Effects of powdered Montmorency tart cherry supplementation on an acute bout of intense lower body strength exercise in resistance trained males

Effects of Acute and One-Week Supplementation with Montmorency Tart Cherry Powder on Food-Induced Uremic Response and Markers of Health: A Proof-of-Concept Study

Metabolic conditions, such as gout, can result from elevated uric acid (UA) levels. Consuming high-purine meals increases UA levels. Therefore, people with hyperuricemia typically must avoid ingesting such foods. Polyphenols have been shown to reduce uric acid levels and tart cherries (TCs) are a rich source of phenolic and anthocyanin compounds. This proof-of-concept study evaluated whether ingesting TCs with a purine-rich meal affects the uricemic response. Methods: A total of 25 adults (15 males and 10 females, 85.0 ± 17 kg, 40.6 ± 9 years, 29.1 ± 4.9 kg/m2) with elevated fasting UA levels (5.8 ± 1.3 mg/dL) donated a fasting blood sample. In a randomized, double-blind, crossover, placebo-controlled, counterbalanced manner, participants ingested capsules containing 960 mg of a placebo (PLA) or concentrated TC powder containing 20.7 mg of proanthocyanins with a serving of hot soup (10 g of carbohydrate, 2 g protein, and 1 g fat) containing 3 g of purines (1 g of adenosine 5'-monophosphate, 1 g of disodium 5'-guanylate, and 1 g of disodium 5'-inosinate). Blood samples were obtained at 0, 60, 120, 180, and 240 min after ingestion to assess changes in uric acid levels and pharmacokinetic profiles. Cell blood counts, a comprehensive metabolic panel, cytokines, inflammatory markers, and subjective side effects ratings were analyzed on baseline (0 min) and post-treatment (240 min) samples. Participants continued consuming two capsules/day of the assigned treatment for one week and then repeated the experiment. Participants observed a 14-day washout and then repeated the experiment while ingesting the alternate treatment. Data were analyzed using general linear model (GLM) statistics with repeated measures, pairwise comparisons, and percentage change from baseline with 95% confidence intervals (CIs). Results: No statistically significant interaction effects or differences between treatments were seen in uric acid levels or PK profiles. Analysis of percent changes from baseline revealed that TC ingestion reduced the blood glucose levels following the ingestion of the high-purine meal (-4.2% [-7.7, -0.7], p = 0017). Additionally, there was some evidence that TC ingestion attenuated the increase from baseline in IL-1β and IL-10 and increased INF-γ. No significant differences were seen in the remaining health markers or subjective side effects ratings. Conclusions: Acute and one-week TC supplementation did not affect the uricemic response to ingesting a high-purine meal in individuals with mildly elevated UA levels. However, there was some evidence that TC supplementation may blunt the glycemic response to ingesting a meal and influence some inflammatory cytokines. Registered clinical trial NCT04837274.

Acute Dosing Strategy with Vistula Tart Cherries for Recovery of Strenuous Exercise-A Feasibility Study

Tart cherry (TC) consumption has become a popular nutritional strategy for recovery, particularly for the attenuation of markers associated with muscle damage. However, there are relatively few studies that have examined an acute dosing strategy. The aim of this pilot study was to explore the feasibility of using powdered Vistula TC for recovery following a bout of muscle-damaging exercise. Twenty-two recreationally active participants (mean ± SD age, stature, and mass were 23 ± 3 years old, 173 ± 10 cm, and 74 ± 17 kg, respectively) performed 40 (5 sets of 8 repetitions) maximal lengthening contractions of the elbow flexors. The participants were randomised to receive either a spray-dried TC extract or a calorie-matched placebo (12 TC, 10 placebo) for 4 days in total, starting on the day of exercise. Dependent measures of maximal voluntary contraction (MVC), muscle soreness (assessed via visual analogue scales; VAS), pain pressure threshold (PPT), range of motion (ROM), and upper arm limb girth were taken at baseline (pre), 24, 48, and 72 h post damaging exercise. There were significant changes over time among all the variables (MVC, VAS, PPT, ROM, and girth, p ≤ 0.014). There were no significant differences between the conditions for any of the variables (MVC, VAS, PPT, ROM, and girth, p > 0.3). The TC group did not recover at an accelerated rate compared to the placebo. This study provides initial insights into the use of powdered Vistula TC and its effect following strenuous (damaging) exercise bouts. Vistula TC did not improve recovery when taken acutely following a bout of damaging exercise to the elbow flexors.

