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Combined Effects of Caloric Restriction and Branched-Chain Amino Acid Supplementation on Body Composition and Exercise Performance in Elite Wrestlers

A. Mourier1, 2, A. X. Bigard1, E. de Kerviler3, B. Roger4, H. Legrand3, C. Y. Guezennec3
1 Centre d'?tudes et de Recherches de M?decine A?rospatiale, D?partement de Physiologie Syst?mique, Br?tigny-sur-orge, France
2 Service d'Endocrinologie, H?pital Saint-Louis, Paris, France
3 Service de Radioltogie, H?pital Saint-Louis, Paris, France
4 Service de Radiologie, H?pital Piti?-Salp?tri?re, Paris, France

Twenty-five competitive wrestlers restricted their caloric intake (28 kcal kg-1 ? day-1) for 19 days, using a hypocaloiric control (hC, n = 6), hypocaloric high-protein (hHP, n = 7), hypocaloric high-branched-chain amino acid (hBCAA, n = 6), hypocaloric low-protein (hLP, n = 6) diet to determine the effects of caloric restriction on body composition and performances versus control diet (C. n = 6). Anthropometric parameters (weight, percent body fat) and adipose tissue (AT) distribution measured by magnetic resonance imaging (MRI) obtained before and after diet, were compared. A significant highest body weight loss (-4 kg, p<0.05) and decrease in the percent of body fat (-17.3 %, p< 0.05) were observed for subjects of the hBCAA group. Subjects of the hBCAA group exhibited a significant reduction (- 34.4 %, p<0.05) in abdominal visceral adipose tissue (VAT). There was no change in aerobic (VO2max) (p>0.75) and anaerobic capacities (Wingate test) (p > 0.81), and in muscular strength (p :> 0.82). We conclude that under our experimental conditions, the combination of moderate energy restriction and BCAA supplementation induced significant and preferential losses of VAT, and allowed maintainance of a high level of performance
PMID: 9059905 [PubMed - indexed for MEDLINE]

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Introduction
Prior to competing, all wrestlers are required to attain aspedfic
body weight (weight class). The majority of wrestlers attempt
to lose body weight, maximise the amount of lean tissue and
minimise the amount of body fat.
Numerous methods are employed to reduce body weight for
wrestling competition. Wrestlers can reduce body weight
either rapidly or gradually. Reduction of body weight in less
than 1 week is defined by Fogelholm (9) as rapid body weight
reduction. Reduction over a longer period (>7 days) is defined
as gradual body weight reduction. The main difference is that
gradual body weight reduction is accomplished by negative
energy balance, whereas active or passive dehydration (fluid
loss) is a necessary part of rapid body weight loss. The primary
goal of restriction of energy intake is the restriction in body
fat. But previous studies in moderately active men have shown
that substantial reductions in body weight include loss of both
lean and fat tissues (22). Therefore, wrestlers cutting weight
through the restriction of energy intake can expect to lose
muscle mass. Results of the effects of gradual body weight reduction
on aerobic performance in athletes are variable. It has
been shown that during gradual body weight reduction, rnaximal
oxygen intake (W0,rnax) might deteriorate (16.38). remain
unchanged (26) or might improve (24). When reducing
body weight gradually with a normal carbohydrate diet (50%
of energy intake, 2.5 g kg-'. day1), anaerobic performance was
impaired (28). Conversely, anaerobic performance was not affected
after body weight loss with a higher intake of carbohydrates
(4.1 g . k g ' . d a y l ) (28). After gradual body weight reduction,
the isometric endurance capacity of the skeletal
muscle was reduced (13,36) while the endurance capacity
during isokinetic exercise was unaffected (36).
Steen and McKinney (34) found that college wrestlers from
several universities consumed diets composed of approximately
15 % protein. 33 to 37 % fat and 43 to 47% carbohydrate
with the composition being somewhat dependent on the time
of the season (pre-season, mid-season, etc.). During periods of
weight reduction, the authors found that 37% of the wrestlers
studied consumed less than two-thirds of the Recommended
Dietary Allowances (RDA) for energy. At the reduced level of
energy intake, all macronutrients were significantly lower, although
theaverage protein intake remained at 0.9g. kg1. day1
(14), which was almost the RDA for these subjeas (Committee
on Dietary Allowances 1989). Based on nitrogen balance. Walberg
et al. (36) suggested that a protein intake of 0.8 g- kg1.
day1 was insufficient to maintain nitrogen balance during
body weight reduction, whereas 1.6g. kg1 .day1 was enough.
It has been shown that in catabolic states such as starvation.
the plasma concentrations of branched-chain amino acids
(BCAA), i.e. leucine, isoleucine and valine, were selectively increased
(33). It has become widely accepted that BCAA and
leucine in particular can directly stimulate protein synthesis.


