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BUILD MUSCLEEnhancing Resistance Training Results WithProtein/Carbohydrate Supplementation

by Wayne L. Westcott, Ph.D., CSCS and Rita La Rosa Loud, B.S.

LEARNING OBJECTIVES

• To realize that following a strength training session muscle protein

breakdown exceeds muscle protein synthesis, resulting in several

hours of net negative protein balance.

• To recognize that ingesting supplemental protein before and/or after

a resistance workout is essential for attaining a net positive protein

balance that enhances the potential for muscle development.

• To review research-based information and recommendations

for effective pretraining/posttraining protein/carbohydrate

supplementation.

Key words:Strength Training, Muscle Development, Muscle Hypertrophy,Protein Intake, Nutritional Supplementation

There presently exists a disconcerting

irony between the health risks associated

with sedentary lifestyles and the small

percentage of American adults who meet the

minimal physical activity standards established

by the American College of Sports Medicine and

the American Heart Association in 2007 (30

minutes of moderate-intensity physical activity

5 or more days a week or 20 minutes of vig-

orous physical activity 3 days a week) (1).

Recent research on the topic reveals that only

3.5% of our adult population attains this

relatively low level of regular physical activity

(25). There seems to be an even greater

disconnection between the well-documented

health benefits of resistance exercise and the

lack of adult participation in strength training. In

fact, a 2010 article in ACSM’s Current Sports

Medicine Reports presented sufficient research

evidence on the health-related outcomes of

resistance training for the authors to recommend

a public health mandate for resistance training

(19). A 2012 review article by Wescott con-

cluded that standard resistance exercise is

effective in reversing muscle loss, recharging

resting metabolism, reducing body fat, facil-

itating physical function, resisting diabetes,

improving cardiovascular health, increasing

bone mineral density, enhancing mental health,

and reversing specific aging factors (27). A more

complete list of resistance training benefits is

presented in Table 1.

In inactive adults, muscle mass decreases by

3% to 8%per decade after age 30 years (8) and by

5% to 10% per decade after age 50 years (15),

averaging about 1 lb of muscle loss per year

after the fifth decade of life (17). Reduced

muscle mass is largely responsible for reduced

resting metabolism (18), which is typically

accompanied by increased fat accumulation (32).

Fortunately, resistance exercise has been

shown to reverse muscle loss in adults of all ages

(27), averaging approximately 1 lb per month

increase in lean weight during the first several

months of strength training (4,22,29,30). The

importance of muscle remodeling and devel-

opment has spawned numerous resistance ex-

ercise programs and strength training protocols

10 ACSM’s HEALTH & FITNESS JOURNALA | www.acsm-healthfitness.org VOL. 17/ NO. 2

Copyright © 2013 American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.

for young, middle-aged, and older adults. In addition to

experimenting with various training methods, several studies

have examined the effects of preexercise/postexercise protein/

carbohydrate consumption on muscle building and related

resistance training outcomes.

PRERESISTANCE/POSTRESISTANCE EXERCISEPROTEIN SUPPLEMENTATION

Protein is an essential nutrient that comprises approximately 22%

of muscle tissue, with water contributing most of the remaining

78%. Although it is easy to assume that almost all Americans eat

sufficient protein, about one quarter of 2,600 men and women

aged 65 to 85 years studied in Maryland were consuming in-

adequate amounts of protein (4). The Recommended Dietary

Allowance (RDA) for adults of all ages is 0.36 g of protein per

pound of body weight or about 55 g of protein per day for a

person who weighs 150 lbs. People older than 50 years who

perform resistance exercise need at least 25% more protein than

the RDA level to maintain their muscle mass and 50% more

protein than the RDA level to increase their muscle tissue (4). As

the amount of protein that can be consumed at one time without

exceeding the anabolic maximum is not yet established, it is

recommended that protein intake be distributed throughout the

day (e.g., breakfast, lunch, dinner, and postexercise snack) rather

than at a single protein-rich meal.