A View on the Chemical and Biological Attributes of Five Edible Fruits after Finishing Their Shelf Life: Studies on Caco-2 Cells

We studied five common perishable fruits in terms of their polyphenols dynamic, minerals distribution, scavenger activity and the effects of 50% ethanolic extracts on the viability of Caco-2 cells in vitro, over a period of time between T = 0 and T = 5/7 days, typically the end of their shelf life. Altogether, there were few changes found, consisting of either an increase or a decrease in their chemical and biological attributes. A slow decrease was found in the antioxidant activity in apricot (-11%), plum (-6%) and strawberry (-4%) extracts, while cherry and green seedless table grape extracts gained 7% and 2% antioxidant potency, respectively; IC50 values ranged from 1.67 to 5.93 μg GAE/μL test extract. The cytotoxicity MTS assay at 24 h revealed the ability of all 50% ethanol fruit extracts to inhibit the Caco-2 cell viability; the inhibitory effects ranged from 49% to 83% and were measured at 28 µg GAE for strawberry extracts/EES, from 22 µg to 45 µg GAE for cherry extracts/EEC, from 7.58 to 15.16 µg GAE for apricot extracts/EEA, from 12.50 to 25.70 µg GAE for plum extracts/EEP and from 21.51 to 28.68 µg GAE for green table grape extracts/EEG. The MTS anti-proliferative assay (72 h) also revealed a stimulatory potency upon the Caco-2 viability, from 34% (EEA, EEG) and 48% (EEC) to 350% (EES) and 690% (EEP); therefore fruit juices can influence intestinal tumorigenesis in humans.

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.

Dose-dependent effect of tart cherry on blood pressure and selected inflammation biomarkers: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials

Objectives

As a nutritious food, Tart cherries (Prunus cerasus L) benefit cardiovascular health. This study aims to clarify the effectiveness of Tart cherry in controlling blood pressure, heart rate, and inflammatory biomarkers, the appropriate dosage for this effect, and suggest directions for future studies.

Methods

PubMed, Scopus, and Web of Science were searched (up to May 2022), to identify eligible randomized controlled trials. It measured publication bias and was assessed for all outcomes. Evidence quality was evaluated using the Cochrane risk of bias tool and GRADE (Grades of Recommendations, Assessment, Development, and Evaluations).

Results

Regarding the 21 included trials, Tart cherry didn't affect blood pressure, heart rate, high-sensitive C-reactive protein, and interleukin-6 (P > 0.05). In contrast, with moderate certainty, it can reduce serum C-reactive protein (WMD: - 0.39 mg/l; 95% CI: - 0.74, - 0.05; P = 0.024) and with very low certainty can decrease tumor necrosis factor-alpha (WMD: - 0.14 pg/ml; 95% CI: - 0.27, - 0.02; P = 0.026). In addition, dose-response analysis implies that with each 30 ml elevation in dose, CRP reduces by 0.19 mg/l (95% CI: - 0.37, - 0.01).

Conclusions

Tart cherry can control inflammation by administering the proper dose. Even though tart cherry generally doesn't affect blood pressure and heart rate, further high-quality studies are needed to determine its effect.

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.

Effectiveness of supplementation with date seed (Phoenix dactylifera) as a functional food on inflammatory markers, muscle damage, and BDNF following high-intensity interval training: a randomized, double-blind, placebo-controlled trial

PURPOSE

High-intensity interval training (HIIT) is one of the most effective protocols, even though acute HIIT causes inflammatory and oxidative damage. The aim of this study was to examine the effect of date seeds powder (DSP) during HIIT sessions on inflammation markers, oxidants and antioxidants, brain-derived neurotrophic factor (BDNF), exercise-induced muscle damage, and body composition.

MATERIAL AND METHODS

Thirty-six recreational runners (men and women), aged 18-35 years, were randomly assigned to consume 26 g/day of DSP or wheat bran powder during HIIT workouts for a period of 14 days. At baseline, at the end of the intervention, and 24 h after the intervention, blood samples were obtained to determine inflammatory, oxidant/antioxidant, and muscle damage markers, as well as BDNF.

RESULTS

DSP supplementation resulted in a significant downward trend in high-sensitivity C-reactive protein (Psupplement × time = 0.036), tumor necrosis factor alpha (Psupplement × time = 0.010), interleukin-6 (Psupplement × time = 0.047), malondialdehyde (Psupplement × time = 0.046), creatine kinase (Psupplement × time = 0.045), and lactate dehydrogenase (Psupplement × time = 0.040) after the intervention, as well as a significant increase in total antioxidant capacity (Psupplement × time ≤ 0.001). However, interleukin-10 (Psupplement × time = 0.523), interleukin-6/interleukin-10 (Psupplement × time = 0.061), BDNF (Psupplement × time = 0.160), and myoglobin (Psupplement × time = 0.095) levels did not change significantly in comparison to the placebo group. Moreover, analysis demonstrated that DSP supplementation over 2 weeks had no significant effect on body composition.

CONCLUSION

During the 2 weeks of the HIIT protocol, the consumption of date seed powder by participants who had engaged in moderate or high physical activity alleviated inflammation and muscle damage.

ETHICS AND DISSEMINATION

This study was approved by the Medical Ethics Committee of TBZMED (No.IR.TBZMED.REC.1399.1011).

TRIAL REGISTRATION

Iranian Registry of Clinical Trials website ( www.IRCt.ir/ , IRCT20150205020965N9).

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.

