ArticlePDF Available

Abstract and Figures

Objective: The objective of this study was to compare the chronic effects of different whey protein forms on body composition and performance when supplemented with resistance training. Methods: Resistance-trained men (N = 56, 21.4 ± 0.4 years, 79.5 ± 1.0 kg) participated in an 8-week resistance training regimen (2 upper-body sessions and 2 lower-body sessions per week) and received one of 4 double-blinded treatments: 30 g/serving carbohydrate placebo (PLA) or 30 g/serving protein from either (a) 80% whey protein concentrate (WPC), (b) high-lactoferrin-containing WPC (WPC-L), or (c) extensively hydrolyzed WPC (WPH). All subjects consumed 2 servings of treatment per day; specifically, once immediately before and after training and between meals on nontraining days. Blood collection, one repetition maximum (1RM) testing for bench press and hack squat, and body composition assessment using dual-energy x-ray absorptiometry (DXA) occurred prior to training and 48 hours following the last training session. Results: Total body skeletal muscle mass increased in all groups (p < 0.0125). There were similar between-group increases in upper-body (4%-7%, analysis of covariance [ANCOVA] interaction p = 0.73) and lower-body (24%-35%, ANCOVA interaction p = 0.85) 1RM strength following the intervention. Remarkably, WPH reduced fat mass (-6%), which was significantly different from PLA (+4.4%, p < 0.0125). No time or between-group differences were present for serum markers of health, metabolism, or muscle damage, with the exception of blood urea nitrogen being significantly lower for WPH than WPC (p < 0.05) following the intervention. Conclusions: WPH may augment fat loss but did not provide any other advantages when used in combination with resistance training. More mechanistic research is needed to examine how WPH affects adipose tissue physiology.
Content may be subject to copyright.
Effects of Hydrolyzed Whey versus Other Whey
Protein Supplements on the Physiological Response
to 8 Weeks of Resistance Exercise in College-Aged
Males
Christopher M. Lockwood, Michael D. Roberts, Vincent J. Dalbo, Abbie E. Smith-Ryan, Kristina L. Kendall, Jordan R.
Moon, and Jeffrey R. Stout
QUERY SHEET
This page lists questions we have about your paper. The numbers displayed at left can be found in the text of the paper for
reference. In addition, please review your paper as a whole for correctness.
Q1. Au: Please provide honorifics/degrees for all Authors.
Q2. Au: This article has been lightly edited for grammar, style, and usage. Please limit any corrections to minor
changes, not substantive. If no change is required in response to a question, please write “OK as set.”
Q3. Au: Please spell out EAA.
Q4. Au: Please spell out NSCA.
Q5. Au: Please spell out cGMP.
Q6. Au: Please provide all Author names in place of et al. throughout reference list.
Q7. Au: Please provide page range, reference 8.
Q8. Au: Please provide page range, reference 11.
Q9. Au: Please provide volume/pages, reference 12.
Q10. Au: Please provide page range, reference 13.
Q11. Au: Please provide page range, reference 26.
Q12. Au: Please provide page range, reference 40.
Q13. Au: Please provide page range, reference 41.
Q14. Au: Please provide page range, reference 50.
TABLE OF CONTENTS LISTING
The table of contents for the journal will list your paper exactly as it appears below:
Effects of Hydrolyzed Whey versus Other Whey Protein Supplements on the Physiological Response to 8 Weeks
of Resistance Exercise in College-Aged Males
Christopher M. Lockwood, Michael D. Roberts, Vincent J. Dalbo, Abbie E. Smith-Ryan, Kristina L. Kendall, Jordan R.
Moon, and Jeffrey R. Stout
UACN #1140094, VOL 0, ISS 0
Effects of Hydrolyzed Whey versus Other Whey
Protein Supplements on the Physiological Response
to 8 Weeks of Resistance Exercise in College-Aged
Males
5Christopher M. Lockwood
1
, Michael D. Roberts
2
, Vincent J. Dalbo
3
, Abbie E. Smith-Ryan
4
, Kristina L. Kendall
5
,
Jordan R. Moon
6
, and Jeffrey R. Stout
7
1
AP Nutrition, Draper, Utah
2
School of Kinesiology, Auburn University, Auburn, Alabama
3
School of Medical and Applied Sciences, Central Queensland University, Queensland, AUSTRALIA
10
4
Department of Exercise and Sports Science, University of North Carolina Chapel Hill, Chapel Hill, North Carolina
5
Bodybuilding.com, Boise, Idaho
6
Department of Sports Fitness and Health, United States Sports Academy, Daphne, Alabama
7
Department of Educational and Human Sciences, University of Central Florida, Orlando, FloridaQ1
Key words: body composition, exercise, sports nutrition, supplements and functional foods, metabolism
15 Objective: The objective of this study was to compare the chronic effects of different whey protein forms on
body composition and performance when supplemented with resistance training.
Methods: Resistance-trained men (ND56, 21.4 §0.4 years, 79.5 §1.0 kg) participated in an 8-week
resistance training regimen (2 upper-body sessions and 2 lower-body sessions per week) and received one of 4
double-blinded treatments: 30 g/serving carbohydrate placebo (PLA) or 30 g/serving protein from either (a)
20 80% whey protein concentrate (WPC), (b) high-lactoferrin-containing WPC (WPC-L), or (c) extensively
hydrolyzed WPC (WPH). All subjects consumed 2 servings of treatment per day; specifically, once immediately
before and after training and between meals on nontraining days. Blood collection, one repetition maximum
(1RM) testing for bench press and hack squat, and body composition assessment using dual-energy x-ray
absorptiometry (DXA) occurred prior to training and 48 hours following the last training session.
25 Results: Total body skeletal muscle mass increased in all groups (p<0.0125). There were similar between-
group increases in upper-body (4%–7%, analysis of covariance [ANCOVA] interaction pD0.73) and lower-
body (24%–35%, ANCOVA interaction pD0.85) 1RM strength following the intervention. Remarkably, WPH
reduced fat mass (¡6%), which was significantly different from PLA (C4.4%, p<0.0125). No time or
between-group differences were present for serum markers of health, metabolism, or muscle damage, with the
30 exception of blood urea nitrogen being significantly lower for WPH than WPC (p<0.05) following the
intervention.
Conclusions: WPH may augment fat loss but did not provide any other advantages when used in
combination with resistance training. More mechanistic research is needed to examine how WPH affects
adipose tissue physiology.
35
INTRODUCTION
Acute protein ingestion significantly increases muscle pro-
tein synthesis and provides an augmented anabolic response
when consumed in combination with strenuous resistance
40exercise [1–3]. To this end, Dreyer et al. [4] reported that acute
heavy resistance exercise alone increased muscle protein syn-
thesis by 41% above baseline levels, whereas a 145% increase
in muscle protein synthesis was observed when a leucine-rich
essential amino acid solution was consumed immediately
Address correspondence to: Michael D. Roberts, PhD, Assistant Professor, School of Kinesiology, Director, Molecular and Applied Sciences Laboratory, Auburn
University, 301 Wire Road, Office 286, Auburn, AL 36849. E-mail: mdr0024@auburn.edu
Christopher M. Lockwood and Michael D. Roberts contributed equally to this work.
Abbreviations ANCOVA Danalysis of covariance DH Ddegree of hydrolysis DXA Ddual-energy x-ray absorptiometry kD Dkiloda lton molecular weight PLA D
carbohydrate placebo RM Drepetition maximum WPC Dwhey protein concentrate WPC-L Dhigh-lactoferrin whey protein concentrate WPH Dwhey protein hydrolysate.
Q2
1
Journal of the American College of Nutrition, Vol. 0, No. 0, 1–12 (2016) ÓAmerican College of Nutrition
Published by Taylor & Francis Group, LLC
45 postexercise. Given the aforementioned findings, as well as
similar findings from others [2,5], many researchers conclude
that essential amino acid availability potentiates the anabolic
response to exercise. Notwithstanding, a body of literature is
beginning to suggest that whey protein supplementation is
50 superior at increasing muscle mass gains with concomitant
resistance training compared to other protein supplements (i.e.,
soy protein, casein protein), which are a rich source of essential
amino acids [6,7].
Commercially, whey protein is categorized as either a whey
55 protein concentrate (WPC), isolate (WPI), or hydrolysate
(WPH, or hydrolyzed whey). WPC contains between 29% and
89% total protein by volume (g/100 g), depending upon its
concentration, with the remaining nutrient composition coming
from carbohydrate (predominantly lactose) and lipid, whereas
60 WPI contains at least 90% protein by volume [8]. WPC70 and
WPC80 (70% and 80% concentrations of protein, respectively)
are the most common forms of whey protein used within pro-
tein supplements, largely due to pricing and organoleptic char-
acteristics compared to other forms of whey [8]. Compared to
65 WPC and WPI, extensively hydrolyzed whey protein, charac-
terized as the majority (>80%) of protein fractions as 1kD
molecular weight or typically less than about 8 amino acids in
length, may provide improved rates of EAA
Q3 availability to sup-
port increased nitrogen retention. Calbet and Holst [9] reported
70 significantly faster rises in plasma amino acid concentrations
from casein hydrolysate as opposed to intact casein, yet no sig-
nificant effect was observed for WPH versus WPI. Conversely,
our group recently used a metabolomics approach in rodents to
demonstrate that a moderately hydrolyzed WPH (15%–20%
75 degree of hydrolysate) elicits a more rapid postprandial
increase in serum amino acids and select di- and oligopeptides
compared to its intact WPC [10]. Moreover, we have demon-
strated that rats gavage-fed moderately hydrolyzed solutions
containing 70% WPH expressed a more prolonged postpran-
80 dial increase in select skeletal muscle Akt-mTOR signaling
and other phosphoproteomic markers compared to WPC [11].
Power et al. [12] also showed that, under fasting conditions,
the consumption of »45 g of WPH increased peak insulin con-
centrations higher than an equal dose of WPI in healthy male
85 subjects, an effect that may potentiate the anabolic effects in
WPH versus WPI, and this phenomenon was also observed in
an additional rodent study published by our group [13]. There-
fore, WPH provision in combination with strenuous resistance
training may significantly improve skeletal muscle recovery
90 and facilitate greater adaptive responses to chronic training
compared to other whey protein forms (i.e., WPI and WPC).
Another developing area of whey protein research has
involved examining the physiological properties of whey pro-
tein-derived bioactives. Specifically, whey-derived lactoferrin
95 possesses known antioxidant and immune supporting functions
[14,15]. Given that resistance exercise stimulates an increase
in oxidative stress [16] and repetitive oxidative stress has been
posited to increase muscle damage [17], it stands to reason that
whey-derived antioxidants may help potentiate training adapta-
100tions. However, to our knowledge, little literature has exam-
ined how adding whey-derived antioxidant bioactives affects
the adaptive response to resistance exercise.
