ArticlePDF Available

Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training Program

Authors:

Abstract and Figures

Aspiring female physique athletes are often encouraged to ingest relatively high levels of dietary protein in conjunction with their resistance-training programs. However, there is little to no research investigating higher vs. lower protein intakes in this population. This study examined the influence of a high vs. low protein diet in conjunction with an 8-week resistance training program in this population. Seventeen females (21.2±2.1 years; 165.1±5.1 cm; 61±6.1 kg) were randomly assigned to a high protein diet (HP: 2.5g/kg/day; n=8) or a low protein diet (LP: 0.9g/kg/day, n=9) and were assessed for body composition and maximal strength prior to and after the 8-week protein intake and exercise intervention. Fat-free mass (FFM) increased significantly more in the HP group as compared to the LP group (p=0.009), going from 47.1 ± 4.5kg to 49.2 ± 5.4kg (+2.1kg) and from 48.1 ± 2.7kg to 48.7 ± 2 (+0.6kg) in the HP and LP groups, respectively. Fat mass significantly decreased over time in the HP group (14.1 ± 3.6kg to 13.0 ± 3.3kg; p<0.01) but no change was observed in the LP group (13.2 ± 3.7kg to 12.5 ± 3.0kg). While maximal strength significantly increased in both groups, there were no differences in strength improvements between the two groups. In aspiring female physique athletes, a higher protein diet is superior to a lower protein diet in terms of increasing FFM in conjunction with a resistance training program.
Content may be subject to copyright.
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Note: This article will be published in a forthcoming issue of the
International Journal of Sport Nutrition and Exercise
Metabolism. This article appears here in its accepted, peer-
reviewed form; it has not been copyedited, proofed, or formatted
by the publisher.
Section: Original Research
Article Title: Effects of High vs. Low Protein Intake on Body Composition and Maximal
Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training
Program
Authors: Bill I. Campbell1, Danielle Aguilar1, Laurin Conlin1, Andres Vargas1, Brad Jon
Schoenfeld2, Amey Corson1, Chris Gai1, Shiva Best1, Elfego Galvan2, and Kaylee Couvillion1
Affiliations: 1Physique and Performance Enhancement Laboratory, University of South Florida,
Tampa, FL. 2Lehman College, Bronx, NY. 3University of Texas Medical Branch, Galveston, TX.
Running Head: Protein intake for female physique athletes
Journal: International Journal of Sport Nutrition and Exercise
Acceptance Date: January 14, 2018
©2018 Human Kinetics, Inc.
DOI: https://doi.org/10.1123/ijsnem.2017-0389
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Title Page
Title of Article: Effects of high vs. low protein intake on body composition and maximal
strength in aspiring female physique athletes engaging in an 8-week resistance training program.
Submission Type: Original Research
Authors: Bill I. Campbell1, Danielle Aguilar1, Laurin Conlin1, Andres Vargas1, Brad Jon
Schoenfeld2, Amey Corson1, Chris Gai1, Shiva Best1, Elfego Galvan2, Kaylee Couvillion1.
Author Affiliations:
1Physique and Performance Enhancement Laboratory, University of South Florida, Tampa, FL
33620
2Lehman College, Bronx, NY 10468
3University of Texas Medical Branch, Galveston, TX 77555
Corresponding Author:
Bill I. Campbell, PhD
University of South Florida
PED 206
Tampa, FL, 33620
813-974-4766
email: bcampbell@usf.edu
Running Head: Protein Intake for Female Physique Athletes
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Abstract:
Aspiring female physique athletes are often encouraged to ingest relatively high levels of dietary
protein in conjunction with their resistance-training programs. However, there is little to no
research investigating higher vs. lower protein intakes in this population. This study examined the
influence of a high vs. low protein diet in conjunction with an 8-week resistance training program
in this population. Seventeen females (21.2±2.1 years; 165.1±5.1 cm; 61±6.1 kg) were randomly
assigned to a high protein diet (HP: 2.5g/kg/day; n=8) or a low protein diet (LP: 0.9g/kg/day, n=9)
and were assessed for body composition and maximal strength prior to and after the 8-week protein
intake and exercise intervention. Fat-free mass (FFM) increased significantly more in the HP group
as compared to the LP group (p=0.009), going from 47.1 ± 4.5kg to 49.2 ± 5.4kg (+2.1kg) and
from 48.1 ± 2.7kg to 48.7 ± 2 (+0.6kg) in the HP and LP groups, respectively. Fat mass
significantly decreased over time in the HP group (14.1 ± 3.6kg to 13.0 ± 3.3kg; p<0.01) but no
change was observed in the LP group (13.2 ± 3.7kg to 12.5 ± 3.0kg). While maximal strength
significantly increased in both groups, there were no differences in strength improvements between
the two groups. In aspiring female physique athletes, a higher protein diet is superior to a lower
protein diet in terms of increasing FFM in conjunction with a resistance training program.
Keywords: sports nutrition, bodybuilding, hypertrophy
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
INTRODUCTION
Dietary protein is an essential component of the human diet. The constituent amino acids
(AA) of dietary proteins are used to build body tissues, and thus protein consumption directly
influences the accretion of muscle mass (Atherton and Smith, 2012). Acute nitrogen balance
studies indicate that individuals involved in regimented resistance training require 1.6 to 1.8
g/kg/day to maximize anabolism approximately double that of sedentary individuals (Lemon,
2000). More recently, research using the indicator amino acid oxidation technique showed these
requirements may be as high as 2.2 g/kg/day in young male bodybuilders (Bandegan et al., 2017).
Interestingly, there is some evidence that protein requirements may be attenuated in resistance-
trained individuals. Moore et al. (2007) found that consumption of ~1.4 g/kg/day was adequate to
maintain a positive nitrogen balance following 12 weeks of regimented resistance training,
suggesting that the body becomes more efficient at using AAs for lean tissue synthesis with
continued performance of resistive exercise.
Despite the compelling acute research showing increased protein needs with resistance
training, there is a paucity of longitudinal studies investigating optimal daily protein intakes to
maximize body composition. In a very short-term study, Lemon et al. (1992) found that protein
intake of 1.35 versus 2.62 g/kg/day produced similar increases in lean body mass and thigh muscle
cross sectional area in novice lifters following a 4-week intensive resistance training program. The
higher protein condition slightly reduced body fat while the lower protein condition showed a
small increase, but these changes were not statistically significant. Antonio et al. (2014) reported
similar body composition changes in resistance trained men and women consuming 4.4 vs 1.8
g/kg/day over the course of an 8-week RT program. Follow-up work from the same lab showed
that resistance-trained individuals lost more body fat with a protein intake of 3.4 versus 2.3
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
g/kg/day after 8 weeks RT; while lean mass increases were similar between groups (Antonio et
al., 2015). The training programs in both of these studies were unsupervised, confounding the
ability to draw causality.
Given the limited research on the topic, significant gaps in the literature remain to be
addressed. In particular, a dearth of evidence exists on protein requirements for resistance-trained
women. This is especially true of female physique athletes, such as those aspiring to compete in
bikini and figure contests. Judging for these contests is based in part on a combination of muscle
symmetry, shape and definition. Lower body fat levels and ample muscle mass are therefore
requisites for success. Accordingly, progressive resistance training is an important component in
preparation for competition. The purpose of this study was to investigate the effects of higher
versus lower daily protein intakes on body composition changes in aspiring female physique
athletes following a supervised daily undulating periodized resistance training program. We
hypothesized that a higher daily protein consumption would result in greater improvements in fat-
free mass.
METHODS
This study utilized a parallel groups, repeated measures design where participants were
randomized to ingest either a high protein diet or a low protein diet in conjunction with a
supervised resistance training program for 8-weeks. Participants visited the laboratory on two
occasions, immediately prior to and after an 8-week supervised resistance-training program.
Before each laboratory visit the participants were instructed to fast for 10-hours (an overnight fast)
and refrain from physical activity for the previous 36 hours. The primary dependent variable (DV)
measured before and after the 8-week resistance training program was body composition (fat-free
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
mass, fat mass, and body fat percentage). Secondary DVs included maximal strength (back squat
and deadlift) and resting metabolic rate (RMR).
Participants
Healthy, young, aspiring female physique athletes volunteered to participate in the study.
