We have no idea whether this study from India is relevant to strength athletes with a high protein intake, but we thought we’d bring it to your attention. You never know. According to the article that nutritionists at St John’s Research Institute in India published a few years ago in Clinical Nutrition, supplementation with the amino acid lysine boosts muscle strength.
Lysine is an essential amino acid. Lysine is the amino acid most quickly compromised in bodybuilders who are vegans. It’s not only found in meat, but also in soya and other beans. An average adult needs about 40 mg lysine per kg bodyweight daily, but pregnant women or elderly people needing more protein require more lysine.
We found the table below on veganhealth.org
Study
The researchers wanted to know how important lysine is for the muscles, so they performed an eight-week human study.
They did an experiment on forty men. Half of them were not well fed, but did consume 40 mg lysine per kg bodyweight. The other half of the men were well fed and consumed 55 mg lysine per kg bodyweight.
The researchers gave half of the men in each group extra lysine for the eight weeks that the experiment lasted. That gave them a daily intake of about 80 mg lysine per kg bodyweight. For a well-fed man weighing 80 kg that would mean about 2 g lysine per day.
Results
The men’s muscles did not grow as a result of the lysine supplementation, but the muscle strength of the well-fed men increased by 7.5 percent. The researchers used a hand grip dynamometer to measure the men’s strength.
The increase in strength in the men who were not well fed was not statistically significant.
Mechanism
The researchers were not able to elucidate how lysine supplementation boosts muscle strength, but in any case found no clear effects on muscle mass or on insulin metabolism.
The effect of a controlled 8-week metabolic ward based lysine supplementation on muscle function, insulin sensitivity and leucine kinetics in young men
Summary
Background & aims
The 2007 FAO/WHO/UNU lysine requirement is 30?mgkg?1d?1. Developing country populations may be at risk of lysine deficiency, with effects on muscle and its function. The effect of an 8?wk lysine supplementation diet on muscle mass and function was assessed.
Methods
Healthy, under and well-nourished men were studied before and after 8?wk, during which low (n=20) and high (n=20) lysine diets were consumed. The low lysine diets (?25 and ?40?mgkg?1d?1 for under and well-nourished respectively) were based on the subjects’ habitual lysine intake, while the high lysine diet supplied 80?mgkg?1d?1. Anthropometry, muscle function, insulin sensitivity (IS) and leucine kinetics were measured before and after the experimental period.
Results
The high lysine diet had a small positive effect (about +7.5%) on muscle strength, but no effect on other parameters. Over the 8?wk period in the whole group, the change in muscle strength correlated with the change in muscle mass (r=0.5, P=0.001), while the change in muscle mass correlated with the change in IS (r=0.3, P=0.04), but there were no intake specific differences.
Conclusion
Over an 8?wk controlled feeding period, an intake of 80?mglysinekg?1d?1 had a small positive effect on muscle strength, but no other effects.
Source: http://www.clinicalnutritionjournal.com/article/S0261-5614(12)00069-6/abstract
