Written by Greg Arnold, DC, CSCS. Supplementation with HMB significantly increased lung capacity and endurance, and decreased body fat in participating athletes compared to the control group.  

HMB, also known as beta-hydroxy-beta-methylbutyric acid, is a breakdown product of the amino acid leucine. It has been a subject of interest regarding sports performance for nearly 20 years (1, 2), specifically for its ability to prevent muscle breakdown after strenuous exercise (3, 4). In addition, HMB has been found to help prevent muscle breakdown and weight loss in people with end-stage cancer (called “cancer cachexia”) (5).

Now a new study (6) suggests HMB may benefit endurance athletes, especially rowers. In the study, 16 elite male rowers (at least 5 years of training experience) between the ages of 17 and 22 were given either 3 grams of HMB (1 gram taken 3 times per day) or placebo for 12 weeks. The subjects underwent a 10-day “washout period” and then switched supplements for the next 12 weeks. The rowers continued their usual training schedules (averaging 17 hours per week) and completed an exercise session before and after the supplementation period to assess lung function and power output.

The researchers found that 12 weeks of HMB increased their lung capacity (called VO2 max) by 4% (67.3 to 70.0 milliliters per minute per kilogram of bodyweight) compared to a 1.5% decrease in the placebo group (68.8 to 67.8 mL/min/kg, p < 0.001). In addition, overall lung health was better in the HMB group as the time it took for their lungs to reach maximum VO2 increased by 9.6% (called “ventilatory threshold”, 12.5 to 13.7 minutes) compared to a 1.6% decrease in the placebo group (12.8 to 12.6 minutes, p = 0.012).

Those in the HMP group also saw a 12.9% increase in power output once reaching ventilatory threshold (3.24 to 3.66 Watts per kilogram of bodyweight) compared to a 1.8% decrease in the placebo group (3.42 to 3.36 W/kg, p = 0.002). Finally, those in the HMB group experienced a 7.3% decrease in total fat (30.36 to 28.16 pounds) compared to a 6% increase in the placebo group (29.26 to 31.02 pounds, p = 0.03).

When suggesting how HMB elicits these benefits, the researchers pointed to studies showing HMB to increase levels of a hormone called insulin-like growth factor 1 (7) as well as increase activity of a protein called mTOR kinase (8). For the researchers, “HMB intake in endurance training has an advantageous effect on the increase in aerobic capacity and the reduction of fat mass. It may also stimulate an increase in peak anaerobic power.”

Source: Durkalec-Michalski, Krzysztof, and Jan Jeszka. “The efficacy of a β-hydroxy-β-methylbutyrate supplementation on physical capacity, body composition and biochemical markers in elite rowers: a randomised, double-blind, placebo-controlled crossover study.” Journal of the International Society of Sports Nutrition 12, no. 1 (2015): 31. 

©  Durkalec-Michalski and Jeszka. 2015 Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)

Click here to read the full text study.

Posted September 3, 2015.

Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY.  You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com.

References:

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  2. Portal S, Eliakim A, Nemet D, Halevy O, Zadik Z. The effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled study. Eur J Appl Physiol. 2011;111:2261–9
  3. Zanchi NE, Gerlinger-Romero F, Guimarães-Ferreira L, de Siqueira Filho MA, Felitti V, Lira FS, et al. HMB supplementation: clinical and athletic performance-related effects and mechanisms of action. Amino Acids. 2011;40:1015–25.
  4. Pimentel GD, Rosa JC, Lira FS, Zanchi NE, Ropelle ER, Oyama LM, et al. β-Hydroxy-β-methylbutyrate (HMβ) supplementation stimulates skeletal muscle hypertrophy in rats via the mTOR pathway. Nutr Metab (Lond). 2011;8(1):11. doi:10.1186/1743-7075-8-11
  5. Aversa Z, Bonetto A, Costelli P, Minero VG, Penna F, Baccino FM, et al. β-hydroxy-β-methylbutyrate (HMB) attenuates muscle and body weight loss in experimental cancer cachexia. Int J Oncol. 2011;38:713–20.
  6. Durkalec-Michalski K. The efficacy of a β-hydroxy-β methylbutyrate supplementation on physical capacity, body composition and biochemical markers in elite rowers: a randomised, double-blind, placebocontrolled crossover study. J Int Soc Sports Nutr 2015 Jul 30;12:31. doi: 10.1186/s12970-015-0092-9. eCollection 2015
  7. Kornasio R, Riederer I, Butler-Browne G, Mouly V, Uni Z, Halevy O. Beta-hydroxy-beta-methylbutyrate (HMB) stimulates myogenic cell proliferation, differentiation and survival via the MAPK/ERK and PI3K/Akt pathways. Biochim Biophys Acta. 2009;1793:755–63
  8. Eley HL, Russell ST, Tisdale MJ. Attenuation of depression of muscle protein synthesis induced by lipopolysaccharide, tumor necrosis factor, and angiotensin IIby beta-hydroxy-beta-methylbutyrate. Am J Physiol Endocrinol Metab. 2008;295:E1409–16.