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Efficacy of a tart cherry juice bland in preventing the symptoms of muscle damage

Authors:
  • Nicholas Institute of Sports Medicine and Athletic Trauma Lenox Hill Hospital

Abstract and Figures

Numerous antioxidant and anti-inflammatory agents have been identified in tart cherries. To test the efficacy of a tart cherry juice blend in preventing the symptoms of exercise induced muscle damage. This was a randomised, placebo controlled, crossover design. Fourteen male college students drank 12 fl oz of a cherry juice blend or a placebo twice a day for eight consecutive days. A bout of eccentric elbow flexion contractions (2 x 20 maximum contractions) was performed on the fourth day of supplementation. Isometric elbow flexion strength, pain, muscle tenderness, and relaxed elbow angle were recorded before and for four days after the eccentric exercise. The protocol was repeated two weeks later with subjects who took the placebo initially, now taking the cherry juice (and vice versa). The opposite arm performed the eccentric exercise for the second bout to avoid the repeated bout protective effect. Strength loss and pain were significantly less in the cherry juice trial versus placebo (time by treatment: strength p<0.0001, pain p = 0.017). Relaxed elbow angle (time by treatment p = 0.85) and muscle tenderness (time by treatment p = 0.81) were not different between trials. These data show efficacy for this cherry juice in decreasing some of the symptoms of exercise induced muscle damage. Most notably, strength loss averaged over the four days after eccentric exercise was 22% with the placebo but only 4% with the cherry juice.
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ORIGINAL ARTICLE
Efficacy of a tart cherry juice blend in preventing the
symptoms of muscle damage
D A J Connolly, M P McHugh, O I Padilla-Zakour
...............................................................................................................................
See end of article for
authors’ affiliations
.......................
Correspondence to:
Dr Connolly, Human
Performance Laboratory,
University of Vermont,
Burlington, VT 05405,
USA; Declan.Connolly@
uvm.edu
Accepted 16 May 2006
Published Online First
21 June 2006
.......................
Br J Sports Med 2006;40:679–683. doi: 10.1136/bjsm.2005.025429
Background: Numerous antioxidant and anti-inflammatory agents have been identified in tart cherries.
Objective: To test the efficacy of a tart cherry juice blend in preventing the symptoms of exercise induced
muscle damage.
Methods: This was a randomised, placebo controlled, crossover design. Fourteen male college students
drank 12 fl oz of a cherry juice blend or a placebo twice a day for eight consecutive days. A bout of
eccentric elbow flexion contractions (2 620 maximum contractions) was performed on the fourth day of
supplementation. Isometric elbow flexion strength, pain, muscle tenderness, and relaxed elbow angle were
recorded before and for four days after the eccentric exercise. The protocol was repeated two weeks later
with subjects who took the placebo initially, now taking the cherry juice (and vice versa). The opposite arm
performed the eccentric exercise for the second bout to avoid the repeated bout protective effect.
Results: Strength loss and pain were significantly less in the cherry juice trial versus placebo (time by
treatment: strength p,0.0001, pain p = 0.017). Relaxed elbow angle (time by treatment p = 0.85) and
muscle tenderness (time by treatment p = 0.81) were not different between trials.
Conclusions: These data show efficacy for this cherry juice in decreasing some of the symptoms of exercise
induced muscle damage. Most notably, strength loss averaged over the four days after eccentric exercise
was 22% with the placebo but only 4% with the cherry juice.
C
yclo-oxygenase inhibitory flavonoids
12
and antho-
cynanins with high antioxidant and anti-inflammatory
activities
134
have been identified in tart cherries, which
are considered good sources of phenolic compounds. This has
led to speculation that cherry consumption may be effective
in alleviating symptoms in inflammatory conditions.
4
Anti-
inflammatory drugs and food products containing anti-
oxidant nutrients have been studied extensively in the
treatment and prevention of exercise induced muscle damage
and its associated symptoms. Some studies have shown
efficacy with anti-inflammatory drugs
5–10
whereas others
have not.
11–14
Similarly, studies examining the effect of
antioxidants—for example, vitamins C and E—on the
symptoms of muscle damage have yielded inconsistent
results.
15–20
Discrepancies in the observed effects may, in
part, be related to factors such as differences in muscle
groups studied, differences in magnitude of muscle damage
between studies, study sample sizes relative to interindivi-
dual differences in symptoms of damage, between group
study designs versus crossover designs, whether the treat-
ment was given before eccentric exercise, after eccentric
exercise, or both, and differences in dosages.
Consumption of about 45 cherries a day has been shown to
reduce circulating concentrations of inflammatory markers in
healthy men and women.
21 22
Considering the natural anti-
inflammatory and antioxidant capacity of tart cherries, it is
plausible that cherry consumption before and after eccentric
exercise may have a protective effect. Therefore the purpose
of this study was to test the effect of a tart cherry juice blend
taken before and after eccentric exercise on the symptoms of
muscle damage.
METHODS
Sixteen men (mean (SD) age 22 (4) years, height 1.78
(0.76) m, weight 90 (18) kg) volunteered to participate in
this study. The protocol was approved by the institutional
review board, and all subjects gave written informed consent.
Protocol
Four days before eccentric exercise, subjects reported to the
laboratory for baseline testing and to be provided with the
cherry juice or placebo. Their arms were randomly assigned to
a treatment or placebo trial and randomly assigned to
perform the treatment or placebo trial first. Pain, muscle
tenderness, relaxed elbow angle, and isometric elbow flexion
strength were measured. Inclusion criteria were no elbow
flexor pain, no upper extremity strength training in the past
three months, and no history of elbow or shoulder injury.
Subjects were also instructed not to take any anti-inflam-
matory or pain relieving drugs during the course of the study,
not to seek any other treatment for any symptoms of muscle
damage, and not to exercise their upper extremities during
the study. They were given 12 oz bottles of placebo or cherry
juice and instructed to drink one bottle in the morning and
the other in the evening for the next eight days. On the
fourth day, subjects returned to the laboratory and performed
a bout of eccentric elbow flexion contractions. On each of the
following four days, pain, muscle tenderness, relaxed elbow
angle, and strength were assessed. Two weeks after the initial
baseline testing (six days after the end of the first trial),
subjects returned to the laboratory and the protocol was
repeated on the contralateral arm with either the placebo or
cherry juice provided, as determined by previous randomisa-
tion. Subjects were scheduled to attend the laboratory for
data collection at the same time each day for both the
exercise session and four days of follow up data collection.
