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Amino Acid Supplements and Recovery from High-Intensity Resistance Training

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The purpose of this study was to investigate whether short-term amino acid supplementation could maintain a short-term net anabolic hormonal profile and decrease muscle cell damage during a period of high-intensity resistance training (overreaching), thereby enhancing recovery and decreasing the risk of injury and illness. Eight previously resistance trained males were randomly assigned to either a high branched chain amino acids (BCAA) or placebo group. Subjects consumed the supplement for 3 weeks before commencing a fourth week of supplementation with concomitant high-intensity total-body resistance training (overreaching) (3 x 6-8 repetitions maximum, 8 exercises). Blood was drawn prior to and after supplementation, then again after 2 and 4 days of training. Serum was analyzed for testosterone, cortisol, and creatine kinase. Serum testosterone levels were significantly higher (p < 0.001), and cortisol and creatine kinase levels were significantly lower (p < 0.001, and p = 0.004, respectively) in the BCAA group during and following resistance training. These findings suggest that short-term amino acid supplementation, which is high in BCAA, may produce a net anabolic hormonal profile while attenuating training-induced increases in muscle tissue damage. Athletes' nutrient intake, which periodically increases amino acid intake to reflect the increased need for recovery during periods of overreaching, may increase subsequent competitive performance while decreasing the risk of injury or illness.
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AMINO ACID SUPPLEMENTS AND RECOVERY FROM
HIGH-INTENSITY RESISTANCE TRAINING
CARWYN P.M. SHARP
1
AND DAVID R. PEARSON
2
1
Department of Health and Human Performance, College of Charleston, Charleston, South Carolina;
and
2
Strength Research Laboratory, Ball State University, Muncie, IN
ABSTRACT
Sharp, CPM and Pearson, DR. Amino acid supplements and
recovery from high-intensity training. J Strength Cond Res
24(4): 1125–1130, 2010—The purpose of this study was to
investigate whether short-term amino acid supplementation
could maintain a short-term net anabolic hormonal profile and
decrease muscle cell damage during a period of high-intensity
resistance training (overreaching), thereby enhancing recovery
and decreasing the risk of injury and illness. Eight previously
resistance trained males were randomly assigned to either
a high branched chain amino acids (BCAA) or placebo group.
Subjects consumed the supplement for 3 weeks before
commencing a fourth week of supplementation with concom-
itant high-intensity total-body resistance training (overreaching)
(3 36–8 repetitions maximum, 8 exercises). Blood was drawn
prior to and after supplementation, then again after 2 and 4 days
of training. Serum was analyzed for testosterone, cortisol, and
creatine kinase. Serum testosterone levels were significantly
higher (p,0.001), and cortisol and creatine kinase levels were
significantly lower (p,0.001, and p= 0.004, respectively) in
the BCAA group during and following resistance training.
These findings suggest that short-term amino acid supplemen-
tation, which is high in BCAA, may produce a net anabolic
hormonal profile while attenuating training-induced increases in
muscle tissue damage. Athletes’ nutrient intake, which
periodically increases amino acid intake to reflect the increased
need for recovery during periods of overreaching, may increase
subsequent competitive performance while decreasing the risk
of injury or illness.
KEY WORDS overreaching, testosterone, cortisol, muscle
damage, BCAA
INTRODUCTION
Physiological adaptations to training are not linear
over time. Subsequently, short-term periods of
greater than normal increases in training volume
and/or intensity (overreaching) with ensuing
tapering periods are often incorporated into an athlete’s
training program to induce increases in performance (9,10).
However, designing and executing an optimum overreaching
program are complex and delicate. The coach must increase
the training stimulus beyond previous levels to induce an
enhanced adaptation but must not overload the athlete too
greatly, otherwise it can lead to illness, injury, and decreased
performance at a crucial period in the athlete’s competition
cycle. Similarly, an overreaching phase should be intention-
ally short in duration to minimize the risk of overtraining or
injury, yet paradoxically this is often the impetus for coaches
to excessively increase intensity. To attenuate these risks and
maximize the desired performance rebound of overreaching,
enhanced recovery methods such as nutritional supplemen-
tation may be pivotal.
Nutritional support for resistance training is essential
during all phases of training. Prior research has shown that
resistance training alone, while it increases skeletal muscle
protein synthesis (MPS), also results in an increase in protein
breakdown (4,19). Although the net effect is an increase
in protein synthesis, skeletal muscle remains in an overall
catabolic state in the absence of adequate nutritional inter-
vention (5,19). The ingestion or infusion of amino acids in
conjunction with an acute bout of resistance training has
been shown by numerous studies to significantly increase
protein synthesis and yield a net anabolic state (5,7,22).
However, the mechanism(s) by which this occurs remains
elusive. Limited research has also examined the potential of
amino acid supplementation to enhance recovery during
periods of overreaching (15,20) and other physically stressful
periods of training commonly experienced by athletes.
It has been shown that fluctuations in endogenous
hormone levels are strongly correlated to both short- and
long-term adaptations from exercise training and reflect
both the catabolic and anabolic physiological state (1,12)
during stress and recovery periods of training. The resistance
exercise-induced hormonal response to acute resistance
exercise in men is well demonstrated and includes an increase
Address correspondence to David Pearson, dpearson@bsu.edu.
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Ó2010 National Strength and Conditioning Association
VOLUME 24 | NUMBER 4 | APRIL 2010 | 1125
in serum cortisol (C); an initial decrease in testosterone (T)
(14); and a decrease in the testosterone:cortisol ratio (TC), an
index of overall anabolism/catabolism (3).
Thus, the purpose of this study was to examine the net
hormonal effect of amino acid supplementation on the
overreaching resistance training–induced hormonal stress
response. We hypothesized that amino acid supplementation
would enhance protein synthesis, thereby enhancing skeletal
muscle repair and thus reducing plasma creatine kinase (CK)
levels. It was further hypothesized that this reduction in
muscle damage would reduce the hormonal stress response to
training, which would be determined by evaluating plasma
cortisol levels. It was also speculated that reduced skeletal
muscle damage would also allow for sustained high-intensity
training, thereby eliciting greater T release. Thus, it was
generally hypothesized that amino acid supplementation
during overreaching would result in a net anabolic hormonal
profile as a response to reduced
skeletal muscle damage or en-
hanced recovery.
