied from sedentary to moderately trained. The trials were heterogeneous, including the timing (pre-exercise or post-exercise), frequency, dose, duration and type of antioxidant supplementation, and the type of preceding exercise. All studies used an antioxidant dosage higher than the recommended daily amount. The majority of trials (47) had design features that carried a high risk of bias due to selective reporting and poorly described allocation concealment, potentially limiting the reliability of their findings.We tested only one comparison: antioxidant supplements versus control (placebo). No studies compared high-dose versus low-dose, where the low-dose supplementation was within normal or recommended levels for the antioxidant involved.Pooled results for muscle soreness indicated a small difference in favour of antioxidant supplementation after DOMS-inducing exercise at all main follow-ups: up to 6 hours (standardised mean difference (SMD) -0.30, 95% confidence interval (CI) -0.56 to -0.04; 525 participants, 21 studies; low-quality evidence); at 24 hours (SMD -0.13, 95% CI -0.27 to 0.00; 936 participants, 41 studies; moderate-quality evidence); at 48 hours (SMD -0.24, 95% CI -0.42 to -0.07; 1047 participants, 45 studies; low-quality evidence); at 72 hours (SMD -0.19, 95% CI -0.38 to -0.00; 657 participants, 28 studies; moderate-quality evidence), and little difference at 96 hours (SMD -0.05, 95% CI -0.29 to 0.19; 436 participants, 17 studies; low-quality evidence). When we rescaled to a 0 to 10 cm scale in order to quantify the actual difference between groups, we found that the 95% CIs for all five follow-up times were all well below the minimal important difference of 1.4 cm: up to 6 hours (MD -0.52, 95% CI -0.95 to -0.08); at 24 hours (MD -0.17, 95% CI -0.42 to 0.07); at 48 hours (MD -0.41, 95% CI -0.69 to -0.12); at 72 hours (MD -0.29, 95% CI -0.59 to 0.02); and at 96 hours (MD -0.03, 95% CI -0.43 to 0.37). Thus, the effect sizes suggesting less muscle soreness with antioxidant supplementation were very unlikely to equate to meaningful or important differences in practice. Neither of our subgroup analyses to examine for differences in effect according to type of DOMS-inducing exercise (mechanical versus whole body aerobic) or according to funding source confirmed subgroup differences. Sensitivity analyses excluding cross-over trials showed that their inclusion had no important impact on results.None of the 50 included trials measured subjective recovery (return to previous activities without signs or symptoms).There is very little evidence regarding the potential adverse effects of taking antioxidant supplements as this outcome was reported in only nine trials (216 participants). From the studies that did report adverse effects, two of the nine trials found adverse effects. All six participants in the antioxidant group of one trial had diarrhoea and four of these also had mild indigestion; these are well-known side effects of the particular antioxidant used in this trial. One of 26 participants in a second trial had mild gastrointestinal distress.

AUTHORS' CONCLUSIONS

There is moderate to low-quality evidence that high dose antioxidant supplementation does not result in a clinically relevant reduction of muscle soreness after exercise at up to 6 hours or at 24, 48, 72 and 96 hours after exercise. There is no evidence available on subjective recovery and only limited evidence on the adverse effects of taking antioxidant supplements. The findings of, and messages from, this review provide an opportunity for researchers and other stakeholders to come together and consider what are the priorities, and underlying justifications, for future research in this area.

Tart Cherries and health: Current knowledge and need for a better understanding of the fate of phytochemicals in the human gastrointestinal tract

Tart cherries are increasingly popular due to purported health benefits. This Prunus cesarus species is cultivated worldwide, and its market has increased significantly in the last two decades due to improvements in agricultural practices and food processing technology. Tart cherries are rich in polyphenols, with a very specific profile combining anthocyanins and flavonols (berries-like) and chlorogenic acid (coffee-like). Tart cherries have been suggested to exert several potentially beneficial health effects including: lowering blood pressure, modulating blood glucose, enhancing cognitive function, protecting against oxidative stress and reducing inflammation. Studies focusing on tart cherry consumption have demonstrated particular benefits in recovery from exercise-induced muscle damage and diabetes associated parameters. However, the bioconversion of tart cherry polyphenols by resident colonic microbiota has never been considered, considerably reducing the impact of in vitro studies that have relied on fruit polyphenol extracts. In vitro and in vivo gut microbiota and metabolome studies are necessary to reinforce health claims linked to tart cherries consumption.

Supplementation with a Polyphenol-Rich Extract, TensLess® , Attenuates Delayed Onset Muscle Soreness and Improves Muscle Recovery from Damages After Eccentric Exercise

High-intensity exercises are known to provoke delayed onset muscle soreness (DOMS). Delayed onset muscle soreness typically occurs within the first 24 h, peaks between 24 and 72 h, and can last as long as 5-7 days post-exercise. Delayed onset muscle soreness is a multifactorial process involving both mechanical and biochemical components, associated with clinical features that may limit range of motion, and athletes seek for effective recovery strategies to optimize future training sessions. TensLess^® is a food supplement developed to help manage post-exercise recovery. The supplement has been investigated on 13 recreationally active athletes of both sex, during a randomized, double-blind, and crossover clinical investigation, including a 3-week washout period. The clinical investigation was based on the study of TensLess^® effects for DOMS management and on the reduction of associated muscle damages following an eccentric exercise protocol. Supplementation with TensLess^® induced significant decrease in DOMS perception (-33%; p = 0.008) as of the first 24 h; this was significantly correlated with a lowered release of muscle damage-associated biomarkers, namely myoglobin, creatinine, and creatine kinase, for the whole length of the recovery period. Taken together, these positive results clearly indicate that post-exercise supplementation with TensLess^® may preserve myocytes and reduce soreness following eccentric exercise-induced damages, and, accordingly, significantly shorten muscle recovery. Copyright © 2017 John Wiley & Sons, Ltd.