In order to qualify for participation into the study, all participants were required to have resistance
trained for the previous three months or longer and needed to be able to deadlift 1.5x bodyweight.
All participants gave written informed consent before enrollment in the study. The study was
approved by the University of South Florida Institutional Review Board and is in compliance with
the Declaration of Helsinki as revised in 1983. Figure 1 summarizes the participant study flow.
There were no differences between groups at pre-training for any dependent variable.
Resting Metabolic Rate, Body Composition, and Maximal Strength
Upon entering the laboratory, participants urinated and then had their body weight
measured on a physician beam scale (Health-O-Meter, Model 402KL, McCook, IL, USA). Next,
RMR testing procedures were conducted in a manner as previously described (Campbell et al.,
2016). Intra and inter-day test-retest correlation calculated for the device used in the present study
were as follows: intra-day RMR Pearson correlation was r = 0.96 (p < 0.01) and the inter-day RMR
Pearson correlation was r = 0.90 (p < 0.01). Intra-day RMR ICC was 0.981 and the inter-day RMR
ICC was 0.946.
After RMR assessments were completed, body composition was assessed using the Body-
Metrix™ BX-2000 A-mode ultrasound (IntelaMetrix, Livermore, CA) with a standard 2.5 MHz
probe according to procedures as previously described (Colquhoun et al. 2017). All body
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
composition assessments were completed by the same technician whose calculated fat-free mass
test-retest reliability was: ICC 0.99; SEM 0.37 kg; minimal difference 1.03kg.
Maximal strength testing took place approximately 24 hours after the body composition
assessment. After completing a body mass warm-up, participants followed the National Strength
and Conditioning Association’s 1RM testing protocol (Sheppard and Triplett, 2016) for the back
squat and deadlift. For both lifts, the same research personnel observed each maximal repetition
attempt.
Dietary Intervention
In the week prior to initiating the resistance-training program, each participant met with a
nutrition counselor to receive instructions on how to track their food intake using a smartphone
app (MyFitness Pal®). After a three-day food tracking familiarization and baseline assessments
were completed, participants were matched according to total fat mass and randomized to the high
protein group (HP; n = 8) or the low protein group (LP; n = 9). Participants in the high protein
group were instructed to ingest at least 2.4 grams of protein/kg body mass per day and participants
in the low protein group were instructed to ingest no more than 1.2 grams of protein/kg body mass.
While the participants were instructed to track all food intake, there were no restrictions or
guidelines placed on dietary carbohydrate or fat intake during the study intervention for either
group. Pre and post-workout protein intake was standardized throughout the study. Participants in
the HP group consumed 25 grams of whey protein isolate (Dymatize ISO-100) immediately before
and another 25 grams immediately after each resistance exercise bout in the presence of research
personnel. Participants in the LP group consumed 5 grams of whey protein isolate (Dymatize ISO-
100) immediately before and another 5 grams immediately after each resistance exercise bout in
the presence of research personnel. Also, in addition to meeting with a nutrition coach at the
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
beginning of the study, each participant had access to their individual nutrition coach throughout
the study duration to answer any nutrition questions related to selection of food choices and
adhering to the assigned low or high protein diet.
Resistance and High Intensity Interval Training Program
After 1RM strength testing, participants began an 8-week resistance-training program.
Twenty-eight workouts were scheduled to be completed over the 8-week period, with four
workouts per week during weeks 1-3 and 5-7, and two workouts per week during the midpoint of
the training program (week 4) and last week of the training program (week 8). The reduced training
frequency during weeks 4 and 8 was a pre-planned reduction in volume and served as a taper. In
order to maintain compliance with the training program, participants had to attend at least 85% of
all scheduled supervised workouts.
The resistance-training program consisted of two upper-body focused days and two lower-
body focused days per week. The lower-body workouts consisted of five exercises per session
and required that each participant complete back squats, deadlifts, and hip thrusts and then choose
from a list of other lower-body exercises to complete the required number of exercises for the
workouts. Upper-body workouts consisted of six exercises per session and required that the
participants complete barbell rows, overhead press, and assisted pull-ups and then choose from a
list of other upper-body exercises to complete the required number of exercises for the workouts.
The set and repetition ranges varied throughout the program, including five sets of 3-5 repetitions,
four sets of 9-11 repetitions, and three sets of 14-16 repetitions. Participants self-selected the load
that would allow them to complete the appropriate number of repetitions within the specified
repetition ranges while allowing for approximately one additional repetition with good form. Each
workout was supervised by two to three research assistants in the Performance and Physique
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Enhancement Laboratory at the University of South Florida, equating to a supervisor:participant
ratio of approximately 1:6.
The high intensity interval training program consisted of a progressive increase in the
number of sets of 30-second, maximal intensity sprints. For the first two weeks of the intervention,
participants engaged in four sets of 30-second high intensity interval exercise sets. The number of
sets increased to five sets for the third and fourth weeks, to six sets for the fifth and sixth weeks,
and to seven sets for the final two weeks of the intervention. Participants could choose their mode
of exercise (treadmill, outdoor sprinting, cycle ergometer, rowing machine, etc.) and were
instructed to rest two minutes between each set.
Statistics
Descriptive statistics (mean ± sd) for all DVs were calculated. The distribution of each
body composition, strength, and resting metabolic rate measure was examined with the Shapiro-
Wilk test (Razali and Wah, 2011; Shapiro and Wilk, 1965). Data for nutrition intake was
analyzed via an independent samples t-test. Data for all other DVs was analyzed via a 2 group
(high protein vs. moderate protein) × 2 time (pre- and post-training) between-within factorial
ANOVA with repeated measures on the second factor. For each outcome, an effect size (ES) was
calculated as the pretest-posttest change, divided by the pooled pretest SD. All analyses were
completed using SPSS (Version 22, IBM. Armonk, NY) software and the alpha criterion for
significance was set at 0.05.
RESULTS
In both protein intake groups for all dependent variables, the skewness and kurtosis
coefficients were within a range of ±1.5 and a Shapiro-Wilk’s test (p > 0.05) and a visual inspection
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
of their histograms, normal Q-Q plots, and box plots showed that data were normally distributed.
There were no differences in any dietary intake variable between the two groups at baseline.
Macronutrient intake and diet composition is summarized in table 1. Body composition, maximal
strength, and resting metabolic rate data are summarized in table 2 and figure 2. There were no
differences between the two groups for upper body training volume, lower body training volume,
or total body training volume.
DISCUSSION
To the authors’ knowledge, this is the first study to assess the effects of different levels of
protein intake on body composition in resistance-trained women in conjunction with a supervised
resistance training program. A primary and novel finding of our study is that a high protein diet
(2.5 g/kg/day) significantly increased FFM compared to a lower protein diet (0.9 g/kg/day) in the
cohort of aspiring female physique athletes. Our results are somewhat in contrast with those of
Lemon et al. (1992), who found that novice male lifters realized similar resistance training-induced
increases in lean mass with protein intakes of 1.35 versus 2.62 g/kg/day, although non-significantly
greater changes were seen with the higher protein consumption. Given that the study lasted just 4
weeks, it is plausible that differences might have reached significance with a longer study period,
as with the 8-week duration employed in our protocol. In addition, the lower protein intake of 1.35
g/kg/day used in this comparison study (Lemon et al., 1992) was still greater than the 0.9 g/kg/day
ingested in our investigation. This level of protein may have been enough protein to elicit a positive
change in fat-free mass.
A recent large-scale meta-analysis encompassing 49 studies with 1,863 participants found
that protein supplementation in conjunction with prolonged resistance training significantly
increased measures of muscle hypertrophy; however, beneficial effects reached a threshold when
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
total protein intakes exceeded ~1.6 g/kg/day (Morton et al. 2017). Therefore, our findings of
greater increases in lean mass with the higher protein condition may be due to suboptimal protein
intake in those consuming lower daily amounts of protein. Recent evidence shows when
resistance-trained individuals consume at least 2 grams of protein/kg body mass during periods of
unsupervised resistance training, additional intake does not enhance lean mass gains (Antonio et
al., 2014; Antonio et al., 2015).
Another important finding from the study was the high protein group lost a significant
amount of fat mass whereas reductions in the low-protein group were not statistically significant.