Polyphenol Supplementation and Antioxidant Status in Athletes: A Narrative Review

Antioxidants in sports exercise training remain a debated research topic. Plant-derived polyphenol supplements are frequently used by athletes to reduce the negative effects of exercise-induced oxidative stress, accelerate the recovery of muscular function, and enhance performance. These processes can be efficiently modulated by antioxidant supplementation. The existing literature has failed to provide unequivocal evidence that dietary polyphenols should be promoted specifically among athletes. This narrative review summarizes the current knowledge regarding polyphenols' bioavailability, their role in exercise-induced oxidative stress, antioxidant status, and supplementation strategies in athletes. Overall, we draw attention to the paucity of available evidence suggesting that most antioxidant substances are beneficial to athletes. Additional research is necessary to reveal more fully their impact on exercise-induced oxidative stress and athletes' antioxidant status, as well as optimal dosing methods.

Effect of a fruit and vegetable drink on muscle recovery after resistance exercise

Objective: To evaluate the effect of fruit and vegetable drink supplementation on muscle recovery after resistance exercise. Methods: 11 men performed two experimental conditions 12 days apart, in a randomized and double-blind manner: 1) Supplementation with Smoothie - drink based on pineapple, mint, sage, ginger, and pomegranate; and 2) Placebo - drink based on artificial pineapple juice. Participants ingested 400 mL of Smoothie or Placebo drinks daily for 9 days, starting one week before performing the exercise (10 sets of 10 unilateral maximum repetitions in leg press 45º). The perceived subjective recovery (PSR), thickness (MT) and soreness (MS) in the anterior thigh muscles, and maximum isometric strength (MIS) were measured before, 24, 48, 72, and 96 h after exercise. Results: There was a reduction in MIS and PSR and an increase in MS 24 h after exercise (p < 0.05). In both situations, MIS returned to baseline values at 72 h (p > 0.05), while PSR and MS returned to baseline values 96 h after exercise. There was no change in MT (p > 0.05). Conclusion: Supplementation with pineapple, mint, sage, ginger, and pomegranate drinks did not accelerate muscle recovery over 96 h after the 45º leg press exercise.

Nutritional Compounds to Improve Post-Exercise Recovery

The metabolic and mechanical stresses associated with muscle-fatiguing exercise result in perturbations to bodily tissues that lead to exercise-induced muscle damage (EIMD), a state of fatigue involving oxidative stress and inflammation that is accompanied by muscle weakness, pain and a reduced ability to perform subsequent training sessions or competitions. This review collates evidence from previous research on a wide range of nutritional compounds that have the potential to speed up post-exercise recovery. We show that of the numerous compounds investigated thus far, only two-tart cherry and omega-3 fatty acids-are supported by substantial research evidence. Further studies are required to clarify the potential effects of other compounds presented here, many of which have been used since ancient times to treat conditions associated with inflammation and disease.

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.

Acute Floatation-REST Improves Perceived Recovery After a High-Intensity Resistance Exercise Stress in Trained Men

PURPOSE

The aim of the present investigation was to determine whether a 1-h floatation-restricted environmental stimulation therapy (floatation-REST) session could augment recovery from high-intensity resistance exercise (6 × 10 back squats, 2-min rest) known to induce significant metabolic, adrenergic, and mechanical stress.

METHODS

Eleven healthy resistance-trained males (age, 22.5 ± 2.3 yr; height, 176.4 ± 6.0 cm; weight, 85.7 ± 6.2 kg; back squat one-repetition maximum, 153.1 ± 20.1 kg; strength-to-weight ratio, 1.8 ± 0.2) completed the within-subject, crossover controlled study design. Participants completed two exercise testing blocks separated by a 2-wk washout. In one block, the high-intensity resistance exercise protocol was followed by a 1-h floatation-REST session, whereas recovery in the alternate block consisted of a passive sensory-stimulating control. Markers of metabolic stress, neuroendocrine signaling, structural damage, inflammation, and perceptions of soreness, mood state, and fatigue were assessed over a 48-h recovery window.

RESULTS

Floatation-REST significantly attenuated muscle soreness across recovery ( P = 0.035) with greatest treatment difference immediately after the intervention ( P = 0.002, effect size (ES) = 1.3). Significant differences in norepinephrine ( P = 0.028, ES = 0.81) and testosterone ( P = 0.028, ES = 0.81) immediately after treatment revealed the modification of neuroendocrine signaling pathways, which were accompanied by greater improvements in mood disturbance ( P = 0.029, ES = 0.81) and fatigue ( P = 0.001, ES = 1.04).

CONCLUSIONS

Because no adverse effects and significant and meaningful benefits were observed, floatation-REST may prove a valuable intervention for managing soreness and enhancing performance readiness after exercise.

Montmorency tart cherry supplementation does not impact sleep, body composition, cellular health, or blood pressure in healthy adults

Background: Sleep disturbances are linked with cardiovascular and metabolic disease as well as poor body composition. Aim: To investigate the use of tart cherry supplements, which are high in antioxidants and may contain melatonin, on parameters of health such as sleep, body composition, cellular health, and blood pressure (BP). Methods: Forty-four participants had completed sleep record data and were included in this analysis. Participants consumed either two 240 ml bottles per day of Montmorency tart cherry (MTC) juice or placebo or two capsules per day of powdered MTC or placebo for 30 days. Participants tracked their sleep daily via questionnaire and completed body composition and BP assessments at baseline, 14 days, and 30 days after supplementation. Results: There were no significant differences in sleep time or quality between groups, though both increased over 30 days. The capsule groups had significantly lower body mass (BM) 14 days versus baseline for placebo group (p = 0.01, mean difference: 0.70 kg) and at 30 days versus 14 days in MTC group (p = 0.02, mean difference: 0.75 kg). No other differences in body composition or cellular health were found. BP was unaffected by MTC supplementation over 30 days. Despite the potential benefits of antioxidants and melatonin, we did not find improvements in sleep time or quality, cellular health or BP in participants consuming MTC for 30 days, though BM decreased in capsule groups. Conclusion: These results conflict with previous data on MTC and sleep and BP, therefore further investigation is warranted.