Therefore, the primary purpose of the current investigation
was to determine whether chronic ingestion of either WPC, its
105extensive hydrolysate (WPH), or a high-lactoferrin-containing
WPC (WPC-L), in combination with chronic resistance exer-
cise, resulted in increased training adaptations (i.e., body com-
position and strength) compared to a placebo supplement. We
hypothesized that because rapid amino acid delivery is impor-
110tant for facilitating muscle protein synthesis following resis-
tance exercise, muscle mass and strength increases may be
greater in WPH-supplemented versus WPC- and placebo
(PLA)-supplemented participants. Moreover, we posited that
the additional lactoferrin in the WPC-L supplement may result
115in increases in muscle mass and strength given the putative
role of lactoferrin being an antioxidant that, over chronic train-
ing, may facilitate enhanced recovery mechanisms.
METHODS
Study Design
120All study procedures were approved by the University of
Oklahoma Institutional Review Board and written informed
consent was obtained from each participant prior to testing.
The study design was selected to simulate real-world applica-
tion of consuming 30 g of whey protein twice daily in combi-
125nation with 4 d/wk heavy resistance training in healthy,
college-aged, resistance-trained males. Subjects were ran-
domly assigned into one of 4 treatment groups: exercise Cdex-
trose (PLA), exercise Cwhey protein concentrate 80% (WPC),
exercise Chigh-lactoferrin-containing whey protein concen-
130trate 80% (WPC-L), or exercise Cextensively hydrolyzed
whey protein concentrate 80% (WPH). Body composition,
strength, and anaerobic endurance testing and blood collection
occurred on day 1 of week 0 (PRE) and at least 48 hours fol-
lowing the eighth complete week of the intervention (POST).
135Repeated lower-body anaerobic endurance testing occurred on
days 2–3 of PRE and, similarly, 24 and 48 hours after strength
and anaerobic endurance testing during POST. All subjects’
POST testing days, times, and 24-hour pretesting dietary
intakes were scheduled to match PRE testing conditions.
140Importantly, participants and investigators were double-
blinded to the treatments.
Subjects
Sixty-eight healthy, resistance-trained men (3 months
uninterrupted training, 3 d/wk resistance training) between
Whey Protein and Resistance Training Adaptations
2 VOL. 0, NO. 0
145 18 and 35 years of age volunteered to participate in the study.
Each participant was assessed for inclusion in or exclusion
from the study via responses provided during verbal interviews
as well as written and signed health history questionnaire and
related documents.
150 Pre- and Postintervention Body Composition Testing
Body composition assessments were performed prior to
(PRE) and following (POST) the supplementation intervention.
Briefly, participants reported to the laboratory following a 12-
hour fast (water intake was allowed up to one hour prior to test-
155 ing). No exercise or diuretic-enhancing products (e.g., caf-
feine) were allowed 48 hours prior to testing and subjects were
instructed to remain well hydrated prior to testing. Hydration
status was determined immediately prior to body composition
testing, using specific gravity via handheld refractometry
160 (model CLX-1, precision D0.001 §0.001, VEE GEE Scien-
tific, Inc., Kirkland, WA) [18]. Subjects with urine-specific
concentrations 1.029 were asked to consume 8 fl oz of drink-
ing water every 15 minutes and were retested every 30 minutes
until an acceptable hydration status was achieved. Subjects
165 with urine-specific concentrations 1.005 ppm were asked to
pedal slowly on an upright cycle ergometer for 15 minutes and
were retested every 30 minutes until an acceptable hydration
status was achieved.
Body mass was measured using a calibrated clinical scale to
170 the nearest 0.001 kg, with subjects wearing only tight-fitting
compression shorts; height was measured to the nearest 0.5 cm
using a calibrated stadiometer. Fat mass and lean soft tissue
were estimated using dual-energy x-ray absorptiometry (DXA;
enCORE 2006, software version 10.50.086, Lunar Prodigy
175 Advance, Madison, WI). The sum of lean soft tissue for both
arms and legs (ALST), as measured by DXA, was used to esti-
mate total body skeletal muscle mass (TBMM) from the equa-
tion of Kim et al. [19]:
TBMM D1:13 £ALSTðÞ¡0:02 £ageðÞC0:97:(1)
180 All DXA assessments were conducted by the same
researcher per the recommendations of past literature [20].
Test–retest measurements of 11 men and women, measured
24–48 hours apart, for dependent DXA variables resulted in
185 intraclass correlation coefficients (ICCs) greater than 0.99 [21].
Pre- and Postintervention Serum and Whole Blood
Analyses
Blood was collected in serum separator tubes and potas-
sium–EDTA tubes immediately following body composition
190 testing during the PRE and POST tests to assess blood glucose
and lipids as well as other select markers of metabolism and
muscle damage. Specifically, certain metabolic variables (i.e.,
glucose and blood lipids) were examined in order to determine
whether the different whey protein supplements differentially
195affected these markers given that different whey protein forms
have been reported to positively affect glucose and lipids [22].
Though the true assessment of nitrogen balance requires a great
deal of methodological attention [23] and was not assessed in
this study, blood urea nitrogen (BUN) was assessed as a surro-
200gate of nitrogen balance. Finally, serum creatinine was
assessed as a safety marker for kidney function (validity of this
marker is described elsewhere [24]), and serum creatine kinase
was assessed as a circulating marker of muscle damage given
that past literature has reported that protein or amino acid sup-
205plementation can reduce markers of muscle damage with
chronic training stress [25]. Blood processing and analyses
were carried out by Diagnostic Labs of Oklahoma (Oklahoma
City, OK) the same day of blood collection.
Pre- and Postintervention Strength and Anaerobic
210Endurance Testing
During the PRE and POST tests and after body composition
assessment, upper- and lower-body strength testing was deter-
mined using standard one repetition (1RM) testing procedures
according to the guidelines of the NSCA Q4with a bench press
215and hack squat machine (Yukon Fitness Equipment, Cleveland,
OH). Moreover, 80% 1RM repetitions to failure (anaerobic
endurance) and repeated lower-body anaerobic endurance
occurred 24 and 48 hours after the PRE and POST tests in
order to assess anaerobic endurance. Test–retest reliability of
220these strength tests on resistance-trained subjects from labora-
tory testers in previous studies have yielded a high reliability
for the bench press (ICC D0.996) and lower-body strength
testing (ICC D0.988) [26].
Eight-Week Resistance Training Protocol
225After the PRE test, subjects participated in a resistance
training intervention involving an 8-week, split-body, linear
periodized program as used previously by Kerksick et al. [27].
All training took place in the laboratory with complete (set-by-
set) supervision from graduate research assistants, and time to
230complete workouts was recorded by laboratory staff (Table 1).
Specifically, the program involved upper- and lower-
body heavy resistance training 2 d/wk for a total of 4 work-
outs per week for 8 weeks. Training and recovery days
followed a 2-on/1-off/2-on/2-off schedule (e.g., Monday,
235upper; Tuesday, lower; Wednesday, off; Thursday, upper;
Friday, lower; Saturday, off; Sunday, off; repeat). A 5-min-
ute moderate-intensity warmup (e.g., stationary cycling or
treadmill jogging) preceded each workout session. After the
5-minute warmup, bench press and hack squat were always
240performed first on upper- and lower-body training days,
respectively. Exercise order for the remaining exercises
was not controlled. Subjects completed 3 sets per exercise,
allowing a timed one-minute rest between sets and
Whey Protein and Resistance Training Adaptations
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION 3
2-minute rest periods between exercises. Furthermore,
245 training intensities of 10–12 RM and 5–8 RM loads were
utilized for weeks 1–4 and 5–8, respectively. Subjects were
instructed to complete each set to volitional muscle failure,
adjusting the load lifted accordingly to ensure that all sets
were completed within the requisite repetition range.
250 Upper- and lower-body as well as total training volume
were calculated weekly as well as over the entire 8 weeks
for each subject as follows:
absolute volume kgðÞDload £repsðÞ
£sets;relative volume kg/minðÞ
Dabsolute volume/time:
256 Subject training logs were assessed weekly, and prescrip-
tive loads were provided for the subsequent week’s workouts.
Eight-Week Supplementation Protocol
260 All 4 supplements were formulated to contain similar
amounts of total energy and lipid, and all treatments were
double-blinded for appearance, taste, texture, and packag-
ing. Acute data indicate that muscle protein synthesis is
significantly elevated as long as provision of EAA is made
265 available within 1–2 hours but not greater than 4–5 hours
postexercise [28–30]. Assuming that peak amino acid con-
centrations occur between 20 and 90 minutes postingestion
of fast-absorbing protein (e.g., whey protein) [9,12,31,32]
and exercise duration lasts 45–90 minutes, we posited that
270 consuming protein both immediately prior to and postexer-
cise would yield the most significant effects on resistance
training adaptations. Therefore, participants were instructed
to consume their respective supplements immediately prior
to and following exercise on training days and twice daily
275between regularly scheduled meals on nontraining days. On
training days, subjects were provided their supplements by
laboratory staff, who mixed the powder contents from
packets into 560 ml of tap water. On nontraining day peri-
ods, subjects reported to the laboratory and were given
280enough of their respective supplement for full compliance
until the next scheduled training day. Subjects were also
instructed to consume the supplement on an empty stomach
(i.e., no sooner than 90 minutesafterapriormeal)with
560 ml of tap water and not to consume food or other
285energy-containing items within 30 minutes after supplement
consumption.
Detailed nutritional comparisons for each supplement
are provided in Table 2. The PLA was formulated with
30 g of dextrose anhydrous per serving, as well as minor
290amounts of reduced-fat dairy creamer and xanthan gum to
equilibrate the lipid content across all treatments and to
double-blind the treatments for viscosity and appearance.