Based on numerous study findings, it would seem that the besttime to ingest extra protein is just before or just after a strengthtraining session because doing so significantly enhances muscledevelopment (2,6,7,13,20,21). The muscle-building effects wereperhaps best demonstrated in a study conducted by Paul Cribb,Ph.D., and Alan Hayes, Ph.D., from Victoria University(Australia) in 2006 (5). Seventeen fit young men (mean age,22 years) performed the strength training programs 4 days aweek for a period of 10 weeks. The resistance training consistedof high-intensity workouts using mostly compound exercisesperformed with free weights in a three-phase periodized protocol(70% to 75% 1 RM, 80% to 85% 1 RM, 90% to 95% 1 RM).All of the study participants consumed similar amounts ofsupplemental protein/carbohydrate twice each day on workoutdays only. Half of the subjects took the supplement immediatelybefore and after each strength training session. The other halftook the supplement in the morning and the evening, at least5 hours from the time of the workout. All of the participantswere prescribed 1 g of the supplement for every kilogram ofbodyweight, so a 100-kg (220-lb) male would ingest 100 g ofsupplement twice each training day. The 100 g of supplementcontained 40 g of protein, 43 g of carbohydrate, and 7 g ofcreatine monohydrate.

After 10 weeks of training, the study participants who took theprotein/carbohydrate supplement preworkout/postworkout gainedsignificantly more lean weight than those who ingested theprotein/carbohydrate supplement morning and evening (+2.8 kgvs. 1.5 kg). The preworkout/postworkout supplement group alsodemonstrated significantly greater increases in bench pressstrength (+12.2 kg vs. 9.0 kg) and squat strength (+20.4 kg vs.16.1 kg) than themorning/evening supplement group. In addition,the preworkout/postworkout supplement subjects experiencedsignificantly greater increases in type IIa muscle fiber cross-sectional area, type IIx muscle fiber cross-sectional area, andcontractile protein content than did the morning/evening sup-plement group. Based on their findings, the authors concluded thatsupplement timing represents a simple but effective strategy toenhance the positive physiological adaptations that are associatedwith resistance training. The authors further suggested that thisstrategy should benefit most healthy adults who perform resistanceexercise.

Other investigators (29) decided to test this hypothesis with

previously untrained middle-aged and older adults (52 women

and men aged 39 to 82 years) who completed a 36-week research

program in 1 of 3 study groups. The control group did not

exercise or take supplemental nutrition. The exercise-only group

performed about 25 minutes of strength training (12 standard

resistance machines; 1 set of 8 to 12 repetitions each) and about

25 minutes of aerobic activity (recumbent cycling). The exercise

plus supplement group performed the same exercise program and

TABLE 1: Research-supported Health Benefitsof Resistance Training*Body composition

Increased lean weight (++)

Increased resting energy expenditure (++)

Decreased fat weight (+)

Physical discomfort

Reduced low back pain (+)

Reduced arthritic pain (+)

Diabetes

Increased insulin sensitivity (+)

Improved glucose control (+)

Cardiovascular health

Reduced resting blood pressure (++)

Improved blood lipid profiles (+)

Musculoskeletal health

Increased bone mineral density (++)

Reversed aging factors in skeletal muscle (+)

Mental health

Improved cognitive ability (+)

Enhanced self-esteem (++)

Activities of daily living

Increased functional independence (++)

Enhanced movement control (+)

* Relative strength of resistance training effect: (+) moderate effect; (++)high effect.

VOL. 17/ NO. 2 ACSM’s HEALTH & FITNESS JOURNALA 11


consumed a protein/carbohydrate shake immediately after each

training session. The supplemental shake provided 24 g of protein

and 36 g of carbohydrate. Only the exercise plus supplement

group attained a significant increase in lean weight (50.3Y52.7 kg).

Based on these findings, it would seem that ingesting a protein/

carbohydrate supplement immediately after strength training

sessions enhances muscle development in middle-aged and

older adults.