Treatment and placebo drinks
The cherry juice blend was prepared by mixing freshly
prepared tart cherry juice with commercially available apple
juice in a proprietary ratio (Cherrypharm Inc, West Hartford,
Connecticut, USA). Frozen tart cultivar Montmorency cher-
ries were used to prepare the cherry juice following standard
procedures that simulate industrial processing. The blended
juice was pasteurised by heating it to 85
˚
C, hot packed into
679
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12 oz glass bottles with a three minute hold time to achieve
commercial sterility, and then forced cooled in a water bath.
One 12 oz bottle of the juice provided at least 600 mg
phenolic compounds, expressed as gallic acid equivalents by
the method of Singleton and Rossi,
23
and at least 40 mg
anthocyanins, calculated as cyanidin-3-glucoside equivalents
by the pH differential method described by Giusti and
Wrolstad.
24
Each bottle contained the equivalent of 50–60
cherries.
The placebo was prepared by mixing unsweetened black
cherry Kool-aid soft drink mix (Kraft Northamerica,
Ryebrook, New York, USA; ingredients listed: citric acid,
salt, calcium phosphate, red 40, artificial flavour, ascorbic
acid, blue 1) with water in the proportion recommended by
the manufacturer (about 2 g/l). Sugar was added to match
the concentration of soluble solids in the cherry juice blend to
a final concentration of 13 Brix (total percentage soluble
solids by weight). The flavoured beverage was then pas-
teurised and bottled following the procedure used for the
juice blend.
Eccentric exercise protocol
The exercise regimen for the induction of delayed onset
muscle soreness consisted of 40 (2 6 20) maximal eccentric
contractions of the elbow flexors using a modified preacher
curl apparatus. In this study, the subject was instructed to
apply maximal resistance through use of their elbow flexor
musculature, while the investigator forced the subject’s
elbow into full extension. This was accomplished by pulling
down on a lever that extended about 60 cm past an
adjustable handle used to grip the lever by the subject. The
added length of the lever past the handle provided a
mechanical advantage over the subject’s maximal flexion
force, while requiring only limited effort to be exerted by the
investigator. The subject’s starting elbow angle position for
each maximally resisted movement was full active elbow
flexion (about 130
˚
flexion). Subjects performed two sets of
20 maximal eccentric contractions, with a three minute rest
period between sets. Each eccentric contraction lasted
approximately three seconds, with 12 seconds of rest
between actions.
Measurement of pain
Pain scores were obtained by asking subjects to verbally rate
their overall discomfort during active elbow flexion and
extension with activities of daily living on a scale of 0–10. A
score of 0 indicated no discomfort whatsoever. A score of 10
indicated extreme pain and discomfort. Subjects were given a
standard description for examples of daily activities which
included brushing teeth, opening a bottle, driving a car, or
opening doors.
Measurement of muscle tenderness
Muscle tenderness scores were assessed using a standard
manual muscle myometer. Measurements were made just
proximal to the distal tendon of the biceps brachii. All
measurements are reported in Newtons (N). Force was
applied via the probe through a 1 cm diameter head until the
subject indicated pain or discomfort. At this point the force
value (N) was recorded. Tenderness scores on the days after
eccentric exercise were subtracted from baseline scores to
provide a measure of tenderness, where zero equalled no
tenderness. Previous studies have used a ceiling of 40 N for
detecting muscle tenderness,
25 26
but it was felt that this
obscured interindividual differences in tenderness sensitivity.
For example, six subjects reported discomfort at less than
40 N at baseline on the treatment arm, and five subjects
reported discomfort at less than 40 N on the placebo arm.
Baseline tenderness was 47 (17) N on the treatment arm and
46 (15) N on the placebo arm. The system was calibrated
daily using a balanced 1 kg mass, 2 kg mass, and 3 kg mass
converted into Newtons (mass 6 9.81 N).
Assessment of relaxed elbow angle
Elbow range of motion was assessed using a standard plastic
goniometer (Lafayette Instrument, Lafayette, Indiana, USA)
with the subject standing. The axis of the goniometer was
placed over the lateral epicondyle of the elbow. The stationary
arm of the goniometer was placed in line with the long axis
of the humerus pointed at the acromion process. The
movement arm was placed in-line with the long axis of the
forearm. The placement locations of the goniometer axis,
movement arm, and stationary arm were marked with
permanent ink for consistency throughout trials.
Measurement of isometric elbow flexion strength
Subjects were tested on a modified, seated, arm curl
(preacher) bench with the upper arm supported by a padded
bench in about 45
˚
shoulder flexion. Isometric strength was
tested at three different elbow flexion angles: 130
˚
,90
˚
, and
30
˚
. The subjects grasped the handle attached to a movement
lever mounted on the arm curl device. Force was recorded by
a force transducer (model L-2352; Futek Inc, Irvine,
California, USA) in series with chains attached to the test
apparatus. Two trials were performed at each test angle with
each contraction lasting three seconds, and 60 seconds rest
between contractions. Peak strength values were recorded in
Newtons, and the mean of the two trials served as the
maximal isometric contraction strength score at that angle.
120
110
100
Strength (% of baseline)
90
80
70
60
Baseline 24 48 72 96
Time (hours)
**
***
*
***
Treatment Placebo
Figure 1 Isometric elbow flexion strength (expressed as a percentage
of baseline strength) after eccentric exercise. Displayed values are
averaged across all three test angles. Time by treatment p,0.0001;
*p,0.05, **p,0.01, ***p,0.001 pairwise comparisons with Bonferroni
corrections for treatment versus placebo values. Values are mean (SE).
10
Pain(0
10)
9
8
7
6
5
4
3
2
1
0
Baseline 24 48
Time (hours)
72 96
Treatment Placebo
Figure 2 Subjective report of pain in the elbow flexors after eccentric
exercise (0–10 scale). Time by treatment, p = 0.017. Values are mean
(SE).
680 Connolly, McHugh, Padilla-Zakour
www.bjsportmed.com
Sample size and statistical analysis
The sample size for this study was based on the difference in
symptoms of muscle damage between arms using the same
eccentric exercise protocol.