The WPC group was formulated to provide 30 g of protein
from an 80% whey protein concentrate (Carbelac, Carbery,
295Cork, Ireland), whereas the WPC-L provided 30 g of pro-
tein from a high-lactoferrin-containing 80% whey protein
concentrate (MG Nutritionals, Melbourne, Australia). The
WPH provided 30 g of protein from an extensively hydro-
lyzed (32% degree of hydrolysis) 80% whey protein con-
300centrate (Optipep, Carbery, Cork, Ireland) designed to
provide greater than 80% of its protein fractions as 1kD
in molecular weight. All treatments were formulated with
sucralose, orange flavouring, and citric acid, whereas the
WPH treatment additionally required the use of a mint-
305based masking agent to reduce bitterness. Final formula-
tion, packaging, and double-blinding were conducted by a
cGMP Q5-compliant manufacturing facility (CSB Nutrition,
Table 1. Resistance Training Regimen
a
Exercise Sets Repetitions (Weeks 1–4/Weeks 5–8)
Upper body Barbell flat bench press 3 10–12/5–8
Standing cable fly 3 10–12/5–8
Bent-over barbell row 3 10–12/5–8
Wide-grip front lat pulldown 3 10–12/5–8
Seated front military press 3 10–12/5–8
Barbell shrug 3 10–12/5–8
Barbell biceps curl 3 10–12/5–8
Lying E-Z bar triceps extension 3 10–12/5–8
Lower body Incline hack squat 3 10–12/5–8
Barbell Romanian deadlift 3 10–12/5–8
Barbell lunge 3 10–12/5–8
Seated leg extension 3 10–12/5–8
Lying leg curl 3 10–12/5–8
Seated calf raise 3 10–12/5–8
Supine abdominal crunch 3 20–25
a
Participants participated in 2 upper-body lifting days and 2 lower-body lifting days per week for 8 weeks.
4 VOL. 0, NO. 0
Whey Protein and Resistance Training Adaptations
Lindon, UT), and unblinding was provided by the man-
ufacturer’s representative agent upon request by the study
310 coordinator (C.M.L.) after all statistical analyses had been
completed.
Nutritional Analysis
All participants were instructed to maintain prestudy ad
libitum dietary habits and asked to provide 3-day nutrition logs
315 for the week prior to PRE testing, as well as for weeks 1, 4–5,
and 8 of the intervention, for a total of 4 weeks of nutrition
logs. Each log included 2 nonconsecutive weekdays and one
weekend day and was used to represent subjects’ average
weekly diets. Logs were analyzed by a registered dietician for
320 energy (kcal/kg/d) and macronutrients (g/kg/d) consumed
using Food Processor Version 8.6.0 (ESHA Research, Salem,
OR). Results obtained for weeks 1, 4–5, and 8 were combined
to provide an average daily value across each nutritional vari-
able for the 8-week intervention.
325
Statistics
All statistical analyses were performed using SPSS 17.0
(SPSS Inc. Chicago, IL). Unless otherwise stated in tables or
figures, separate 4 £2 2-way repeated measure analyses of
covariance (ANCOVAs; group [PLA vs WPH vs WPC-L vs
330WPC] £time [PRE vs POST]) were used to analyze all depen-
dent variables in order to identify main effects for time and/or
Group £Time (G £T) interactions. In the event of significant
baseline differences of a dependent variable, as determined by
multiple one-way analyses of variance, homogeneity-of-slopes
335tests were used to determine the interaction between the covar-
iate and factor and to assess the appropriateness of including
the variable as a covariate within subsequent ANCOVA analy-
ses. Based upon these analyses, subjects’ baseline training sta-
tus as assessed by the ACSM’s adapted percentile rankings for
340one-repetition maximum bench press–to–body mass ratio [33],
total 8-week relative training volume (kg/min), and average
8-week relative protein intake (g/kg/d) were selected as covari-
ates. If a significant time effect was observed, pairwise com-
parisons were performed within each group on PRE and POST
345values using dependent sample t-tests and Bonferroni correc-
tions were applied to adjust for multiple within-group compari-
sons (p<0.0125). If a significant G £T interaction was
observed, (1) pairwise comparisons were performed within
each group as described above and (2) ANCOVAs across each
350group at the POST time point were performed with Tukey’s
post hoc test.
RESULTS
Subject Characteristics
One subject from WPC-L withdrew because of a shoulder
355injury (received outside of the study), 2 subjects (1 WPH and
1 WPC) were removed for noncompliance and missed work-
outs, 2 subjects from WPH were removed because of viral
infections requiring the use of antibiotics, 4 subjects (1 PLA,
2 WPH, and 1 WPC) withdrew because the training intensity
360was too high, and 2 subjects (1 PLA and 1 WPH) withdrew
because of headaches brought about during lower-body train-
ing. Data from one subject within WPC were removed from
final analysis on the basis of being an extreme (>3 SD) outlier
for baseline body mass, percentage body fat, 1RM on the bench
365press, and height. Therefore, 57 subjects completed the study,
and data from 56 subjects (PLA nD15, WPC nD13, WPC-L
nD15, and WPH nD13) were used for final data analysis.
Baseline (PRE) measures for age, height, body mass, per-
centage body fat, and training status did not differ between
370groups (p>0.05; Table 3). A trend toward significant differ-
ences (pD0.079) at PRE was observed for body mass. How-
ever, homogeneity of slopes tests did not preclude PRE body
Table 2. Nutritional Comparisons for the Different
Supplements
Variable PLA WPC WPC-L WPH
Energy (kcal) 176 157 163 166
Fat (g) 5 3 3 3
Saturated fat (g) 0 2 2 2
Unsaturated fat (g) 4 1 1 1
Trans-fat (g) 0 0 0 0
Cholesterol (mg) 1 68 70 60
Carbohydrate (g) 32 3 3 5
Sugars (g) 31 3 3 5
Fiber (g) 1 0 0 0
Protein (g) 1 30 30 30
Calcium (mg) 23 188 195 188
Sodium (mg) 81 57 59 113
Potassium (mg) 0 150 156 563
Magnesium (mg) 0 19 19 23
Phosphorus (mg) 29 131 136 244
Chloride (mg) 0 38 39 19
Iron (mg) 0 0 0 0
Vitamin A (IU) 5 0 0 0
Vitamin C (mg) 0 0 0 0
Protein supplement properties
Degree of hydrolysis (%) N/A N/A 32%
Molecular weight profile (%)
>10 kD 82
*
»80
y
4
*
5–10 kD 11
*
»20
y
1
*
2–5 kD 7* <1
y
4
*
1–2 kD 0
*
<1
y
9
*
0.5–1 kD 0
*
<1
y
17
*
<0.5 kD 0* <1
y
65
*
Average molecular weight >10 kD
*
>10 kD
y
1.6 kD
*
PLA Dplacebo, WPC D80% whey protein concentrate, WPC-L Dhigh-lacto-
ferrin WPC, WPH Dextensively hydrolyzed WPC.
*Molecular weight as determined by size exclusion chromatography and reported
by the raw material supplier.
yMolecular weight of WPC as reported by Perea et al. [52].
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION 5
Whey Protein and Resistance Training Adaptations
mass to be a significant (p>0.05) covariate for between-sub-
jects analyses.
375 Nutritional Analyses
No significant main effects for time or G £T interaction
were observed for relative energy, protein, carbohydrate, or fat
consumed (Table 4).
Body Composition Adaptations
380 Body composition adaptations are presented in Fig. 1 For
total body mass, there was no time effect (pD0.85) or G £T
interaction (pD0.27; Fig. 1a). For fat mass, there tended to be
a time effect (pD0.09) and there was a G £T interaction (p<
0.05; Fig. 1b); notably, post hoc analysis revealed reductions
385 in fat mass occurred within the WPH group (p<0.0125), and
this reduction was greater in the WPH group versus the PLA
group (p<0.05). For lean soft tissue mass, there tended to be
a time effect (pD0.09), although there was no G £T interac-
tion (pD0.41; Fig. 1c). For total body muscle mass there was
390 a time effect (p<0.05) because this variable increased across
all groups (p<0.0125), although there was no G £T interac-
tion (pD0.82; Fig. 1d).
Strength and Anaerobic Endurance Adaptations
Strength adaptations are presented in Fig. 2 For 1RM bench
395press, there was a time effect (p<0.05) because this variable
increased across all groups (p<0.0125), but there was no G £
T interaction (pD0.73; Fig. 2a). For 1RM hack squat, there
was a time effect because this variable increased across all
groups (p<0.0125), but there was no G £T interaction (pD
4000.85; Fig. 2a). For upper- and lower-body 80% 1RM anaerobic
endurance, there was a time effect because this variable
increased across all groups (p<0.0125), but there was no G £
T interaction (pD0.80; data not shown).
Clinical Serum and Whole Blood Alterations
405PRE and POST serum measures are presented in Table 5.
There were no time effects or G £T interactions for serum glu-
cose, high-density lipoprotein cholesterol, low-density lipopro-
tein cholesterol, triglycerides, creatinine, or creatine kinase. A
significant G £T interaction existed for serum urea nitrogen
410(p<0.05), and post hoc tests indicated that the PRE to POST
change in this variable occurred when comparing the WPH
versus the WPC group (p<0.05). There was no time effect or
G£T interaction for white blood cell counts (p>0.05; data
not shown).
Table 3. Subject Demographics
a
Variable Group nMean SEM p-Value
Age (years) PLA 15 20.9 0.4 0.83
WPC 13 21.3 0.7
WPC-L 15 21.8 0.9
WPH 13 21.5 0.9
All groups 56 21.4 0.4
Height (cm) PLA 15 179 2 0.45
WPC 13 180 1
WPC-L 15 178 1
WPH 13 178 1
All groups 56 179 1
Body mass (kg) PLA 15 76.2 2.2 0.08
WPC 13 83.8 1.6
WPC-L 15 78.9 2.2
WPH 13 79.6 1.8
All groups 56 79.5 1.0
% Body fat PLA 15 17.3 1.4 0.11
WPC 13 19.7 1.2
WPC-L 15 17.4 1.6
WPH 13 21.5 1.0
All groups 56 18.9 0.7
Training status (1RM bench/body mass) PLA 15 1.21 0.06 0.80
WPC 13 1.29 0.07
WPC-L 15 1.24 0.04
WPH 13 1.23 0.05
All groups 56 1.24 0.03
PLA Dplacebo, WPC D80% whey protein concentrate, WPC-L Dhigh-lactoferrin WPC, WPH Dextensively hydrolyzed WPC, 1RM Done repetition maximum.
aBaseline characteristics of subjects prior to the training and supplementation interven tions were compared using one-way analyses of variance and are presented as
mean §SEM.
6 VOL. 0, NO. 0
Whey Protein and Resistance Training Adaptations
415DISCUSSION
This is the first study to compare the effects of different
whey protein forms on the physiological adaptations to
chronic resistance exercise. We hypothesized that WPH
and WPC-L would support greater increases in muscle
420mass due to more rapid amino acid absorption qualities,
increased insulinotropic response to WPH, greater bioactive
peptide availability, and/or potential reductions in repetitive
muscle damage resulting in improved postexercise recov-
ery. Contrary to our hypotheses, we report that 8 weeks of
425heavy resistance training plus supplementation with whey
protein twice daily, regardless of whey protein form or
molecular weight distribution, was no more effective than
PLA at increasing total body skeletal muscle mass in previ-
ously trained young men when total protein intake is
430removed as a potential confounding variable (i.e., g/kg/d
protein was used as a covariable for ANCOVA analyses).
