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2059-J.SM./Original articles. J SPORTS MED PHYS FITNESS 2006;46:00-00
The effects of vitamin C supplementation on symptoms
of delayed onset muscle soreness
Aim.The aim of this study was to compare the effects of 8 days
of vitamin C (VC) supplementation on elbow flexor delayed
onset muscle soreness (DOMS) to 8 days of placebo ingestion.
Methods. For 3 days prior to an exercise bout (2××20 eccentric
elbow extensions), and for 5 days after, a treatment group
ingested 3××1 000 mg/day of VC versus 3××50 mg/day of glucose
ingestion for the placebo group over the same time period. All
subjects were prescreened via dietary recall to exclude any
subjects with habitual VC consumption greater than 400
mg/day. Subject comprised 24 subjects (male and female) ran-
domly divided into 2 groups of 12 subjects. Treatment group
comprised 5 females and placebo group comprised 8 females.
Results. Data from a repeated measures ANOVA indicate that
DOMS was successfully induced in both groups via significant
time effects for strength loss (P=0.0001), point tenderness
(P=0.0001), elbow flexor decreased range of motion (P=0.013),
and subjective pain (P=0.0001). However, there were no sig-
nificant between group differences in response to any of the
aforementioned variables: strength loss (P=0.202), point ten-
derness (P=0.824), elbow flexor range of motion (P=0.208),
subjective pain (P=0.342).
Conclusion. The results of this study suggest that a VC sup-
plementation protocol of 3××1 000 mg/day for 8 days is ineffec-
tive in protecting against selected markers of DOMS.
K
EY WORDS
:DOMS - Muscle damage - Antioxidants - Exercise -
Vitamin C.
M
uscle soreness is a common symptom of unfa-
miliar or excessive bouts of exercise in both
trained and untrained individuals. The soreness usu-
ally develops within 24-48 h of an activity, and typically
involves eccentric movements or high peak forces.1, 2
This delayed expression of muscle soreness is most
commonly referred to as delayed onset muscle soreness
(DOMS). While eccentric exercise can be used as part
of an effective strengthening program if used correct-
ly, it is more common for eccentric exercise to lead to
muscle overuse, especially in the first stages of expo-
sure to the exercise. DOMS is a temporary condition
with symptoms that usually taper within 6 days after the
exercise.2Symptoms of DOMS include muscle
swelling, decreased range of motion, strength loss, and
pain. DOMS is currently being treated by a variety of
methods including ice, ultrasound, anti-inflammatory
medications, massage and stretching. Currently there
are no acknowledged methods for preventing the occur-
rence of DOMS. The most debilitating symptom of
DOMS is muscle pain. There are several hypotheses as
to what causes this pain. Some suggest this pain is
associated with the increased pressure within the mus-
cle tissues, other studies suggest that perhaps elevated
prostaglandin production causes an increase in the sen-
sitivity of free nerve endings of the irritated muscle
tissue.2It has also been shown that eccentric exercise
causes a loss of calcium from within the muscle cell.3
Human Performance Laboratory
University of Vermont, Burlington, VT, USA
Received May 5, 2005.
Accepted for publication February 9, 2006.
Address reprint requests to: Dr. D. A. J. Connolly, 212 Patrick
Gymnasium, UVM, Burlington, VT 05401, USA.