C group hC group hHP group h0CAA group hLP group composition1.
Variable (n - 6) (n = 6) (n = 7) (n = 6) (n = 6)
Carbohydrates (%)2 55 55 60 60 60
Proteins (%) 12 12 25 20 15
Fats (%) 33 33 15 20 2 5
Energy intake (kcal . kg-' . day-') 40 28 28 28 28
' C= normocaloric control diet: hC = hypocaloric diet: hHP = high-protein diet; hBCAA = high-branched-chain amino acids diet;
hLP = low-protein diet
percentage of calorie intake


Louard et al. (25) observed that in normal man. BCAA infusion
suppresses skeletal muscle proteolysis independently of any
rise of plasma insulin. Furthermore, Schena et al. (31) concluded
that the administration of a suitable amount of BCAA
can prevent the ubiquitous muscle loss observed during high
altitude exposure. BCAA administration potentiated the release
of some anabolic hormones, mainly human growth hormone
(GH) (17), known to accelerate amino acid uptake and protein
synthesis in skeletal muscle (32). It may thus be suggested that
under conditions of increased protein catabolism (hypercaloric
diet), BCAA will help minimise muscle wasting.
The purpose of this study was to investigate the effects of 19-
day qualitatively and quantitatively varied energy intakes on
body composition and exercise performance in elite male
wrestlers.



Material and Methods
Subjects

Thirty-one male wrestlers from the French National Institute
of Sports volunteered to serve as subjects in this study. Testing
was conducted mid-season. The study was approved by Cochin-
Port Royal Hospital Ethics Committee. All subjects were
informed of risks and signed consent fonns. All were highly
trained in prolonged exercise and had been wrestling for many
years. None reported ever using anabolic steroids. The subjects
were randomly assigned to one of five groups and consumed
diets whichvaried in their energy and macronutrient composition
(four levels of dietary protein intake, detailed in Table 1):
.N ormocaloric control (n = 6): C Hypocaloric control (n =x6): hC
Hypocaloric high-protein (n = 7): hHP
.H ypocaloric high-branched-chain amino acid (n = 6): hBCAA Hypocaloric low-protein (n = 6): hLP

Anthropometric measurements
Height, weight and BMI
Height of the barefoot subject was measured to the nearest
0.1 cm. Before and immediately after the dietary period, body
weight (BW)of subjects wearing same shorts was measured
on the same standard medical balance with an accuracy of
+ 100g. Body Mass Index (kg. m-2) was then calculated (5).

Skinfold thickness
The anthropometric assessment consisted of three skinfold
sites: chest, quadriceps and abdomen, which were measured
with a Harpenden skinfold calliper (18). A minimum of two
measurements were made at each skinfold site by the same
experienced investigator at each time of measurement. The
values were averaged and used to estimate body fat percentage
using an equation developed by Jackson and Pollock (18).


MRI
Magnetic resonance images were taken at 0.5 Tesla (General
Electric. Milwaukee. WIS. U.S.A.). Before and after the dietary
period, subjects were positioned in the magnet in a supine feetfirst-
position. A multislice spin-echo sequence (TR = 500 ms.
TE = 25 rns) was used to obtain TI-weighted images with a reasonable
contrast between adipose tissue (AT) and lean tissue.
The magnetic resonance examination consisted of two series
of 7 mm thick (3 mm gap) axial images. One series was taken
at midthigh. and two other series were taken in the abdomen
at the level of the umbilicus.
As discussed by Ross et al. (30). magnetic resonance imaging
(MRI) pixel intensity value for a given tissue may not be consistent
from slice to slice or between individuals. To set a common
dynamic range for all images, a 1.5-cm diameter reference
tube was filled to capacity with a solution ofGadolioium-DOTA
(0.5 mmol. I-') and placed on either of the sides of the subjects
during data acquisition.The end points ofthe signal range were
0 for air and 4095 (maximum value for the 12 bit integers returned
by the MRI system) for the reference tube. All the images
were transferred onto personal Iris Computer (Silicon
graphics) for further analysis.