WPH did, however, result in greater fat mass loss versus
PLA.
Though several studies suggest whey protein supplementa-
435tion increases muscle mass compared to a carbohydrate pla-
cebo [6,7,34–36], the nonsignificant effect observed herein
between the whey protein-supplemented groups and carbohy-
drate placebo-supplemented is also supported by the literature.
For example, Candow et al. [37] reported that 1.2 g/kg body
440mass per day of whey protein supplementation over 6 weeks of
Table 4. Macronutrient Intakes Prior to and during the
Intervention
a
PRE Average for Weeks 1–8
Treatment Mean SEM Mean SEM Change Score
Energy consumed (kcal/kg/d)
PLA 40.0 2.6 41.6 1.6 1.6
WPC 25.9 2.3 31.9 1.4 6.0
WPC-L 27.6 2.2 31.7 1.4 4.1
WPH 29.2 2.4 30.2 1.5 1.0
Protein consumed (g/kg/d)
PLA 1.45 0.20 1.58 0.13 0.12
WPC 1.11 0.15 1.85 0.10 0.74
WPC-L 1.31 0.15 1.97 0.09 0.66
WPH 1.33 0.17 1.90 0.11 0.57
Carbohydrate consumed (g/kg/d)
PLA 5.07 0.39 5.15 0.26 0.08
WPC 3.24 0.34 3.37 0.23 0.13
WPC-L 3.34 0.33 3.29 0.22 ¡0.05
WPH 3.33 0.36 3.26 0.24 ¡0.08
Fat consumed (g/kg/d)
PLA 1.40 0.13 1.39 0.08 ¡0.01
WPC 0.92 0.12 1.11 0.07 0.19
*
WPC-L 1.07 0.11 1.14 0.07 0.07
WPH 1.20 0.12 1.01 0.07 ¡0.19
PLA Dplacebo, WPC D80% whey protein concentrate, WPC-L Dhigh-lacto-
ferrin WPC, WPH Dextensively hydrolyzed WPC.
a
These macronutrient consumption data are from self-reported food logs prior to
(PRE) and during (weeks 1, 4–5, and 8) the intervention and are presented as
mean §SEM.
*
Different from PRE (p0.0125).
PLA WPC W PC-L WPH
0
20
40
60
80
100
Body mass
kilograms
70.7 73.1
83.5 85.0 82.2 83.7 82.3 82.9
PRE POST PRE POS T PRE POST PRE POST
PLA W PC WPC-L WPH
0
5
10
15
20
Fat mass
kilograms
*
13.4 14.0
16.6 16.5
14.1 14.0
17.2
16.2
PRE POST PRE PO ST PRE POST PRE POST
PLA W PC WPC-L WPH
0
20
40
60
80
Lean soft tissue m ass
kilograms
60.4 61.7 64.4 66.2
62.3 64.0
59.7 61.7
PRE POST PRE POS T PRE POST PRE POST
PLA W PC WPC-L WPH
0
10
20
30
40
50
Total body muscle mass
kilograms
34.2 35.3 37.2 38.7
37.0 38.4
35.2 36.6
PRE POST PRE PO ST PRE POST PRE POST
*
*
*
*
a b
c d
Fig. 1. Body composition adaptations. These body composition data are from subjects prior to (PRE) and after (POST) the intervention and are pre-
sented as mean §SEM. *Different from PRE (p0.0125);
D
Group £Time interaction revealed that change was different from PLA (p0.05).
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION 7
Whey Protein and Resistance Training Adaptations
resistance training increased body mass by 2.5 kg, although
this was not significantly different from the carbohydrate pla-
cebo group. Likewise, Cribb et al. [38] reported that lean mass
did not statistically increase in subjects who consumed either
445 1.5 g/kg body mass per day of whey protein or a carbohydrate
placebo. Weisgarber et al. [39] also reported that older post-
menopausal women supplementing with whey protein or a car-
bohydrate placebo experienced similar increases in muscle
mass and strength over a 10-week resistance training regimen.
450 We contend that the nonsignificant differences in total
body muscle mass gains between protein-supplemented and
carbohydrate-supplemented subjects herein may have been
due to one of 2 phenomena: (1) the training program did
not provide ample time to achieve between-group signifi-
455 cance for muscle hypertrophy and strength in previously
trained men or (2) the supplemental protein dosages did
not provide adequate amounts of dietary protein to achieve
some minimum necessary difference needed to gain muscle
mass. It is well known that trained individuals benefit from
460 more dietary protein [40]. However, Bosse and Dixon [41]
published a meta-analysis that determined that positive
training adaptations occur when daily protein intake is
increased by at least 66%. Also consistent with this hypoth-
esis are the findings by Hoffman et al. [42], who reported
465 that trained football players and male sprinters who con-
sumed >2 g protein/kg body mass per day gained more
lean body mass and lower-body strength over a 12-week
training period compared to athletes who consumed 1.0–
1.4 g/kg/d. In the current investigation, the placebo group
470 consumed 1.58 g/kg/d of protein, whereas the protein-sup-
plemented groups consumed 1.85–1.97 g/kg/d; of note, the
WPH group increased protein intake from PRE by 42.9%,
the WPC-L group increased protein intake by 50.4%, and
the WPC group increased protein intake by 66.7%. There-
475 fore, our data along with the aforementioned data collec-
tively suggest that, though postexercise protein
supplementation optimizes muscle protein synthesis [43–
45], trained subjects may also require daily protein intakes
that either exceed 66% of their presupplement intakes and/
480or >2.0 g/kg/d in order to realize gains in muscle mass and
strength over shorter training periods (i.e., 8–12 weeks).
Despite no significant differences between groups for
changes in muscle mass, it is plausible that WPH supple-
mentation improves metabolic efficiency. For example, our
485lab has previously reported that an acute feeding of moder-
ate-to-low hydrolyzed WPH resulted in an increase in
serum metabolomic markers of Krebs cycle activity and
carbohydrate and fat metabolism as well as a decrease in
protein catabolism compared to WPC [10]. Similarly, gross
490clinical chemistry measures in the current investigation
indicate that the WPH supplementation may have resulted
in an improved retention of ingested nitrogen from whey.
Specifically, WPH significantly reduced BUN from PRE to
POST (¡18.3%; p<0.0125), which is significantly differ-
495ent than the BUN response to WPC (C16.7%; p<0.0125).
Though rapidly digested proteins have typically been
shown to increase BUN and have a more profound effect
on stimulating protein synthesis, Dangin et al. [46] reported
that the ingestion of a rapidly digested protein not only
500increased protein synthesis but also significantly reduced
protein loss in elderly versus younger males. Koopman
et al. [47] reported similar findings in elderly males in
response to consuming a hydrolyzed casein protein versus
its intact form; specifically, these authors postulated that
505the improved nitrogen retention in response to the hydroly-
sate was most likely the result of an increased insulin
response. Indeed, our study did not assess the acute hor-
monal response to each treatment, although it is plausible
that hydrolyzed protein in general elicits a more efficient
510metabolic state than is achieved in response to the con-
sumption of its intact form. In this regard, more research is
needed in order to assess whether chronic supplementation
with hydrolyzed versus native proteins promotes an
increase in nitrogen retention across various populations
515(i.e., athletes, clinical populations, etc.).
Remarkably, WPH did elicit a significant decrease in fat
mass compared to the PLA condition, whereas WPC and/or
WPC-L did not. This is not the first evidence suggesting
PLA WPC W PC-L WPH
0
50
100
150
1RM bench press
kilograms
*
89
95 104
110
101
107
101 105
PRE POST PRE PO ST PRE POST PRE POST
*
**
PLA WPC WPC-L WPH
0
50
100
150
200
250
1RM hack squat
kilograms
*
167
210
141
191
171
216
164
204
PRE POST PRE PO ST PRE POST PRE POST
**
*
a b
Fig. 2. Strength adaptations. These strength data are from subjects prior to (PRE) and after (POST) the intervention and are presented as mean §SEM.
*Different from PRE (p0.0125).
8 VOL. 0, NO. 0
Whey Protein and Resistance Training Adaptations
that hydrolyzed whey protein may promote decreases in fat
520 mass and/or initiate lipolytic mechanisms. Specifically,
Cribb et al. [6] reported that a hydrolyzed WPI decreased
fat mass by 1.4 kg over a 10-week training period in previ-
ously trained subjects; of note, counterparts supplemented
with hydrolyzed casein did not lose body fat. We have also
525 used animal models to demonstrate that (1) hydrolyzed
whey protein significantly increased serum levels of glyc-
erol and free fatty acid levels 30 minutes postfeeding com-
pared to rats fed WPC [10] and (2) rats fed a test solution
containing a high percentage of WPH presented significant
530 increases in subcutaneous adipose tissue cyclic adenosine
monophosphate levels as well as phosphorylated (activated)
hormone-sensitive lipase levels 180 minutes postfeeding
relative to fasting rats [11]. Though the mechanisms of
WPH-induced lipolysis were not deciphered in this study,
535our prior rodent study demonstrated that, compared to
WPC, WPH elicited a robust increase in circulating epi-
nephrine [10]. Given that epinephrine is a lipolytic cate-
cholamine that acts to increase intra-adipocyte cyclic
adenosine monophosphate and hormone sensitive lipase
540activity, it is plausible that WPH-supplemented subjects
may have experienced fat loss through repetitive stimula-
tion of catecholamine-induced lipolysis. It also remains
plausible that non-epinephrine-mediated mechanisms (i.e.,
WPH-derived bioactives) may stimulate lipolysis. For
545instance, others have reported that inhibiting GLP-1 follow-
ing hydrolyzed whey protein ingestion increases lipolysis in
rats compared to whey protein feeding alone, and these
findings led the authors to conclude that bioactive oligopep-
tides derived from whey protein digestion may cross the
550intestinal lumen to elicit these physiological effects [48].
Thus, we contend that the potential lipolytic action of
WPH could be an exciting and novel avenue for research
and further efforts are needed in order to delineate how
WPH facilitates lipolysis.
555It should finally be noted that the different protein forms did
not affect select serum variables measured in this investigation.