27
Based on the SD of the
difference in strength loss between arms, it was estimated
that, with a sample of 16 subjects, a 14% difference in
strength loss could be detected between the placebo and
cherry juice trials (p,0.05; power = 80%). The correspond-
ing estimated effect sizes were 1.2 points for pain, 6 N for
tenderness, and 6
˚
for motion loss.
Changes in the symptoms of muscle damage (pain,
tenderness, relaxed elbow angle, strength) between the
cherry juice and placebo trials were assessed using treatment
(cherry juice versus placebo) by time (baseline, 24, 48, 72,
and 96 hours) repeated measures analyses of variance, with
Bonferroni corrections on pairwise comparisons between
placebo and treatment trials. Mean (SD) is reported in the
text, and mean (SE) is shown in the figures.
RESULTS
Of the 16 subjects who started the protocol, two withdrew
before completion. Both were students who left school at the
end of the semester before completing the protocol. The
remaining 14 subjects completed the study.
Isometric elbow flexion strength loss was significantly
greater in the placebo trial than the cherry juice trial
(treatment by time p,0.0001; fig 1). This effect was not
different between test angles (angle by treatment by time p
= 0.41). Strength loss (averaged across all three test angles)
was 22 (12)% over the four days after the placebo trial but
only 4 (15)% after the cherry juice trial (p,0.0001). Strength
loss was not different between test angles (p = 0.31). In the
placebo trial, strength loss was 24 (13)% at 130
˚
of elbow
flexion (short muscle length), 20 (16)% at 90
˚
, and 20 (13)%
at 30
˚
(long muscle length). In the cherry juice trial, these
values were 5 (19)%, 5 (18)%, and 2 (13)% respectively.
The development of pain in the elbow flexors after
eccentric exercise was also significantly different in the
placebo and cherry juice trials (treatment by time, p = 0.017;
fig 2). Pain values (averaged across the four days) tended to
be higher in the placebo trial (3.2 (1.1)) compared with the
cherry juice trial (2.4 (0.7); p = 0.051). Pain peaked at
24 hours in the cherry juice trial (3.4 (1.2)) and subsequently
declined, whereas pain continued to increase in the placebo
trial to peak at 48 hours (4.5 (1.7)).
Loss of range of motion with the relaxed elbow angle
measurement was not different between cherry juice and
placebo trials (treatment by time, p = 0.85; fig 3). Mean
motion loss for the four days after the cherry juice trial was
3.5 (6.0)
˚
and 4.4 (5.6)
˚
after the placebo trial.
Muscle tenderness was also not different between cherry
juice and placebo trials (treatment by time, p = 0.81; fig 4).
Mean tenderness for the four days after the cherry juice trial
was 8.8 (9.7) N and 8.2 (10.1) N after the placebo trial (p =
0.84).
DISCUSSION
To our knowledge, this is the first study to examine the effect
of consumption of cherries, or a cherry product, on symptoms
of exercise induced muscle damage. Consumption of a cherry
juice blend for three days before a bout of eccentric exercise
and for the subsequent four days was shown to decrease
some of the symptoms of muscle damage. Strength loss and
pain were diminished in the cherry juice trial, but motion loss
and muscle tenderness were unaffected.
A randomised crossover design was used because the
variability in symptoms of muscle damage between limbs
within a subject is typically less than the variability in
symptoms between subjects.
27 28
The use of the contralateral
arm rather than the same arm in the second trial (cherry
juice or placebo depending on randomisation) avoided the
impact of the repeated bout effect. Although it is well
established that symptoms of muscle damage are diminished
after a repeated bout of eccentric exercise, this protective
effect does not cross over to the non-exercised limb.
28–30
Of
the 16 subjects who began the study, nine started with the
placebo trial and seven started with the cherry juice trial.
However, the two subjects who left school before the end of
the study started with the cherry juice trial. Therefore, only
five of 14 subjects who completed the study started with the
cherry juice trial. To verify that the apparent effect of cherry
juice on diminished strength loss and pain was not due to a
crossover protective effect, we reanalysed the data for the five
subjects who started with the cherry juice trial. Despite the
small sample size, the treatment by time interaction was
significant for strength loss in this group of five subjects (p
= 0.001). Strength loss was 3 (2)% for the cherry juice trial
and 24 (3)% for the placebo trial. The treatment by time
interaction was not significant for pain in these five subjects
(p = 0.83). However, the pattern was similar to the whole
group, with pain declining after 24 hours in the cherry juice
trial and peaking at 48 hours in the placebo trial.
The lack of effect of cherry juice supplementation on
muscle tenderness and relaxed elbow angle indicates that
either these symptoms reflect different aspects of the injury
response or the measurements were insensitive to real
differences between cherry juice and placebo trials.
Considering that muscle tenderness and pain typically follow
the same time course, peaking two days after eccentric
exercise of the elbow flexors,
25 26
it is unlikely that they reflect
different aspects of injury. Tenderness and pain also peaked
two days after exercise in the present study, and therefore the
effect of cherry juice would have been expected to be
apparent in both measures. The fact that the tenderness
Treatment Placebo
10
Loss of range of motion (degrees)
9
8
7
6
5
4
3
2
1
0
Baseline 24 48
Time (hours)
72 96
Figure 3 Changes in relaxed elbow angle after eccentric exercise. Time
by treatment, p = 0.85. Values are mean (SE).
20
15
Tenderness (N)
10
5
0
Baseline 24 48
Time (hours)
72 96
Treatment Placebo
Figure 4 Changes in muscle tenderness after eccentric exercise. Time
by treatment, p = 0.81. Values are mean (SE).
Juice supplementation and muscle damage 681
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measurement was only made at one site may have been a
limiting factor. Tenderness was measured distally because
peak tenderness has been shown to occur distally.
25 31
Although measurements at additional sites may have
increased the ability to detect a difference between trials, it
is important to note that tenderness values were very similar
between the trials, indicating no effect of cherry juice
supplementation. However, the tenderness measurement is
a measure of the threshold of tenderness—that is, the force at
which the subject first experiences discomfort. The measure-
ment does not indicate the magnitude of tenderness for a
fixed force application. Two studies have shown an effect of
anti-inflammatory drugs on muscle tenderness.