In addition to the positive results observed in youngmen (5) and

middle-aged and older adults (29), studies have demonstrated that

posttraining protein/carbohydrate supplementation can enhance

the desired effects of resistance exercise in young women (13)

and elderly men (7). According to John Ivy, Ph.D., and Lisa

Ferguson, M.S., from the University of Texas, (12) postexercise

protein/carbohydrate supplementation is an effective means of

restoring muscle glycogen, repairing muscle damage, attenuating

protein degradation, and initiating protein synthesis.

PROTEIN PLUS CARBOHYDRATE OR PROTEIN ALONEMany of the studies on resistance training supplementation have

used a combination of protein and carbohydrate (5Y7,13,29).

However, protein alone has been shown effective for increasing

muscle fiber size (2), and some studies have indicated that

adding carbohydrate to protein does not increase postexercise

muscle protein synthesis (14,24). In contrast, a review by

Jay Hoffman, Ph.D., concluded that ‘‘the combination of

carbohydrate with protein or amino acids in a supplement

may contribute to a more effective protein uptake and enhanced

synthesis rate of muscle protein’’ (11). The authors of another

research review article concluded that ‘‘Carbohydrates play a

limited role in protein synthesis I(but) are vital to replenish

glycogen stores diminished from prolonged or high-intensity

exercise’’ (21).

Researchers from the University of Texas have proposed that

resistance exercise adaptations may be optimized by taking

appropriate posttraining protein/carbohydrate supplementation

(12). Based on their interpretation of the research, they

recommend a supplement that provides 0.5 to 0.6 g of protein

plus 1.0 to 1.2 g of carbohydrate per kilogram of bodyweight.

As an example, they suggest that a person weighing 70 kg

(154 lbs) should ingest a posttraining supplement that contains

35 to 42 g of protein and 70 to 84 g of carbohydrate.

COMMERCIAL SUPPLEMENTS OR FOOD SOURCESMany of the preexercise/postexercise supplement studies have

used commercial products to provide various combinations of

protein and carbohydrate sources. However, other research has

been conducted with readily available food such as whole milk,

fat-free milk, and whole eggs. Research with men (10) and women

(13) has demonstrated greater lean weight gain and greater fat

weight loss with postexercise fat-free milk compared with those

with a carbohydrate supplement. A similar study (31) compared

skim milk with soy protein for promoting net muscle protein

balance after resistance training. The results indicated that milk-

based proteins promote muscle protein accretion better than soy-

based proteins when ingested after resistance exercise. Another

study (6) compared the effects of fat-free milk and whole milk

taken 1 hour after resistance exercise on net muscle protein

synthesis. When the quantities ingested were the same (237 g),

whole milk was more effective than fat-free milk. However,

when the calories ingested were the same (requiring 393 g of fat-

free milk and 237 g of whole milk), there were no significant

differences between fat-free milk and whole milk supple-

mentation. In his research review, the findings on postexercise

milk supplementation led Dr. Hoffman to conclude that ‘‘a food

source such as milk appears to be suitable for ingestion during

recovery from resistance exercise and may be a cheaper and

effective alternative to protein supplements’’ (11).

Another study (16) examined the effects of ingesting different

amounts of whole egg protein on muscle protein synthesis. The

study participants ingested 0, 5, 10, 20, or 40 g of whole egg

protein after lower body strength training sessions. Higher doses

of protein produced correspondingly higher rates of muscle

protein synthesis through the 20-g supplement. The 40-g dose

did not generate more muscle protein synthesis, indicating that


Protein Supplements and Resistance Training


20 g of whole egg protein may represent an optimal amount of

this postexercise supplement.