D. A. J. CONNOLLY, C. LAUZON, J. AGNEW, M. DUNN, B. REED
Vol. 46 - No. THE JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS 1
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As muscle enzymes work to repair the damaged mus-
cle cells we can observe a subsequent increase in free
radical production. Free radicals work to disrupt the
integrity of the cell membranes, which in turn can lead
to swelling and pain. Vitamin C (VC) is one of sever-
al antioxidant nutrients capable of reducing free radi-
cals within the body and has been shown to interact
with free radicals before they can initiate damage to
cell lipids.4VC, also known as ascorbic acid or ascor-
bate, is an essential micronutrient that plays a vital role
in multiple physiological functions. VC can be con-
sidered essential in nutritional terms in that the human
body cannot synthesize it. It therefore must be con-
sumed from exogenous sources via the diet. At pre-
sent the U.S. RDA for VC is 60 mg.5
Among the many roles of VC is its recognized func-
tion as an anti-oxidant. The proposed mechanism in
which this occurs is via a reduction in aqueous free rad-
icals.6VC also performs non-enzymatic reductive
functions in multiple reactions. This redox potential and
its role as a free radical intermediate permits VC to
have the desired effect as a reducing agent (anti-oxi-
dant). Free radical proliferation is a strongly suggest-
ed mechanism in the damage response to exercise
occurring mainly via the loss of calcium from within
the muscle cell.1The response of free radicals also
appears to be intensity related, whereby super-oxide
radical formation occurs as a function of the total oxy-
gen flux through the muscle. Since eccentric activity
tends to recruit fewer motor units and causes greater
damage per unit of active area one could argue that
the resultant free radical circulation is higher and thus
the potential for DOMS greater. Hence, it seems plau-
sible that supplementation with antioxidants prior to
exercise may reduce damage. In general, the treat-
ment of DOMS using conventional antioxidants (vit-
amins C and E) has been inconsistent and few well-con-
trolled studies exist. Kaminski et al.7presupplement-
ed subjects for 3 days with 1-g of VC 3 times a day and
then induced damage in the posterior calf muscles.
Supplementation continued for 7 days postexercise.
Subjects treated with VC reported reduced soreness rat-
ings ranging from 25-44% less than a control group.
More recent work by Thompson et al.8-10 appears to add
confusion to the role of VC in that these authors report
both no effect and a potential effect depending upon the
muscle damage marker measured and protocol used.
Additional work by Shafat et al.11 reports a smaller
loss of strength following VC supplementation in sub-
jects exposed to leg extension exercises. Thus, it
appears that many factors may contribute to the lack of
consensus regarding any possible effect of VC sup-
plements including dosage, timing of dosage, exer-
cise mode, and intensity.
As aforementioned, a proposed mechanism caus-
ing DOMS is an increase in free radical production.
Given this potential causative factor and the role of
VC as an antioxidant it would be of interest to evalu-
ate the relationship between VC supplements and the
alternative on signs and symptoms of DOMS, name-
ly strength, tenderness and range of motion. Therefore,
the purpose of this study is to evaluate the role of VC
supplementation in the prevention of DOMS follow-
ing elbow extension exercises.
Materials and methods
General overview
Twenty-four healthy college males and females with-
out upper extremity injury, or previous known history
of injury, were recruited for this study. Potential subjects
who indicated arm discomfort during any baseline
assessments were excluded. Subjects who reported
habitually participating in a strenuous resistance-train-
ing program involving the elbow flexors, or unusual
upper extremity activity were also excluded. Informed
consent, which included a description of the purposes
of this study and method of DOMS induction was
obtained from each subject prior to any testing.
All procedures were approved by The Institutional
Review Board prior to the investigation. Baseline mea-
surements on both arms of overall arm discomfort,
passive elbow extension range of motion, and iso-
metric elbow flexion strength were recorded. Following
baseline measurements subjects were randomly
assigned to a treatment or placebo treatment condi-
tion. Descriptive data are presented in Table I. No sig-
nificant differences existed between groups for any
descriptive variables. Supplementation of either place-
TABLE I.—Descriptive data (mean±SD).
Treatment Placebo Totals
Age 22.3±3.9 22.6±4.6 22.5±4.3
Height (cm) 172.8±11.2 167.6±6.8 73.6±16.2
Mass (kg) 77.4±17.1 69.8±15.1 170.6±9.6
No difference detected for any variables between treatment and control groups.