78
The target
muscle group was the quadriceps in both studies. In one
study,
8
the subjects were asked to rate the soreness from 0 to
10 while a force transducer was pressed into the quadriceps
at four different locations.
8
In the other study, the force
required to elicit soreness was recorded from multiple sites on
the quadriceps, and the product of soreness intensity (N) and
area (number of 2 cm sites registering a soreness measure-
ment below a ceiling of 50 N) was recorded for analysis.
7
The
use of a larger muscle group and multiple sites probably
improves the ability to detect treatment effects.
The relaxed elbow angle data reflect a similar lack of effect
of cherry juice supplementation. Given that the average loss
of motion was less than 5
˚
in each trial and that the
estimated effect size was 6
˚
, this negative finding could be
attributed to inadequate power to detect a real difference
between trials. A more damaging eccentric exercise protocol
or a larger sample size may be necessary to assess the effect of
cherry juice supplementation on this marker of damage. Of
note, only one of the six studies showing efficacy with anti-
inflammatory drugs
5–10
used the elbow flexors,
10
and the
relaxed elbow angle was not examined in that study.
Plasma or serum measures of myoglobin or creatine kinase
activity are often used as markers of muscle damage, but
were not used in this study. When using blood markers, it is
important to control the activity levels of the subjects
immediately before and during the study to ensure that
other activities are not causing increases in these markers.
Such restrictions were not thought to be necessary in this
study because of the crossover design. In this study, subjects
were screened for previous upper extremity strengthening
exercise and instructed not to use their arms in strenuous
activities during the study. However, they were not instructed
to avoid exercising other body parts—for example, running—
and therefore serum markers were not appropriate. Serum
markers might be used in future studies where activity level
is strictly controlled.
Although the results of this study indicate a protective
effect of cherry juice, it is not possible to conclude that cherry
juice supplementation prevented muscle damage, because
only two of four indirect markers of damage showed an
effect. However, there was clearly a preservation of muscle
function attributable to the cherry juice. For the placebo trial,
strength loss was 30% at 24 hours and still 12% at 96 hours
after eccentric exercise. By contrast, in the cherry juice trial,
strength loss was only 12% at 24 hours, and strength was
actually 6% above baseline at 96 hours. Other studies have
shown a treatment effect on isometric strength, but on a
smaller magnitude. Loss of isometric knee extension strength
was about 3% 24 hours after eccentric exercise in subjects
taking ibuprofen four hours before exercise compared with
about 13% for subjects taking a placebo.
7
Loss of isometric
knee extension strength was about 15% 24 hours after
eccentric exercise in subjects supplemented with vitamin C
and E for 30 days compared with 27% in subjects taking a
placebo.
19
By contrast, other studies have shown no effect of
ibuprofen
11 13 14
or vitamin E and C
15–17 20
on strength loss.
Although it was not within the scope of this study to
establish a specific mechanism of the preservation of
strength, the hypothesis was that antioxidant and anti-
inflammatory effects of cherry juice supplementation may
lessen the damage response. The initial damage response of
eccentric contractions is a mechanical disruption of myo-
fibrils and injury to the cell membrane. When myofibrillar
disruption is extensive, this triggers a local inflammatory
response that leads to an exacerbation of damage.
32
Leukotrienes increase the vascular permeability, attracting
neutrophils to the injury site, resulting in free radical
production.
33
It is possible that the anti-inflammatory and/
or the antioxidant effects of cherry juice mediated this
secondary response and avoided the proliferation of myo-
fibrillar disruption. This possibility could be examined in
future work by measuring neutrophil and monocyte activa-
tion after eccentric exercise.
The apparent efficacy of this particular cherry juice in
diminishing some of the symptoms of exercise induced
muscle damage may be a function of the formulation of the
drink. Consumption of about 45 cherries a day has been
shown to reduce circulating concentrations of inflammatory
markers in healthy men and women.
21
In the present study,
each 12 oz bottle of cherry juice contained the equivalent of
50–60 cherries, and therefore subjects were consuming the
equivalent of 100–120 cherries a day. In addition, the juice
contained fresh cherries—that is, not from concentrate—and
it is likely that this helped to preserve the phenolic
compounds and anthocyanins. The concentrations of phe-
nolic compounds and anthocyanins reported in the methods
section can provide a reference for future studies examining
the efficacy of similar supplements.
In conclusion, these data show efficacy for this cherry juice
in decreasing some of the symptoms of exercise induced
muscle damage. Most notably, strength loss averaged over
the four days after eccentric exercise was 22% with the
placebo but only 4% with the cherry juice. These results have
important practical applications for athletes, as performance
after damaging exercise bouts is primarily affected by
strength loss and pain. In addition to being an efficacious
treatment for minimising symptoms of exercise induced
muscle damage, consumption of cherry juice is much more
convenient than many of the treatments that have been
presented in the literature.
33
What is already known on this topic
N
Numerous antioxidant and anti-inflammatory agents
have been identified in tart cherries, and consumption
of cherries reduces circulating concentrations of
inflammatory markers
N
Many interventions have been studied for the preven-
tion and treatment of exercise induced muscle damage
but few have shown efficacy
What this study adds
N
Consumption of cherry juice before and after eccentric
exercise significantly reduced symptoms of muscle
damage
N
This is a practical intervention for alleviating the
symptoms of muscle damage
682 Connolly, McHugh, Padilla-Zakour
www.bjsportmed.com
ACKNOWLEDGEMENTS
This study was funded by Cherrypharm Inc (West Hartford,
Connecticut, USA).
Authors’ affiliations
.....................
D A J Connolly, Human Performance Laboratory, University of Vermont,
Burlington, VT, USA
M P McHugh, Nicholas Institute of Sports Medicine and Athletic Trauma,
Lenox Hill Hospital, New York, NY, USA
O I Padilla-Zakour, Department of Food Science & Technology, Cornell
University, Geneva, NY, USA
Competing interests: the authors each have 2.5% equity in Cherrypharm
Inc.
REFERENCES
1 Seeram NP, Bourquin LD, Nair MG. Degradation products of cyanidin
glycosides from tart cherries and their bioactivities. J Agric Food Chem
2001;49:4924–9.
2 Wang H, Nair MG, Strasburg GM, et al. Antioxidant and antiinflammatory
activities of anthocyanins and their aglycon, cyanidin, from tart cherries. J Nat
Prod 1999;62:294–6.