Specifically, there were no between-treatment differences for
blood glucose or lipids. Though past literature has reported
that whey protein supplementation can improve these circulat-
560ing biomarkers in hyperglycemic or hyperlipidemic subjects
[22], our study examined the effects of different whey protein
supplements on exercise adaptations in healthy individuals
who presented normal values for blood glucose, triglycerides,
and cholesterol. Hence, though we may have observed an
565effect in diseased populations, it appears that the tested whey
protein forms do not alter these markers in otherwise young/
healthy test subjects. Notably, the different whey protein sup-
plements did not affect serum creatinine levels, which, like
other literature [49,50], continues to suggest that shorter-term
570protein supplementation does not adversely affect this bio-
marker reflective of kidney function. Finally, it should be noted
that the different whey protein supplements did not affect cir-
culating levels of creatine kinase, a surrogate of muscle dam-
age. Interestingly, whey protein supplementation has been
575reported to decrease this marker in chronically trained animals
[25]. However, recent human data suggest that, though hydro-
lyzed whey protein ingestion can promote muscle recovery
(i.e., a rebound in peak torque) from rigorous eccentric exer-
cise, it does not affect serum creatine kinase levels [51]; this
580finding suggests that hydrolyzed whey protein may reduce
postexercise inflammation and/or positively affect neuromus-
cular recovery rather than affect exercise-induced muscle dam-
age. Notwithstanding, our findings continue to suggest that
Table 5. PRE and POST Levels of Select Serum Variables
a
PRE POST
Treatment Mean SEM Mean SEM Change Score
Serum glucose (mg/dL)
PLA 88.7 1.7 88.7 1.8 0.0
WPC 88.4 1.4 89.1 1.6 0.6
WPC-L 89.4 1.4 89.8 1.5 0.4
WPH 86.3 1.6 87.3 1.7 1.0
Serum high-density lipoprotein cholesterol (mg/dL)
PLA 48.1 4.3 52.4 3.7 4.3
WPC 57.8 3.8 55.1 3.2 ¡2.7
WPC-L 55.0 3.7 55.8 3.1 0.7
WPH 58.5 3.9 55.2 3.3 ¡3.3
Serum low-density lipoprotein cholesterol (mg/dL)
PLA 86.7 7.4 82.4 6.8 ¡4.4
WPC 85.0 6.5 89.0 6.0 4.0
WPC-L 76.9 6.4 81.0 5.8 4.1
WPH 85.9 6.8 81.8 6.2 ¡4.0
Serum triglycerides (mg/dL)
PLA 87.6 12.4 101.3 10.4 13.7
WPC 100.1 10.8 95.4 9.1 ¡4.7
WPC-L 94.2 10.6 88.3 8.9 ¡5.9
WPH 86.1 11.2 86.8 9.5 0.6
Serum urea nitrogen (mg/dL)
PLA 14.9 1.0 14.7 0.9 ¡0.2
WPC 12.6 0.9 14.7 0.8 2.1
*
WPC-L 15.2 0.8 15.0 0.8 ¡0.2
WPH 15.3 0.9 12.5 0.9 ¡2.8
Serum creatinine (mg/dL)
PLA 1.03 0.04 0.96 0.03 ¡0.07
WPC 1.04 0.04 0.98 0.03 ¡0.06
WPC-L 1.12 0.04 1.06 0.03 ¡0.05
WPH 1.03 0.04 0.91 0.03 ¡0.12
Serum creatine kinase (U/L)
PLA 246.6 41.6 212.6 39.1 ¡34.0
WPC 140.0 36.3 125.9 34.1 ¡14.1
WPC-L 285.2 35.8 191.8 33.6 ¡93.4
WPH 192.3 39.3 196.0 36.9 3.7
PLA Dplacebo, WPC D80% whey protein concentrate, WPC-L Dhigh-lacto-
ferrin WPC, WPH Dextensively hydrolyzed WPC.
a
These serum data are from subjects prior to (PRE) and after (POST) the inter-
vention, and are presented as mean §SEM.
*Different from PRE (p0.0125).
D
Group * Time interaction revealed that the change was different from WPC (p
0.05).
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION 9
Whey Protein and Resistance Training Adaptations
whey protein does not alter circulating markers of muscle dam-
585 age in humans.
CONCLUSIONS
Our study contains limitations; specifically, it was only
8 weeks in length and, though this is common with protein sup-
plementation studies, longer supplementation studies are
590 needed to compare the physiological effects of different whey
protein forms. Moreover, our study did lack mechanistic fea-
tures in that we are unable to determine how WPH facilitated
fat mass loss with training. Thus, more mechanistic in vitro or
omics in vivo approaches are needed in order to determine how
595 WPH affects adipose tissue signaling, metabolism, and gene
expression. Notwithstanding, our data are consistent with other
data suggesting that trained subjects may require protein
intakes that either exceed 66% of their presupplement intakes
and/or >2.0 g/kg/d in order to realize gains in muscle mass,
600 strength, and anaerobic endurance over shorter training peri-
ods. Moreover, WPH supplementation is seemingly more ben-
eficial than WPC in reducing body fat while simultaneously
increasing muscle mass during resistance training, and this
finding should be further investigated in overweight/obese
605 populations.
Competing Interests
C.M.L. is currently the President and Owner of AP Nutri-
tion, which provides consulting services to dietary supplement
companies. However, his role in AP Nutrition has no conflicts
610 of interest with these presented data. K.L.K. is currently Sci-
ence Editor of Bodybuilding.com, which provides editorial
content within the fitness industry, and is an online retailer and
manufacturer of dietary supplements. However, her role at
Bodybuilding.com has no conflicts of interest with these pre-
615 sented data. All other authors declare that they have no other
competing interests.
Author Contributions
C.M.L. conceived of the study and participated in its design
and coordination, data collection, analysis, and interpretation
620 and drafting of the article. M.D.R. participated in the study
design, data collection, analysis, and interpretation and drafting
of the article. V.J.D. contributed to data collection, analysis,
and interpretation. A.E.S. contributed to data collection and
interpretation. K.L.K. contributed to data collection and inter-
625 pretation. J.R.M. contributed to data analysis and interpreta-
tion. J.R.S. participated in the study design, data analysis, and
interpretation. All authors read and approved the final article.
ACKNOWLEDGMENTS
The authors thank all of the participants involved in the
630study as well as David Peebles, Dr. David Fukuda, Michael
Young, Annie Maruska, Dr. Chris Poole, Dr. Kyle Sunderland,
and Bryan Baranowski for their support.
FUNDING
AP Nutrition, Scivation Inc., and Progenex Inc. funded the
635study.
COMPETING INTERESTS
C.M.L. is currently the President and Owner of AP Nutri-
tion, which provides consulting services to dietary supplement
companies. However, his role in AP Nutrition has no conflicts
640of interest with these presented data. K.L.K. is currently Sci-
ence Editor of Bodybuilding.com, which provides editorial
content within the fitness industry, and is an online retailer and
manufacturer of dietary supplements. However, her role at
Bodybuilding.com has no conflicts of interest with these pre-
645sented data. All other authors declare that they have no other
competing interests.
REFERENCES Q6
1. Kumar V, et al.: Human muscle protein synthesis and breakdown
during and after exercise. J Appl Physiol 106:2026–2039, 2009.
6502. Burd NA, et al.: Exercise training and protein metabolism: influ-
ences of contraction, protein intake, and sex-based differences. J
Appl Physiol 106:1692–1701, 2009.
3. Tang JE, Phillips SM: Maximizing muscle protein anabolism: the
role of protein quality. Curr Opin Clin Nutr Metab Care 12:66–71,
6552009.
4. Dreyer HC, et al.: Leucine-enriched essential amino acid and car-
bohydrate ingestion following resistance exercise enhances
mTOR signaling and protein synthesis in human muscle. Am J
Physiol Endocrinol Metab 294:E392–E400, 2008.
6605. Miller SL, et al.: Independent and combined effects of amino
acids and glucose after resistance exercise. Med Sci Sports Exerc
35:449–455, 2003.
6. Cribb PJ, et al.: The effect of whey isolate and resistance training
on strength, body composition, and plasma glutamine. Int J Sport
665Nutr Exerc Metab 16:494–509, 2006.
7. Volek JS, et al.: Whey protein supplementation during resistance
training augments lean body mass. J Am Coll Nutr 32:122–135,
2013.
8. Hulmi JJ, Lockwood CM, Stout JR: Effect of protein/essential
670amino acids and resistance training on skeletal muscle hypertro-
phy: a case for whey protein. Nutr Metab (Lond) 7:51, 2010. Q7
10 VOL. 0, NO. 0
Whey Protein and Resistance Training Adaptations
9. Calbet JA, Holst JJ: Gastric emptying, gastric secretion and
enterogastrone response after administration of milk proteins or
their peptide hydrolysates in humans. Eur J Nutr 43:127–139,
675 2004.
10. Roberts MD, et al.: Comparing serum responses to acute feedings
of an extensively hydrolyzed whey protein concentrate versus a
native whey protein concentrate in rats: a metabolomics approach.
Appl Physiol Nutr Metab 39:158–167, 2014.
680 11. Mobley CB, et al.: Effects of protein type and composition on
postprandial markers of skeletal muscle anabolism, adipose tissue
lipolysis, and hypothalamic gene expression. J Int Soc Sports Nutr
12:14, 2015.
Q8
12. Power O, Hallihan A, Jakeman P: Human insulinotropic response
685 to oral ingestion of native and hydrolysed whey protein. Amino
Acids 2008.
Q9
13. Toedebusch RG, et al.: Postprandial leucine and insulin responses
and toxicological effects of a novel whey protein hydrolysate-
based supplement in rats. J Int Soc Sports Nutr 9:24, 2012.
Q10
690 14. Weinberg ED: Antibiotic properties and applications of lactofer-
rin. Curr Pharm Des 13:801–811, 2007.
15. Mulder AM, et al.: Bovine lactoferrin supplementation supports
immune and antioxidant status in healthy human males. Nutr Res
28:583–589, 2008.
695 16. Hudson MB, et al.: The effect of resistance exercise on humoral
markers of oxidative stress. Med Sci Sports Exerc 40:542–548,
2008.
17. Nikolaidis MG, et al.: The effect of muscle-damaging exercise on
blood and skeletal muscle oxidative stress: magnitude and time-
700 course considerations. Sports Med 38:579–606, 2008.
18. Armstrong LE: Assessing hydration status: the elusive gold stan-
dard. J Am Coll Nutr 26(Suppl):575S–584S, 2007.
19. Kim J, et al.: Total-body skeletal muscle mass: estimation by a
new dual-energy x-ray absorptiometry method. Am J Clin Nutr
705 76:378–383, 2002.
20. Lohman M, et al.: Reproducibility of dual-energy x-ray absorpti-
ometry total and regional body composition measurements using
different scanning positions and definitions of regions. Metabo-
lism 58:1663–1668, 2009.
710 21. Weir JP: Quantifying test–retest reliability using the intraclass
correlation coefficient and the SEM. J Strength Cond Res 19:231–
240, 2005.
22. Pasin G, Comerford KB: Dairy foods and dairy proteins in the
management of type 2 diabetes: a systematic review of the clinical
715 evidence. Adv Nutr 6:245–259, 2015.