METHODS
Experimental Approach to the
Problem
This investigation involveda bal-
anced, cross-over, placebo-con-
trolled, double-blind, repeated-
measures design, shown sche-
matically in Figure 1. Subjects
acted as their own control.
Subjects were randomly as-
signed to 1 of 2 treatment
groups: branched chain amino
acids (BCAA) or placebo (P).
The amino acid composition of
the supplement Nutri-Build II (per 12 capsules) consists of the
following: L-Glutamine, 2000 mgs; L-leucine, 1800 mgs; L-
isoleucine, 750 mgs; and L-valine, 750 mgs. The BCAA group
consumed 6 g (12 capsules, which is the manufacturer’s
recommended daily dose) of Nutri-Build II (Nutrient
Technology, Inc.) per day, whereas P consumed 12 capsules
of lactose (virtually identical in size, shape, and color). Subjects
consumed 6 capsules in the morning and 6 capsules in the
evening with meals. Each treatment was consumed for 3
weeks (Day 0 to 21) followed by a fourth week of concurrent
supplementation and resistance exercise (Day 22 to 28). This
was followed by a 5-week wash-out period with no
supplementation or resistance training, then a subsequent 4-
week supplementation period consuming the alternative
treatment.
Neither subjects nor trainers were aware which treatment
was consumed. All subjects were instructed to maintain their
normal daily activity levels
throughout the duration of the
13-week study period. Subjects
completed a 7-day dietary recall
before each supplementation
period and during the final
supplementation period to de-
termine their nutritional status
prior to supplementation. Sub-
jects with a dietary protein
intake in excess of the recom-
mended daily allowance (0.8
g/kg/day) were excluded from
the study.
Two weeks prior to consum-
ing any treatment, subjects’
maximum strength (1 repetition
maximum, or 1RM) was as-
sessed (Cybex, Ronkonkona,
New York). Strength measures
Figure 1. Schematic representation of crossover experimental design for branched-chain amino acid (BCAA) and
placebo (P) supplementation and resistance training.
Figure 2. Mean serum cortisol levels (6SE) during the final 7 days of 28 days of supplementation with either
placebo or a branched chain amino acid (BCAA)–rich supplement. Blood was obtained 12 hours following the first
2 consecutive days of intense resistance training (Day 24) and 12 hours (Day 27) and 36 hours (Day 28) following
the final training session. Resistance training occurred on days 22, 24, 26, and 27. *p,0.05 versus baseline
(Day 0); n=8.
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were completed for leg press, leg curl, leg extension, chest
press, military press, latissimus pulldown, dumbbell curl, and
triceps pushdown following National Strength and Condi-
tioning Association testing recommendations (2).
Subjects
Ten healthy, recreationally active males were recruited from
a university population, and 8 subjects completed the study
(1 withdrew because of illness, and 1 withdrew because of
injury not related to the study) (mean 6SE; age 22.9 62y;
weight 77.9 63.6 kg; height 177.1 61.8 cm). All subjects
completed a medical history and activity questionnaire prior
to initiation of the study. All subjects had a minimum of
1 year previous resistance training experience but had not
participated in resistance train-
ing in the 6 months prior to
commencement of the study.
Approval for conducting the
study was obtained from the
Ball State University Institu-
tional Review Board, and each
subject was informed of the
benefits and risks of the in-
vestigation and subsequently
signed an approved consent
form outlining the risks associ-
ated with the experiment prior
to participation. In addition,
none of the subjects were
taking any medications, nutri-
tional supplements, or anabolic
drugs that would confound the
results of this study.
Procedures
Resistance Training. Training included 4 supervised sessions
between days 22 and 28 of supplementation (Monday,
Tuesday, Thursday, Friday), each consisting of 5 minutes of
passive stretching followed by three sets of 6–8 repetitions at
80% of 1RM of each of the exercises outlined previously.
A 60-second passive rest was observed between sets and
exercises. Subjects were instructed not to cool down or
engage in any heat, cold, or massage treatments for the
duration of the study.
Blood Collection and Analysis. Five antecubital venous blood
draws were obtained following an overnight 12-hour fast
during each 4-week supplementation period (Figure 1).
Samples were taken 2 days
prior to and 3 weeks after
supplementation and again
within an hour after 2 and 4
days of training. The final
sample was obtained 36 hours
after the last training session.
Blood samples were allowed to
coagulate at room temperature
then centrifuged, and the serum
is frozen at –80°C until analysis.
Cortisol and testosterone con-
centrations were determined in
duplicate from thawed serum
using a solid phase
125
I radioim-
munoassay kits (DSL-2100 and
DSL-4000, respectively, Diag-
nostic Systems Laboratories,
Inc, Webster, Texas). Creatine
kinase levels were determined in
duplicate using an enzymatic
Figure 3. Serum cortisol percent change from baseline (area under the curve [AUC]) during 28 days of
supplementation with either placebo or a branched chain amino acid (BCAA)–rich supplement and 7 days
(4 sessions) of concomitant high-intensity total-body resistance training (overreaching) (3 36–8 repetitions
maximum [RM], 8 exercises). Blood was obtained at baseline (day 0), 12 hours following the first 2 consecutive
days of intense resistance training, and 12 hours (Day 27) and 36 hours (Day 28) following the final training session.
*p,0.05 versus placebo; n= 8. Data presented are means 6SE.
Figure 4. Serum testosterone concentration percent change from baseline (area under the curve [AUC]) during 28
days of supplementation with either placebo or a branched chain amino acid (BCAA)–rich supplement and 7 days
(4 sessions) of concomitant high-intensity total-body resistance training (overreaching) (3 36–8 repetitions
maximum [RM], 8 exercises). Blood was obtained at baseline (day 0), 12 hours following the first 2 consecutive
days of intense resistance training, and 12 hours (Day 27) and 36 hours (Day 28) following the final training session.