3 Blando F, Gerardi C, Nicoletti I. Sour Cherry (Prunus cerasus L) anthocyanins
as ingredients for functional foods. J Biomed Biotechnol 2004:253–8.
4 Tall JM, Seeram NP, Zhao C. Tart cherry anthocyanins suppress inflammation-
induced pain behavior in rat. Behav Brain Res 2004;153:181–8.
5 Donnelly AE, McCormick K, Maughan RJ, et al. Effects of non-steroidal anti-
inflammatory drug on delayed onset muscle soreness and indices of damage.
Br J Sports Med 1988;22:35–38.
6 Dudley GA, Czerkawski J, Meinrod A, et al. Efficacy of naproxen sodium for
exercise-induced dysfunction muscle injury and soreness. Clin J Sport Med
1997;7:3–10.
7 Hasson SM, Daniels JC, Divine JG, et al. Effect of ibuprofen use on muscle
soreness, damage, and performance: a preliminary study. Med Sci Sports
Exerc 1993;25:9–17.
8 Lecomte JM, Lacroix VJ, Montgomery DL. A randomized controlled trial of the
effect of naproxen on delayed onset muscle soreness and muscle strength.
Clin J Sport Med 1998;8:82–7.
9 O’Grady M, Hackney AC, Schneider K, et al. Diclofenac sodium (Voltaren)
reduced exercise-induced injury in human skeletal muscle. Med Sci Sports
Exerc 2000;32:1191–6.
10 Sayers SP, Knight CA, Clarkson PM, et al. Effect of ketoprofen on muscle
function and sEMG after eccentric exercise. Med Sci Sports Exerc
2001;33:702–10.
11 Donnelly AE, Maughan RJ, Whiting PH. Effects of ibuprofen on exercise-
induced muscle soreness and indices of muscle damage. Br J Sports Med
1990;24:191–5.
12 Howell JN, Conatser RR, Chleboun GS, et al. The effect of nonsteroidal anti-
inflammatory drugs on recovery from exercise-induced muscle injury. 1.
Flurbiprofen. Journal of Musculoskeletal Pain 1998;6:59–68.
13 Howell JN, Conatser RR, Chleboun GS, et al. The effect of nonsteroidal anti-
inflammatory drugs on recovery from exercise-induced muscle injury. 2.
Ibuprofen. Journal of Musculoskeletal Pain 1998;6:69–83.
14 Pizza FX, Cavender D, Stockard A, et al. Anti-inflammatory doses of
ibuprofen: effect on neutrophils and exercise-induced muscle injury. Int J Sports
Med 1999;20:98–102.
15 Beaton LJ, Allan DA, Tarnopolsky MA, et al. Contraction-induced muscle
damage is unaffected by vitamin E supplementation. Med Sci Sports Exerc
2002;34:798–805.
16 Bloomer RJ, Goldfarb AH, McKenzie MJ, et al. Effects of antioxidant therapy
in women exposed to eccentric exercise. Int J Sport Nutr Exerc Metab
2004;14:377–88.
17 Connolly DAJ, Lauzon C, Agnew J, et al. The effects of vitamin C
supplementation on symptoms of delayed onset muscle soreness. J Sports Med
Phys Fitness, 2006;in press.
18 Jakeman P, Maxwell S. Effect of antioxidant vitamin supplementation on
muscle function after eccentric exercise. Eur J Appl Physiol 1993;67:426–30.
19 Shafat A, Butler P, Jensen RL, et al. Effects of dietary supplementation with
vitamins C and E on muscle function during and after eccentric contractionsin
humans. Eur J Appl Physiol 2004;93:196–202.
20 Warren JA, Jenkins RR, Packer L, et al. Elevated muscle vitamin E does not
attenuate eccentric exercise-induced muscle injury. J Appl Physiol
1992;72:2168–75.
21 Kelley DS, Rasooly R, Jacob RA, et al. Consumption of bing sweet cherries
lowers circulating concentrations of inflammation markers in healthy men and
women. J Nutr 2006;136:981–6.
22 Jacob RA, Spinozzi GM, Simon VA, et al. Consumption of cherries lowers
plasma urate in healthy women. J Nutr 2003;133:1826–9.
23 Singleton VJ, Rossi JA. Colorimetry of total phenolics with phosphomolybdic-
phosphotungstic acid reagent. Am J Enol Vitic 1965;16:144–58.
24 Giusti MM, Wrolstad RE. Characterization and measurement with UV-visible
spectroscopy. In: Wrolstad RE, eds. Current protocols in food analytical
chemistry. New York: John Wiley & Sons, Inc, 2001:F1.2.1–13.
25 Cleak MJ, Eston RG. Muscle soreness, swelling, stiffness and strength loss after
intense eccentric exercise. Br J Sports Med 1992;26:267–72.
26 Newham DJ, Jones DA, Ghosh G, et al. Muscle fatigue and pain after
eccentric contractions at long and short length. Clin Sci 1988;74:553–7.
27 Tourville TW, Connolly DAJ, Reed BV. Effects of sensory-level high-volt pulsed
electrical current on delayed onset muscle soreness. J Sports Sci, 2006;in
press..
28 McHugh MP, Pasiakos S. The role of exercising muscle length in the protective
adaptation to a single bout of eccentric exercise. Eur J Appl Physiol
2004;93:286–93.
29 Clarkson PM, Byrnes WC, Gillisson E, et al. Adaptation to exercise-induced
muscle damage. Clin Sci 1987;73:383–6.
30 Connolly DAJ, Reed BR, McHugh MP. The repeated bout effect: a central or
local mechanism? J Sports Sci Med 2002;3:80–6.
31 Newham DJ, Mills KR, Quigley BM, et al. Pain and fatigue after concentric
and eccentric muscle contractions. Clin Sci 1983;64:55–62.
32 Pizza FX, McLoughlin TJ, McGregor SJ, et al. Neutrophils injure cultured
skeletal myotubes. Am J Physiol Cell Physiol 2001;281:C335–41.
33 Connolly DAJ, Sayers SP, McHugh MP. Treatment and prevention of delayed
onset muscle soreness. J Strength Cond Res 2003;17:197–208.
.............
COMMENTARY 1
............