Comparison of the polyphenol content and in vitro antioxidant capacity of fruit-based nutritional supplements commonly consumed by athletic and recreationally active populations

Background

Methods

Results

Conclusion

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 Physical Exercise Under Different Intensity and Antioxidative Supplementation for Plasma Superoxide Dismutase in Healthy Adults: Systematic Review and Network Meta-Analysis

Background

The dynamic balance between oxidation and anti-oxidation in the body’s internal environment has a significant meaning for human health. Physical exercise and antioxidative supplementation could affect the balance of oxidation and anti-oxidation systems. The evidence on the effects of physical exercise and antioxidative supplementation is mixed.

Aims

To identify the effects of physical exercise, antioxidative supplementation, and their combination on the dynamic balance between oxidation and anti-oxidation in different subgroups of healthy adults.

Methods

All studies which reported randomized controlled trials with healthy participants were screened and included from the databases of PubMed, Medline, Embase, and Ovid. All participants were reclassified according to their different daily life activities. All physical exercise interventions were reclassified according to the intensity. The effect size would be calculated in percent or factor units from the mean level change with its associated random-effect variance.

Result

There were 27 studies included in this review. The agreement between authors by using The Cochrane Collaboration Risk of Bias Assessment Tool reached a kappa-value of 0.72. Maintaining a regular physical exercise routine in an appropriate intensity would be beneficial to the body’s anti-oxidative potential. Anti-oxidative supplementation could have some positive but limited effects on the body’s anti-oxidative status and complex interaction with physical exercise.

Conclusion

Keeping a regular physical exercise routine and gradually increasing its intensity according to the individual’s daily life activity might be a better choice to maintain and enhancing the body’s antioxidation potential, only using anti-oxidative supplementation is not recommended. More research is needed to explore the best combination protocol.

Registration Number

CRD42021241995.

Thirty Days of Montmorency Tart Cherry Supplementation Has No Effect on Gut Microbiome Composition, Inflammation, or Glycemic Control in Healthy Adults

Tart cherries possess properties that may reduce inflammation and improve glycemic control, however human data on supplementation and the gut microbiota is equivocal. Processing (i.e., juice concentrate, dried, frozen) may affect the properties of tart cherries, and therefore alter their efficacious health benefits. Therefore, the purpose of this study was to investigate the effect of 30 days of supplementation with Montmorency tart cherry (MTC) in concentrate or freeze-dried form on the gut microbiome and markers of inflammation and glycemic control. Healthy participants with no known disease (n = 58, age: 28 ± 10 y, height: 169.76 ± 8.55 cm, body mass: 72.2 ± 12.9 kg) were randomly allocated to four groups and consumed either concentrate or freeze-dried capsules or their corresponding placebos for 30 days. Venous blood samples were drawn at baseline, day 7, 14, and 30 and analyzed for inflammatory markers TNF-alpha, uric acid, C-reactive protein, and erythrocyte sedimentation rate and glycemic control markers glycated albumin, glucose and insulin. A fecal sample was provided at baseline, day 14 and 30 for microbiome analysis. TNF-alpha was significantly lower at 30 vs. 14 days (p = 0.01), however there was no other significant change in the inflammatory markers. Insulin was not changed over time (p = 0.16) or between groups (p = 0.24), nor was glycated albumin different over time (p = 0.08) or between groups (p = 0.56), however glucose levels increased (p < 0.001) from baseline (4.79 ± 1.00 mmol·L^-1) to 14 days (5.21 ± 1.02 mmol·L^-1) and 30 days (5.61 ± 1.22 mmol·L^-1) but this was no different between groups (p = 0.33). There was no significant change in composition of bacterial phyla, families, or subfamilies for the duration of this study nor was there a change in species richness. These data suggest that 30 days of MTC supplementation does not modulate the gut microbiome, inflammation, or improve glycemic control in a healthy, diverse group of adults. Clinical Trail Registration:https://clinicaltrials.gov/ct2/show/NCT04467372, identifier: NCT04467372.

The effects of phosphocreatine disodium salts plus blueberry extract supplementation on muscular strength, power, and endurance

BACKGROUND

Numerous studies have demonstrated the efficacy of creatine supplementation for improvements in exercise performance. Few studies, however, have examined the effects of phosphocreatine supplementation on exercise performance. Furthermore, while polyphenols have antioxidant and anti-inflammatory properties, little is known regarding the influence of polyphenol supplementation on muscular strength, power, and endurance. Thus, the purpose of the present study was to compare the effects of 28 days of supplementation with phosphocreatine disodium salts plus blueberry extract (PCDSB), creatine monohydrate (CM), and placebo on measures of muscular strength, power, and endurance.