*p,0.05 versus placebo; n= 8. Data presented are means 6SE.
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assay (Procedure No. 47-UV, Sigma Diagnostic, St. Louis,
Missouri) and spectrophotometry (Spectronic 601, Milton
Roy Company, Rochester, New York).
Statistical Analyses
A 2-way repeated measures analysis of variance (ANOVA)
was used to determine differences (p-value ,0.05) between
groups (P versus BCAA) over time for each variable: C, T,
T:C ratio, and CK. Subsequent differences were determined
using a Tukey post-hoc test when appropriate.
Area under the curve (AUC) was utilized to compare
the effect of treatment over the entire treatment and
training period. AUC was calculated as AUC =
S[b(c+a)/2, where b is the time in days between the two
data points (c and a) and Sis the
sum of each AUC for all sub-
jects. Student’s t-test was used
to assess significance between
treatments (p#0.05).
RESULTS
No significant change in height
or weight of any subject
was observed over the course
of the study. No significant
difference in workload during
each training week was ob-
served for any subject.
Serum cortisol concentrations,
as a percent change from base-
line, were significantly lower
for BCAA compared to P at 2
(p=0.011)and4daysoftraining
(p= 0.005) and 36 hours
after the last bout of training
(p= 0.022) (Figure 2). Total area
under the curve (AUC) for
serum cortisol compared to
baseline was significantly lower
(p,0.001) for BCAA (Figure 3).
Total serum testosterone levels,
measured as AUC, were signif-
icantly greater (p,0.001) with
BCAA supplementation com-
paredtoP(Figure4).
The net hormonal anabolic
effect of supplementation, mea-
sured as the TC ratio, was also
significantly greater (p,0.001)
for BCAA supplementation
compared to P (Figure 5).
Total CK levels were signifi-
cantly lower (p= 0.004) with
BCAA supplementation versus
P (Figure 6).
DISCUSSION
The major findings of this study are (a) that an amino acid
supplement high in BCAA is capable of significantly
decreasing the elevated cortisol response of overreaching
resistance training; (b) testosterone levels may be significantly
increased during overreaching training if accompanied by
BCAA supplementation; and (c) markers of skeletal muscle
damage (CK) in response to chronic high-intensity resistance
training can be significantly decreased with concomitant
BCAA ingestion in previously resistance trained men.
Effective and efficient recovery protocols are critical for
optimal training-induced adaptations and subsequently
achieving enhanced performance-related goals. This is
Figure 5. Serum testosterone: cortisol ratio percent change from baseline (area under the curve [AUC]) during 28
days of supplementation with either placebo or a branched chain amino acid (BCAA)–rich supplement and 7 days
(4 sessions) of concomitant high-intensity total-body resistance training (overreaching) (3 36–8 repetitions
maximum [RM], 8 exercises). Blood was obtained at baseline (day 0), 12 hours following the first 2 consecutive
days of intense resistance training, and 12 hours (Day 27) and 36 hours (Day 28) following the final training session.
*p,0.05 versus placebo; n= 8. Data presented are means 6SE.
Figure 6. Mean serum creatine kinase levels (area under the curve [AUC]) during 28 days of supplementation with
either placebo or a branched chain amino acid (BCAA)–rich supplement and 7 days (4 sessions) of concomitant
high-intensity total-body resistance training (overreaching) (3 36–8 repetitions maximum [RM], 8 exercises). Blood
was obtained at baseline (day 0), 12 hours following the first 2 consecutive days of intense resistance training, and
12 hours (Day 27) and 36 hours (Day 28) following the final training session. *p,0.05 versus placebo; n= 8. Data
presented are means 6SE.
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Amino Acids and Recovery from High-Intensity Training
particularly true of athletes who utilize the rebound enhanced
performance effect of overreaching (9), which occurs only
with adequate recovery.
The results of the present study indicate that an amino acid
supplement high in BCAA exerts an anticatabolic hormonal
effect by significantly decreasing serum cortisol levels in
response to resistance training overreaching. Bird et al. (6)
previously reported in untrained males that essential amino
acid ingestion during an acute bout of resistance exercise
resulted in no significant increase in cortisol compared to
baseline. Thus, our findings support those of previous inves-
tigations that amino acid ingestion is capable of attenuating
exercise-induced increases in cortisol. The implications for
those athletes who engage in overreaching prior to competi-
tion is a reduced risk of opportunistic infections such as upper
respiratory tract infections and increased potential for
maximizing the rebound effect associated with overreaching.
Our results support earlier findings, which indicate that amino
acid supplementation may enhance recovery from overreaching
by reducing skeletal muscle breakdown, indicated by significant
decreases in serum CK levels following exercise (8).
An interesting finding of the present study was that the
results outlined herein may be achieved with low relative and
absolute amino acid supplementation. The amount of BCAA
administered in this study was in accordance with the
manufacturers recommended dosage, which was lower
in absolute and relative terms than that used in other studies
in this area that have shown statistically significant improve-
ments (8,21). Insufficient plasma availability of the BCAA (a
combination of low dosage and splanchnic and gastrointes-
tinal use) may dampen their effects (16). In absolute terms,
recent research indicates that a minimum of 12 g of BCAA per
day (8) is required to elicit an ergogenic effect; however, the
literature supports the use of up to 40 g (21) as a bolus
ingestion postexercise. The current study provided 718 mg
each of valine and isoleucine and 1,442 mg of leucine (i.e., total
of 2.878 g) per day. This is only 24% of that used by Coombes
and McNaughton (8) and a mere 7% used by Tipton and
colleagues (21).