Segmentation of Adipose Tissue (AT)
Two large regions of interest (ROI) were drawn manually. One
ROI included the largest cross-sectional area of subcutaneous
adipose tissue (SAT) and the other R01 included the largest
cross-sectional area of visceral adipose tissue (VAT). The next
step consisted of highlighting and counting the pixels which
correspond to AT in each ROI. The reference tube allows determination
of the threshold of AT. The threshold selected for AT
was based on the analysis of a sample of typical images and
their respective gray level histograms. The optimal threshold
for AT was 180 (on a scale of 256); above this value, pixels were
considered as representing AT. The next step involved

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highlighting the pixels that were counted as AT in response to
the selected threshold. Each slice was reviewed using an interactive
slice editor program that allowed verification and. when
necessary, correction of the segmentation result. The operation
was facilitated by superimposing the original gray level image
on the binary segmented image using a transparency mode.
Visceral and subcutaneous adipose tissue regions on each
abdominal slice were then assigned different colour codes.
Similar operations were performed on each midthigh slice to
identify adipose tissue and muscle tissue (MT).

Calculation of areas
The areas of the respective AT regions in each slice were computed
automatically by summing AT pixels and multiplying by
the pixel surface area. A previous investigation (30) verified
that the error in the spatial dimensions of MR images using
this system ranged from 0.1 to 1.5 %. Thus the AT area on the
MR images is fairly accurate.

Diet analysis
Wrestlers recorded their daily weighed-meals intake over
seven successive days in notebooks supplied by the investigators.
One training session was held to show the subjects how
to keep records. During the weeks of the recording, the investigators
met with the subjects and reminded them to record
the amount and type of all foods consumed. The complete records
of food intake of all subjects were analysed using Dietetique
1 software (copyright S.D. Crun for SDG '1986-1987,
Database by Mouton-Pastre-Peres for SPEFS "1985-1986-
1987) before the beginning of the study. Total daily intake of
energy, protein, carbohydrate and fat were estimated daily and
averaged for one week.

Dietary protocol
During the study, all the meals of the wrestlers were eaten in
the same refectory. Estimates of the nutrient compositions of
food ingested were made by weighing foods and recording the
energy content of each portion. All wrestlers generally ate from
a common menu. A dietician gave instructions on what to
choose to obtain the desired diet. according to the specifications
of the diet group.
The 19day diet period began immediately following the period
of nutrient composition food intake analysis. In all groups, diets
exceeded RDA for protein intake (0.8 g . kg' . day'). Subjects on
hypocaloric diets consumed the same food and received a commercial
supplement depending on the group they belonged to.
The experimental diets were isocaioric and the daily energy
intake of each subject (except C subjects) was estimated to be
28 kcal . kg1. The commercial dietary supplements used in the
ptesent study represented 3.6 kcal. kg1 .day1.
Subjects of the C group consumed ad libitum (normocaloric
diet), while subjects of the hC group consumed a 28 ltcal. kg1
body weight .day-' hypocaloric diet without any supplementation.
The subjects of the hHP group consumed a hypocaloric diet
(24.4 kcal - kg1. day') and a dietary supplement which consisted
of a mixture of soja protein (0.9g. k g ' - day') so that
protein intake was increased to 2 g . kg' . day': 25% of the total
energy intake (6.1 g BW/100g protein: 46% leucine. 22%
isoleucine and 32 % valine) with 60 %carbohydrate and 15 % fat.
The hBGQA diet consisted of a hypocaloric diet (24.4 kcal. kg1
. day-') and a protein dietary supplement enriched with 0.9 g -
kg1. day'' branched-chain amino acids (51.9g BCAA/lOOg protein:
76% leucine. 19% isoleucine and 5% valine), approximately
20% protein. 60% carbohydrate and 20% fat.
The hLP diet consisted of a hypocaloric diet (24.4 kcal . kg'.
day1) and a dietary supplement of 0.9g glucose. kg1. day1
(3.6 kcal .kg1. day'), approximately 15% protein, 60% carbohydrate
and 25 % fat.