PROTEIN INTAKE AND PROTEIN TIMINGWith the exception of older adults, most Americans attain

adequate amounts of protein on a daily basis. However, re-

searchers (33) have suggested that the quantity, quality, and

timing of protein consumption are all important factors in muscle

development. Progressive resistance exercise provides the

stimulus for muscle development. However, the tissue micro-

trauma resulting from a resistance training session requires suf-

ficient protein to sustain the muscle-building processes that lead

to increased strength and size (hypertrophy). Basically, muscle

hypertrophy is dependent on a positive protein balance such that

muscle protein synthesis exceeds muscle protein breakdown.

Although resistance exercise increases the rate of muscle protein

synthesis, it also increases the rate of muscle protein breakdown,

resulting in a net negative protein balance for several hours after

the training session (3). Of course, it is beneficial to promote a

net positive protein balance as much of the time as possible. To

experience a net positive protein balance after resistance exercise,

it is necessary to consume supplemental protein in close prox-

imity to the training session (preworkout/postworkout). In their

review article, Chris Poole, M.Sc., and colleagues (21) stated that

‘‘It is necessary for individuals who seek to gain lean muscle

mass to induce a positive protein turnover as often as possible. It

has been confirmed that protein and/or amino acid ingestion is

required to reach a positive protein/nitrogen balance.’’ Based on

the research reviewed, these authors presented four key findings.

First, resistance exercise increases both muscle protein synthesis

and muscle protein breakdown. Second, the increase in muscle

protein breakdown exceeds the rate of muscle protein synthesis.

Third, consumption of dietary protein and/or amino acids after

strength training sessions augments a net positive protein balance

and enhances the potential for muscle hypertrophy over time.

Fourth, ingestion of dietary protein and/or amino acids im-

mediately after resistance training is more effective than post-

poned supplementation for enabling muscle hypertrophy.

Research also has shown that ingesting supplemental protein

before a resistance training session elicits a significantly greater

increase in resting energy expenditure 24 hours after the workout

compared with that after ingesting supplemental carbohydrate (9).

Therefore, it would seem that consuming supplemental protein,

or protein/carbohydrate, in close time proximity to resistance

exercise sessions may provide dual benefits of enhanced muscle

hypertrophy and increased resting energy expenditure. This may

be one reason why some studies have shown both greater muscle

gain and greater fat loss for subjects ingesting supplemental

protein, or protein/carbohydrate, at the time of their resistance

training sessions (10,13,28).

SUMMARYAs reported in a previous issue of ACSM’s Health & Fitness

JournalA (26), research clearly reveals that resistance exercise is

an effective means for rebuilding muscle, recharging meta-

bolism, and reducing fat in previously inactive adults and older

adults. The studies addressed in this article indicate that these

training outcomes may be enhanced by ingesting supplemental

protein, or protein and carbohydrate, near the time of the

exercise session (just before, just after, or both). Based on these

research findings, it would seem that pretraining/posttraining

protein/carbohydrate supplementation can induce significantly

greater increases in lean weight and resting energy expenditure

and significantly greater decreases in fat weight than those after

resistance exercise without supplementation. Although many

studies have incorporated commercial protein/carbohydrate

products, other studies have demonstrated significant body

composition improvement from ingesting milk after the strength

TABLE 2: Recommended Grams ofPretraining/Posttraining Protein and CarbohydrateSupplementation for Selected Body Weights

Body Weight,kg (lbs)

ProteinSupplement, g

CarbohydrateSupplement, g

50 (110) 18Y22 28Y32

60 (132) 22Y26 34Y38

70 (154) 26Y30 40Y44

80 (176) 30Y34 46Y50

90 (198) 34Y38 52Y56

100 (220) 38Y42 58Y62



training sessions. Some experts have recommended that pre-

training/posttraining supplements contain at least 0.5 g of protein

and 1.0 g of carbohydrate per kg of body weight for optimum

results (~35 g of protein and 70 g of carbohydrate for a 70-kg

individual). However, studies have shown excellent responses to

smaller supplement amounts (~24 g of protein and 36 g of

carbohydrate) for subjects averaging 70 kg of body weight.