More important, in relative amounts, the current study also
seems to have provided much less amino acids than the
literature suggests, even with the addition of the subject’s
normal daily protein intake. Data from Meguid and cow-
orkers’ (16) investigation illustrate that leucine intake should
be a minimum of 20 mg/kg per day to maintain a positive
leucine balance (take in more than is oxidized). Therefore, it
seems that 20 mg of leucine per kilogram of body weight per
day is an advisable minimum for a normal adult population to
meet their daily needs. The current study used a total of 1,442
mg of leucine per day, which represents an intake of $20
mg/kg per day for only 1 subject. Although this is not
indicative of the total daily intake, to meet amino acid and
energy demands of exercise stress, the amount of amino acids
required for additional protein synthesis for tissue repair and
energy oxidation is necessarily greater. Following a high-
intensity training program (6 days per week) over 5 weeks in
10 previously trained sprinters and jumpers, basal fasting
levels of leucine decreased by 20%, isoleucine by 21%, and
valine by 18% (17). During this study by Mero and colleagues
(17), total serum amino acids decreased by 19% despite
a daily protein intake of 1.26 g/kg per day, which is above the
recommended dietary intake of 0.8 g/kg per day. These
observations concur with Hood and Terjung’s (13) review of
literature, which suggests an increased leucine consumption
in excess of 45 mg/kg per day for regularly active individuals.
Golgan’s (11) more extensive review-based estimate of
a leucine intake of 60 mg/kg per day, valine 50, and
isoleucine 20, for those people engaged in prolonged or
intense training may be more accurate. In the present study,
dietary analysis showed that no subjects were consuming
more than 0.7 g/kg per day of protein during the course of
the study. It is likely, then, that for these virtually novice
lifters, the commencement of resistance training would have
increased their amino acid demands higher than that of
normal individuals. As such, even with the addition of their
normal dietary protein intake to that supplemented, the
subjects in the present study may not have received adequate
BCAA to promote an increase serum BCAA concentration
required to elicit an ergogenic effect.
It is encouraging, however, that in light of the limited
intake of BCAA in this study, relative to other noted studies
that have found significant effects, the consistently observed
trends may imply that small doses of BCAA, such as that
consumed in this study, may provide sufficient BCAA
availability to reduce skeletal muscle cell damage, increase
testosterone, and decrease cortisol. The limited number of
subjects in this study negated the ability to analyze the data
according to mass. Larger sample size is consistently cited in
statistical literature as reducing variability and producing
more meaningful and accurate results.
PRACTICAL APPLICATIONS
The goal of BCAA supplementation is to increase amino acid
availability, thereby increasing substrate and energy avail-
ability for MPS and recovery and decreasing the catabolic and
increasing the anabolic hormonal profile. The consumption
of supplements high in BCAA by individuals and teams that
have athletes ranging in mass and metabolism is likely to yield
variability in results, based on mass and individual physio-
logical differences (e.g., BCAA oxidation and skeletal muscle
uptake) because heavier subjects may need to consume larger
quantities of the BCAA to produce both a more anabolic
hormonal profile and greater muscle membrane integrity.
In conjunction, consultation with a qualified nutritional expert
and the manufacturer is advised to determine the appropriate
amount of supplement to be consumed to ensure adequate
presentation to the skeletal muscle and other tissues because
heavier subjects may need to consume larger quantities of
the BCAA to produce both a more anabolic hormonal profile
and greater muscle membrane integrity.
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BCAA supplementation has been demonstrated to increase
plasma and muscular BCAA concentrations, thereby in-
creasing substrate availability for protein synthesis and energy
production to support protein manufacture. An increase in
amino acid transport postresistance training with a concom-
itant increase in plasma and muscle substrate availability may
increase protein synthesis. In conjunction, if MPS increases
postexercise, the opportunity to exacerbate protein repair and
adaptation is maximized with optimum substrate and energy
availability.
Tipton and colleagues (21) showed oral ingestion of
essential amino acids (including the BCAA) resulted in net
MPS, and, in conjunction with resistance exercise, an even
greater increase in MPS has been shown (18). Thus, sufficient
availability of amino acids following exercise appears
necessary for maximizing increases in skeletal muscle protein
synthesis following an acute bout of resistance exercise.
ACKNOWLEDGMENTS
This research was funded by the Office of Academic Research
and Sponsored Programs Research Grant, Ball State
University, Muncie, Indiana, and Nutrient Technologies,
Inc., Oklahoma City, Oklahoma. The results of this study do
not constitute endorsement of this product by the authors or
the National Strength and Conditioning Association.
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... Studies designed to investigate potential diagnostic markers of NFOR/OTS have incorporated well-controlled but varied resistance exercise OT protocols. Such studies have included both high-volume [23][24][25] and high-intensity training [18,[26][27][28][29][30][31][32][33] that have utilized either single exercise protocols (typically a variation on a squat) [18,[26][27][28][29][30][31]33] or multiple exercise training programs [23,24,32,[34][35][36][37]. To explore the mechanisms that underpin the response to OT, several of these training protocols have not been designed to improve physical performance (i.e., achieve FOR), but to induce a state of OT for the purpose of elucidating diagnostic and mechanistic information. ...
... Studies designed to investigate potential diagnostic markers of NFOR/OTS have incorporated well-controlled but varied resistance exercise OT protocols. Such studies have included both high-volume [23][24][25] and high-intensity training [18,[26][27][28][29][30][31][32][33] that have utilized either single exercise protocols (typically a variation on a squat) [18,[26][27][28][29][30][31]33] or multiple exercise training programs [23,24,32,[34][35][36][37]. To explore the mechanisms that underpin the response to OT, several of these training protocols have not been designed to improve physical performance (i.e., achieve FOR), but to induce a state of OT for the purpose of elucidating diagnostic and mechanistic information. ...
Article
Full-text available
Short-term periods of increased resistance exercise training are often used by athletes to enhance performance, and can induce functional overreaching (FOR), resulting in improved physical capabilities. Non-functional overreaching (NFOR) or overtraining syndrome (OTS), occur when training demand is applied for prolonged periods without sufficient recovery. Overtraining (OT) describes the imbalance between training demand and recovery, resulting in diminished performance. While research into the effects of resistance exercise OT has gathered attention from sports scientists in recent years, the current research landscape is heterogeneous, disparate, and underrepresented in the literature. To date, no studies have determined a reliable physiological or psychological marker to assist in the early detection of NFOR or OTS following periods of resistance exercise OT. The purpose of this work is to highlight the conceptual and methodological limitations within some of the current literature, and to propose directions for future research to enhance current understanding.