These results held true despite the fact that those the higher protein group ingested significantly
more kilocalories (approximately 400 kcals) in the form of protein. These results are consistent
with those of Antonio et al. (2015), who reported a loss of 2.4% body fat with consumption of 3.4
g/kg/day versus only a 0.7% decrease when consuming 2.3 g/kg/day. Considering that weight loss
is a function of energy balance (Thomas et al., 2009), these findings may seem counterintuitive.
However, dietary protein has been shown to have a much higher thermic effect (25-30% of total
calories) compared to less than 10% for carbohydrate or lipid (Halton and Hu, 2004). Thus, a
substantial portion of protein calories consumed are lost as heat. Moreover, increases in non-
exercise activity thermogenesis also have been observed following overfeeding (Levine et al.,
1999), and it is conceivable that higher protein intakes may enhance this effect. Therefore,
differences in fat loss may be explained by a greater portion of energy from the additional protein
to be used for lean tissue building as opposed to adipose storage, as well an ability for higher levels
of protein intake to positively influence the energy expenditure side of the energy balance equation.
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Both training groups experienced a body recomposition (the gaining of fat-free mass while
simultaneously losing fat mass). While this finding has been repeatedly observed in overweight
and obese populations undergoing a resistance training program (Longland et al., 2016; Josse et
al. 2011), this outcome is not typically observed in well-trained individuals that are not classified
as overweight/obese. Garthe and coworkers (2011) recruited elite male and female athletes to
follow a slow vs. fast weight loss program in which both groups ingested approximately 1.5 grams
of protein/kg body mass and resistance trained four days per week. Athletes in the slower weight
loss group realized significant increases in lean body mass (~1kg) and significant reductions in fat
mass (~4.9kg) during the 8.5-week study intervention. When taken together, the Garthe study
(2011) and the present investigation indicate that body recompositiion is possible during both a
hypocaloric and hypercaloric state provided that a structured exercise and nutritional protocol is
followed.
Both protein intake groups experienced significant increases in maximal strength.
However, the influence of higher protein intake did not improve maximal strength in comparison
to the lower protein intake. This finding was consistent with the data reported by Josse and
coworkers (2010) in which non-resistance trained females did not increase lower-body strength
when additional protein was ingested (in the form of milk) in conjunction with a 12-week
resistance training program. The finding was also consistent with data reported by Hida et al.
(2012) in which collegiate female athletes did not increase maximal strength when additional
protein was ingested (in the form of egg white protein) in conjunction with an 8-week training
regimen. Also, non-resistance trained overweight females increasing protein intake (in the form of
yogurt supplementation) did not improve maximal strength as compared to a lower protein
ingestion group (Thomas et al., 2011). Despite the difference in FFM between the two protein
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
intake groups, there was no associated difference in resting metabolic rate. While males tend to
realize an increase in resting metabolic rate with an increase in resistance-training induced fat-free
mass, females are void of such elevations in resting metabolic rate (Lemmer et al., 2001; Bonganha
et al. 2011). The present study reinforces this observation.
Although our study had several notable strengths (supervised workouts, high adherence to
daily food tracking, and personalized nutritional counseling), there nevertheless are some
limitations that must be considered when drawing practical inferences. For one, there was a large
discrepancy between the two protein intakes investigated. Prudent follow-up research would
compare protein intakes of approximately 1.6 to 1.8 g/kg/day (a likely zone of optimality) to a
super-optimal daily intake of approximately 2.4 g/kg/day as was investigated in the present study.
Also, we did not attempt to control for the subjects’ menstrual cycles when testing. This may have
influenced body water and thus assessment of lean mass (Stachoń, 2016). While it can be
speculated that random distribution in the cohort would render any observed differences small, we
nevertheless cannot rule out confounding effects on body composition. Another potential
confounding issue was that the high protein group consumed 25 g of whey protein immediately
before and after the workouts while the low protein group consumed only 5 grams during these
periods. It has been suggested that there is an “anabolic window of opportunity” whereby pre- and
post-workout protein consumption heightens the accretion of muscle proteins, and that intake of
at least 20 grams of high quality protein is needed to maximize this response (Ivy and Ferguson-
Stegall, 2014; Macnaughton et al., 2016). This raises the possibility that the timing of consumption
may have been at least partly attributable to results. However, recent meta-analytic data indicates
that total protein intake, not precise peri-workout timing, is the determining factor in exercise-
induced muscular adaptations (Schoenfeld et al., 2013). Further, given that the intent of the
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
methodological design was to implement dietary changes to only protein (while keeping dietary
carbohydrate and fat consistent between the two groups), this also resulted in a difference in total
caloric intake between the two groups, with the high protein group ingesting significantly more
kcals per day as compared to the low protein group. It is possible that the changes in lean body
mass observed in both groups were, at least in part, due to the elevated caloric intake in the high
protein group and the decreased caloric intake in the low protein group during the 8-week dietary
intervention. Finally, our findings are specific to young, resistance-trained women; results cannot
necessarily be extrapolated to other populations.
SUMMARY AND PRACTICAL APPLICATIONS
This is the first study to demonstrate that an under-represented population (female physique
athletes) engaging in resistance training benefit from higher protein intakes. Specifically, the
findings suggest that higher protein intakes are advisable for these types of athletes seeking to
optimize body composition. As there is a large discrepancy between 0.9g/kg/day and 2.5g/kg/day,
additional research is required to determine the necessity of intakes as high as 2.5g/kg/day in order
to achieve the body recompositiion observed in the present study.
Acknowledgement, authorships, declarations:
This study was funded by Dymatize Athletic Nutrition Institute (DANI). The study was designed
by BIC, DA, LC, AV, AC, CG, and SB. Data interpretation and manuscript preparation were
undertaken by BIC, BJS, EG, and KC. BIC is on the scientific advisory board for Dymatize
Athletic Nutrition Institute.
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
References
Antonio, J., Peacock, C.A., Ellerbroek, A., Fromhoff, B., & Silver, T. (2014). The effects of
consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals.
Journal of the International Society of Sports Nutrition, 12;11:19.
Antonio, J., Ellerbroek, A., Silver, T., Orris, S., Scheiner, M., Gonzalez, A., et al. (2015). A high
protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body
composition in healthy trained men and women--a follow-up investigation. Journal of the
International Society of Sports Nutrition, 20;12:39.
Atherton, P.J. & Smith, K. (2012). Muscle protein synthesis in response to nutrition and exercise.
The Journal of Physiology, 590(5):1049-57.
Bandegan, A., Courtney-Martin, G., Rafii, M., Pencharz, P.B., & Lemon, P.W. (2017). Indicator
amino acid-derived estimate of dietary protein requirement for male bodybuilders on a
nontraining day is several-fold greater than the current recommended dietary allowance. The
Journal of Nutrition, 147(5):850-857.
Bonganha, V., Conceicao, M.S., Chacon-Mikahil, M.P.T., & Madruga, V.A. (2011). Response of
the resting metabolic rate after 16 weeks of resistance training in postmenopausal women.
Revista da Associao Mdica Brasileira, 17:350353.
Campbell, B., Zito, G., Colquhoun, R., Martinez, N., Kendall, K., Buchanan, L., et al. (2016).
The effects of a single-dose thermogenic supplement on resting metabolic rate and hemodynamic
variables in healthy females--a randomized, double-blind, placebo-controlled, cross-over trial.
Journal of the International Society of Sports Nutrition, 13:13.
Colquhoun, R., Gai, C., Walters, J., Brannon, A.R., Kilpatrick, M.W., D’Agostino, D.P., et al.
(2017). Comparison of powerlifting performance intrained men using traditional and flexible
daily undulating periodization. Journal of Strength and Conditioning Research, 31(2):283-91.
Garthe, I., Raastad, T., Refsnes, P.E., Koivisto, A., & Sundgot-Borgen, J. (2011). Effect of two
different weight-loss rates on body composition and strength and power-related performance in
elite athletes. International Journal of Sport Nutrition and Exercise Metabolism, 21(2):97-104.
Halton, T.L., & Hu, F.B. (2004). The effects of high protein diets on thermogenesis, satiety and
weight loss: a critical review. Journal of the American College of Nutrition, 23(5):373-85.
Hida, A., Hasegawa, Y., Mekata, Y., Usuda, M., Masuda, Y., Kawano, H., et al. (2012). Effects
of egg white protein supplementation on muscle strength and serum free amino acid
concentrations. Nutrients, 4(10):1504-17.