The investigation offers originality and a significant con-
tribution in the area of delayed onset muscle soreness and
antioxidant/anti-inflammatory treatments. There are many
studies in the literature on the use of more commonly known
antioxidants such as vitamin C and vitamin E, with varying
results. So this is both potentially promising and interesting.
L Carlson
Castleton State College, Castleton, VT, USA; lara.carlson@castleton.edu
.............
COMMENTARY 2
............
The question of what to do when muscles are sore and
damaged has persisted for many years. An increasing number
of studies have attempted to treat the symptoms of exercise
induced muscle damage with strategies of growing complex-
ity. Such treatments have included transcutaneous electrical
stimulation, pulsed ultrasound, immobilisation, hyperbaric
oxygen therapy, combined low intensity laser therapy/
phototherapy, and compression sleeves, just to name a few.
In many ways, these treatment strategies do not represent a
practical or realistic option for either the competitive or
recreational athlete. Other choices available for people with
sore and damaged muscle are pharmacological treatments
such as non-steroidal anti-inflammatory drugs; however,
some may hesitate to ingest these pharmacological agents
because of potential side effects or gastric discomfort. Thus
the choices for relief from exercise induced muscle damage
are limited. This study may have taken an important step
toward providing a sensible and realistic treatment option for
those suffering from sore and damaged muscles. The
scientific question of how to treat the damaged muscle is
an important one, and these researchers should be applauded
for finding a potential treatment that is not only practical,
but one that can be enjoyed!
S P Sayers
University of Missouri-Columbia, Columbia, MO, USA;
sayerss@missouri.edu
Juice supplementation and muscle damage 683
www.bjsportmed.com
... Therefore, the hypothesis is that the anti-inflammatory properties of phenolics would reduce the inflammatory process caused by the secondary muscle damage 4,5 . Studies have shown that daily supplementation of 650 to 1,300 mg of phenolics for 8 to 9 days accelerates the recovery of MS 6,7 . When supplementation was lower than 600 mg daily, even for 14 or 45 days, muscle recovery was not affected 8,9 . ...
... Another study did not observe the effect of supplementation with 1,000 mg of phenolics daily for 13 days on muscle recovery (e.g., strength, range of motion, muscle swelling) 11 . In these studies, phenolic supplementation was carried out in different ways, such as 1) fresh fruit-based beverages 6,12 , fruit dry in powder 9 or fruit extract 7,13 ; 2) energy bars with added isolated phytochemicals 11 ; and 3) isolated phytochemical capsules 10 or combined with other substances 8 . Additionally, the main base of the beverages evaluated in the abovementioned studies were pomegranate 7,13 , grape 9 , blueberry 12 , and cherry 6 . ...
... Of the six studies that showed a positive effect of supplementation, three administered beverages whose phenolic compound was hydrolyzed tannins 7,13,30 or anthocyanin, a class of flavonoids 31 . In the other two studies, the beverages contained anthocyanin and phenolic acids 6,12 . In those who did not observe the effect of supplementation, two had the presence of catechin (flavonoid class) 10,11 , one had phenolic acid 33 , and the other had flavonoids (catechin and anthocyanin) and stilbenes 9 . ...
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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.
... Montmorency tart cherry (TC), which can be consumed as a beverage made from powdered extract or liquid concentrate, contains polyphenols primarily from the anthocyanin (flavonoid) subclass. It has been associated with improved post-exercise muscle force and functional recovery (performance in a jump or agility task) across a variety of exercise types, including resistance-based [39,40], repeated sprint [41,42] and endurance exercise [43,44] tasks, and in both trained [39,41,42,[44][45][46] and untrained/recreationally active [40] participants. This has typically been accompanied by a decrease in post-exercise muscle soreness [40][41][42]45,46]. ...
... Montmorency tart cherry (TC), which can be consumed as a beverage made from powdered extract or liquid concentrate, contains polyphenols primarily from the anthocyanin (flavonoid) subclass. It has been associated with improved post-exercise muscle force and functional recovery (performance in a jump or agility task) across a variety of exercise types, including resistance-based [39,40], repeated sprint [41,42] and endurance exercise [43,44] tasks, and in both trained [39,41,42,[44][45][46] and untrained/recreationally active [40] participants. This has typically been accompanied by a decrease in post-exercise muscle soreness [40][41][42]45,46]. ...
... It has been associated with improved post-exercise muscle force and functional recovery (performance in a jump or agility task) across a variety of exercise types, including resistance-based [39,40], repeated sprint [41,42] and endurance exercise [43,44] tasks, and in both trained [39,41,42,[44][45][46] and untrained/recreationally active [40] participants. This has typically been accompanied by a decrease in post-exercise muscle soreness [40][41][42]45,46]. ...
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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.
... Montmorency cherry juice (MCJ), also known as tart cherry juice, has been suggested to diminish oxidative stress, inflammation, and muscle soreness in various study populations (18). Specifically, MCJ has been investigated as an ergogenic aid targeting inflammation after endurance exercise (3-5, 13, 17, 19, 21), and resistance training (6,12,20). These findings suggest that MCJ may minimize inflammation associated with acute exercise responses (3,4,6,13,17,20,21) through decreasing inflammatory markers such as Interleukin-6 (IL-6) (3,4,17) and attenuating pain sensations (3,12,17,19,20). ...
... Specifically, MCJ has been investigated as an ergogenic aid targeting inflammation after endurance exercise (3-5, 13, 17, 19, 21), and resistance training (6,12,20). These findings suggest that MCJ may minimize inflammation associated with acute exercise responses (3,4,6,13,17,20,21) through decreasing inflammatory markers such as Interleukin-6 (IL-6) (3,4,17) and attenuating pain sensations (3,12,17,19,20). The anti-inflammatory effects of MCJ are thought to be due to its high anthocyanin content acting as antioxidants (26), and have been shown to attenuate the cyclooxygenase 2 (COX-2) pathway (28). ...
... Another indicator of skeletal muscle inflammation is perceptual muscle soreness. Previous literature has shown a minimization of pain while consuming MCJ following an exercise bout (3,12,17,19,20) providing support for MCJ as an ergogenic aid in sports with minimal rest between competitive bouts. While our data appears to illustrate a non-significant increase in perceived soreness following the exercise bout there is no observed difference between beverages. ...
Article
Full-text available
International Journal of Exercise Science 15(6): 686-701, 2022. 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 within-subjects 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.