Other research has demonstrated net muscle protein synthesis

from postexercise servings of milk that contained about 8 g of

protein and 12 g of carbohydrate. The available evidence

indicates that desired resistance training results, such as muscle

development, strength gain, and fat loss, may be enhanced by

consuming supplemental protein/carbohydrate in close time

proximity to the workout session. Based on the research results

reviewed in this article, general guidelines for pretraining/

posttraining protein and carbohydrate supplementation for exer-

cisers of selected body weights are presented in Table 2.

References1. American Heart Association and American College of Sports Medicine.

Physical activity and health: Updated recommendations for adults formthe American College of Sports Medicine and the American HeartAssociation. Circulation. 2007;116:1081Y93.

2. Anderson L, Tufekovic G, Zebis M. The effects of resistance trainingcombined with timed ingestion of protein on muscle fiber size andmuscle strength. Metabolism. 2005;54:151Y6.

3. Biolo G, Maggi SP, Williams BD, Tipton KD, Wolfe RR. Increased ratesof muscle protein turnover and amino acid transport after resistanceexercise in humans. Am J Physiol. 1995;268:E514Y20.

4. Campbell WW, Crim MC, Young VR, Evans WJ. Increased energyrequirements and changes in body composition with resistance trainingin older adults. Am J Clin Nutr. 1994;60:167Y75.

5. Cribb P, Hayes A. Effect of supplement timing on skeletal musclehypertrophy. Med Sci Sports Exerc. 2006;38(11):1918Y25.

6. Elliot T, Cree M, Sanford A, et al. Milk ingestion stimulates net muscleprotein synthesis following resistance exercise. Med Sci Sports Exerc.2006;38(4):667Y74.

7. Esmarck B, Anderson J, Olsen S, et al. Timing of post-exercise proteinintake is important for muscle hypertrophy with resistance training inelderly humans. J Physiol. 2001;535:301Y11.

8. Flack KD, Davy KP, Huber MAW, et al. Aging, resistance training, anddiabetes prevention. J Aging Res. 2011;2011:127315.

9. Hackney KJ, Bruenger AJ, Lemmer JT. Timing protein intake increasesenergy expenditure 24 h after resistance training. Med Sci Sports Exerc.2010;42(5):998Y1003.

10. Hartman JW, Tang JE, Wilkinson SB, et al. Consumption of fat-free fluidmilk after resistance exercise promotes greater lean mass accretion thandoes consumption of soy or carbohydrate in young, novice, maleweightlifters. Am J Clin Nutr. 2007;86(2):373Y81.

11. Hoffman J. Protein intake: Effect of timing. Strength Cond J. 2007;29(6):26Y34.

12. Ivy J, Ferguson L. Optimizing resistance exercise adaptations through thetiming of post-exercise carbohydrate-protein supplementation. StrengthCond J. 2010;32(1):30Y6.

13. Josse A, Tang J, Tarnopolsky M, Phillips S. Body composition andstrength changes in women with milk and resistance exercise. Med SciSports Exerc. 2010;42(6):1122Y30.

14. Koopman R, Beelen M, Stellingwerff T, et al. Coingestion ofcarbohydrate with protein does not further augment postexercise muscleprotein synthesis. Am J Physiol Endocrinol Metab. 2007;293(3):E833Y42.

15. Marcell TJ. Sarcopenia: Causes, consequences, and preventions.J Gerontol A Biol Sci Med Sci. 2003;58:M911Y6.

16. Moore DR, Robinson MJ, Fry JL, et al. Ingested protein dose responseof muscle and albumin protein synthesis after resistance exercise inyoung men. Am J Clin Nutr. 2009;89:161Y8.

17. Nelson ME, Fiatarone M, Morganti C, et al. Effects of high-intensitystrength training on multiple risk factors for osteoporosis fractures.JAMA. 1994;272:1909Y14.

18. Phillips SM. Resistance exercise good for more than just grandma andgrandpa’s muscles. Appl Physiol Nutr Metab. 2007;32:1198Y1205.