... The contribution of BCAAs to promote protein synthesis and attenuate proteolysis is activated by the mTORC1, an anabolic signal, which is dependent of insulin and insulinlike growth factor 1 [2]. Among eight recreational active participants with at least one year of training experience, three weeks of BCAA supplementation combined with resistance training favored an anabolic profile with reference to cortisol and creatine kinase reductions, and an increased testosterone level [46]. This study excluded participants that exceeded 0.8 g.kg −1 .day ...
... If an adequate intake of protein is ingested, the effects of BCAA on strength and hypertrophy are questioned [6]. The participants in the previous study [46], likely to meet the individual recommendations of protein intake and, consequently, the BCAA supplementation had a significant effect on cortisol, testosterone and creatine kinase. Comparable results were observed among 20 male soccer players 24-h post-strength session [48]. ...
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Branched-chain amino acids (BCAAs) are oxidized in the muscle and result in stimulating anabolic signals—which in return may optimize performance, body composition and recovery. Meanwhile, among athletes, the evidence about BCAA supplementation is not clear. The aim of this study was to review the effects of BCAAs in athletic populations. The research was conducted in three databases: Web of Science (all databases), PubMed and Scopus. The inclusion criteria involved participants classified both as athletes and people who train regularly, and who were orally supplemented with BCAAs. The risk of bias was individually assessed for each study using the revised Cochrane risk of bias tool for randomized trials (RoB 2.0). From the 2298 records found, 24 studies met the inclusion criteria. Although BCAAs tended to activate anabolic signals, the benefits on performance and body composition were negligible. On the other hand, studies that included resistance participants showed that BCAAs attenuated muscle soreness after exercise, while in endurance sports the findings were inconsistent. The protocols of BCAA supplements differed considerably between studies. Moreover, most of the studies did not report the total protein intake across the day and, consequently, the benefits of BCAAs should be interpreted with caution.
... In contrast to the intuitive, instinctive approach to POR revealed by participants of this research, previous studies have used well-controlled prescriptive high-volume (Fatouros et al., 2006;Wilson et al., 2013;Lowery et al., 2016) and high-intensity (Fry et al., 1994a(Fry et al., ,c,d, 1998(Fry et al., , 2000b(Fry et al., , 2006Sharp and Pearson, 2010;Nicoll et al., 2016;Sterczala et al., 2017) resistance exercise POR protocols to investigate potential diagnostic markers of FOR and NFOR/OTS. Such protocols have incorporated either single exercise (typically the barbell back squat) (Fry et al., 1994a(Fry et al., ,c,d, 1998(Fry et al., , 2000b(Fry et al., , 2006Nicoll et al., 2016;Sterczala et al., 2017) and multiple exercises (Ratamess et al., 2003;Volek et al., 2004;Fatouros et al., 2006;Kraemer et al., 2006;Sharp and Pearson, 2010;Lowery et al., 2016;Drake et al., 2017), and both traditional strength-based exercises (squat variations, pulls and presses) and sport-specific exercises (snatch, clean and jerk, throwing drills) (Fry et al., 1993(Fry et al., , 2000aHartman et al., 2007;Bazyler et al., 2017) have been selected. ...
... In contrast to the intuitive, instinctive approach to POR revealed by participants of this research, previous studies have used well-controlled prescriptive high-volume (Fatouros et al., 2006;Wilson et al., 2013;Lowery et al., 2016) and high-intensity (Fry et al., 1994a(Fry et al., ,c,d, 1998(Fry et al., , 2000b(Fry et al., , 2006Sharp and Pearson, 2010;Nicoll et al., 2016;Sterczala et al., 2017) resistance exercise POR protocols to investigate potential diagnostic markers of FOR and NFOR/OTS. Such protocols have incorporated either single exercise (typically the barbell back squat) (Fry et al., 1994a(Fry et al., ,c,d, 1998(Fry et al., , 2000b(Fry et al., , 2006Nicoll et al., 2016;Sterczala et al., 2017) and multiple exercises (Ratamess et al., 2003;Volek et al., 2004;Fatouros et al., 2006;Kraemer et al., 2006;Sharp and Pearson, 2010;Lowery et al., 2016;Drake et al., 2017), and both traditional strength-based exercises (squat variations, pulls and presses) and sport-specific exercises (snatch, clean and jerk, throwing drills) (Fry et al., 1993(Fry et al., , 2000aHartman et al., 2007;Bazyler et al., 2017) have been selected. Overall, the number of studies reporting either no performance maladaptation (i.e., return to baseline) or performance improvement outweigh those that have observed NFOR/OTS (Bell et al., 2020;Grandou et al., 2020b). ...
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Functional overreaching (FOR) occurs when athletes experience improved athletic capabilities in the days and weeks following short-term periods of increased training demand. However, prolonged high training demand with insufficient recovery may also lead to non-functional overreaching (NFOR) or the overtraining syndrome (OTS). The aim of this research was to explore strength coaches' perceptions and experiences of planned overreaching (POR); short-term periods of increased training demand designed to improve athletic performance. Fourteen high-performance strength coaches (weightlifting; n = 5, powerlifting; n = 4, sprinting; n = 2, throws; n = 2, jumps; n = 1) participated in semistructured interviews. Reflexive thematic analysis identified 3 themes: creating enough challenge, training prescription, and questioning the risk to reward. POR was implemented for a 7 to 14 day training cycle and facilitated through increased daily/weekly training volume and/or training intensity. Participants implemented POR in the weeks (~5–8 weeks) preceding competition to allow sufficient time for performance restoration and improvement to occur. Short-term decreased performance capacity, both during and in the days to weeks following training, was an anticipated by-product of POR, and at times used as a benchmark to confirm that training demand was sufficiently challenging. Some participants chose not to implement POR due to a lack of knowledge, confidence, and/or perceived increased risk of athlete training maladaptation. Additionally, this research highlights the potential dichotomy between POR protocols used by strength coaches to enhance athletic performance and those used for the purpose of inducing training maladaptation for diagnostic identification.