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Ivy, J.L., & Ferguson-Stegall, L.M. (2014). Nutrient timing: the means to improved exercise
performance, recovery, and training adaptation. American Journal of Lifestyle Medicine,
8(4):246-59.
Josse, A.R., Atkinson, S.A., Tarnopolsky, M.A., & Phillips, S.M. (2011). Increased consumption
of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss
and lean mass gain in overweight and obese premenopausal women. The Journal of Nutrition,
141(9):1626-34.
Josse, A.R., Tang, J.E., Tarnopolsky, M.A., and Phillips S.M. (2010). Body composition and
strength changes in women with milk and resistance exercise. Medicine and Science in Sports
and Exercise, 42(6):1122-30.
Lemmer, J.T., Ivey, F.M., Ryan, A.S., Martel, G.F., Hurlbut, D.E., Metter, J.E., et al. (2001).
Effect of strength training on resting metabolic rate and physical activity: age and gender
comparisons. Medicine and Science in Sports and Exercise, 33(4):532-41.
Lemon, P.W. (2000). Beyond the zone: protein needs of active individuals. Journal of the
American College of Nutrition, 19(5 Suppl):513S-521S.
Lemon, P.W., Tarnopolsky, M.A., MacDougall, J.D., & Atkinson, S.A. (1992). Protein
requirements and muscle mass/strength changes during intensive training in novice bodybuilders.
Journal of Applied Physiology (1985). 73(2):767-75.
Levine J.A., Eberhardt N.L., & Jensen M.D. (1999). Role of nonexercise activity thermogenesis
in resistance to fat gain in humans. Science, 283(5399):212-4.
Longland, T.M., Oikawa, S.Y., Mitchell, C.J., Devries, M.C., & Phillips, S.M. (2016). Higher
compared with lower dietary protein during an energy deficit combined with intense exercise
promotes greater lean mass gain and fat mass loss: a randomized trial. American Journal of
Clinical Nutrition, 103(3):738-46.
Mcnaughton, L.S., Wardle, S.L., Witard, O.C., McGlory, C., Hamilton, D.L., Jeromson S, et al.
(2016). The response of muscle protein synthesis following whole-body resistance exercise is
greater following 40 g than 20 g of ingested whey protein. Physiological Reports, 4(15).
Moore, D.R., Del Bel, N.C., Nizi, K.I., Hartman, J.W., Tang, J.E., Armstrong, D, et al. (2007).
Resistance training reduces fasted- and fed-state leucine turnover and increases dietary nitrogen
retention in previously untrained young men. The Journal of Nutrition, 137(4):985-91.
Morton, R.W., Murphy, K.T., McKellar, S.R., Schoenfeld, B.J., Henselmans, M., Helms, E., et
al. (2017). A systematic review, meta-analysis and meta-regression of the effect of protein
supplementation on resistance training-induced gains in muscle mass and strength in healthy
adults. British Journal of Sports Medicine [epub ahead of print].
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Razali, N.M. and Wah, Y.B. (2011). Power comparisons of Shapiro-Wilk, Kolmogorov-
Smirnov, Lilliefors and Anderson-Darling tests. Journal of Statistical Modeling and Analytics,
2(1):21-33.
Schoenfeld, B.J., Aragon, A.A., Krieger, J.W. (2013). The effect of protein timing on muscle
strength and hypertrophy: a meta-analysis. Journal of the International Society of Sports
Nutrition. 10(1):53.
Shapiro, S.S, and Wilk, M.B. (1965). An analysis of Variance Test for Normality (Complete
Samples). Biometrika, 52(3/4):591-611.
Sheppard, J.M. and Triplett, N.T. Program design for resistance training. (2016). In G.G. Haff
and N.T. Triplett (Eds.), NSCA’s essentials of strength training and conditioning, 4th Edition (pg.
452). Champaign, IL: Human Kinetics.
Stachoń, A.J. (2016). Menstrual Changes in Body Composition of Female Athletes. Collegium
Antropologicum. 40(2):111-22.
Thomas, D.M., Ciesla, A., Levine, J.A., Stevens, J.G., and Martin, C.K. (2009). A mathematical
model of weight change with adaptation. Mathematical Biosciences and Engineering. 6(4):873-
87.
Thomas, D.T., Wideman, L., Lovelady, C.A. (2011). Effects of a dairy supplement and
resistance training on lean mass and insulin-like growth factor in women. International Journal
of Sport Nutrition & Exercise Metabolism, 21(3):181-8.
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Figure 1. CONSORT Participant Flow
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Figure 2. Individual Fat-Free Mass Responses
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes
Engaging in an 8-Week Resistance Training Program” by Campbell BI et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2018 Human Kinetics, Inc.
Table 1. Macronutrient Intake at Baseline and During the 8-Week Dietary Intervention
High Protein (n=8)
Low Protein (n=9)
Baseline
8-Week
Average
Baseline
8-Week
Average
Kcals
1,588 ± 438
1,839 ± 316#
1,708 ± 419
1,416 ± 204#
CHO (grams)
157 ± 61
156 ± 47
188 ± 62
177 ± 33
PRO (grams)
89 ± 23
157 ± 18*
90 ± 35
56 ± 5*
Fat (grams)
67 ± 24
65 ± 21
66 ± 23
54 ± 13
Kcal/kg body mass
27 ± 10
30 ± 5#
28 ± 9
24 ± 3#
CHO (g/kg/day)
2.7 ± 1.3
2.5 ± 0.3
3.1 ± 1.2
2.9 ± 0.2
PRO (g/kg/day)
1.5 ± 0.5
2.5 ± 0.2*
1.5 ± 0.5
0.9 ± 0.1*
Fat (g/kg/day)
1.1 ± 0.4
1.1 ± 0.3
1.1 ± 0.4
0.9 ± 0.2
CHO/PRO/Fat (%)
40-22-38
34-34-32
44-21-35
50-16-34
CHO = carbohydrate; PRO = protein; g/kg/day = grams/kilogram body mass/day.
Significant difference (independent samples t-test); * = p < 0.001; # = p < 0.05
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
High Protein (n=8)
Low Protein (n=9)
Pre
Post
Change
Cohen’s d
Pre
Post
Change
Cohen’s d
Body Weight (kg)
61.2 ± 7.9
62.2 ± 8.2
+1.0
0.12
61.4 ± 4.4
61.2 ± 4.6
-0.2
0.04
Fat-Free Mass (kg)
47.1 ± 4.5
49.2 ± 5.4#
+2.1
0.42
48.1 ± 2.7
48.7 ± 2.0
+0.6
0.25
Fat Mass (kg)
14.1 ± 3.6
13.0 ± 3.3*
-1.1
0.32
13.3 ± 3.7
12.5 ± 3.0
-0.8
0.24
Body Fat (%)
22.7 ± 3.0
20.7 ± 3.1#
-2.0
0.66
21.4 ± 5.2
20.3 ± 3.9
-1.1
0.24
1RM Squat (kg)
69.3 ± 18.4
78.7 ± 16.0#
+9.4
0.55
72.0 ± 15.1
81.8 ± 20.1#
+9.8
0.56
1RM Deadlift (kg)
86.9 ± 14.8
102.8 ± 18.5#
+15.9
0.95
97.2 ± 16.7
111.4 ± 17.6#
+14.2
0.83
RMR (kcals/day)
1,466 ± 152
1,446 ± 151#
-20
0.13
1,451 ± 104
1,510 ± 196
+59
0.39
Downloaded by UNIVERSITY OF SOUTH FLORIDA on 02/08/18, Volume ${article.issue.volume}, Article Number ${article.issue.issue}
... This thought is supported by the large amount of fat, which would be more easily reduced when compared to another group with lower percentages 8 . However, it is important to point out that BR has already been observed in adolescents 13 and elderly people 9 , in sedentary individuals of both sexes 13 to sportsmen of different modalities 10 , including bodybuilders 6,14 . That is there are no restrictions on age, sex, or training status to observe BR. ...
... High-intensity interval training (HIIT) has also become a valid strategy for inducing BR, both in conjunction with weight training 14 and performed in isolation 15 . In a classic study with obese and inactive men (24.7±4.8 years and Body Mass Index = 28.4±0.5), the effects of a repeated sprints training (RST) with a 12-week intervention (3x/week, 20 min/session). ...
