The Truth about HMB (Hydroxymethyl butyrate)
The exponential growth of the sports supplement industry is due to the increase in research that emphasises their potential benefits on performance, recovery, and general health.
HMB, also known as Hydroxymethyl butyrate or ꞵ-hydroxy ꞵ-methyl butyrate, is an active metabolite of the amino acid leucine, the most potent activator of protein synthesis out of all the amino acids. Despite the increasing popularity of HMB, the numerous health benefits are frequently overlooked. Regarding muscle protein synthesis, the role of HMB and leucine are reasonably similar, with leucine potentially being more potent on a gram basis (and cheaper). However, when comparing their role in preventing muscle loss, HMB is said to be 20-fold more potent than leucine and equivalent to 20-60g of leucine supplementation.
This blog aims to examine the mechanisms of HMB and emphasise how supplementation can improve your overall health and performance.
Why supplement with HMB?
- Support muscle growth and strength: HMB may improve muscle growth and strength by increasing the activity of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis (Kaczka et al., 2019)
- Enhance exercise performance: HMB may also improve exercise performance by reducing muscle fatigue and increasing endurance. HMB stimulates the mammalian target of rapamycin (mTOR), which regulates cell growth and differentiation (Delgoffe et al., 2011)
- Prevent muscle loss: HMB may prevent skeletal muscle atrophy and reduce protein degradation (protein breakdown) by inhibiting the activity of the ubiquitin-proteasome system and caspases. These two pathways break down proteins (proteolysis) under catabolic states such as fasting, immobilisation, disuse, aging, and disease (Examine.com, 2022)
The optimal dosage:
The recommended dosage for HMB varies depending on your body composition and training goals; however, 3g/day is considered safe and generally recommended for most populations.
- Recommended dosage: 1-3g/day, divided into smaller doses and consumed at different times throughout the day (e.g. Consume 1g of HMB three times a day)
- Athletes wanting to reduce muscle soreness and damage consume 3g of HMB 30-45 minutes before training.
Note: These are general guidelines, and the ideal dosage of HMB for an individual may vary depending on factors such as age, weight, sex, and individual response to the supplement.
Supplementing with HMB at a dose of 3 grams per day appears well tolerated and is not associated with any adverse side effects. Higher doses may be equally safe, but very few studies have investigated amounts of HMB above 3 grams per day. HMB also appears safe when taken with other amino acids (i.e., arginine, lysine, and glutamine) or supplemented alongside creatine. It is important to consult with a healthcare professional before taking HMB or any other dietary supplement, particularly if you have a medical condition or are taking medication.
HMB is considered a valuable dietary supplement that plays an anti-catabolic role in muscle tissue and may improve muscle growth, strength, and recovery. However, more research is needed to understand its potential benefits, particularly in athletic populations.
If you're looking to maximise on the benefits of HMB, plus taking your recovery game to the next level, we recommend using UM Sports Resurrect.
Ciechanover, A., & Schwartz, A. L. (1998). The Ubiquitin-proteasome pathway: The complexity and myriad functions of proteins death. Proceedings of the National Academy of Sciences, 95(6), 2727–2730. https://doi.org/10.1073/pnas.95.6.2727
Delgoffe, G. M., Pollizzi, K. N., Waickman, A. T., Heikamp, E., Meyers, D. J., Horton, M. R., Xiao, B., Worley, P. F., & Powell, J. D. (2011). The kinase mTOR regulates the differentiation of helper T cells through the selective activation of signaling by mtorc1 and mtorc2. Nature Immunology, 12(4), 295–303. https://doi.org/10.1038/ni.2005
Examine.com. (2022, November 2). HMB health benefits, dosage, safety, side-effects, and more: Supplements. Examine. Retrieved February 15, 2023, from https://examine.com/supplements/hmb/
Gerlinger-Romero, F., Guimarães-Ferreira, L., Yonamine, C. Y., Salgueiro, R. B., & Nunes, M. T. (2017). Effects of beta-hydroxy-beta-methylbutyrate (HMB) on the expression of ubiquitin ligases, protein synthesis pathways and contractile function in extensor digitorum longus (EDL) of Fed and fasting rats. The Journal of Physiological Sciences, 68(2), 165–174. https://doi.org/10.1007/s12576-016-0520-x
Kaczka, P., Michalczyk, M. M., Jastrząb, R., Gawelczyk, M., & Kubicka, K. (2019). Mechanism of action and the effect of beta-hydroxy-beta-methylbutyrate (HMB) supplementation on different types of physical performance - A systematic review. Journal of Human Kinetics, 68(1), 211–222. https://doi.org/10.2478/hukin-2019-0070
Teigen Faux, Exercise Physiologist (Honours)
Arianna Fthinoyiannis, Nutrition Science
Stephen Brumwell, Nutritionist (ANTA #40048) for Scientific Accuracy