The purpose of this review was to determine whether past research provides conclusive evidence about the effects
of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two
essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the
consumption of 1.2-2.0 g protein.kg -1 of body weight, and ≥44-50 kcal.kg-1 of body weight. Researchers have
tested the effects of timing of protein supplement ingestion on various physical changes in weightlifters. In general,
protein supplementation pre- and post-workout increases physical performance, training session recovery, lean
body mass, muscle hypertrophy, and strength. Specific gains, differ however based on protein type and amounts.
Studies on timing of consumption of milk have indicated that fat-free milk post-workout was effective in promoting
increases in lean body mass, strength, muscle hypertrophy and decreases in body fat. The leucine content of a
protein source has an impact on protein synthesis, and affects muscle hypertrophy. Consumption of 3–4 g of
leucine is needed to promote maximum protein synthesis. An ideal supplement following resistance exercise
should contain whey protein that provides at least 3 g of leucine per serving. A combination of a fast-acting
carbohydrate source such as maltodextrin or glucose should be consumed with the protein source, as leucine
cannot modulate protein synthesis as effectively without the presence of insulin. Such a supplement post-workout
would be most effective in increasing muscle protein synthesis, resulting in greater muscle hypertrophy and
strength. In contrast, the consumption of essential amino acids and dextrose appears to be most effective at
evoking protein synthesis prior to rather than following resistance exercise. To further enhance muscle hypertrophy
and strength, a resistance weight- training program of at least 10–12 weeks with compound movements for both
upper and lower body exercises should be followed.