... Many studies have reported that BCAA supplementation attenuated increased serum CK after performing ECCs [7,16,23,31]. A systematic review and meta-analysis concluded that BCAA significantly reduces efflux of CK after exercise [18]. ...
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Background This study investigated the combined effect of branched-chain amino acids (BCAA) and fish oil (FO) on muscle damage caused by eccentric contractions (ECCs) of the elbow flexors, with a special focus on muscular function. Methods Twenty-nine untrained male participants were enrolled in this double-blind, placebo-controlled, parallel study. The participants were randomly assigned to the placebo (PL) group (n = 9), BCAA supplement group (n = 10), and BCAA+FO supplement group (n = 10). The BCAA+FO group consumed eicosapentaenoic acid (EPA) 600 mg and docosahexaenoic acid (DHA) 260 mg per day for 8 weeks, while the BCAA and BCAA+FO groups consumed 9.6 g per day for 3 days prior to and until 5 days after ECCs. Participants performed six sets of 10 ECCs at 100% maximal voluntary contraction (MVC) using dumbbells. Changes in MVC torque, range of motion (ROM), muscle soreness using visual analog scales, upper circumference, muscle thickness, echo intensity, and serum creatine kinase (CK) were assessed before, immediately after, and 1, 2, 3, and 5 days after ECCs. Results The MVC torque was significantly higher in the BCAA+FO group than in the PL group immediately after ECCs (p < 0.05) but not in the BCAA group. Both BCAA and BCAA+FO groups showed greater ROM and lower muscle soreness than the PL group (p < 0.05). CK was significantly lower in the BCAA group than in the PL group at 5 days after ECCs (p < 0.05). Conclusions This study reveals that supplementation with BCAA and FO may favorably impact immediate recovery of peak torque production. Alternatively, in comparison to PL group, BCAA supplementation favorably reduces creatine kinase.
... However, the studies to define thresholds for adverse effect have not yet been performed or reviewed in human participants. Aside from these concerns, many studies have shown the positive effects of BCAA intake, such as with the noted decreased muscle enzyme release (1), reduced skeletal muscle damage following high intensity exercise (2), and reduced protein degradation seen in subjects (3). In contrast, it is significant to state that BCAA intake could potentially have a negative impact. ...
... Our results support those of past investigations showing that amino acid consumption may play a role in reducing exercise-induced increases in cortisol (Sharp & Pearson, 2010). Cortisol, is a catabolic hormone and basic glucocorticoid form in humans, secreted from the adrenal cortex in response to psychological and physical stress (Brownlee et al., 2005). ...
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Background: β-hydroxy β-methylbutryate (HMB) is a metabolite of leucine amino acid and it has several ergogenic benefits. Previous studies also showed that it may affect beneficially the testosterone and cortisol concentration in athletes. Due to the contradiction results between studies, we aimed to conduct this meta-analysis to assess the HMB supplementation effect on testosterone and cortisol in trained athletes. Methods: Scopus, Medline, and Google scholar were systematically searched up to August 2021. The Cochrane Collaboration tool for evaluating the risk of bias was applied for assessing the studies' quality. Random-effects model, weighted mean difference (WMD), and 95% confidence interval (CI) were used for estimating the overall effect. Between-study heterogeneity was evaluated applying the chi-squared and I2 statistic. Results: Seven articles were included in the meta-analysis. Although the meta-analysis generally showed that HMB consumption did not have any effect on the cortisol and testosterone concentration (p > .05), subgroup analysis based on the exercise type showed a significant decrease in the cortisol concentration in resistance training exercises (WMD = -3.30; 95% CI: -5.50, -1.10; p = .003) and a significant increase in the testosterone concentration in aerobic and anaerobic combined sports (WMD = 1.56; 95% CI: 0.07, 3.05; p = .040). Conclusion: The results indicate that HMB supplementation in athletes can reduce the concentration of cortisol in resistance exercises and increase the concentration of testosterone in aerobic and anaerobic combined exercises. Nevertheless, more studies are required to confirm these results.
... This process is crucial for the SMM remodeling process induced by exercise (Izquierdo et al. 2009;Hackney and Walz 2013). Moreover, during energy depletion, COR may induce the use of branched chain amino acids as a fuel (Sharp and Pearson 2010). Although COR induces catabolic effects on skeletal muscle, these actions seem to be beneficial for a shortterm recovery process and long-lasting exercise. ...
Article
During ageing, anabolic status is essential to prevent the decrease in quantity and quality of skeletal muscle mass (SMM). Exercise modulates endocrine markers of muscle status. We studied the differences of endocrine markers for muscle status in 62 non-sarcopenic Mexican swimmer adults aged 30-70 y/o, allocated into two groups: the systematic training (ST) group including master athletes with a physical activity level (PAL) >1.6, and the non-systematic training group (NST) composed by subjects with a PAL <1.5. Body composition, diet, biochemical and endocrine markers were analyzed. The ST group showed lower myostatin (MSTN) and irisin (IRI) levels, two strong regulators of SMM. The insulin growth factor-1 (IGF-1) was higher in the ST. This is consistent with most of the evidence in young athletes and resistance training programs, where IGF-1 and IRI seem to play a crucial role in maintaining anabolic status in master athletes.
... Our data showed higher testosterone levels and lower CK in the PSBCAA group than PLA, suggesting that BCAA may induce an anabolic hormonal profile and attenuate muscle damage induced by training. Sharp and Pearson (2010) investigated the effect of short-term BCAA supplementation (3 weeks) during high-intensity training and reported that BCAA may produce a net anabolic hormonal and attenuate muscle tissue damage. Thus, our data may suggest the combination of these supplements since PS can have an ergogenic action and BCAA affects cell recovery, testosterone concentration, testosterone: corticosterone ratio, and CK concentration. ...