19. Phillips SM, Winett RA. Uncomplicated resistance training andhealth-related outcomes: Evidence for a public health mandate. CurrSports Med Rep. 2010;9:208Y13.

20. Phillips SM, Hartman J, Wilkinson S. Dietary protein to supportanabolism with resistance exercise in young men. J Am Coll Nutr.2005;24(2):134SY9S.

21. Poole C, Wilborn C, Taylor L, Kerksick C. The role of post-exercisenutrient administration on muscle protein synthesis and glycogensyntheses. J Sports Sci Med. 2010;9:354Y63.

22. Pratley R, Nicklas B, Rubin M, et al. Strength training increases restingmetabolic rate and norepinephrine levels in healthy 50- to 65-year-oldmen. J Appl Physiol. 1994;76:133Y7.

23. Schardt D. Saving muscle: How to stay strong and healthy as you age.Nutr Action Health Lett. 2007;34(3):3Y8.

24. Staples AW, Burd NA, West DW, et al. Carbohydrate does not augmentexercise-induced protein accretion versus protein alone. Med SciSports Exerc. 2011;43(7):1154Y61.

25. Troiano R, Berrigan D, Dodd K, et al. Physical activity in the United Statesmeasured by accelerometer. Med Sci Sports Exerc. 2008;40(1):181Y8.

26. Westcott WL. ACSM strength training guidelines: Role in bodycomposition and health enhancement. ACSM’s Health Fitness J. 2009;13(4):14Y22.

27. Westcott WL. Resistance training is medicine: Effects of strength trainingon health. Curr Sports Med Rep. 2012;11(4):209Y16.

28. Westcott WL, Martin W, La Rosa Loud R, Stoddard S. Proteinsupplementation and body composition changes. Fitness Manage. 2008;24(5):50Y3.

29. Westcott WL, Varghese J, DiNubile N, et al. Exercise and nutrition moreeffective than exercise alone for increasing lean weight and reducingresting blood pressure. J Exerc Physiol Online. 2011;14(4):120Y33.

30. Westcott WL, Winett RA, Annessi JJ, et al. Prescribing physical activity:Applying the ACSM protocols for exercise type, intensity, and durationacross 3 training frequencies. Phys Sports Med. 2009;2:51Y8

31. Wilkinson SB, Tarnopolsky MA, Macdonald MJ, Macdonald JR,Armstrong D, Phillips SM. Consumption of fluid skim milk promotesgreater muscle protein accretion after resistance exercise than doesconsumption of isonitrogenous and isoenergetic soy-protein beverage.Am J Clin Nutr. 2007;85(4):1031Y40.

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Disclosure: The authors declare no conflict of interest and do

not have any financial disclosures.


Protein Supplements and Resistance Training


Wayne L. Westcott, Ph.D., CSCS, directs the

exercise science programs and the fitness

research programs at Quincy College in

Quincy, Massachusetts. His research interests

include the variables, acute responses, and

chronic adaptations associated with re-

sistance exercise. He writes the Health &

Fitness Column for ACSM’s Certified News.

Rita La Rosa Loud, B.S., teaches exercise

science and coordinates fitness research

programs at Quincy College in Quincy,

Massachusetts. She is an active member of

the New England Chapter of the American

College of Sports Medicine.

CONDENSED VERSION AND BOTTOM LINE

Inactive adults lose muscle mass at the rate of 3% to 8%per decade, resulting in reduced resting metabolism andincreased fat accumulation. Progressive resistance exerciseprovides the stimulus for strength development, butmuscle hypertrophy requires a net positive protein balance.An effective means for attaining posttraining net positiveprotein balance is supplemental protein (~10Y40 g) con-sumed in close time proximity (e1 hour) of the resistanceworkout. Several studies have shown that pretraining/posttraining protein/carbohydrate ingestion enhancesmuscle development, strength gain, and fat loss in menand women of all ages.



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