Take Essential Amino Acids (EAAs) and be sure to get your leucine after resistance training for the greatest muscle protein synthesis and anabolic response. New research shows that EAAs and leucine equalize the anabolic response after training for old and young individuals alike. This is critically important for anyone over 35 because we know that there are significant age-related differences in anabolic signaling and muscle building from resistance training. Older individuals do not have the same magnitude of anabolic response as younger individuals to the muscle building stimulus of training—both acute and chronic training have shown significantly greater increases in muscle protein synthesis in young individuals in the fasted state. Additionally, it is well known that aging is associated with a natural loss of muscle mass, particularly if no resistance training is done.
The good news is that regular high-quality protein meals in addition to EAA and leucine supplementation with training can counter the aging-related muscle loss and equalize the divide between young and old. Of course, leucine is one the EAAs, but I stress its importance here because leucine-enriched EAAs are proven to be the only supplement to equalize the anabolic response between young and old trainees. Research shows that young individuals experienced an equal increase in muscle protein synthesis after training with the ingestion of both EAAs that contained only 25 percent leucine and leucine-enriched EAAs (41 percent leucine), while older subjects only experienced a significant increase in muscle protein synthesis from training after ingesting the leucine-enriched EAAs.
There is a dose-dependent response to EAAs for both older and younger trainees, meaning that more is better. Additionally, for older people when eating intact protein in the form of meat such as lean beef, a plateau exists such that moderately sized regular meals (in the range of 4 oz.) are better than one large meal (12 oz.) to stimulate protein synthesis. Essentially, this really means that older adults retain the ability to respond to amino acid and protein ingestion, highlighting the crucial importance of combining EAA and leucine supplementation with regular high protein meals and training. You’re leaving muscle on the table if you’re not doing this.
The reason EAA supplementation results in maximal muscle protein synthesis is that is increases the intracellular availability of amino acids and activates the mTORC1 signaling pathway that is essential for muscle building. Aging is associated with an impaired ability to activate mTORC1 signaling and protein synthesis. Are you getting this? In older individuals, this pathway is not activated to the same extent as younger trainees after training unless leucine-enriched EAAs are ingested!
Remember, more is better when it comes to EAAs, and make sure it is leucine-enriched. Moderate sized high protein meals throughout the day with resistance training are the best bet. This supplementation strategy will equalize the age-related discrepancy in protein synthesis and help you get the best anabolic response. To learn more, please read The Benefits of BCAAs.
Walker, D., Dickinson, J., et al. Exercise, Amino Acids, and Aging in the Control of Human Muscle Protein Synthesis. Medicine and Science in Sports and Exercise. May 2011. Published Ahead of Print.