... A reduction in physiological stressors that negatively impact exercise training [30] may support fast and slow phases of recovery, influencing performance in both prolonged or repeated bouts of exercise. Evidence for enhanced functional recovery from foods/supplements high in polyphenol compounds (e.g., Montmorency cherries > 5-days) have been exhibited in both trained and untrained individuals in a multitude of general exercise settings [31][32][33]. However, further research is warranted to investigate other polyphenols or novel food products, to assess markers of exercise recovery and identify the potential impact of phenolic compounds in specific exercise settings. ...
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There is current scientific interest in naturally sourced phenolic compounds and their potential benefits to health, as well as the effective role polyphenols may provide in an exercise setting. This study investigated the chronic effects of supplementation with a biodynamic and organic olive fruit water phytocomplex (OliPhenolia® [OliP]), rich in hydroxytyrosol (HT), on submaximal and exhaustive exercise performance and respiratory markers of recovery. Twenty-nine recreationally active participants (42 ± 2 yrs; 71.1 ± 2.1 kg; 1.76 ± 0.02 m) consumed 2 × 28 mL∙d−1 of OliP or a taste- and appearance-matched placebo (PL) over 16 consecutive days. Participants completed a demanding, aerobic exercise protocol at ~75% maximal oxygen uptake (V˙ O2max) for 65 min 24 h before sub- and maximal performance exercise tests prior to and following the 16-day consumption period. OliP reduced the time constant (τ) (p = 0.005) at the onset of exercise, running economy (p = 0.015) at lactate threshold 1 (LT1), as well as the rating of perceived exertion (p = 0.003) at lactate turnpoint (LT2). Additionally, OliP led to modest improvements in acute recovery based upon a shorter time to achieve 50% of the end of exercise V˙ O2 value (p = 0.02). Whilst OliP increased time to exhaustion (+4.1 ± 1.8%), this was not significantly different to PL (p > 0.05). Phenolic compounds present in OliP, including HT and related metabolites, may provide benefits for aerobic exercise and acute recovery in recreationally active individuals. Further research is needed to determine whether dose-response or adjunct use of OliP alongside longer-term training programs can further modulate exercise-associated adaptations in recreationally active individuals, or indeed support athletic performance. Keywords: polyphenols; OliPhenolia®; hydroxytyrosol; exercise; oxygen uptake kinetics; lactate threshold; running economy
... One polyphenolic-rich food commonly used for investigation is tart cherry (TC) juice. Vitale et al. [12] summarized data from 11 studies using TC supplementation in athletes to accelerate recovery, for example, after eccentric elbow flexion contractions [12,13]. Other polyphenolicrich foods commonly used are pomegranate juice [14], New Zealand blueberry [15], beetroot juice [16], cocoa pods [17] and black currant nectar [18]. ...
Article
Full-text available
Previous studies have shown that polyphenol consumption enhances recovery of the muscle after exercise-induced muscle damage (EIMD). However, EIMD markers have not been studied by sport type. The main aim of this research was to perform a systematic review to determine the efficacy of polyphenolic consumption in increasing muscle recovery for performing team sport skills. Eligible studies included, following PICOS structure, presented at least one of the following outcomes: maximal isometric voluntary contraction (MVIC); countermovement jump (CMJ); delayed onset muscle soreness (DOMS); 20 m sprint test; creatine kinase (CK); and C-reactive protein (hsCRP). A structured search was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The risk of bias was assessed using the PEDro scale tool. The review showed a possibly positive impact of polyphenol consumption on recovery after EIMD in team sports athletes. No differences were found between sexes. Considering the limitations, there is moderate to very low certainty of polyphenol supplementation effects on recovery of team sport females and males. A dose of 60 mL/day, divided into two times per day, ingested for >7 days may present positive effects on muscle function and muscle soreness in team sport athletes. However, further investigation is required, specifically in females.
... Some disagreement between studies probably reflects differences in study design, but possible variation in the dose of polyphenols supplied by different fruit supplements could also be a contributing factor. For example, Connolly et al. [10] reported that consumption of a tart cherry/apple juice blend supplying 1200 mg of polyphenols for 4 days prior to and 4 days following 2 sets of 20 maximal eccentric contractions of the elbow flexors enhanced recovery of muscle strength. In contrast, Levers et al. [11] reported that a lower intake of 480 mg/d of Montmorency tart cherry powder for 7 d before and 2 days after 10 × 10 back squats failed to accelerate recovery of muscle strength. ...
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Background: Polyphenol-rich fruit supplements are commonly consumed by recreationally active and athletic populations because of their proposed benefits to both exercise performance and recovery from prior exercise. While it has been proposed that 300 mg of polyphenols pre-exercise enhances performance and 1000 mg per day accelerates recovery from muscle damage, it is difficult for consumers to optimize their intake because the polyphenol content of most fruit supplements is not available. Therefore, this study aimed to profile the phenolic and anthocyanin content and in vitro antioxidant capacity of a range of polyphenol-rich fruit supplements on sale in the UK. Methods: Ten polyphenol-rich fruit supplements (six cherry, two pomegranate, one blueberry, and one New Zealand blackcurrant) commonly consumed by athletes were analyzed for total phenols (Folin-Ciocalteu method), total anthocyanins (pH differential method), and in vitro antioxidant capacity (ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Results: The ten tested supplements varied markedly per serving in total phenolics (range: 13.8-1007.3 mg/gallic acid equivalents), anthocyanin content (range: 0.19-40.52 mg/cyanidin-3-glucoside), ORAC (range: 150-10,072 µmol of trolox equivalents), and FRAP (range: 72-14,320 µmol of Fe2+ equivalents). Different brands of tart cherry concentrate also exhibited a marked variation in their content of total phenolics (208-591 mg/GAE), anthocyanins (1.5-23.7 mg/cyd-3-glu), and antioxidant capacity (FRAP: 1724-4489 µmol of Fe2+ equivalents; ORAC: 6015-10,072 µmol of TE per serving) per serving. Conclusion: As expected, supplements based on different fruits contained different quantities of anthocyanins and polyphenols. However, there was also a substantial variation within different brands of tart cherry supplements. Because limited compositional information is available on the labels of most fruit-based supplements, the data in this article will enable consumers to select the required volume of the ten tested supplements to meet suggested recommendations for polyphenol intake to enhance performance (300 mg pre-exercise) and accelerate recovery (1000 mg per day) from prior exercise.
