From the Guidelines
Effects of Beta-Hydroxy Beta-Methylbutyrate (HMB) Supplementation
HMB supplementation is effective in reducing muscle damage and improving recovery after intense exercise, with a recommended dose of 1-2 grams per day 1.
Key Points
- The usual dose of HMB is 3 g/day, which has been claimed to be an anti-catabolic agent that minimizes protein breakdown 1.
- HMB supplementation has been shown to be effective in reducing muscle loss and improving muscle mass gain during bed rest and rehabilitation phases 1.
- A study found that HMB supplementation resulted in a significant reduction in muscle loss and increase in muscle mass gain during an 8-week rehabilitation phase 1.
- HMB may also be beneficial in improving handgrip strength and increasing body weight in patients with chronic obstructive pulmonary disease (COPD) 1.
Clinical Applications
- HMB supplementation may be useful in cancer patients to minimize muscle loss and improve recovery 1.
- HMB may also be beneficial in critically ill patients to improve muscle mass and strength, although more research is needed to confirm its effectiveness in this population 1.
Dosage and Administration
- A typical loading dose of 2 grams per day for the first 2-3 days may be followed by a maintenance dose of 1 gram per day 1.
- HMB supplementation should be taken in divided doses, 30-60 minutes before exercise and immediately after exercise, for a duration of 4-12 weeks 1.
From the Research
Effects of HMB Supplementation on Muscle Damage and Recovery
- HMB supplementation may help reduce muscle damage and promote muscle recovery, which can promote muscle growth/repair 2
- HMB consumption in close proximity to an exercise bout may be beneficial to increase muscle protein synthesis and attenuate the inflammatory response 2
- Studies have shown that HMB supplementation can reduce muscle damage following eccentric contractions, with benefits seen after 2-4 weeks of supplementation 3, 4
- However, not all studies have found a significant effect of HMB supplementation on muscle damage, particularly with short-term supplementation 5
Effects of HMB Supplementation on Strength and Power
- HMB supplementation may improve strength and power in untrained individuals, but its performance benefits in trained athletes are mixed and increase with an increase in study duration (>6 weeks) 2
- A meta-analysis found that HMB supplementation during resistance training resulted in small but clear overall and leg strength gains in previously untrained men, but effects in trained lifters were trivial 6
- Low-dose HMB supplementation has been shown to alleviate muscle strength loss and limited joint flexibility following eccentric contractions 4
Effects of HMB Supplementation on Body Composition
- Daily HMB supplementation in combination with exercise training may improve body composition through increasing lean mass and/or decreasing fat mass, with benefits seen in participants across age, sex, and training status 2
- However, a meta-analysis found that the effects of HMB supplementation on body composition were trivial 6