23. Roberts RG, Louden JD, Goodship TH: An assessment of the
methods available to determine nutritional equilibrium in patients
with chronic renal failure. Nephrol Dial Transplant 15:1906–
1908, 2000.
720 24. Trof RJ, et al.: Biomarkers of acute renal injury and renal failure.
Shock 26:245–253, 2006.
25. Chen WC, et al.: Whey protein improves exercise performance
and biochemical profiles in trained mice. Med Sci Sports Exerc
46:1517–1524, 2014.
725 26. Roberts MD, et al.: Effects of arachidonic acid supplementation
on training adaptations in resistance-trained males. J Int Soc
Sports Nutr 4:21, 2007.
Q11
27. Kerksick CM, et al.: Early-phase adaptations to a split-body,
linear periodization resistance training program in college-aged
730and middle-aged men. J Strength Cond Res 23:962–971, 2009.
28. Kumar V, et al.: Age-related differences in the dose–response
relationship of muscle protein synthesis to resistance exercise in
young and old men. J Physiol 587(Pt 1):211–217, 2009.
29. Moore DR, et al.: Differential stimulation of myofibrillar and sar-
735coplasmic protein synthesis with protein ingestion at rest and after
resistance exercise. J Physiol 587(Pt 4):897–904, 2009.
30. Tang JE, et al.: Resistance training alters the response of fed state
mixed muscle protein synthesis in young men. Am J Physiol
Regul Integr Comp Physiol 294:R172–R178, 2008.
74031. Claessens M, et al.: The effect of different protein hydrolysate/
carbohydrate mixtures on postprandial glucagon and insulin
responses in healthy subjects. Eur J Clin Nutr 63:48–56, 2009.
32. Koopman R, et al.: Ingestion of a protein hydrolysate is accompa-
nied by an accelerated in vivo digestion and absorption rate when
745compared with its intact protein. Am J Clin Nutr 90:106–115,
2009.
33. Whaley MH, (ed): “ACSM’s Guidelines for Exercise Testing and
Prescription.” 7th ed. Philadelphia: Lippincott Williams & Wil-
kins, 2006.
75034. Willoughby DS, Stout JR, Wilborn CD: Effects of resistance train-
ing and protein plus amino acid supplementation on muscle anab-
olism, mass, and strength. Amino Acids 32:467–477, 2007.
35. Andersen LL, et al.: The effect of resistance training combined
with timed ingestion of protein on muscle fiber size and muscle
755strength. Metabolism 54:151–156, 2005.
36. Burke DG, et al.: The effect of whey protein supplementation with
and without creatine monohydrate combined with resistance train-
ing on lean tissue mass and muscle strength. Int J Sport Nutr Exerc
Metab 11:349–364, 2001.
76037. Candow DG, et al.: Effect of whey and soy protein supplementa-
tion combined with resistance training in young adults. Int J Sport
Nutr Exerc Metab 16:233–244, 2006.
38. Cribb PJ, et al.: Effects of whey isolate, creatine, and resistance
training on muscle hypertrophy. Med Sci Sports Exerc 39:298–
765307, 2007.
39. Weisgarber KD, Candow DG, Farthing JP: Whey protein and
high-volume resistance training in postmenopausal women. J Nutr
Health Aging 19:511–517, 2015.
40. Campbell B, et al.: International Society of Sports Nutrition posi-
770tion stand: protein and exercise. J Int Soc Sports Nutr 4:8, 2007.
Q12
41. Bosse JD, Dixon BM: Dietary protein to maximize resistance
training: a review and examination of protein spread and change
theories. J Int Soc Sports Nutr 9:42, 2012. Q13
42. Hoffman JR, et al.: Effect of protein intake on strength, body com-
775position and endocrine changes in strength/power athletes. J Int
Soc Sports Nutr 3:12–18, 2006.
43. Tang JE, et al.: Ingestion of whey hydrolysate, casein, or soy pro-
tein isolate: effects on mixed muscle protein synthesis at rest and
following resistance exercise in young men. J Appl Physiol
780107:987–992, 2009.
44. Koopman R, et al.: Co-ingestion of leucine with protein does not
further augment post-exercise muscle protein synthesis rates in
elderly men. Br J Nutr 99:571–580, 2008.
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION 11
Whey Protein and Resistance Training Adaptations
45. Reidy PT, et al.: Protein blend ingestion following resistance
785 exercise promotes human muscle protein synthesis. J Nutr
143:410–416, 2013.
46. Dangin M, et al.: The rate of protein digestion affects protein gain
differently during aging in humans. J Physiol 549(Pt 2):635–644,
2003.
790 47. Koopman R, et al.: Ingestion of a protein hydrolysate is accompa-
nied by an accelerated in vivo digestion and absorption rate when
compared with its intact protein. Am J Clin Nutr 90:106–115, 2009.
48. Aziz A, et al.: Hyperglycemia after protein ingestion concurrent
with injection of a GLP-1 receptor agonist in rats: a possible role
795 for dietary peptides. Am J Physiol Regul Integr Comp Physiol
289:R688–R694, 2005.
49. Poole CN, et al.: The combined effects of exercise and ingestion
of a meal replacement in conjunction with a weight loss
801 supplement on body composition and fitness parameters in col-
lege-aged men and women. J Strength Cond Res 25:51–60, 2011.
50. Lockwood CM, et al.: Minimal nutrition intervention with high-
protein/low-carbohydrate and low-fat, nutrient-dense food supple-
805ment improves body composition and exercise benefits in over-
weight adults: a randomized controlled trial. Nutr Metab (Lond)
5:11, 2008. Q14
51. Buckley JD, et al.: Supplementation with a whey protein hydroly-
sate enhances recovery of muscle force-generating capacity fol-
810lowing eccentric exercise. J Sci Med Sport 13:178–181, 2010.
52. Perea A, et al.: Preparation and characterization of whey protein
hydrolysates: applications in industrial whey bioconversion pro-
cesses. Enzyme Microb Technol 15:418–423, 1993.
Received September 20, 2015; accepted December 3, 2015
12 VOL. 0, NO. 0
Whey Protein and Resistance Training Adaptations
... ,94 Changes in strength data resulting from the additional protein intervention were extracted from 50 studies testing 2283 subjects for lower-body strength33,36-39,43,44,47-49,52-58,61-65,67-70, 72,74-78,82,84,86,88-92,94,96,100-104 and only three studies with intervention groups without RE.41,99,105 Thirty-four studies tested bench-press strength33,[36][37][38]43,[47][48][49][53][54][55][62][63][64][65]67,68,70,72,74,75,77,78,82,84,[86][87][88]90,91,93,95,96,99 with 1049 subjects. The duration of the studies was, on average, 12 weeks for both bench-press and lower body strength. ...
Article
Full-text available
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.
... The electropherograms of both samples A47 and C64 present a series of peaks likely resulting from the hydrolysis process of the whey proteins. Hydrolysed whey proteins are less commonly used in PSS formulation since their physiological advantages are still under debate [26]. Furthermore, hydrolysis makes addition of cheaper proteins undetectable, unless proteomic approaches are implemented [27]. ...
Article
Full-text available
Increasing awareness of balanced diet benefits is boosting the demand for high-protein food and beverages. Sports supplements are often preferred over traditional protein sources to meet the appropriate dietary intake since they are widely available on the market as stable ready-to-eat products. However, the protein components may vary depending on both sources and processing conditions. The protein fraction of five commercial sports supplements was characterized and compared with that of typical industrial ingredients, i.e., whey protein concentrates and isolates and whey powder. The capillary electrophoresis profiles and the amino acid patterns indicated that, in some cases, the protein was extensively glycosylated and the supplemented amino acids did not correspond to those declared on the label by manufacturers. The evaluation by confocal laser scanning microscopy evidenced the presence of large aggregates mainly enforced by covalent crosslinks. The obtained findings suggest that, beside composition figures, provisions regarding sports supplements should also consider quality aspects, and mandatory batch testing of these products would provide more reliable information to sport dieticians.
... This supplement provides them with essential amino acids and bioactive peptides. Lockwood et al. [163] concluded that whey protein supplementation increased muscle mass after eight weeks in collegeaged males. Hansen and co-workers [164] demonstrated that consumption of whey protein hydrolysates before an exercise session, followed by ingestion of more protein hydrolysates plus carbohydrates for a training period of six weeks, improved specific mitochondrial protein adaptations compared to the intake of carbohydrates. ...
Article
Full-text available
There are two types of milk whey obtained from cheese manufacture: sweet and acid. It retains around 55% of the nutrients of the milk. Milk whey is considered as a waste, creating a critical pollution problem, because 9 L of whey are produced from every 10 L of milk. Some treatments such as hydrolysis by chemical, fermentation process, enzymatic action, and green technologies (ultrasound and thermal treatment) are successful in obtaining peptides from protein whey. Milk whey peptides possess excellent functional properties such as antihypertensive, antiviral, anticancer, immunity, and antioxidant, with benefits in the cardiovascular, digestive, endocrine, immune, and nervous system. This review presents an update of the applications of milk whey hydrolysates as a high value-added peptide based on their functional properties.
... In the equation, a is equal to the distance between the superficial fascia and the deep aponeurosis and θ is equal to the angle of pennation. Importantly, to minimize variability in measurements as suggested in previous studies (Lohman et al., 2009;Lockwood et al., 2017), all measures were taken by the same investigator (S.C.O.), and this person in a testretest validation on 10 participants had an ICC of 0.991 and an SEM of 0.06 cm. Critically, this investigator was not privy to the training condition for each participant's leg. ...
Article
Full-text available
We evaluated the effects of higher-load (HL) versus (lower-load) higher-volume (HV) resistance training on skeletal muscle hypertrophy, strength, and muscle-level molecular adaptations. Trained men (n = 15, age: 23 ± 3 years; training experience: 7 ± 3 years) performed unilateral lower-body training for 6 weeks (3× weekly), where single legs were randomly assigned to HV and HL paradigms. Vastus lateralis (VL) biopsies were obtained prior to study initiation (PRE) as well as 3 days (POST) and 10 days following the last training bout (POSTPR). Body composition and strength tests were performed at each testing session, and biochemical assays were performed on muscle tissue after study completion. Two-way within-subject repeated measures ANOVAs were performed on most dependent variables, and tracer data were compared using dependent samples t-tests. A significant interaction existed for VL muscle cross-sectional area (assessed via magnetic resonance imaging; interaction p = 0.046), where HV increased this metric from PRE to POST (+3.2%, p = 0.018) whereas HL training did not (−0.1%, p = 0.475). Additionally, HL increased leg extensor strength more so than HV training (interaction p = 0.032; HV < HL at POST and POSTPR, p < 0.025 for each). Six-week integrated non-myofibrillar protein synthesis (iNon-MyoPS) rates were also higher in the HV versus HL condition, while no difference between conditions existed for iMyoPS rates. No interactions existed for other strength, VL morphology variables, or the relative abundances of major muscle proteins. Compared to HL training, 6 weeks of HV training in previously trained men optimizes VL hypertrophy in lieu of enhanced iNon-MyoPS rates, and this warrants future research.