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THE EFFECTS OF VITAMIN C SUPPLEMENTATION ON SYMPTOMS OF DELAYED ONSED MUSCLE SORENESS CONNOLLY
bo or VC then began for 3 days prior to an exercise bout
designed to induce damage and for 5 days after. DOMS
was induced in the subjects’dominant or non-dominant
arm as determined by randomization. Subjects per-
formed two sets of 20 repetitions, of maximal eccen-
tric elbow flexor contractions while seated on a mod-
ified preacher bench. Subjects returned to the lab at 24,
48, 72, and 96 h post-DOMS induction for reevalua-
tion of baseline measurements. Subjects were instruct-
ed not to stretch, utilize ice, massage, anti-inflamma-
tory medications, or use any other self-treatment dur-
ing the study. The specifics of data collection are out-
lined in the following sections.
Interventions
During the trials, subjects were given either 1 000 mg
of ascorbic acid 3 times per day for 8 days or 50 mg of
glucose 3 times per day for 8 days. Supplementation
began 3 days prior to the exercise bout designed to
induce muscle damage and continued for 5 days after.
Furthermore, prior to enrolling in this study all subjects
had a dietary history analysis to evaluate baseline VC
intake. Any subject with routine VC intake greater
than 400 mg per day was excluded from this study.
Mean VC intake in this population was approximate-
ly 151.9±139.1 mg/day.
DOMS induction
The exercise regimen for the induction of DOMS
consisted of 40 (2×20) maximal eccentric contrac-
tions of the elbow flexors using a modified preacher
curl apparatus. A similar method of inducing DOMS
in the elbow flexor musculature has been previously
described.12-14
In the current study the subject was instructed to
apply maximal resistance through use of their elbow
flexor musculature, while the investigator forced the
subjects’elbow into full extension. This was accom-
plished by pulling down on a lever which extended
approximately 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 advan-
tage over the subjects’maximal flexion force, while
requiring only limited effort to be exerted by the inves-
tigator. The subject’s starting elbow angle position for
each maximally resisted movement was full active
elbow flexion (approximately 130° flexion). Subjects
performed two sets of 20 maximal eccentric contrac-
tions, with a 3-min rest period between sets. Each
eccentric contraction lasted approximately 3 s, with 12
s of rest between actions.
Strength assessment
Maximal isometric strength was assessed at baseline
and at 24, 48, 72, and 96 h post-DOMS induction.
Subjects were tested on a modified seated arm-curl
(preacher) bench at baseline and all other time inter-
vals. Using a protocol previously described13, 14 sub-
jects were seated on the preacher curl apparatus with
the upper arm supported by a padded bench in approx-
imately 45o shoulder flexion. The elbow was flexed at
90o, with the test hand grasping the handle attached to
a movement lever mounted on the arm-curl device.
Two chains (one mounted to the base of the arm-curl
bench, the other attached to the pivoting force lever
handle) were utilized to attach a Futek load-cell (mod-
el L-2352, Futek Inc., Irvine, CA, USA) to the preach-
er bench apparatus. The load cell was connected to a
D501 digital display (Futek Inc., Irvine, CA, USA)
and calibrated by Futek Advanced Sensor Technology
Inc. for use in our application. Two trials were per-
formed for each isometric strength measurement. Each
trial consisted of a maximal isometric contraction held
for 3 s, with a 60 s rest period between trials. Peak
strength values were recorded in Newtons, and the
average of the two trials served as the maximal iso-
metric contraction strength score.
Flexibility assessment
Passive elbow extension was assessed prior to the ini-
tial eccentric exercise bout, and at 24, 48, 72, and 96
h post-DOMS induction. Range of motion was assessed
with the subject in a supine position, using a standard
(31.75 cm) plastic goniometer (Lafayette Instrument,
Lafayette, IN, USA). A small bolster was placed below
the subjects’ upper arm to elevate it from the table.
The forearm was placed in neutral position. The axis
of the goniometer was placed over the lateral epi-
condyle 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. This procedure for testing elbow ROM is
a modification of that described by Norkin et al.15 In
the current trial a forearm neutral position was uti-
lized for consistency and control purposes. The
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goniometer axis, movement arm, and stationary arm
placement locations were marked with permanent ink
for consistency throughout trials.
