From the Guidelines
HMB, or beta-hydroxy beta-methylbutyrate, is a supplement that may help with muscle recovery and growth, particularly in reducing muscle protein breakdown and potentially enhancing protein synthesis, and I recommend taking 3 grams of HMB daily, divided into three 1-gram doses with meals, as this dosage has been shown to be effective in research studies, such as the one published in 2020 1.
Key Points
- HMB works by reducing muscle protein breakdown and potentially enhancing protein synthesis, particularly beneficial during periods of intense training or caloric restriction.
- The recommended dosage of 3 grams of HMB daily has been shown to be effective in reducing muscle loss and increasing muscle mass gain during periods of immobilization, such as bedrest 1.
- HMB is generally considered safe with minimal side effects, though it is essential to consult with a healthcare provider before starting any supplement, especially if you have existing health conditions or take medications.
- The evidence for HMB's effectiveness in cancer patients is mixed, with some studies showing promise, but others, such as the larger RCT in 472 cachectic cancer patients, failing to demonstrate statistically significant differences due to compliance issues 1.
Considerations
- When considering HMB supplementation, it is crucial to weigh the potential benefits against the potential risks and to consult with a healthcare provider, especially in cancer patients or those with underlying health conditions.
- The quality of the evidence for HMB's effectiveness varies, and more research is needed to fully understand its effects, particularly in specific populations, such as older adults or those with cancer cachexia.
- Other nutritional interventions, such as increasing protein intake to exceed 1 g/kg body weight/day, administering essential amino acid mixtures, or combining these with carbohydrate or leucine, valine, and isoleucine, may also be beneficial in reducing muscle wasting during bedrest or surgery 1.
From the Research
Significance of Beta-Hydroxy Beta-Methylbutyrate (HMB)
- HMB is a metabolite of the branched-chain amino acid leucine, used by athletes and bodybuilders to increase strength, muscle mass, and exercise performance 2.
- The supplement has been shown to be effective in preventing exercise-related muscle damage in healthy trained and untrained individuals, as well as muscle loss during chronic diseases 2, 3.
- HMB has been demonstrated to increase lean body mass and functionality in elderly, sedentary populations, and may result in greater declines in fat mass when ingested in conjunction with a structured exercise program 3.
Mechanisms of Action
- The ergogenic effects of HMB supplementation are related to the enhancement of sarcolemma integrity, inhibition of protein degradation, decreased cell apoptosis, increased protein synthesis, and stimulation of the growth hormone/insulin-like growth factor-1 axis 4.
- HMB's mechanisms of action include an inhibition and increase of proteolysis and protein synthesis, respectively, which can lead to increased muscle mass and strength 3, 5.
Effects on Physical Performance
- HMB supplementation has been shown to have positive effects on specific aerobic capacity variables in endurance and martial arts athletes, as well as changes in strength, body fat, and muscle mass in resistance-trained athletes 4, 6.
- The supplement may also enhance muscle hypertrophy, strength, and power in trained individuals, particularly when consumed in close proximity to workouts and for a period of 2 weeks prior to an exercise bout 3, 6.
Safety and Dosage
- The usual dose of 3 g/day of HMB may be routinely recommended to maintain or improve muscle mass and function in health and disease, with a safety profile that is unequivocal 2.
- Chronic consumption of HMB has been demonstrated to be safe in both young and old populations, with no reports of adverse effects 3, 5.