... The potential impact of WP on FM agrees with studies in non-military populations as well (40,41). WP has been shown to promote FM loss in conjunction with exercise in healthy (41,42) and obese individuals (40,41). Animal and cell culture models suggest WP may promote fat metabolism by influencing both adipose and muscle (43,44). ...
Article
Full-text available
This study assesses if a lower dose of whey protein can provide similar benefits to those shown in previous work supplementing Army Initial Entry Training (IET) Soldiers with two servings of whey protein (WP) per day. Eighty-one soldiers consumed one WP or a calorie matched carbohydrate (CHO) serving/day during IET (WP: n = 39, height = 173 ± 8 cm, body mass = 76.8 ± 12.8 kg, age = 21 ± 3 years; CHO: n = 42, 175 ± 8 cm, 77.8 ± 15.3 kg, 23 ± 4 years). Physical performance (push-ups, sit-ups, and a two-mile run) was assessed during weeks two and eight. All other measures (dietary intake, body composition, blood biomarkers) at weeks one and nine. There was a significant group difference for fat mass ( p = 0.044) as WP lost 2.1 ± 2.9 kg and had a moderate effect size (Cohen's d: −0.24), whereas the CHO group lost 0.9 ± 2.5 kg and had only a small effect size (d: −0.1). There was no significant group-by-time interaction on fat-free mass ( p = 0.069). WP gained 1.2 ± 2.4 (d: 0.1) and CHO gained 0.1 ± 3 (d: 0) kg of FFM on average. There was a significant group by week 1-fat free mass interaction ( p = 0.003) indicating individuals with higher initial fat-free mass benefitted more from WP. There were no group differences for push-up ( p = 0.514), sit-up ( p = 0.429) or run (p = 0.313) performance. For all biomarkers there was a significant effect of time as testosterone ( p < 0.01), testosterone to cortisol ratio ( p = 0.39), and IGF-1 ( p < 0.01) increased across training and cortisol ( p = 0.04) and IL-6 ( p < 0.01) decreased. There were no differences in groups across IET for any of the biomarkers. We conclude one WP serving is beneficial for FM and for FFM in soldiers with high baseline FFM but may not significantly alter biomarker response or physical performance of IET soldiers who have high relative dietary protein intakes.
... ,94 Changes in strength data resulting from the additional protein intervention were extracted from 50 studies testing 2283 subjects for lower-body strength33,36-39,43,44,47-49,52-58,61-65,67-70, 72,74-78,82,84,86,88-92,94,96,100-104 and only three studies with intervention groups without RE.41,99,105 Thirty-four studies tested bench-press strength33,[36][37][38]43,[47][48][49][53][54][55][62][63][64][65]67,68,70,72,74,75,77,78,82,84,[86][87][88]90,91,93,95,96,99 with 1049 subjects. The duration of the studies was, on average, 12 weeks for both bench-press and lower body strength. ...
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 (
... Whey protein são proteínas extraídas da parte aquosa (soro) gerada durante o processo de fabricação do queijo (FISCHBORN, 2009). O soro pode ser processado por várias técnicas de separação de proteínas, buscando obter um concentrado, whey protein concentrado, ou um isolado, whey protein isolado, e existe também o whey protein hidrolisado (SOUZA et al., 2015;LOCKWOOD et al., 2017). ...
... Many nutritional supplements are effective in various experimental models in terms of their protective effects on these biomarkers [30][31][32]. In a study of acute effects, whey protein hydrolysate showed more remarkable improvement of muscle damage markers compared to carbohydrate drink [33]. ...
Article
Full-text available
This study was focused on the creation of high-protein bars formulated using whey protein isolate (24%) and soy protein isolate (6%) as the sources of proteins; oat flakes and inulin, both abundant in dietary fibres, and creatine monohydrate and other minor ingredients (vitamin and mineral mixture, potassium sorbate) to achieve the requirements for a meal replacement formula for physically active people. The nutritional profile of the high-protein bar was examined (energy 1215 kJ/288 kcal; protein 34.1 ± 0.20 g, fat 6.01 ± 0.13 g of which was saturated 3.12 ± 0.08 g, fibre 3.10 ± 0.17 g carbohydrate 23.0 ± 0.16 g of which sugars 1.50 ± 0.19 g and starch 21.5 ± 0.11 g in 100 g), and sensory properties with instrumental parameters (texture and colour) were determined and compared with bars commercially available on the market. The created high-protein bar was sensorily acceptable in comparison to other commercially available bars. The dietary intervention study was conducted on elite athletes (professional handball players) to evaluate effects of created versus control bar consumption on their metabolic parameters. The baseline characteristics (mean age, body mass index (BMI), fat mass, muscle mass, lean mass and fat percentage) of the athletes (8) were determined at the start of the study. The cross-over intervention study was organized in two successive phases (5 days each) with a seven-day long washout period between phases. Bars were consumed after the afternoon training unit. Blood samples were collected at the start and the end of the intervention study to analyse the metabolic profiles of the athletes. Serum levels of high-density cholesterol (HDL), low-density cholesterol (LDL) and total cholesterol (HOL), glucose, triacylglycerides (TAG), total and direct bilirubin, creatine kinase (CK), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured. The results showed that bar consumption significantly decreased serum aspartate transaminase (AST) and lactate dehydrogenase (LDH) and increased total and direct bilirubin levels, suggesting lower exercise-induced muscle damage and increased antioxidative response, respectively. Therefore, it can be concluded that the consumption of the created high-protein bar was able to improve physiological adaptation after training.
Article
Many studies have evaluated the effects of resistance training (RT) and protein intake to attenuate the age-related loss of skeletal muscle. However, the effects of graded protein intake with conjunctive RT in older adults are unclear. Older adults (n = 18) performed 10 weeks of whole-body RT with progressions to intensity and volume while consuming either a constant protein (CP) diet (0.8–1.0 g/kg/d) with no protein supplement or a graded protein (GP) diet progressing from 0.8 g/kg/d at week 1 to 2.2 g/kg/d at week 10 with a whey protein supplement. Data were collected prior to commencement of the RT protocol (PRE), after week 5 (MID), and after week 10 (POST). Dual Energy X-ray Absorptiometry derived lean/soft tissue mass, ultrasonography derived muscle thickness, and a proxy of muscle quality were taken at PRE and POST, while isokinetic dynamometry derived peak torque were taken at PRE, MID, and POST. This study demonstrated the feasibility of the RT protocol (attendance = 96%), and protein intake protocol (CP in range all weeks; GP deviation from prescribed = 7%). Peak torque, muscle quality scores, and appendicular lean/soft tissue mass demonstrated the main effects of time (p < 0.05) while no other main effects of time or group * time interactions were seen for any measure. In conclusion, RT improved appendicular lean/soft tissue mass, peak torque, and muscle quality, with no differential effects of graded or constant protein intake.
Article
Full-text available
With the increasing incidence of obesity resulting from sedentary lifestyle the consciousness towards maintaining a healthier lifestyle, particularly toned body is also increasing. Due to time paucity the people are more attracted towards achieving a healthy body in short time leading to increased enrolment rates in gymnasiums. Gymnasium is a place for physical training and is associated with consumption of high protein diets including fitness supplement intake for improved muscle mass and better health outcomes. With the increase of fitness supplement industries in the market and their claims of enhancing physical fitness components and performance, their popularity among the people is increasing particularly of protein supplements that claims to increase muscle mass and strength. Intake of protein rich diets and extreme exercise without the proper guidance of nutrition professional can lead to deleterious effects on the body. Hence, intake of proper balanced diet along with proper fluid intake is important component of overall fitness and better health outcomes. This article highlights the intake of protein particularly protein supplements among the gymnasium users and its current recommendations for intake.
Article
Full-text available
Type 2 diabetes mellitus (T2DM) is a growing public health concern affecting hundreds of millions of people worldwide and costing the global economy hundreds of billions of dollars annually. This chronic disease damages the blood vessels and increases the risk of other cardiometabolic ailments such as cardiovascular disease and stroke. If left unmanaged it can also lead to nerve damage, kidney damage, blindness, and amputation. For the most part, many of these symptoms can be prevented or reduced through simple dietary modifications and proper nutrition. Therefore, identifying relatively inexpensive and easily implementable dietary modifications for the prevention and management of T2DM is of considerable value to human health and healthcare modalities around the globe. Protein-rich dairy products have consistently been shown in epidemiologic studies to be beneficial for reducing the risk of developing T2DM. The clinical evidence regarding both dairy foods and dairy proteins (i.e., casein and whey protein) have shown promise for improving insulin secretion in individuals with T2DM. However, the clinical research on dairy protein supplementation in subjects with T2DM has been limited to acute studies. These studies have been mostly descriptive and have not been focused on important T2DM endpoints such as prevention, management, or treatment. Long-term studies are clearly needed to help researchers and medical professionals better understand the effects of consistent dairy protein intake on the metabolic health of humans with T2DM. © 2015 American Society for Nutrition.
Article
Full-text available
We examined the acute effects of different dietary protein sources (0.19 g, dissolved in 1 ml of water) on skeletal muscle, adipose tissue and hypothalamic satiety-related markers in fasted, male Wistar rats (~250 g). Oral gavage treatments included: a) whey protein concentrate (WPC, n = 15); b) 70:30 hydrolyzed whey-to-hydrolyzed egg albumin (70 W/30E, n = 15); c) 50 W/50E (n = 15); d) 30 W/70E (n = 15); and e) 1 ml of water with no protein as a fasting control (CTL, n = 14). Skeletal muscle analyses revealed that compared to CTL: a) phosphorylated (p) markers of mTOR signaling [p-mTOR (Ser2481) and p-rps6 (Ser235/236)] were elevated 2-4-fold in all protein groups 90 min post-treatment (p < 0.05); b) WPC and 70 W/30E increased muscle protein synthesis (MPS) 104% and 74% 180 min post-treatment, respectively (p < 0.05); and c) 70 W/30E increased p-AMPKα (Thr172) 90 and 180-min post-treatment as well as PGC-1α mRNA 90 min post-treatment. Subcutaneous (SQ) and omental fat (OMAT) analyses revealed: a) 70 W/30 W increased SQ fat phosphorylated hormone-sensitive lipase [p-HSL (Ser563)] 3.1-fold versus CTL and a 1.9-4.4-fold change versus all other test proteins 180 min post-treatment (p < 0.05); and b) WPC, 70 W/30E and 50 W/50E increased OMAT p-HSL 3.8-6.5-fold 180 min post-treatment versus CTL (p < 0.05). 70 W/30E and 30 W/70E increased hypothalamic POMC mRNA 90 min post-treatment versus CTL rats suggesting a satiety-related response may have occurred in the former groups. However, there was a compensatory increase in orexigenic AGRP mRNA in the 70 W/30E group 90 min post-treatment versus CTL rats, and there was a compensatory increase in orexigenic NPY mRNA in the 30 W/70E group 90 min post-treatment versus CTL rats. Higher amounts of whey versus egg protein stimulate the greatest post-treatment anabolic skeletal muscle response, though test proteins with higher amounts of WPH more favorably affected post-treatment markers related to adipose tissue lipolysis.
