By Steven J. Fleck, Ph.D.
Q: I take a protein supplement right after my weight-training sessions. Is this one of the better times to take a protein supplement to increase lean body mass?
There’s discussion concerning whether taking a protein supplement immediately prior to, or right after, a weight-training session is best to increase protein synthesis. Increased protein synthesis is important because over the long term, it will result in an increase in lean body mass aka muscle. It’s clear that supplementation either right before or right after a weight-training session can increase muscle protein synthesis. Sports science studies involving ingestion of protein immediately prior to (Tipton et al., 2001) or within three hours after a weight-training session (Borsheim et al., 2002; Gibala, 2000; Rasmussen et al., 2000) show increases in muscle protein synthesis. This increase appears to be related to a more favorable anabolic environment as a result of changes in hormonal concentrations, such as an increase in blood insulin or growth hormone (Hulmi et al., 2005; Volek, 2004).
Some evidence indicates that protein supplementation immediately prior to exercise increases protein synthesis to a greater extent compared to supplementation at various times after exercise (Tipton et al., 2001). The increased protein synthesis with supplementation prior to exercise may be related to a boost in blood flow during exercise, which increases amino acid availability to the muscle being trained during the session (Volek, 2004; Wolfe, 2001). With an increase in blood flow, greater delivery of the amino acids from the supplement takes place. With greater delivery of amino acids to the muscle being trained, there’s a possibility that more of these amino acids will be used in the protein synthesis of muscle. An alternative explanation is that protein synthesis is stimulated by exercise due to both an increase in blood flow and an increased hormonal response when a supplement is consumed before exercise. As a result, the stimulation of protein synthesis continues – not just during the exercise session but after the session as well. When a protein supplement is taken immediately after a training session, there’s little effect of increased blood flow on muscle protein synthesis, and the increase in muscle protein synthesis is more dependent on the hormonal response to the training session. However, one bottom-line aspect of this evidence is that supplementation either before or after a weight-training session will increase muscle protein synthesis.
Another sports science study indicates that supplementation after a weight-training session increases the androgen receptor content of muscle (Kraemer et al., 2006). Although we spend a great deal of time talking about the hormonal response (such as an increase in testosterone or growth hormone in the blood) because of supplementation and weight training, we tend to forget that hormonal response is only part of what needs to happen to increase protein synthesis. One important aspect of this process is that the hormone needs a receptor within the muscle with which to bind in order to trigger increased protein synthesis. This study shows that supplementation immediately after a weight-training session results in increased androgen receptor content of muscle. This widens the possibility that a hormone circulating in the blood will actually bind to a muscle’s receptor, increasing the chance that the hormone will cause a rise in protein synthesis, because if the hormone doesn’t bind to a receptor, nothing will happen. There was no comparison to supplementation prior to a weight-training session in this study, so we don’t know if supplementation prior to the session would also increase androgen receptor content in muscle, or if there’s any difference in androgen receptor content when a supplement is taken immediately before or immediately after training.
Protein supplementation immediately prior to, or right after, a weight-training session increases protein synthesis. An increase in protein synthesis over long periods of training can result in an increase in muscle. Therefore, taking a protein supplement right after your weight-training session should be a valuable tool to increase lean body mass over time.
1. Borsheim E, Tipton KD, Wolf SE and Wolfe RR. Essential amino acids and protein recovery from resistance exercise. Am J Physiol Endocrinol Metab, 283: E684-E687, 2002.
2. Gibala MJ. Nutritional supplementation and resistance exercise: What is the evidence for enhanced skeletal muscle hypertrophy? Can J Appl Physiol, 25: 524-535, 2000.
3. Hulmi JJ, Volek JS, Selanne H and Mero AA. Protein ingestion prior to strength exercise affects blood hormones and a metabolism. Med Sci Sports Exerc, 37: 1990-1997, 2005.
4. Kraemer WJ, et al. Androgenic responses to resistance exercise: effects of feeding and L-carnitine. Med Sci Sports Exerc, 38: 1288-1296, 2006.
5. Rasmussen BB, Tipton KD, Miller SL, Wolfe SE and Wolfe RR. An oral amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J Appl Physiol, 88: 386-392, 2000.
6. Tipton K, Rasmussen BB, Miller SL, Wolfe SL, Wolfe SE, Owens-Stovall SK, Petrini BE and Wolfe RR. Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am J Physiol, 281: E197-E206, 2001.
7. Volek JS. Influence of nutrition on responses to resistance training. Med Sci Sports Exerc, 36: 689-696, 2004.
8. Wolfe RR. Effects of amino acid intake on anabolic processes. Can J Appl Physiol, 26: S220-S 227, 2001.