METHODS

Thirty-three men were randomly assigned to consume either PCDSB, CM, or placebo for 28 days. Peak torque (PT), average power (AP), and percent decline for peak torque (PT%) and average power (AP%) were assessed from a fatigue test consisting of 50 maximal, unilateral, isokinetic leg extensions at 180°·s^- 1 before and after the 28 days of supplementation. Individual responses were assessed to examine the proportion of subjects that exceeded a minimal important difference (MID).

RESULTS

The results demonstrated significant (p < 0.05) improvements in PT for the PCDSB and CM groups from pre- (99.90 ± 22.47 N·m and 99.95 ± 22.50 N·m, respectively) to post-supplementation (119.22 ± 29.87 N·m and 111.97 ± 24.50 N·m, respectively), but no significant (p = 0.112) change for the placebo group. The PCDSB and CM groups also exhibited significant improvements in AP from pre- (140.18 ± 32.08 W and 143.42 ± 33.84 W, respectively) to post-supplementation (170.12 ± 42.68 W and 159.78 ± 31.20 W, respectively), but no significant (p = 0.279) change for the placebo group. A significantly (p < 0.05) greater proportion of subjects in the PCDSB group exceeded the MID for PT compared to the placebo group, but there were no significant (p > 0.05) differences in the proportion of subjects exceeding the MID between the CM and placebo groups or between the CM and PCDSB groups.

CONCLUSIONS

These findings indicated that for the group mean responses, 28 days of supplementation with both PCDSB and CM resulted in increases in PT and AP. The PCDSB, however, may have an advantage over CM when compared to the placebo group for the proportion of individuals that respond favorably to supplementation with meaningful increases in muscular strength.

Effects of Beetroot Supplementation on Recovery After Exercise-Induced Muscle Damage: A Systematic Review

CONTEXT

Beetroots have antioxidant and anti-inflammatory properties, which may help attenuate inflammation and oxidative stress, enhancing recovery from exercise-induced muscle damage (EIMD).

OBJECTIVE

To evaluate the effects of beetroot supplementation on oxidative stress, inflammation, and recovery after EIMD.

DATA SOURCES

SPORTDiscus, PubMed, Web of Science, and Scopus databases were searched, and hand-searching was performed by looking to relevant studies that were cited in other studies.

STUDY SELECTION

For a study to be included in this review, the following inclusion criteria had to be met: (1) research conducted with human participants, (2) original articles in peer-reviewed publications, (3) original studies that had investigated beetroot supplementation intervention on muscle damage and recovery, (4) research conducted with 1 control/placebo group, and (5) articles published from inception to October 2020.

STUDY DESIGN

Systematic review using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

Two of the 4 authors independently extracted data and assessed the methodological quality of the articles with the PEDro scale. All discrepancies were resolved through a consensus meeting.

RESULTS

A total of 9 studies were included in this review. The methodological quality of the included studies ranged from moderate to high. Most of the studies found a better recovery of functional variables and muscle soreness, but improvements in markers of muscle damage, inflammation, and oxidative stress were not reported.

CONCLUSION

The existing evidence suggests that a short-term beetroot supplementation has the potential to accelerate recovery of functional measures and muscle soreness, but further research is needed to clarify if a longer supplementation period (with some days before exercise and some days after) could also promote recovery of markers of muscle damage, inflammation, and oxidative stress.

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.

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.

Use, Practices and Attitudes of Elite and Sub-Elite Athletes towards Tart Cherry Supplementation

Tart cherry (TC) supplementation can improve exercise recovery and performance; and may also improve sleep duration and quality. This study investigated the use and knowledge of TC supplementation by athletes of all competitive levels. Eighty participants (52.5% elite (international, national, professional), 47.5% sub-elite (semi-professional, state/regional, county level, club level, recreational)) completed an online questionnaire investigating their attitudes towards and use of TC supplementation. Overall, 22.6% of participants were using or had previously used TC supplements, and 12.5% of participants planned to used TC supplements. Improved recovery (71.4%), sleep (32.1%) and immunity and general health (32.1%) were the most frequently indicated goals by respondents using TC supplements. In total, 32.1% of respondents were supplemented with TC chronically, 39.3% acutely and 28.6% used a combination of chronic and acute supplementation. The majority of those employing TC supplementation chronically used TC either over 2-3 days (37.0%) or continuously (37.0%). The most popular TC pre- and post-loading period was one day (34.3% and 41.5%, respectively). There were no significant differences between elite and sub-elite athletes in any parameters assessed (p > 0.05). TC supplementation is not widely used by the athletes surveyed, and athletes using TC supplements showed poor awareness of an evidence-led dosing strategy, regardless of competitive level.

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.

Flavonoid Containing Polyphenol Consumption and Recovery from Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis

BACKGROUND

Flavonoid polyphenols are bioactive phytochemicals found in fruits and teas among other sources. It has been postulated that foods and supplements containing flavonoid polyphenols may enhance recovery from exercise-induced muscle damage (EIMD) through upregulation of cell signalling stress response pathways, particularly the nuclear factor erythroid 2-related factor 2 (NRF2) pathway.