... As final consideration it is pointed out that Body Recomposition is a term that has emerged in the scientific literature in the areas of Sports Medicine and Physical Education and deserves attention, while it is emphasized that this phenomenon is not recent. In opposition to what is usually postulated, studies indicate the possibility of reducing body fat in energy surplus 7,14 and muscle hypertrophy in caloric restriction 5,8 , in addition to the simultaneous occurrence of both phenomena. Finally, it is pointed out that body recomposition can occur in different groups and with different types of exercises -especially when associated with nutritional adjustments that involve increased protein intake. ...
Article
Full-text available
Redução de tecido adiposo e aumento de massa magra se constituem como objetivos frequentes em programas de exercícios voltados à saúde e à estética. Nesse contexto, ao se postular a necessidade de déficit energético para o emagrecimento e superavit calórico para a hipertrofia muscular, desenvolveu-se a ideia de que não seria possível a existência de ambos os fenômenos de forma simultânea. Contrariamente, emerge na literatura o termo "Recomposição Corporal" (RC), fenômeno no qual ocorre emagrecimento e hipertrofia muscular ao mesmo tempo. A RC já foi observada com emprego de diferentes técnicas de análise da composição corporal, desde métodos duplamente indiretos até ressonância nuclear magnética, e em diversos grupos populacionais, a saber: adolescentes, adultos sedentários ou fisicamente ativos, idosos e pessoas com excesso de peso, além de praticantes de modalidades esportivas, inclusive fisiculturismo. A RC ocorre com ajuste nutricional preciso, com consumo de proteínas acima da ingestão diária recomendada (0,8 g/kg), em faixas entre 2,4 e 3,4 g/kg de massa corporal/dia. Diferentes tipos de exercícios físicos podem conduzir à RC, desde o treinamento de força, passando pelo treinamento em circuito em alta intensidade, treinamento intervalado de alta intensidade e, inclusive, treinamento concorrente-na maioria das vezes com elevada frequência semanal.
... This thought is supported by the large amount of fat, which would be more easily reduced when compared to another group with lower percentages 8 . However, it is important to point out that BR has already been observed in adolescents 13 and elderly people 9 , in sedentary individuals of both sexes 13 to sportsmen of different modalities 10 , including bodybuilders 6,14 . That is there are no restrictions on age, sex, or training status to observe BR. ...
... High-intensity interval training (HIIT) has also become a valid strategy for inducing BR, both in conjunction with weight training 14 and performed in isolation 15 . In a classic study with obese and inactive men (24.7±4.8 years and Body Mass Index = 28.4±0.5), the effects of a repeated sprints training (RST) with a 12-week intervention (3x/week, 20 min/session). ...
... As final consideration it is pointed out that Body Recomposition is a term that has emerged in the scientific literature in the areas of Sports Medicine and Physical Education and deserves attention, while it is emphasized that this phenomenon is not recent. In opposition to what is usually postulated, studies indicate the possibility of reducing body fat in energy surplus 7,14 and muscle hypertrophy in caloric restriction 5,8 , in addition to the simultaneous occurrence of both phenomena. Finally, it is pointed out that body recomposition can occur in different groups and with different types of exercises -especially when associated with nutritional adjustments that involve increased protein intake. ...
Article
Full-text available
Adipose tissue reduction and lean mass increase are frequent goals in exercise programs aimed at health and aesthetics. In this context, when postulating the need for an energy deficit for weight loss and a caloric surplus for muscle hypertrophy, was developed the idea that it would not be possible for both phenomena to exist simultaneously. Contrarily, the term “Body Recomposition” (BR) emerges in the literature, a phenomenon in which weight loss and muscle hypertrophy occur at the same time. BR has already been observed using different techniques for analyzing body composition, from doubly indirect methods to magnetic resonance imaging, and in different population groups, namely: adolescents, sedentary or physically active adults, the elderly and people with excess weight, as well as practitioners of sports, including bodybuilding. BR occurs with precise nutritional adjustment, with protein consumption above the recommended daily intake (0.8 g/kg), in ranges between 2.4 and 3.4 g/kg of body mass/day. Different types of exercises can lead to BR, from strength training, through high-intensity circuit training, high-intensity interval training, and even concurrent training – most often with a high weekly frequency.
... Following a supervised eight-week training intervention, Campbell et al. (2018) reported a loss of fat mass and increases in fat-free mass in both low and high intakes. However, increases in FFM were significantly greater in the high protein group compared to the low protein group 10 . Fat and carbohydrate intake for these physique athletes were not controlled. ...
Article
Full-text available
Introduction: Whether it is the athletic population or the general population, it is essential to understand considerations regarding the amount of protein consumed daily. Protein, often referred to as the body's building blocks, is an integral part of the diet. This macronutrient plays a vital role in developing and maintaining skeletal muscle mass. This paper aims to discuss protein intake at low (<1.2 g/kg/day), medium (1.2-2.2 g/kg), and high (>2.2 g/kg/day) levels that should be consumed with consideration of physically active populations and potential benefits or detrimental effects on body composition and performance. Methods: Searches of electronic databases PubMed and Google Scholar were undertaken to identify peer-reviewed journal articles that reported on dietary protein intake on body composition, and performance/strength. Discussion: Low protein intakes may not meet the needs of all physically active individuals. Medium and high protein intakes positively influenced body composition. Medium protein intakes can benefit strength and performance; however, these effects are not consistently reported with higher intakes. Conclusions: The minimum protein requirement for active individuals is 1.2 g/kg, and higher intakes are safe and effective for healthy, physically active individuals.
... When considering the distribution of macronutrients, the carbohydrate-to-protein ratio has been shown to be important for supporting optimal body composition and fat loss in women. The consumption of a ratio of 2:1 carbohydrate to protein has demonstrated significant losses in percent body fat while supporting a gain in LM [67][68][69]. This ratio supports a higher protein intake while supporting lower carbohydrate needs to optimize fat oxidation. ...
Article
Full-text available
Women are the largest consumers of dietary supplements. Dietary supplements can play a role in health and performance, particularly for women. Growing evidence and innovations support the unique physiological and nutrient timing needs for women. Despite the need for more nutrition and exercise-specific research in women, initial data and known physiological differences between sexes related to the brain, respiration, bone, and muscle support new product development and evidence-based education for active women regarding the use of dietary supplements. In this narrative review, we discuss hormonal and metabolic considerations with the potential to impact nutritional recommendations for active women. We propose four potential areas of opportunity for ingredients to help support the health and well-being of active women, including: (1) body composition, (2) energy/fatigue, (3) mental health, and (4) physical health.
... Hal ini dikarenakan, pada kelompok yang mengonsumsi tinggi protein setidaknya telah memenuhi kebutuhan protein dalam sehari secara optimal dibandingkan dengan kelompok yang mengonsumsi rendah protein 14 . Meskipun begitu, beberapa penelitian menyebutkan bahwa diet tinggi protein dapat meningkatkan massa otot secara signifikan apabila diikuti dengan adanya olahraga ketahanan secara rutin dan terstruktur 12 Kesimpulannya adalah diet tinggi protein dapat memepengaruhi komposisi tubuh seperti cairan tubuh, massa lemak, massa otot dan massa tulang 13 . ...