Article
Acute phosphatidylserine (PS) or branched-chain amino acids (BCAA) supplements alone may have an adrenocorticotropic hormone, cortisol suppressive effect and increase the testosterone/cortisol ratio, but the associated effect of these supplements during a period of high-intensity physical stress is not yet known. The study investigated the effects of chronic PS supplementation alone and combined with BCAA during high-intensity interval training (HIIT) on training volume tolerance, anabolic-catabolic balance and stress biomarkers in rats. Thirty-three rats were separated into: placebo (PLA, n=11), PS alone (n=11) and combined with BCAA (PSBCAA, n=11). Groups performed swimming sessions of HIIT (5 series × 1 min × 1 min recovery; external load equivalent to 13% of body mass) and nine recovery sessions of moderate-intensity training (30 min at 5% of body mass) alternately. One-way ANOVA was used to compare biochemical variables and two-way ANOVA was calculated to compare training volume. Training volume performed (TVP) was higher in first, fourth, fifth, sixth, and eighth HIIT sessions in the PS group in comparison to PLA (P<0.05). TVP was higher in the fourth session in PSBCAA compared to PLA. There were no differences in TVP during the sessions between PS and BCAA groups. Creatine kinase (CK) was lower in PSBCAA in comparison to PS alone (P=0.03) and PLA (P=0.04) after the experimental period. Testosterone concentration was enhanced in PSBCAA group compared to PLA (P=0.01); testosterone/corticosterone ratio was higher in PSBCAA compared to PS (P=0.05) and PLA (P=0.004) after protocol. PS combined with BCAA increases testosterone concentration and testosterone/corticosterone ratio, demonstrating an enhancement of anabolic state in trained rats.
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Purpose: Branched-chain amino acid (BCAA) can boost anabolism through an increase in the internal concentration of BCAA, which leads to facilitating anabolic hormone release to stimulate the power of the muscles. Studies on administration of BCAA to minimize fatigue substances during long periods of high intensity exercise have been conducted. However, there are disagreements concerning the results of these studies. Method: A comprehensive search was performed on electronic databases up to November 2019 for trials evaluating the effects of BCAA on recovery following exercise. Mean ± standard deviation of follow-up cortisol, insulin, ammonia, and lactate concentrations were extracted to calculate the effect size for meta-analysis. Results: A total of 146 participants for cortisol and 279 participants for lactate were found from the 7 and 15 studies, respectively. The results revealed a significant effect of BCAA supplementation on cortisol concentration during 120≤ min post exercise follow-up. Moreover, without considering follow-up times, an overall analysis showed that BCAA was effective in reducing blood lactate in aerobic exercise and the trained status of athletes. Conclusions: The advantages of BCAA administration relate to a reduction in cortisol concentration after 2h and ameliorated muscle function because of a probable attenuation of fatigue substances immediately after exercise.
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Purpose: Branched-chain amino acid (BCAA) can boost anabolism through an increase in the internal concentration of BCAA, which leads to facilitating anabolic hormone release to stimulate the power of the muscles. Studies on administration of BCAA to minimize fatigue substances during long periods of high intensity exercise have been conducted. However, there are disagreements concerning the results of these studies. Method: A comprehensive search was performed on electronic databases up to November 2019 for trials evaluating the effects of BCAA on recovery following exercise. Mean ± standard deviation of follow-up cortisol, insulin, ammonia, and lactate concentrations were extracted to calculate the effect size for meta-analysis. Results: A total of 146 participants for cortisol and 279 participants for lactate were found from the 7 and 15 studies, respectively. The results revealed a significant effect of BCAA supplementation on cortisol concentration during 120≤ min post exercise follow-up. Moreover, without considering follow-up times, an overall analysis showed that BCAA was effective in reducing blood lactate in aerobic exercise and the trained status of athletes. Conclusions: The advantages of BCAA administration relate to a reduction in cortisol concentration after 2h and ameliorated muscle function because of a probable attenuation of fatigue substances immediately after exercise.
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A study was carried out with 12 young men to examine the relationships between the intake of leucine and indices of leucine kinetics, using L-[1-13C]leucine as a tracer. Six subjects received L-amino acid diets during 7-day periods supplying leucine in the range of 79 to 20 mg.kg-1.day-1 (Group I) and another six subjects (Group II) received leucine intakes ranging from 20 to 4 mg.kg-1.day-1. Estimations were made of leucine kinetics, at the end of each diet period, when subjects were receiving small isonitrogenous, isocaloric meals during the isotope infusion period. Leucine flux declined with reduced leucine intake and leucine oxidation tended not to change at intakes below 20 mg.kg-1.day-1 (slope not statistically different than zero). Plasma valine increased markedly with further restriction in leucine intake below this level. The daily mass balance of leucine, estimated from the difference between intake and oxidation, became negative at an intake of about 20 mg.kg-1.day-1. These findings are discussed in relation to the published mean and upper range of requirement for leucine in healthy adults, currently taken to be 11 mg.kg-1.day-1 and 14 mg.kg-1.day-1, respectively.