Pain assessment
Pain scores were obtained by asking the subject 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. Pain scores were the first variables
recorded during each visit for both trials. This method
of pain assessment is an adaptation of that described
and utilized by Byrnes et al.16
Point tenderness
Muscle tenderness scores were assessed using a
standard manual muscle myometer. Measurements
were made at the insertion 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. Baseline val-
ues for tenderness were determined to be ≥40 N once
force application reached 40 N. Therefore, decreas-
ing force scores indicate increasing tenderness, a reflec-
tion of muscle damage. We used a baseline value of 40
N as force application greater than 40 N would likely
cause localized damage. This protocol has been pre-
viously described by Connolly et al.14
Statistical analysis
Data were analyzed using a 5×2 (time×treatment)
repeated measures analysis of variance (ANOVA) to
determine significant differences between treatments,
and over time. Repeated measures ANOVA assump-
tion of sphericity was verified through use of the
Mauchly sphericity test. Greenhouse-Geisser correc-
tions were made for analyses that did not meet
Mauchly’s test of sphericity. Alpha was set at P<0.05.
All analyses were performed with SPSS 11.0.1
Standard Edition (SPSS Inc., Chicago, IL, USA) sta-
tistical analysis software.
Results
Repeated measures analysis of variance of strength
loss data indicate that DOMS was successfully induced
in both groups (P≤0.0001). Percent strength loss for
both treatment and control groups are presented in
Figure 1. Point tenderness data are presented in Figure
2. Analysis of additional variables confirm significant
time effects for pain (P≤0.0001), range of motion
(P=0.013), and point tenderness (P≤0.0001). Average
percent strength loss from baseline in the first 24 h
was 30.1±21.2% for both groups and 34±21% and
Treatment Control
% strength loss
Days
60
50
40
30
20
10
012345
Figure 1.—Percent strength loss over time. Figure 2.—Point tenderness over time.
Treatment Control
Point Tenderness (N)
Days
60
50
40
30
20
10
012345
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THE EFFECTS OF VITAMIN C SUPPLEMENTATION ON SYMPTOMS OF DELAYED ONSED MUSCLE SORENESS CONNOLLY
26±20% for treatment and control, respectively. There
were no significant between group differences for any
of the four variables suggesting no treatment effect: per-
cent strength loss (P=0.202), point tenderness
(P=0.824), range of motion (P=0.208) and subjective
pain (P=0.342). Data for percent strength loss and pain
is presented in Table II. Thus the pattern of change
over time was similar for both groups. This data sug-
gests that VC as administered under this protocol is
ineffective in preventing against DOMS.
Discussion
The purpose of this study was to evaluate if 8 days
of VC supplementation could provide any protective
effective against a bout of damage designed to induce
DOMS in the biceps brachii group. Our data suggests
that while DOMS was successfully induced in both
our control and treatment groups, ingestion of VC as
a protective supplement was unsuccessful. These find-
ings are both in agreement,8, 9 and disagreement 10, 11
with previous findings.
The early work of Kaminski et al.7was the first to
suggest a protective effect of VC from muscle dam-
age due to unaccustomed exercise. Kaminski et al.7
presupplemented subjects for 3 days with 1 g of VC
and then induced damage into the posterior calf. The
supplement regime then continued for a further 7
days following the damage bout. They reported that
those subjects treated with VC recorded reduced sore-
ness ratings ranging from 25-44% less than untreat-
ed controls. The nature of the soreness rating and the
absence of more recently accepted indicator variables
of muscle strength and biochemical markers make
full evaluation and comparison of these findings dif-
ficult. To date and to our knowledge these findings
have not been wholly replicated in any muscle dam-
age study.
More recent work appears to refute the work of
Kaminski et al.7A series of studies by Thompson et al.
using a downhill running model has yielded varying
findings. In an initial investigation Thompson et al.8
exposed 9 habitually active males to 90 min of inter-
mittent shuttle running. Two hours prior to the exercise
bout each subject consumed a 1 g dose of VC. Subjects
served as their own control and performed a similar
exercise bout under placebo conditions at a later date.