Article
Full-text available
Latar Belakang: Perilaku self-made diet dan intensitas latihan yang tinggi pada anggota komunitas akan berdampak buruk bagi fungsi ginjal dan komposisi tubuh mereka. Tujuan: Menganalisis hubungan asupan makan dan intensitas latihan dengan fungsi ginjal dan komposisi tubuh pada komunitas gym. Metode: Penelitian ini merupakan penelitian cross-sectional yang dilakukan di beberapa pusat kebugaran di Kota Semarang dan melibatkan 54 pria anggota komunitas gym berusia 19-53 tahun. Data komposisi tubuh diperoleh menggunakan BIA. Kuesioner digunakan untuk memperoleh data intensitas latihan (durasi, frekuensi dan lama Latihan) sedangkan asupan makan menggunakan metode Semi Quantitative Food Frequency Questionnaire. Pemeriksaan kadar ureum menggunakan metode kalorimetri sedangkan kadar kreatinin menggunakan metode jaffe reaction. Analisis data menggunakan uji Rank-Spearman dan uji regresi linear berganda. Hasil: Mayoritas subjek memiliki frekuensi latihan sebanyak 5-7 kali dalam seminggu dengan rerata durasi 105,5±35,8 menit per kunjungan. Sebesar 85,2% subjek memiliki kadar ureum yang tinggi. Terdapat korelasi negatif antara asupan energi, protein, lemak dan durasi latihan dengan persen lemak tubuh. Semakin tinggi lama latihan dan semakin rendah asupan karbohirat maka massa otot dan tulang akan semakin meningkat. Peningkatan asupan protein dan lemak serta frekuensi latihan per pekan dapat meningkatkan kadar ureum dalam tubuh. Hasil uji multivariat menyatakan bahwa frekuensi latihan berpengaruh terhadap kadar ureum (21,5%) sedangkan durasi latihan memiliki pengaruh sebesar 9,7% terhadap persen lemak tubuh. Kesimpulan: Semakin lama frekuensi latihan per pekan maka semakin tinggi kadar ureum dalam darah dan semakin lama durasi latihan tiap kunjungan maka semakin rendah persen lemak tubuh.
Article
Multi-ingredient thermogenic supplements can acutely increase resting energy expenditure (REE) and subjective energy. However, less is understood about the effects of chronic consumption on body composition, metabolism, and subjective variables such as mood, sleep quality, and eating behaviors. Fifty-two healthy, exercise-trained participants (50% female; mean ± SD age: 23.5 ± 3.0 years; body fat percentage: 27.3 ± 8.0%) were randomized 2:2:1 to take a whey protein supplement alone (PRO; n = 20), in combination with a thermogenic supplement (PRO + FB; n = 19), or no supplement at all (CON; n = 13) for four weeks. Body composition, anthropometric, metabolic, hemodynamic, and subjective outcomes were collected before and after the intervention. Greater changes in REE occurred in PRO + FB as compared to CON (111.2 kcal/d, 95% CI 2.4 to 219.9 kcal/d, p = 0.04), without significant differences between PRO and CON (42.7 kcal/d, 95% CI −65.0 to 150.3 kcal/d, p = 0.61) or between PRO + FB and PRO (68.5 kcal/d, 95% CI −28.3, 165.3, p = 0.21). No changes in hemodynamic outcomes (blood pressure and heart rate) were observed. In exercising adults, four weeks of supplementation with protein and a multi-ingredient thermogenic product maintained fasted REE as compared to no supplementation, for which a decrease in REE was observed, without differential effects on body composition, anthropometrics, or subjective variables.
Chapter
A number of nutrients, foods, and supplements have the potential to augment health, exercise performance, and/ or recovery, particularly in women, due to the fluctuation of sex hormones, or reductions thereof. Some of these for which significant amounts of research have provided evidence include: Carbohydrate (CHO) loading can overcome lower resting muscle glycogen in the follicular phase but an increase in total energy intake may be required. Pre-exercise feeding and/or CHO ingestion can negate the estrogen-induced reduction in gluconeogenesis during endurance exercise. Increased protein during recovery may help offset the increase in protein catabolism in the luteal phase. Special attention to not overhydrating and replacing sodium losses in the luteal phase of the menstrual cycle may help reduce the increased risk of hyponatremia that is due to differences in fluid and electrolyte handling and thirst in this phase. Supplementing with dietary sources of antioxidants may be prudent in those with amenorrhea or in menopause and, thus, low estrogen, as estrogen enhances the antioxidant capacity. However, this may not fully compensate for the lack of estrogen. Fish oil (omega-3 fatty acid source) may aid in inflammatory disorders such as dysmenorrhea and those associated with menopause. Vitamin D and calcium influence fertility, possibly dysmenorrhea, as well as bone health; however, supplementation cannot fully compensate for the lack of estrogen. Branched-chain amino acid oxidation may be greater when estrogen is low; this may have dietary implications for those with amenorrhea or in menopause, particularly when training regularly and or on low energy diets. Pre- and probiotics have the potential to help with dysmenorrhea and menopause as well as bone health; however, a healthy microbiota is largely influenced by the diet as a whole. In general, it is acknowledged that the dietary matrix is important to the effects of specific dietary components and that supplementing with a single component rarely achieves the same outcome as when eating a complement of foods, containing myriad phytochemicals and nutrients.KeywordsFemalesDietary supplementsMenstrual cycleDietNutritionEstrogenReactive oxygen speciesAntioxidants
Book
Full-text available
O livro está organizado em quatro capítulos. O primeiro capítulo apresenta um breve histórico regulatório do código de deontologia farmacêutica e publicações científicas relacionadas aos serviços de Farmácia Clínica ou Cuidado Farmacêutico. O Prof. Dr. Jean Leandro do Santos descreve a evolução nacional do ensino, pesquisa e extensão em Cuidado Farmacêutico. Registra-se as atividades realizadas desde 2007 por entidades estudantis, projetos de pesquisa, extensão universitária e atividades de internacionalização desenvolvidas pelo Núcleo de Atenção Farmacêutica (NAF) da UNESP. No segundo capítulo, descrevemos a regulamentação sanitária de Farmacovigilância à Segurança do Paciente, as estratégias e ferramentas que podem ser utilizadas na prestação de serviços farmacêuticos de rastreamento em saúde, revisão da farmacoterapia, conciliação de medicamentos ou acompanhamento farmacoterapêutico para detectar, prevenir e resolver problemas relacionados à farmacoterapia, incluindo grupos específicos (idosos, crianças e gestantes). A proposta foi a organização dos resultados e materiais dos projetos de pesquisa e extensão universitária desenvolvidos em Farmacovigilância e Farmácia Clínica no Hospital de Américo Brasiliense, de 2013 a 2019. No terceiro capítulo é descrito um modelo de prática de acompanhamento farmacoterapêutico e suas etapas, incluindo os serviços de conciliação de medicamentos, manejo de problemas de saúde autolimitados (e.g., dor), e educação em saúde para compreensão do estado de saúde e farmacoterapia, melhorando a adesão e transformando a experiência farmacoterapêutica do paciente. Também são abordados os procedimentos de verificação de parâmetros clínicos, organização de medicamentos conforme os protocolos da doença de Alzheimer e as comorbidades associadas para a gestão da condição de saúde para pessoas com diagnóstico provável de Alzheimer. O capítulo sistematiza o método empregado nos projetos de mestrado, iniciação científica e de extensão da entidade estudantil Atenção Farmacêutica Estudantil Permanente (AFEP) da UNESP desenvolvidas no Centro de Referência do Idoso de Araraquara (CRIA) de 2012 a 2015. Os indicadores de resultados do serviço de cuidado farmacêutico implantado no CRIA foram premiados pelo Conselho Federal de Farmácia, como experiências exitosas no Sistema Único de Saúde, em 2016. No quarto capítulo, descrevemos os atos de prescrição farmacêutica e indicação farmacêutica a fim de apoiar decisões nos serviços de manejo de problemas autolimitados, ou de acompanhamento farmacoterapêutico. A Profª. Dr. Hellen Maluly e o Prof. Dr. Max Viana descrevem a prescrição e o manejo de suplemento alimentar e a Profª. Dr. Eliana Rodrigues, Bárbara Migioli e colaboradores, o manejo de produtos à base de plantas para problemas de saúde autolimitados. O livro é um trabalho conjunto de professores, pós-graduandos e extensão universitária da Faculdade de Ciências Farmacêuticas da UNESP e amigos colaboradores da Universidade Federal de São Paulo (UNIFESP), Universidade de São Paulo (USP-RP), Universidade Federal da Bahia (UFBA) e Faculdade Oswaldo Cruz (FOC) e tem como objetivo apoiar atividades de ensino, pesquisa e extensão em Cuidado Farmacêutico, a nível de graduação, pós-graduação stricto e lato sensu e profissionais farmacêuticos em sua prática profissional.