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This investigation examined hormonal and biochemical changes in basketball players during a 4-week training camp before the European championships. Ten members of the Israel national team (mean +/- SD; age: 26.4 +/- 4.3 years; weight: 100.7 +/- 12.3 kg; and height: 196.4 +/- 8.0 cm) participated in this study, which began 4 weeks after the regular season. Plasma samples of testosterone, cortisol, luteinizing hormone, thyroid-stimulating hormone, triiodothyronine, free thyroxine, creatine kinase, and urea were obtained before (T1) and after 9 (T2), 17 (T3), and 28 (T4) days of practice. Questionnaires concerning appetite, quality of sleep, muscle soreness, and recovery time following practice were filled out before each blood draw. Differences (p < 0.05) in the volume of training were seen between T1 and T2 (150 +/- 29 min*d-1) and T3 and T4 (92 +/- 28 min*d-1). Muscle soreness and recovery time following practice were greater (p < 0.05) at T2 than T1, T3, and T4. A significant increase in cortisol, although remaining within normal physiological range, was observed between T1 (260 +/- 91 nmol*L-1) and T4 (457 +/- 99 nmol*L-1). No changes from Tl were seen in testosterone (14.2 +/- 5.6 nmol*L-1), luteinizing hormone (4.2 +/- 1.6 IU*mH-1), creatine kinase, and urea or in the testosterone-to-cortisol ratio. In addition, no significant changes from T1 were observed in any of the thyroid hormones. These results suggest that a 28-day training camp may not cause significant disturbances in hormonal or biochemical stress markers in elite athletes. (C) 1999 National Strength and Conditioning Association
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The purpose of this study was to examine the effects of amino acid supplementation on muscular strength, power, and high-intensity endurance during short-term resistance training overreaching. Seventeen resistance-trained men were randomly assigned to either an amino acid (AA) or placebo (P) group and underwent 4 weeks of total-body resistance training consisting of two 2-week phases of overreaching (phase 1: 3 X 8-12 repetitions maximum [RM], 8 exercises; phase 2: 5 X 3-5RM, 5 exercises). Muscle strength, power, and high-intensity endurance were determined before (T1) and at the end of each training week (T2-T5). One repetition maximum squat and bench press decreased at T2 in P (5.2 and 3.4 kg, respectively) but not in AA, and significant increases in 1RM squat and bench press were observed at T3-T5 in both groups. A decrease in the ballistic bench press peak power was observed at T3 in P but not AA. The fatigue index during the 20-repetition jump squat assessment did not change in the P group at T3 and T5 (fatigue index = 18.6 and 18.3%, respectively) whereas a trend for reduction was observed in the AA group (p = 0.06) at T3 (12.8%) but not T5 (15.2%; p = 0.12). These results indicate that the initial impact of high-volume resistance training overreaching reduces muscle strength and power, and it appears that these reductions are attenuated with amino acid supplementation. In addition, an initial high-volume, moderate-intensity phase of overreaching followed by a higher intensity moderate-volume phase appears to be very effective for enhancing muscle strength in resistance-trained men.
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Exercise results in marked alterations in amino acid metabolism within the body. The branched-chain amino acids, especially leucine, are particularly important since they contribute as energy substrates and as nitrogen donors in the formation of alanine, glutamine and aspartate. Leucine oxidation increases during whole-body exercise. Nonetheless, leucine's contribution as a muscle energy substrate is amll, being 3 to 4% at rest, and even lower (1%) during exercise. Traditional energy substrates (carbohydrates, lipid) remain most important. These rates of leucine oxidation can be readily attributed to skeletal muscle. Following endurance training, whole-body leucine oxidation is increased at rest and during exercise. Since its oxidation by muscle is not augmented, this whole-body increase is not due to muscle. Thus, other tissues within the body (i.e. liver) must account for this. Comparisons of leucine oxidation in rats and humans indicate that species differences exist. Much larger increases in leucine oxidation are brought about by exercise in humans. Calculations based on steady-state rates of leucine oxidation at rest and during exercise indicate that the recommended dietary intake of leucine is inadequate, since it is lower than measured whole-body rates of leucine oxidation. This inadequacy is exacerbated in individuals who are physically active.
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The purpose of this brief review is to examine resistance training responses of selected hormones related to acute stress and growth promoting actions. Hormonal mechanisms appear to be involved with both short-term homeostatic control and long-term cellular adaptations. Few studies have modeled the exercise stimulus in resistance training to determine the role of different exercise variables to the hormonal response. A variety of resistance exercise protocols result in increases in peripheral hormonal concentrations. It appears that single factor variables such as the intensity (% of RM) of exercise and amount of muscle mass utilized in the exercise protocol are important determinants of hormonal responses. The volume (sets x repetitions x intensity) of exercise also appears to be an important determinant of hormonal response. Still, little is known with regard to other single and multiple factor variables (e.g., rest period length) and their relationships to peripheral hormonal alterations. Collectively, such information will allow greater understanding concerning the nature of the exercise stimulus and its relationship to training adaptations resulting from heavy resistance exercise.
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The integrated use of several energy sources allows high muscular power outputs to be sustained. Muscle glycogen provides the major fuel source for muscular exercise, but other fuels can provide alternative energy sources which allow for muscle glycogen-sparing and an increased potential for prolonged high metabolic rates. Blood-borne glucose, derived from liver glycogenolysis and glyconeogenesis, as well as intra-muscular lipids and plasma free fatty acids derived from adipose tissue provide the main energy alternatives to muscle glycogen. Several amino acids, including the essential amino acid leucine, are also used directly as oxidizable fuels during exercise. Depending on the duration and intensity of exercise and other factors such as glycogen stores and energy intake, amino acids can provide from a few to approximately 10% of the total energy for sustained exercise. Additionally, many amino acids can be converted to glutamate (via glutamate dehydrogenase) and then to alanine (via glutamate-pyruvate transaminase). Alanine, along with lactate and pyruvate, are recognized as the major gluconeogenic precursors. Via this mechanism, several amino acids play crucial roles in providing the carbon sources for maintaining blood glucose homeostasis during exercise and glycogen restitution during recovery. And finally, during exercise and recovery, amino acids likely play important anaplerotic functions sustaining the whole metabolic apparatus.
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Nine elite male junior weightlifters (mean age 17.6 +/- 0.3 yrs) performed weightlifting tests before (Test 1) and after (Test 2) 1 week of increased training volume (overreaching) and repeated the protocol after 1 year of their training program. Strength increased by Year 2 (p < 0.05) but did not change during either week of increased training volume. The 1-week overreaching stimulus resulted in attenuated exercise-induced testosterone concentrations during Year 1, but augmented exercise-induced testosterone concentrations during Year 2. Testosterone concentrations at 7 a.m. decreased for only Year 1. For both years, the 1-week overreaching stimulus increased cortisol at 7 a.m, indicative of the increased training volumes. Testosterone/cortisol was not affected by increased training volume for either year. One year of chronic weightlifting and prior exposure to the overreaching stimulus appears to decrease the detrimental effects of stressful training on the endocrine system.