... Oral intake of anti-inflammatory compounds has also been suggested (D. A. Connolly et al., 2003). Indeed, several studies have reported that supplementation with some anti-inflammatory substances is beneficial for attenuating exercise-induced muscle damage (EIMD) (D. Connolly, McHugh, & Padilla-Zakour, 2006;Howatson et al., 2010;Trombold, Barnes, Critchley, & Coyle, 2010), although some studies did not find such an effect (O'Fallon et al., 2012). ...
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Tribulus terrestris L. contains compounds with antioxidant and anti-inflammatory properties, but its effects on exercise-induced oxidative stress and inflammatory responses are unclear. The aim of this study was to examine whether Tribulus terrestris L. supplementation can attenuate oxidative stress and inflammatory responses to acute aerobic exercise and improve DOMS. In a randomized, double-blind, crossover design study, thirteen healthy men received either a daily supplement of Tribulus terrestris L. or a placebo for 4 weeks (2-week wash-out period between trials). Before and after the supplementation periods, participants performed an exercise test to exhaustion (75% VO2max). DOMS, thigh girth, and knee joint range of motion (KJRM) were assessed before and after the exercise (2, 24, and 48 h). Blood samples were analyzed for reduced (GSH) and oxidized (GSSG) glutathione, GSH/GSSG ratio, protein carbonyls, total antioxidant capacity, creatine kinase activity, white blood cell count, and TBARS. Acute exercise to exhaustion induced inflammatory responses and changed the blood redox status in both Tribulus and Placebo groups (p < 0.050). Tribulus terrestris L. improved GSH fall (p = 0.005), GSSG rise (p = 0.001) and maintained a higher level of GSH/GSSG ratio at the 2 h point (p = 0.034). TBARS were lowered, protein carbonyls, creatine kinase activity, and white blood cell count elevation diminished significantly (p < 0.050). Tribulus terrestris L. administration did not affect DOMS, thigh girth, or KJRM (p > 0.050). 4-weeks of Tribulus terrestris L. supplementation effectively attenuates oxidative stress responses but cannot improve DOMS.
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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.
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1. The effect of muscle length on the development of muscle pain and fatigue has been studied. 2. Eight normal young adults performed maximal eccentric contractions of the elbow flexors. The muscles of one arm were exercised at short length, and the contralateral muscle at long length. Each contraction lasted approximately 1 s, and was repeated once every 10 s for 30 min. 3. Muscle strength and frequency-force characteristics were measured from isometric contractions before, immediately after and at 24 h intervals for the next 4 days. Muscle tenderness was assessed daily. 4. The muscle strength was reduced by approximately 10% by exercise at short length, and by 30% by exercise at long length. 5. The 20:100 ratio (force generated by stimulation at 20 Hz/force generated at 100 Hz) fell by 30% after exercise at short length and had recovered after 24 h. Exercise at long length reduced this ratio by 65% and the muscles had not fully recovered 4 days later. 6. Muscle pain developed after both exercise regimens, but was slightly worse after that at long length. 7. It is concluded that there is a length-dependent component in the development of pain and fatigue after eccentric exercise, which had previously been thought to be caused solely by high force generation.
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Objectives: The objective was to assess the effects of two doses of the nonsteroidal anti-inflammatory drug, ibuprofen, 1600 mg and 3200 mg per day administered for six days, compared to placebo on muscle soreness, strength, swelling, and stiffness following experimentally-induced muscle injury in volunteer subjects. Methods: A one-time exercise consisting of repeated lowering of heavy loads with the elbow flexors was used to induce injury, which was manifested by soreness, swelling, stiffness, a reduction in relaxed arm angle, and a 50% loss in muscle strength from which recovery was only 50% complete in two weeks. After carrying out the exercise, subjects were randomly assigned to one of four groups, each with 20 subjects: 1. no treatment, 2. ibuprofen, 400 mg q.i.d., 3. ibuprofen, 800 mg q.i.d., or 4. placebo, q.i.d. The study was double-blind with respect to groups two, three, and four. Drug or placebo administration was begun on the day preceding the exercise. Measurements were made for two post-exercise weeks and compared to pre-exercise values. Results: In the repeated-measures analysis of variance, neither group differences nor group-by-time interactions were observed with respect to any of the variables measured. Power analysis demonstrated that differences ranging from 3% to 20% could have been detected by the methods used. Separate analysis of data from males and females also demonstrated no differences between them. The time course of stiffness, measured between elbow angles of 90°and 140°, differed from that of the relaxed arm angle, suggesting that these two parameters involve different underlying processes. Conclusions: Ibuprofen provides no detectable therapeutic benefit over a two week period following injury induced in the elbow flexors by eccentric contraction, as judged by subjective reports of muscle soreness and by objective measurements of maximum voluntary contractile strength, of muscle swelling, of muscle stiffness, or of relaxed arm angle.
Article
The purpose of this study was to evaluate the effect of elevated muscle vitamin E content on skeletal muscle damage from eccentric exercise. Sixty Sprague-Dawley rats were put on a normal (40 IU vitamin E/kg food) or supplemented (10,000 IU vitamin E/kg food) diet for 5 wk. Injury in soleus muscle was determined using several criteria: reductions in maximal tetanic force and number of intact fibers per square millimeter and elevations in muscle glucose 6-phosphate dehydrogenase activity and plasma creatine kinase activity, either immediately (0 h) or 2 days (48 h) after a downhill walking protocol. Sedentary animals were also tested but did not exercise. Muscle vitamin E levels were significantly elevated (approximately 3- to 4-fold), and susceptibility of the muscles to oxidant stress was decreased, after supplementation. However, vitamin E supplementation did not attenuate injury by any of the criteria employed. Maximal tetanic force decreased approximately 20% at 0 and 48 h after exercise in both groups. The number of intact fibers per square millimeter decreased approximately 30-35% in both groups at 0 and 48 h. Glucose 6-phosphate dehydrogenase activity increased approximately 50-100% in both groups at 48 h, and plasma creatine kinase activity was elevated approximately 2- to 2.5-fold at 0 h in both groups. These findings do not support a major role for free radical damage to muscle membranes in the initiation of injury from eccentric exercise, although they do not disprove free radical involvement in the etiology.