OBJECTIVES

This study aims to investigate the ability of polyphenol treatments containing flavonoids to enhance recovery of skeletal muscle strength, soreness and creatine kinase post EIMD.

METHODS

Medline (Pubmed), Embase and SPORTdiscus were searched from inception to August 2020 for randomised placebo-controlled trials which assessed the impact of 6 or more days of flavonoid containing polyphenol ingestion on skeletal muscle recovery in the 96-h period following a single bout of EIMD. A total of 2983 studies were screened in duplicate resulting in 26 studies included for analysis. All meta-analyses were undertaken using a random-effects model.

RESULTS

The pooled results of these meta-analyses show flavonoid polyphenol treatments can enhance recovery of muscle strength by 7.14% (95% CI [5.50-8.78], P < 0.00001) and reduce muscle soreness by 4.12% (95% CI [- 5.82 to - 2.41] P = 0.00001), no change in the recovery of creatine kinase concentrations was observed.

CONCLUSION

These results indicate that ingestion of polyphenol treatments which contain flavonoids has significant potential to improve recovery of muscular strength and reduce muscle soreness in the 4-day period post EIMD. However, the characterisation of polyphenol dosage and composition of study treatments should be prioritised in future research to facilitate the development of specific guidelines for the inclusion of flavonoid-rich foods in the diet of athletes and active individuals.

Acute Ingestion of Montmorency Tart Cherry Reduces Serum Uric Acid but Has no Impact on High Sensitivity C-Reactive Protein or Oxidative Capacity

Tart cherries are particularly high in anthocyanins and are believed to have many health benefits, including reducing inflammation and oxidative stress. However, comparison between dosages and formulations are lacking. Forty-eight participants were randomly allocated to one of six experimental treatment groups where they ingested tart cherry or placebo in either juice (240 ml per bottle) or powdered capsule form (480 mg per capsule) once or twice daily for 48 h and markers of inflammation (uric acid (UA), high-sensitivity C-reactive protein (hsCRP)) and oxidative capacity (plasma oxygen radical absorbance capacity (ORAC)) were measured. There was a group x time interaction for UA (p = 0.02), which declined up to 24 h post ingestion for a single capsule dose, up to 8 h for a two capsule dose, and up to 2 h for a single juice dose. There was an increase in UA from 8 h until 48 h post ingestion in a single juice dose. Overall, there was an average 8% decrease in UA. There was no significant change over time in hsCRP (p = 0.64) or ORAC (p = 0.42) or between groups in hsCRP (p = 0.47) or ORAC (p = 0.21). Our data indicates tart cherry ingestion can transiently decrease UA and not maintained with continued supplementation. Additionally, there were differences in formulations and doses indicating a single powdered capsule is most effective for lowering UA suggesting capsules may be used by those who do not enjoy the taste of tart cherry juice. This study was registered at ClinicalTrials.gov , NCT04497077, 7/29/2020, retrospectively registered.

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.

Oxidative Stress in Rats is Modulated by Seasonal Consumption of Sweet Cherries from Different Geographical Origins: Local vs. Non-Local

Sweet cherries (Prunus avium L.) are a source of bioactive compounds, including phenolic compounds, which are antioxidants that contribute to protection against oxidative stress. It is known that the composition of cherries is influenced by external conditions, such as the geographic origin of cultivation, and that biological rhythms have a significant effect on oxidative stress. Therefore, in this study, Fischer 344 rats were exposed to various photoperiods and were supplemented with Brooks sweet cherries from two different geographical origins, local (LC) and non-local (NLC), to evaluate the interaction of supplementation and biological rhythms with regard to the oxidative stress status. The results indicate that the two fruits generated specific effects and that these effects were modulated by the photoperiod. Consumption of sweet cherries in-season, independently of their origin, may promote health by preventing oxidative stress, tending to: enhance antioxidant status, decrease alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, reduce liver malondialdehyde (MDA) levels, and maintain constant serum MDA values and reactive oxygen species (ROS) generation.

Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice

(Poly)phenol-rich diets have been associated with reduced risk of various diseases. Coffee and tea are typically identified as dietary sources of chlorogenic acid and flavan-3-ols; however, 100% fruit juice greatly contributes to anthocyanin, flavonol, flavan-3-ols, and flavanone intake, making them complementary sources of dietary (poly)phenols. Thus, the aim of this narrative review was to provide an overview of fruit (poly)phenols and their potential health benefits. Fruit (poly)phenols have been associated with several health benefits (eg, reduced risk of cardiovascular disease and neurocognitive benefits). Although perspectives on 100% fruit juice consumption are controversial due to the perception of sugar content, growing evidence supports the role of fruit in whole and 100% juice forms to provide consumer benefits in alignment with dietary guidance. However, differences in (poly)phenol profiles and bioavailability likely exist between whole fruit and 100% fruit juice due to processing and the presence/absence of fiber. Ongoing studies are better defining similarities and differences between whole fruit and 100% fruit juice to elucidate protective mechanisms and align with processing and consumer products.