Exercise testing
During the two days prior to the dietary program, the maximal
oxygen uptake (W0,max) was determined using an open system
to analyse the expired gases (Sensor Medics 2900. Sensor
Medics corporation. Yorba Linda. CA, USA). On the morning of
the first day. the subjects exercised on a treadmill according
to an incremental protocol for V0,max determination (W0,max
T). The exercise session of W0,max T consisted of a five min
warm-up at 12 km. h-I followed by an incremental test during
which successive speeds of 1 km. h-I were reached every two
minutes. On the second morning, they exercised on an arm
ergometer (881 E, Monark-Crescent AB., Valberg, Sweden) for
V0,max determination (V02max U). The exercise session of
V0,rnax U consisted of a two min warm-up at 36.8 W followed
by incremental work during which successive loads of 18.4 W
were reached every two minutes. A pedalling frequency of
75 rpm was selected until 110 W was obtained and then upwards
to 85 rpm. The test protocol was adjusted to ensure attainment
of maximal effort within 15 to 20 min. Oxygen intake.
minute ventilation. respiratory exchange ratio (R) and heart
rate (HR) were continuously monitored. V0,max was the value
obtained over 60s when two of the following criteria were retained:
1 ) an increase in exercise intensity produced no further
increase in V02, 2) a respiratory exchange ratio > 1.1, and 3)
visuals signs of tiredness and distress on the treadmill or with
the crankam ergometer.
The first afternoon, right isometric knee extensions were performed
using an isokineticdynamometer (Cybex 11. Lumex Inc.,
N.Y., U.S.A.). The subjects were in a sitting position, securely
strapped into the muscle-test chair. The seated posture met
the following specifications: hip angle IOU, knee angle 80'. The
experimental procedure comprised the following steps: 1 )subjects
were asked to perform maximal isometric contractions
of short duration (2-2s) of the knee extensor muscles. The
maximal force was measured, and the best performance after
4 trials was selected as maximal voluntary isometric contraction
(MVC). Approximately 2-3 minutes elapsed between each
of the 4 trials. 2) following a sufficient recovery period lasting
between 15 and 17 minutes, subjects maintained a prolonged
isometric contraction of the knee extensor muscles at 50% MV
as long as possible. The required force of contraction was
shown by an oscilloscope placed in front of the subject. The
endurance time for this submaximal muscle contraction was
measured until the subject was unable to maintain the required
tension.
The second afternoon, the anaerobic capacity was determined
using the Wingate Anaerobic Capacity Test (2). Subjects
completed a 30-sec Wingate Anaerobic Capacity Test on a
Monark cycle ergometer (Monark-Crescent A.B., Valberg,
Sweden) with two clips and adapted with an electronic reed
switch to measure speed (revolutions per minute, rprn). The
resistance for each subject (0.098. kg' body weight) was determined
according to Evans and Quinney (7). Five sec revolutions
were counted For 30sec using an electronic rpm counter.
From these measurements, peak power. total power and mean
power were calculated (2).
All physical performance tests were conducted two days prior
to the initiation of the study and the two last days of the dietary
period.

Blood sample analyses
Blood samples of approximately 10ml were collected from an
antecubital vein at rest, and at the end of the incremental
treadmill exercise. Blood samples were collected before and
after the dietary program, and plasma was immediately obtained
by centribgation and frozen until assays were performed
within 30 days. At rest, glucose, lactate and glycerol
were assayed in neutralised blood samples using an enzymatic
method (3). Free fatty acids (FFA) were assayed according to
the method of Ho (12). Because low caloric diets are known to
affect the regulation of peripheral thyroid hormones (27) and
because protein and amino acid intakes promote a rise in
growth hormone serum levels (19.27). the endocrine responses
to diets were tested. Hormone determinations were
made in duplicate using commercially available radioimmunoassay
kjts (CIS-bio International. Gif-sur-Yvette. France):
insulin (SB-INSI-5), growth hormone (GH) (SB-GH)an d triiodothyronine
(RIA-gnost T3).