Article
Objectives This systematic review, meta-analysis, and meta-regression aimed to determine if increasing daily protein ingestion contributes to gaining lean mass (LM), muscle strength, and physical/functional test performance in healthy persons. Methods The present review was registered on PROSPERO - CRD42020159001. A systematic search in Medline, Embase, CINAHL, and Web of Sciences databases was undertaken. Randomized controlled trials (RCT) including healthy and non-obese adult participants increasing daily protein intake were selected. Subgroup analysis, splitting the studies by participation in resistance exercise training (RE), age (< 65 or ≥ 65 y), and daily protein ingestion were also performed. Results 74 RCT fit our inclusion criteria. The age range of the participants was 19 to 85 y, and study protocols in the trials lasted from 6 to 108 wks (76% of the studies between 8 and 12 wks). In ∼80% of the studies, baseline protein ingestion was at least 1.2 g of protein/kg/d. Increasing daily protein ingestion may lead to small gains in LM in subjects enrolled in RE (SMD [standardized mean difference] = 0.22, CI95% [95% confidence interval] 0.14:0.30, P < 0.01, 62 studies, moderate level of evidence). Also, ≥ 65 y subjects ingesting 1.2–1.59 g of protein/kg/d and younger subjects (< 65 y) increasing their ingestion to ≥ 1.6 g of protein/kg/d during RE showed a higher LM gain. Lower-body strength gain was slightly higher at ≥ 1.6 g of protein/kg/d during RE (SMD = 0.40, CI95% 0.09:0.35, P < 0.01, 19 studies, low level of evidence). Bench press strength was slightly increased by ingesting more protein in < 65 y subjects during RE (SMD = 0.18, CI95% 0.03:0.33, P = 0.01, 32 studies, low level of evidence). Effects on handgrip strength are unclear and only marginal for performance in physical function tests. Conclusions The number of studies increasing daily protein ingestion alone was too low (n = 6) to conduct a meta-analysis. The current evidence shows that increasing protein ingestion by consuming supplements or food, resulted in small additional gain in LM, and lower body muscle strength in healthy adults enrolled in RE. Effects on bench press strength and performance in physical function tests are minimal. The effect on handgrip strength was unclear. Funding Sources This research received a grant from the International Life Science Institute (Europe) and CNPq.
Article
Full-text available
Abstract We performed a systematic review, meta‐analysis, and meta‐regression to determine if increasing daily protein ingestion contributes to gaining lean body mass (LBM), muscle strength, and physical/functional test performance in healthy subjects. A protocol for the present study was registered (PROSPERO, CRD42020159001), and a systematic search of Medline, Embase, CINAHL, and Web of Sciences databases was undertaken. Only randomized controlled trials (RCT) where participants increased their daily protein intake and were healthy and non‐obese adults were included. Research questions focused on the main effects on the outcomes of interest and subgroup analysis, splitting the studies by participation in a resistance exercise (RE), age (
Article
Full-text available
Objective We performed a systematic review, meta-analysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced gains in muscle mass and strength. Data sources A systematic search of Medline, Embase, CINAHL and SportDiscus. Eligibility criteria Only randomised controlled trials with RET ≥6 weeks in duration and dietary protein supplementation. Design Random-effects meta-analyses and meta-regressions with four a priori determined covariates. Two-phase break point analysis was used to determine the relationship between total protein intake and changes in fat-free mass (FFM). Results Data from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p<0.05) increased changes (means (95% CI)) in: strength—one-repetition-maximum (2.49 kg (0.64, 4.33)), FFM (0.30 kg (0.09, 0.52)) and muscle size—muscle fibre cross-sectional area (CSA; 310 µm² (51, 570)) and mid-femur CSA (7.2 mm² (0.20, 14.30)) during periods of prolonged RET. The impact of protein supplementation on gains in FFM was reduced with increasing age (−0.01 kg (−0.02,–0.00), p=0.002) and was more effective in resistance-trained individuals (0.75 kg (0.09, 1.40), p=0.03). Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further RET-induced gains in FFM. Summary/conclusion Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM.
Article
Full-text available
Background: Despite a number of studies indicating increased dietary protein needs in bodybuilders with the use of the nitrogen balance technique, the Institute of Medicine (2005) has concluded, based in part on methodologic concerns, that “no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise.” Objective: The aim of the study was to assess the dietary protein requirement of healthy young male bodybuilders ( with ≥3 y training experience) on a nontraining day by measuring the oxidation of ingested L-[1-¹³C]phenylalanine to ¹³CO2 in response to graded intakes of protein [indicator amino acid oxidation (IAAO) technique]. Methods: Eight men (means ± SDs: age, 22.5 ± 1.7 y; weight, 83.9 ± 11.6 kg; 13.0% ± 6.3% body fat) were studied at rest on a nontraining day, on several occasions (4–8 times) each with protein intakes ranging from 0.1 to 3.5 g · kg⁻¹ · d⁻¹, for a total of 42 experiments. The diets provided energy at 1.5 times each individual's measured resting energy expenditure and were isoenergetic across all treatments. Protein was fed as an amino acid mixture based on the protein pattern in egg, except for phenylalanine and tyrosine, which were maintained at constant amounts across all protein intakes. For 2 d before the study, all participants consumed 1.5 g protein · kg⁻¹ · d⁻¹. On the study day, the protein requirement was determined by identifying the breakpoint in the F¹³CO2 with graded amounts of dietary protein [mixed-effects change-point regression analysis of F¹³CO2 (labeled tracer oxidation in breath)]. Results: The Estimated Average Requirement (EAR) of protein and the upper 95% CI RDA for these young male bodybuilders were 1.7 and 2.2 g · kg⁻¹ · d⁻¹, respectively. Conclusion: These IAAO data suggest that the protein EAR and recommended intake for male bodybuilders at rest on a nontraining day exceed the current recommendations of the Institute of Medicine by ∼2.6-fold. This trial was registered at clinicaltrials.gov as NCT02621294.
Article
Full-text available
The aim of the study was to determine whether the tendencies and scope of changes in body mass, body composition and body girths across the menstrual cycle were similar or different in women of different body build. Anthropometric examinations were carried out in a group of 40 naturally regularly menstruated females practicing team sports (aged 19–21, B-v 169.3+/–6.4 cm, body mass 59.6+/–7.0 kg), in the follicular, ovulatory and luteal phases of the menstrual cycle. The phases were determined on the basis of data from two consecutive menstrual cycles taking into account the cycle’s length. To establish the type of body build, Body Mass Index, hydration status and skin fold thickness were measured. For a statistical analysis, a multiple comparisons with multiple confidence intervals were applied. The increase in body mass between the follicular and the luteal phases was observed in all groups of women, the biggest gain was recorded in slim women, who in the luteal phase weighted 0.8 kg more. The amount of fat mass increased significantly across the menstrual cycle only in more hydrated (by about 0.66 kg) and slim women (by about 0.54 kg). Significant changes between consecutive phases of the menstrual cycle in waist and hip girths, and suprailiac skinfold thickness in some groups of women also indicate influence of fatness and hydration status and slenderness. In view of the presented results, the body build seems important for an analysis of the pattern of each component’s changes across the menstrual cycle, especially for female athletes. Certain changes can be seen only in some groups of women, therefore somatic features can be considered as a predictor of the intensity of changes.
Article
Full-text available
The currently accepted amount of protein required to achieve maximal stimulation of myofibrillar protein synthesis (MPS) following resistance exercise is 20–25 g. However, the influence of lean body mass (LBM) on the response of MPS to protein ingestion is unclear. Our aim was to assess the influence of LBM, both total and the amount activated during exercise, on the maximal response of MPS to ingestion of 20 or 40 g of whey protein following a bout of whole-body resistance exercise. Resistance-trained males were assigned to a group with lower LBM (≤65 kg; LLBM n = 15) or higher LBM (≥70 kg; HLBM n = 15) and participated in two trials in random order. MPS was measured with the infusion of 13C6-phenylalanine tracer and collection of muscle biopsies following ingestion of either 20 or 40 g protein during recovery from a single bout of whole-body resistance exercise. A similar response of MPS during exercise recovery was observed between LBM groups following protein ingestion (20 g – LLBM: 0.048 ± 0.018%·h−1; HLBM: 0.051 ± 0.014%·h−1; 40 g – LLBM: 0.059 ± 0.021%·h−1; HLBM: 0.059 ± 0.012%·h−1). Overall (groups combined), MPS was stimulated to a greater extent following ingestion of 40 g (0.059 ± 0.020%·h−1) compared with 20 g (0.049 ± 0.020%·h−1; P = 0.005) of protein. Our data indicate that ingestion of 40 g whey protein following whole-body resistance exercise stimulates a greater MPS response than 20 g in young resistance-trained men. However, with the current doses, the total amount of LBM does not seem to influence the response.