Fruit supplementation reduces indices of exercise-induced muscle damage: a systematic review and meta-analysis

This systematic review and meta-analysis examined the effects of fruit supplements on indices of muscle damage and physical performance measures following muscle-damaging exercise protocols. The PEDro scale and Cochrane's risk of bias tool was used to critically appraise each study, whilst forest plots were generated to report on standardised mean differences (SMD) and p-values. The studies employed a crossover-randomised design, or a randomised controlled placebo design, with measures compared between the supplement (SUPP) and placebo (PLA) conditions at 24 and 48 h following the muscle-damaging exercise protocols. Compared to the PLA condition, the SUPP condition exhibited significantly lower levels of indirect muscle damage markers (p = 0.02; I² = 44%), inflammatory markers (p = 0.03; I² = 45%) and oxidative stress (p < 0.001; I² = 58%), whilst antioxidant capacity was significantly increased (p = 0.04; I² = 82%) at 24 h post-exercise. The maximal isometric voluntary contraction was significantly greater for the SUPP condition than the PLA at 24 h (p < 0.001; I² = 81%) and 48 h (p < 0.001; 84%) post-exercise. Only a few studies reported on functional outcome measures (i.e. countermovement jump, cycling, sprint and running maximal oxygen uptake), and the findings appeared conflicting according to qualitative analyses. Fruit supplementation minimised the level of several biomarkers of muscle damage, inflammation and oxidative stress, whilst improved muscular contractility during periods of EIMD. These findings demonstrate that fruit supplements could be used as recovery strategies from strenuous exercise sessions.

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.

The Effects of Asparagus Racemosus Supplementation Plus 8 Weeks of Resistance Training on Muscular Strength and Endurance

Previous studies have demonstrated that ayurvedic ingredients exhibit ergogenic (performance enhancing) properties, however, no previous studies have examined the ergogenic potential of Asparagus racemosus. The purpose of the present study was to examine the ergogenic efficacy of supplementation with 500 mg·d-1 of A. racemosus during bench press training. Eighteen recreationally trained men (mean ± SD; age = 20.4 ± 0.5 yrs; height = 179.7 ± 1.5 cm; weight = 84.7 ± 5.7 kg) were randomly assigned either 500 mg·d-1 of A. racemosus (n = 10) or placebo (n = 8). An overlapping sample of 10 participants were used to determine test-retest reliability. Pre- and post-training testing included bench press with one repetition maximum (1RM) and repetitions to failure at 70% of pre-training 1RM. The participants performed two sets of bench press to failure three times a week for eight weeks. Independent t-tests, Analyses of covariance (ANCOVA), and regression analyses were used to analyze the dependent variables. The results demonstrated greater mean percentage (14.3 ± 7.7% vs. 7.8 ± 4.5%; p = 0.048) and individual (80% vs. 50%) increases in 1RM, mean (17.5 ± 2.2 repetitions vs. 15.2 ± 2.2 repetitions; p = 0.044) and individual (80% vs. 38%) increases in repetitions to failure, and a greater rate of increase in training loads for the Asparagus racemosus group than the placebo group. In conjunction with bench press training, supplementation with A. racemosus provided ergogenic benefits compared to placebo.

Tart Cherry Juice: No Effect on Muscle Function Loss or Muscle Soreness in Professional Soccer Players After a Match

PURPOSE

To investigate the effects of tart cherry juice (TCJ) on recovery from a soccer match in professional players.

METHODS

In a double-blind, placebo-controlled, crossover design, 10 male professional soccer players from the reserve team of an English Premier League Club (age 19 [1] y, height 1.8 [0.6] m, body mass 77.3 [6.4] kg) consumed 2 × 30-mL servings of TCJ or an isocaloric cherry-flavored control drink (CON) before and after a 90-minute match and 12 and 36 hours after the match. Muscle function (countermovement jump height and reactive strength index), subjective well-being, and subjective muscle soreness were measured before and 12, 36, and 60 hours after each match.

RESULTS

Countermovement jump height was similarly reduced in the days after the match after TCJ and CON supplementation, with the greatest loss occurring at 12-hour postmatch (-5.9% [3.1%] vs -5.4% [2.9%], of baseline values, respectively; P = .966; ηp2=.010). Decrements in reactive strength index were also greatest at 12-hour postmatch (TCJ -9.4% [8.4%] vs CON -13.9% [4.8%], of baseline values), but no group differences were observed at any time point (P = .097; ηp2=.205). Muscle soreness increased 12- to 60-hour postmatch in both groups, peaking at 12-hour postmatch (TCJ 122 [27] mm vs CON 119 [22] mm), but no group differences were observed (P = .808; ηp2=.024). No interaction effects were observed for subjective well-being (P = .874; ηp2=.025).

CONCLUSIONS

TCJ did not hasten recovery after a soccer match in professional players. These findings bring into question the use of TCJ as a recovery aid in professional soccer players.