Statistical analysis
All data are given as means &standard error of the mean (SEM).
Significant time (pre- and post-diet measurements) and diet
effects (C, hC, hHP, hBCAA. hLP) were determined by a two-way
repeated measures analysis of variance (ANOVA). If the F-value
indicated significance between group variance. comparisons
between pre- and post-values in each experimental group (C,
hC. hHP, hBCAA and hLP) were determined using a paired Student's
t-test p<0.05 after adjustment using the Bonferroni
correction was considered to indicate a significant difference
between groups. The percentage differences between measurements
obtained pre- and post-dietary period in each group
were compared with an unpaired Student's t-test. A level of
p < 0.05 was selected to indicate significant differences between
mean values.

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Body weight
Analysis of variance (ANOVA) showed that there is a global effect
of both time and diet on BW changes (p <0.05, Table 2).
BW losses recorded in all hypoenergy groups were significantly
higher than those observed in control subjects (Fig. 1, p < 0.05).
Moreover, the highest BW loss was observed for subjects of
the hBCAA group. who reduced significantly their BW (4kg.
- 5.4%, Fig. 1).

Body composition
Body fat estimated by skinfold thickness

There was a global effect of both time and diet on body fat
changes (Table 2. p < 0.05). The decrease in the percentage of
body fat (BF) of hBCAA subjects was significantly higher than
that recorded in the other hypoenergy groups (p<0.05). Subjects
receiving BCAA supplementation lost an average of 17.3 %
of their estimated % BF using skinfold measures (Fig. 2).

Body fat estimated by MRI
Adipose tissue and lean tissue were clearly identified due to
large differences in signal on magnetic resonance images
(MRI).cated a significant effect of diets on SAT area changes
(p < 0.05). The percent changes in SAT were not significantly
different between hypoenergy groups (p = 0.12. Fig. 5). Analysis
of variance showed a global effect of both time and diet on VAT
area changes (p < 0.05). The VAT losses (- 34.4 %) observed in
the hBCAA group were significantly higher than those recorded
in other groups (p < 0.05, Fig. 5).
As shown in Fig.4. AT at midthigh were clearly distinguished
from muscle tissue. Analysis of variance showed a significant
effect of both time and diet on thigh muscle AT(p < 0.05). After
the 19-day hBCAA diet, losses of AT were significantly higher
(- 23.4 %) than those observed in other hypoenergy groups
(p dc0.05, Fig. 6). However, muscle mass loss was not significantly
affected by the diets in hypoenergy groups.

Exercise capocity
The 19-day diet program did not significantly affect V@max
measured either on the treadmill or using the crankann
ergometer in any group (Table 3).
Nineteen days of caloric restriction did not reduce peak power
output in any group. Dieting did not significantly alter the subject's
capacity to perform anaerobic work.
The MVC of the knee extensor muscle was unaffected by the
dietary protocol (Table 3) as well as the endurance time of the
knee extensor muscle at 50 % MVC.

Blood metabolic changes
Plasma concentrations of glucose, lactate and insulin were unchanged
after the 19day dietary regimen (Table 4). However,
the nitrogen-enriched (N-enriched) diets induced lower blood
concentrations of FFA (- 25 %, - 35.7 %, in the hBCAA and hHP
groups, respectively) and higher blood concentrations of
glycerol (62.9 %, 58.7 %, in hBCAA and hHP groups, respectively,
p < 0.05).
Plasma T3 concentration was significantly decreased after 19-
day N-enriched diets (p i 0.05). Prior to dietary restriction, resting
GH concentrations were similar for all groups. The 19-day
diet affected all groups equally, resulting in a significant rise
at rest (p< 0.05). In conditions of pre- or post-diet, exercise increased
the GH concentrations for all groups. However, the Nenriched
diets induced a significant increase in post-exercise
plasma GH concentrations (p < 0.05).

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Thanks a million

you are welcome. For legal reasons, I cannot post the entire pdf, but the most important parts (Methods & Results) are covered.