HMB: What is it and how can it benefit me in my fitness goals?

HMB

What is it and how can it benefit me in my fitness goals?

HMB (beta-hydroxyl-beta-methylbutyrate) is a metabolite of the branched chain amino acid (BCAA) leucine. BCAAs have been studied for three decades in regards to their ability to increase and maintain lean body mass, improve strength, and decrease body fat and skeletal muscle soreness. The effects of leucine on preventing muscle breakdown are greatest at 10-20 times to concentration required to stimulate protein synthesis. Thus these effects are mostly if not entirely due to HMB.

 

 

Why do you need to supplement with HMB?

 

Only about 2-5% of leucine is converted to HMB as it is a less favored metabolic pathway. In addition, quality protein sources only consist of approximately 10% leucine content. The effective dose of HMB used in most studies is 3 grams daily (divided in 3 equal doses). This would require one to consume 60 grams of leucine daily or 600 grams of quality protein. Even if this was possible to do on a consistent basis, conversion of protein to leucine and leucine to HMB may not remain steady with increased protein consumption.

 

 

What results can I expect?  

• Faster recovery time
• Decreased muscle breakdown
• Particularly with calorie restricted diets
• Decreased markers of muscle breakdown
• Increased strength
• 15-20% average increase
• 9 lb and 6 lb greater increases on bench and squat with HMB supplementation   
• Enhanced aerobic performance
• Increases time to reach peak oxygen consumption (VO2 peak) by 8%
• Improved fat loss in experienced athletes
• Theorized to increase lipid oxidation
• Studies have shown up to 8% decreased in fat mass
• Strength loss of 5% vs 11% with HMB supplementation 
• Increased muscle hypertrophy via stimulation of mTOR and/or GH/IGF-1 axis      

 

What is the effective dose for HMB?

• 3 grams daily (usually divided in 2-3 equivalent doses)
• Studies show it may take up to 2-3 weeks until maximal effects are achieved
• Dose timing is shown to be most effective with one dose taken 60 minutes prior to exercise. 

 

For more information about the ISSN official stand on HMB click here:

http://www.jissn.com/content/pdf/1550-2783-10-6.pdf