Resistance Training, Antioxidant Status, and Antioxidant Supplementation

Resistance training is known to promote the generation of reactive oxygen species. Although this can likely upregulate the natural, endogenous antioxidant defense systems, high amounts of reactive oxygen species can cause skeletal muscle damage, fatigue, and impair recovery. To prevent these, antioxidant supplements are commonly consumed along with exercise. Recently, it has been shown that these reactive oxygen species are important for the cellular adaptation process, acting as redox signaling molecules. However, most of the research regarding antioxidant status and antioxidant supplementation with exercise has focused on endurance training. In this review, the authors discuss the evidence for resistance training modulating the antioxidant status. They also highlight the effects of combining antioxidant supplementation with resistance training on training-induced skeletal muscle adaptations.

Impact of anthocyanin-rich whole fruit consumption on exercise-induced oxidative stress and inflammation: a systematic review and meta-analysis

CONTEXT

Supplementing with fruits high in anthocyanins to reduce exercise-induced oxidative stress and inflammation has produced mixed results.

OBJECTIVE

This systematic review and meta-analysis aims to discuss the impact of whole fruits high in anthocyanins, including processing methods and the type and amount of fruit, on inflammation and oxidative stress.

DATA SOURCES

PICOS reporting guidelines and a customized coding scheme were used to search 5 databases (SPORTDiscus, Science Direct, Web of Science [BIOSIS], Medline [Pubmed], and the Cochrane Collaboration) with additional cross-referencing selection.

DATA EXTRACTION

A random-effects meta-analysis was used to measure effects of the fruit supplements with 3 statistics; the QTotal value based on a χ2 distribution, τ2 value, and I2 value were used to determine homogeneity of variances on 22 studies (out of 807). Outliers were identified using a relative residual value.

RESULTS

A small significant negative summary effect across the sum of all inflammatory marker outcomes (P < 0.001) and a moderate negative effect for the sum of all oxidative stress marker outcomes (P = 0.036) were found. Moderator analyses did not reveal significant (P > 0.05) differences between subgrouping variables.

CONCLUSIONS

Results indicate that consumption of whole fruit high in anthocyanins can be beneficial for reducing inflammation and oxidative stress.

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.

SPRINTING. . . Dietary Approaches to Optimize Training Adaptation and Performance

Although sprint athletes are assumed to primarily be interested in promoting muscle hypertrophy, it is the ability to generate explosive muscle power, optimization of power-to-weight ratio, and enhancement of anaerobic energy generation that are key outcomes of sprint training. This reflects the physique of track sprinters, being characterized as ecto-mesomorphs. Although there is little contemporary data on sprinters dietary habits, given their moderate energy requirements relative to body mass, a carbohydrate intake within the range of 3-6 g·kg^-1·day^-1 appears reasonable, while ensuring carbohydrate availability is optimized around training. Similarly, although protein needs may be twice general population recommendations, sprint athletes should consume meals containing ∼0.4 g/kg high biological value protein (i.e., easily digested, rich in essential amino acids) every 3-5 hr. Despite the short duration of competitions and relative long-recovery periods between races, nutrition still plays an important role in sprint performance. As energy expenditure moderates during competition, so too should intake of energy and macronutrients to prevent unwanted weight gain. Further adjustments in macronutrient intake may be warranted among athletes contemplating optimization of power-to-weight ratio through reductions in body fat prior to the competitive season. Other novel acute methods of weight loss have also been proposed to enhance power-to-weight ratio, but their implementation should only be considered under professional guidance. Given the metabolic demands of sprinting, a few supplements may be of benefit to athletes in training and/or competition. Their use in competition should be preceded with trialing in training to confirm tolerance and perceived ergogenic potential.

Montmorency cherry supplement does not affect aerobic exercise performance in healthy men

Aim: To determine the effects of short-term Montmorency cherry (MC) supplementation upon exercise performance, total blood nitrate levels, muscle oxygenation, and slow-component [Formula: see text]O₂ kinetics. Methods: Twelve healthy male participants ingested a MC or placebo (PL) supplement in a randomized cross-over fashion over a six day period then cycled at a power output achieved at 70% of [Formula: see text]O₂ peak for a maximum of 30 minutes or until exhaustion. Near-Infrared Spectroscopy sensors were used to determine muscle oxygenation. Blood was collected one hour post-supplement consumption on day one, day six, and one hour post-exercise. Results: All results are presented as mean ± SEM. Blood nitrate (μM/L) levels were not different one hour post-ingestion (MC = 8.30 ± 2.15, PL = 8.18 ± 1.86), following six days of supplementation (MC = 9.14 ± 1.89, PL = 7.24 ± 1.75) or one hour post-exercise (MC = 9.63 ± 1.61, PL = 7.97 ± 1.92) for treatment F = 0.26, p = 0.62; for time F = 0.45, p = 0.64; or treatment by time interaction F = 2.28, p = 0.13. Muscle oxygenation was not different between treatments for the right or left vastus lateralis, F = 0.68, p = 0.81 nor was time to respiratory compensation point (minutes) (MC = 18.40 ± 1.48, PL = 17.16 ± 1.78) F = 0.52, p = 0.60. MC supplement ingestion does not alter blood nitrate levels. Conclusion: Short-term MC ingestion does not increase muscle oxygenation during cycling exercise nor does it change slow-component [Formula: see text]O₂ kinetics.