Article
Full-text available
Recent investigations have identified that commercially available dietary supplements, containing a combination of thermogenic ingredients, can increase resting metabolic rate (RMR). Thermogenic dietary supplements can have a positive influence on RMR, but the magnitude can vary based on the active ingredient and/or combination of active ingredients. Additionally, further safety evaluation is needed on multi-ingredient supplements that contain caffeine, due to its potential effect on heart rate (HR) and blood pressure (BP). The purpose of this study was to examine the effects of a commercially available dietary supplement on RMR and hemodynamic variables in healthy females. 13 female participants (26.1 ± 11.3 years; 163.4 ± 9.1 cm; 63.7 ± 8.0 kg, and 24 ± 5 BMI) volunteered to participate in this investigation. Participants underwent two testing sessions separated by approximately 7 days. On their first visit, participants arrived to the laboratory after an overnight fast and underwent a baseline RMR, HR, and BP assessment. Next, each participant ingested a thermogenic dietary supplement or placebo and repeated the RMR, HR, and BP assessments at 60, 120, and 180-minutes post-ingestion. Approximately 1-week later, the alternative supplement was ingested and the assessments were repeated in the exact same manner. Data were analyzed via a 2-factor [2x4] within-subjects repeated measures analysis of variance (ANOVA). Post-hoc tests were analyzed via paired samples t-tests. Repeated measures ANOVA revealed a significant effect for time relative to raw RMR data. Post-hoc analysis revealed that the dietary supplement treatment significantly increased RMR at 60-minutes, 120-minutes, and 180-minutes post ingestion (p < 0.05) as compared to baseline RMR values. No changes in RMR were observed for the placebo treatment (p > 0.05). Heart rate was not significantly affected at any time point with either supplement; however, main effects of treatment and time were observed for both systolic and diastolic blood pressure (p < 0.05). The thermogenic dietary supplement treatment experienced greater elevations in RMR as compared to baseline. Due to the slight elevations in blood pressure, caution should be taken for those with increased risk for hypertension or pre-hypertension. Taken on a daily basis, thermogenic dietary supplementation may increase overall energy expenditure, potentially leading to reductions in fat mass over time.
Article
Full-text available
Background: The consumption of a high protein diet (>4 g/kg/d) in trained men and women who did not alter their exercise program has been previously shown to have no significant effect on body composition. Thus, the purpose of this investigation was to determine if a high protein diet in conjunction with a periodized heavy resistance training program would affect indices of body composition, performance and health. Methods: Forty-eight healthy resistance-trained men and women completed this study (mean ± SD; Normal Protein group [NP n = 17, four female and 13 male]: 24.8 ± 6.9 yr; 174.0 ± 9.5 cm height; 74.7 ± 9.6 kg body weight; 2.4 ± 1.7 yr of training; High Protein group [HP n = 31, seven female and 24 male]: 22.9 ± 3.1 yr; 172.3 ± 7.7 cm; 74.3 ± 12.4 kg; 4.9 ± 4.1 yr of training). Moreover, all subjects participated in a split-routine, periodized heavy resistance-training program. Training and daily diet logs were kept by each subject. Subjects in the NP and HP groups were instructed to consume their baseline (~2 g/kg/d) and >3 g/kg/d of dietary protein, respectively. Results: Subjects in the NP and HP groups consumed 2.3 and 3.4 g/kg/day of dietary protein during the treatment period. The NP group consumed significantly (p < 0.05) more protein during the treatment period compared to their baseline intake. The HP group consumed more (p < 0.05) total energy and protein during the treatment period compared to their baseline intake. Furthermore, the HP group consumed significantly more (p < 0.05) total calories and protein compared to the NP group. There were significant time by group (p ≤ 0.05) changes in body weight (change: +1.3 ± 1.3 kg NP, -0.1 ± 2.5 HP), fat mass (change: -0.3 ± 2.2 kg NP, -1.7 ± 2.3 HP), and % body fat (change: -0.7 ± 2.8 NP, -2.4 ± 2.9 HP). The NP group gained significantly more body weight than the HP group; however, the HP group experienced a greater decrease in fat mass and % body fat. There was a significant time effect for FFM; however, there was a non-significant time by group effect for FFM (change: +1.5 ± 1.8 NP, +1.5 ± 2.2 HP). Furthermore, a significant time effect (p ≤ 0.05) was seen in both groups vis a vis improvements in maximal strength (i.e., 1-RM squat and bench) vertical jump and pull-ups; however, there were no significant time by group effects (p ≥ 0.05) for all exercise performance measures. Additionally, there were no changes in any of the blood parameters (i.e., basic metabolic panel). Conclusion: Consuming a high protein diet (3.4 g/kg/d) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition. Furthermore, there is no evidence that consuming a high protein diet has any deleterious effects.
Article
Full-text available
The importance of normal distribution is undeniable since it is an underlying assumption of many statistical procedures such as t-tests, linear regression analysis, discriminant analysis and Analysis of Variance (ANOVA). When the normality assumption is violated, interpretation and inferences may not be reliable or valid. The three common procedures in assessing whether a random sample of independent observations of size n come from a population with a normal distribution are: graphical methods (histograms, boxplots, Q-Q-plots), numerical methods (skewness and kurtosis indices) and formal normality tests. This paper* compares the power of four formal tests of normality: Shapiro-Wilk (SW) test, Kolmogorov-Smirnov (KS) test, Lilliefors (LF) test and Anderson-Darling (AD) test. Power comparisons of these four tests were obtained via Monte Carlo simulation of sample data generated from alternative distributions that follow symmetric and asymmetric distributions. Ten thousand samples of various sample size were generated from each of the given alternative symmetric and asymmetric distributions. The power of each test was then obtained by comparing the test of normality statistics with the respective critical values. Results show that Shapiro-Wilk test is the most powerful normality test, followed by Anderson-Darling test, Lilliefors test and Kolmogorov-Smirnov test. However, the power of all four tests is still low for small sample size.
Article
Daily undulating periodization (DUP) is a growing trend, both in practice and in the scientific literature. A new form of DUP, flexible daily undulating periodization (FDUP), allows for athletes to have some autonomy by choosing the order of their training. The purpose of this study was to compare an FDUP model to a traditional model of DUP on powerlifting performance in resistance-trained men. Twenty-five resistance-trained men were randomly assigned to one of 2 groups: FDUP (N = 14) or DUP (N = 11). All participants possessed a minimum of 6 months of resistance training experience and were required to squat, bench press, and deadlift 125, 100, and 150% of their body mass, respectively. Dependent variables assessed at baseline and after the 9-week training program included bench press 1 repetition maximum (1RM), squat 1RM, deadlift 1RM, powerlifting total, Wilks Coefficient, fat mass, and fat-free mass (FFM). Dependent variables assessed during each individual training session were motivation to train, Session Rating of Perceived Exertion (Session RPE), and satisfaction with training session. After the 9-week training program, no significant differences in intensity or volume were found between groups. Both groups significantly improved bench press 1RM (FDUP: +6.5 kg; DUP: +8.8 kg), squat 1RM (FDUP: +15.6 kg; DUP: +18.0 kg), deadlift 1RM (FDUP: +14.8 kg; DUP: +13.6 kg), powerlifting total (FDUP: +36.8 kg; DUP: +40.4 kg), and Wilks Coefficient (FDUP: +24.8; DUP: +26.0) over the course of study (p = <0.001 for each variable). There was also a significant increase in FFM (FDUP: +0.8 kg; DUP: +0.8 kg) for both groups (p = 0.003). There were no differences in motivation to train, session RPE, or satisfaction with training session measurements between groups (p = 0.369-0.702, respectively). In conclusion, FDUP seems to offer similar resistance training adaptations when compared with a traditional DUP in resistance-trained men.
Article
Background: A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise. Objective: The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition. Design: We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (∼40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention. Results: As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = -0.34, P = 0.03). Conclusions: Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg(-1) · d(-1) was more effective than consumption of a diet containing 1.2 g protein · kg(-1) · d(-1) in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359.