The authors reported no differences between conditions
for muscle soreness or biochemical markers of creatine
kinase (CK), aspartate, aminotransferase and malon-
aldehyde. It is interesting to note in this study that
subjects served as their own controls which raises con-
cern over the repeated bout effect which has been pre-
viously described by Nosaka et al.17 This is of method-
ological concern since this literature clearly describes
that a second bout of similar exercise within a given
time period results in significantly less damage.
Interestingly, follow-up work by Thompson et al.9
used separate groups and a different dosage (2×200
mg/d) while exposing subjects to a similar protocol.
The exercise session was administered 14 days after
supplementation began. The authors again reported
no differences in CK between groups but did report that
VC had modest beneficial effects on muscle soreness
and function. The authors concluded this study by stat-
ing the VC supplementation had modest beneficial
effects on recovery from unaccustomed exercise. It is
difficult to explain the variations in findings by the
same authors but certainly the variations in dosage
amounts and use of a separate control group could be
factors. Further work by Thompson et al.10 again
exposed two groups to a bout of unaccustomed exer-
cise. VC supplementation this time was 200 mg imme-
diately after exercise. Subjects then consumed the
same amount of VC later that day and again twice the
following day. They reported no effects on post exer-
cise recovery in any measured variables again lead-
ing them to conclude the VC does not improve recov-
ery or protect against damage from an unaccustomed
exercise bout.
Recent work by Shafat et al.11 refutes the findings of
Thompson et al.9, 10 and that of Kaminski et al.7Shafat
et al.11 randomly assigned 12 males to either a VC
and vitamin E combo supplement group or a control
group receiving glucose. Supplementation was for 37
days total with an exercise session designed to induce
DOMS administered after 30 days. The authors report
that although decreased contractile forces were
TABLE II.—Percent strength loss and pain between groups over time.
Baseline 24 h 48 h 72 h 96 h
% strength loss
T003,34±21.7 31.7±23.4 31.8±26.9 26.7±28.8
C 00 26.3±20.6 20.4±22.3 17.6±20.6 11.1±23.6
Pain
T 00 2.54±2.46 2.25±1.92 2.58±2.07 1.66±1.92
C 00 2.75±2.14 2.75±2.07 2.16±1.93 0.71±0.91
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observed in both groups following exercise, a small-
er decrement was observed in the supplement group.
The authors concluded that supplementation with
dietary antioxidants can reduce the negative effects
of unaccustomed exercise. This raises the issue about
whether or not a combination supplement is more the
causative factor versus a single anti-oxidant supple-
ment. Previous investigators have reported beneficial
effects of VE supplement,18, 19 however, others have
reported no effect.20
The lack of agreement in the literature can most
likely be explained by variations in dosage, limb
involvement, activity status of subjects and other
individual variation. To our knowledge, we are the
first to investigate VC using an arm model with such
a high dosage. For the most part our work is in agree-
ment with the work of Thompson et al.8, 9 It is our
belief that the original work by Kaminski et al.7and
indeed others does not adequately consider the effects
of the repeated bout effect, the subjects’current VC
status, their dietary practices, or supplemented
dosages and thus may be flawed. We attempted to
control for this by monitoring and evaluating dietary
VC intake.
Conclusions
Thus, while there is conflict in the literature and
anecdotal evidence in support of the protective prop-
erties of VC, we feel further improved study design
using similar dosages, better controlled populations
and consistent measurement variables, is necessary to
adequately answer the question as to the protective
role of VC against DOMS. Advances in experimental
design and a better understanding of the mechanisms
of DOMS have lead to better control in recent exper-
imental conditions allowing more confidence in find-
ings. Regardless, additional work using varying exper-
imental conditions are still needed to confidently
describe the role of VC supplementation in protect-
ing against DOMS.
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