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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
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.
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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.
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Disclosure: The authors declare no conflict of interest and do
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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