Article
Full-text available
To verify the beneficial effects of whey protein (WP) supplementation on health promotion and enhancing exercise performance in an aerobic-exercise training protocol. In total, 40 male ICR mice (4 weeks old) were divided into 4 groups (n=10 per group): sedentary control with vehicle (SC) or WP supplementation (4.1 g⋅kg, SC+WP), and exercise training with vehicle (ET) or WP supplementation (4.1 g⋅kg, ET+WP). Animals in the ET and ET+WP groups underwent swim endurance training for 6 weeks, 5 days per week. Exercise performance was evaluated by forelimb grip strength and exhaustive swim time as well as by changes in body composition and biochemical parameters at the end of the experiment. ET significantly decreased final body and muscle weight and levels of albumin, total protein, blood urea nitrogen, creatinine, total cholesterol, and triacylglycerol. ET significantly increased grip strength; relative weight (%) of liver, heart, brown adipose tissue (BAT) and levels of aspartate aminotransferase (AST), alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase (LDH), creatine kinase (CK), and total bilirubin. WP supplementation significantly decreased final body, muscle, liver, BAT, and kidney weight, and relative weight (%) of muscle, liver, and BAT as well as levels of AST, LDH, CK, and uric acid. In addition, WP supplementation slightly increased endurance time and significantly increased grip strength and levels of albumin and total protein. WP supplementation improved exercise performance, body composition and biochemical assessments in mice and may be an effective ergogenic aid in aerobic exercise training.
Article
Full-text available
We examined how gavage feeding extensively hydrolyzed whey protein (WPH) versus a native whey protein concentrate (WPC) transiently affected serum biochemical profiles in rodents. Male Wistar rats (250-300 g) were 8 h fasted and subsequently fed isonitrogenous amounts of WPH or WPC, or remained unfed (control). Animals were sacrificed 15 min, 30 min, and 60 min post-gavage for serum extraction, and serum was analyzed using untargeted global metabolic profiling via gas chromatography/mass spectrometry (MS) and liquid chromatography/MS/MS platforms. We detected 333 serum metabolites amongst the experimental and control groups. Both WPH and WPC generally increased amino acids (1.2-2.8-fold), branched-chain amino acids (1.2-1.7-fold), and serum di- and oligo-peptides (1.1-2.7-fold) over the 60 min time course compared with control (q < 0.05). However, WPH increased lysine (false discovery rate using a q-value <0.05) and tended to increase isoleucine and valine 15 min post-feeding (q < 0.10) as well as aspartylleucine 30 min post-feeding compared with WPC (q < 0.05). While both protein sources led to a dramatic increase in free fatty acids compared with control (up to 6-fold increases, q < 0.05), WPH also uniquely resulted in a 30 min post-feeding elevation in free fatty acids compared with WPC (q < 0.05), an effect which may be due to the robust 30 min postprandial increase in epinephrine in the WPH cohort. These data provide a unique postprandial time-course perspective on how WPH versus WPC feedings affect circulating biochemicals and will guide future research comparing these 2 protein sources.
Article
Full-text available
Unlabelled: Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis. Objective: To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups who consumed daily isocaloric supplements containing carbohydrate (carb; n = 22), whey protein (whey; n = 19), or soy protein (soy; n = 22). Methods: All subjects completed a supervised, whole-body periodized resistance training program consisting of 96 workouts (~9 months). Body composition was determined at baseline and after 3, 6, and 9 months. Plasma amino acid responses to resistance exercise followed by supplement ingestion were determined at baseline and 9 months. Results: Daily protein intake (including the supplement) for carb, whey, and soy was 1.1, 1.4, and 1.4 g·kg body mass⁻¹, respectively. Lean body mass gains were significantly (p < 0.05) greater in whey (3.3 ± 1.5 kg) than carb (2.3 ± 1.7 kg) and soy (1.8 ± 1.6 kg). Fat mass decreased slightly but there were no differences between groups. Fasting concentrations of leucine were significantly elevated (20%) and postexercise plasma leucine increased more than 2-fold in whey. Fasting leucine concentrations were positively correlated with lean body mass responses. Conclusions: Despite consuming similar calories and protein during resistance training, daily supplementation with whey was more effective than soy protein or isocaloric carbohydrate control treatment conditions in promoting gains in lean body mass. These results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training.
Article
Full-text available
High-quality proteins such as soy, whey, and casein are all capable of promoting muscle protein synthesis postexercise by activating the mammalian target of rapamycin (mTORC1) signaling pathway. We hypothesized that a protein blend of soy and dairy proteins would capitalize on the unique properties of each individual protein and allow for optimal delivery of amino acids to prolong the fractional synthetic rate (FSR) following resistance exercise (RE). In this double-blind, randomized, clinical trial, 19 young adults were studied before and after ingestion of ∼19 g of protein blend (PB) or ∼18 g whey protein (WP) consumed 1 h after high-intensity leg RE. We examined mixed-muscle protein FSR by stable isotopic methods and mTORC1 signaling with western blotting. Muscle biopsies from the vastus lateralis were collected at rest (before RE) and at 3 postexercise time points during an early (0-2 h) and late (2-4 h) postingestion period. WP ingestion resulted in higher and earlier amplitude of blood BCAA concentrations. PB ingestion created a lower initial rise in blood BCAA but sustained elevated levels of blood amino acids later into recovery (P < 0.05). Postexercise FSR increased equivalently in both groups during the early period (WP, 0.078 ± 0.009%; PB, 0.088 ± 0.007%); however, FSR remained elevated only in the PB group during the late period (WP, 0.074 ± 0.010%; PB, 0.087 ± 0.003%) (P < 0.05). mTORC1 signaling similarly increased between groups, except for no increase in S6K1 phosphorylation in the WP group at 5 h postexercise (P < 0.05). We conclude that a soy-dairy PB ingested following exercise is capable of prolonging blood aminoacidemia, mTORC1 signaling, and protein synthesis in human skeletal muscle and is an effective postexercise nutritional supplement.
Article
Full-text available
An appreciable volume of human clinical data supports increased dietary protein for greater gains from resistance training, but not all findings are in agreement. We recently proposed "protein spread theory" and "protein change theory" in an effort to explain discrepancies in the response to increased dietary protein in weight management interventions. The present review aimed to extend "protein spread theory" and "protein change theory" to studies examining the effects of protein on resistance training induced muscle and strength gains.Protein spread theory proposed that there must have been a sufficient spread or % difference in g/kg/day protein intake between groups during a protein intervention to see muscle and strength differences. Protein change theory postulated that for the higher protein group, there must be a sufficient change from baseline g/kg/day protein intake to during study g/kg/day protein intake to see muscle and strength benefits. Seventeen studies met inclusion criteria. In studies where a higher protein intervention was deemed successful there was, on average, a 66.1% g/kg/day between group intake spread versus a 10.2% g/kg/day spread in studies where a higher protein diet was no more effective than control. The average change in habitual protein intake in studies showing higher protein to be more effective than control was +59.5% compared to +6.5% when additional protein was no more effective than control. The magnitudes of difference between the mean spreads and changes of the present review are similar to our previous review on these theories in a weight management context. Providing sufficient deviation from habitual intake appears to be an important factor in determining the success of additional protein in enhancing muscle and strength gains from resistance training. An increase in dietary protein favorably effects muscle and strength during resistance training.
Article
Different dietary proteins affect whole body protein anabolism and accretion and therefore, have the potential to influence results obtained from resistance training. This study examined the effects of supplementation with two proteins, hydrolyzed whey isolate (WI) and casein (C), on strength, body composition, and plasma glutamine levels during a 10 wk, supervised resistance training program. In a double-blind protocol, 13 male, recreational bodybuilders supplemented their normal diet with either WI or C (1.5 gm/kg body wt/d) for the duration of the program. Strength was assessed by 1-RM in three exercises (barbell bench press, squat, and cable pull-down). Body composition was assessed by dual energy X-ray absorptiometry. Plasma glutamine levels were determined by the enzymatic method with spectrophotometric detection. All assessments occurred in the week before and the week following 10 wk of training. Plasma glutamine levels did not change in either supplement group following the intervention. The WI group achieved a significantly greater gain (P < 0.01) in lean mass than the C group (5.0 +/- 0.3 vs. 0.8 +/- 0.4 kg for WI and C, respectively) and a significant (P < 0.05) change in fat mass (-1.5 +/- 0.5 kg) compared to the C group (+0.2 +/- 0.3 kg). The WI group also achieved significantly greater (P < 0.05) improvements in strength compared to the C group in each assessment of strength. When the strength changes were expressed relative to body weight, the WI group still achieved significantly greater (P < 0.05) improvements in strength compared to the C group.
Article
To examine the combined effects of whey protein supplementation and low intensity, high-volume resistance training in healthy postmenopausal women. Postmenopausal women (n=12; age: 57 ± 4.7 years, weight: 75 ± 17.4 kg, height: 163 ± 5.5 cm, body mass index: 28.3 ± 7.0) consumed whey protein (4 x 10 gram aliquots) or placebo (maltodextrin) during unilateral resistance training sessions 2 days per week (Monday, Thursday) and consumed the opposite beverage during training the other side of the body on alternating days (Tuesday, Friday) for 10 weeks. Participants performed 3 sets at 30% baseline 1-repetition maximum (1RM) to volitional muscle fatigue for 4 exercises (leg curl, biceps curl, leg extension, triceps extension). Prior to and following training, assessments were made for upper and lower limb lean tissue mass (dual energy x-ray absorptiometry), muscle thickness of the elbow and knee flexors and extensors (ultrasound) and muscle strength (1RM leg curl, biceps curl, leg extension, triceps extension). There was a significant increase over time for muscle strength (biceps curl, leg extension, triceps extension; P = 0.006) and muscle thickness (elbow flexors and extensors; P = 0.022) with no differences between whey protein and placebo. High volume resistance training is effective for improving some indices of muscle mass and strength in postmenopausal women, but the strategic ingestion of whey protein during training sessions does not augment this response.