HMB. Exactly what is it, and what is it not?
In the world of bodybuilding, β-hydroxy-β-methylbutyrate (HMB) is marketed as a safe and effective way to improve body composition, enhance recovery, and increase strength. HMB is widely recognized as a safe supplement and is even permitted by the International Olympic Committee (IOC). This means that HMB is a legal supplement and is in compliance with anti-doping regulations. Despite being around since the 1990s, HMB has remained relatively under the radar. This supplement is typically found in protein supplements or as a standalone product and claims to reduce body fat and increase strength. With such alluring claims, some might think that HMB is the ultimate solution. Let’s take a closer look at HMB, its benefits, and whether research supports its claims.
HMB is a chemical that the body can produce by breaking down leucine, an essential amino acid. Leucine triggers the activation of the mTOR pathway in the body, which is responsible for muscle tissue adaptations. It has been suggested that converting leucine to HMB can promote muscle development while reducing muscle breakdown. Foods that are high in leucine include milk, yogurt, beef, poultry, and chicken. However, even when consuming leucine-rich meals, only a small amount of around 5% is converted to HMB. As a result, supplementation is necessary to increase HMB levels.
HMB is a well-researched chemical, and findings related to exercise performance and muscle health are somewhat inconsistent. In one study, 12 weeks of HMB supplementation led to an increase in muscle mass and improved physical fitness markers in combat athletes. However, water polo athletes did not experience significant gains in strength or performance after four weeks of supplementation. According to the International Society of Sports Nutrition, long-term supplementation (over six weeks) can provide minor benefits to trained athletes.
In people who regularly exercise, HMB did not consistently improve muscle protein breakdown or muscle repair. On the other hand, untrained individuals tend to experience a reduction in muscle breakdown, indicating that HMB supplementation is not exclusive to bodybuilders and fitness enthusiasts. In one trial, HMB helped preserve muscle mass in older people with limited mobility compared to a placebo. Another study found that taking 3-4g of HMB daily prevented muscle breakdown in patients at risk of losing muscle. HMB supplementation has also been associated with improved mood, lower blood pressure, and increased immune function.
HMB Supplements
Are you ready to incorporate HMB into your workout routine? HMB supplements are available in two forms: the free acid form of HMB and the calcium salt form of HMB. The free acid form may have greater bioavailability than the calcium salt form. The calcium salt form should be consumed 60-120 minutes before a workout, while the free acid form should be taken 30-60 minutes before. Doses of up to 6g are considered safe. Most of the evidence suggests that supplementing with more than 1.5-3g per day has little benefit. When combined with exercise, HMB can promote the formation of lean tissue and potentially improve performance.
HMB while cutting
HMB has been shown to be particularly effective at helping the body maintain muscle mass during periods of calorie restriction or cutting. This is because when the body is in a calorie deficit, it can start to break down muscle tissue for energy, a process known as catabolism. However, HMB has been shown to inhibit this breakdown of muscle tissue and instead promote muscle protein synthesis, or the creation of new muscle tissue.
One study found that when athletes were placed on a calorie-restricted diet, those who supplemented with HMB were able to maintain their muscle mass and strength compared to those who did not supplement with HMB. Additionally, another study found that HMB supplementation helped to preserve muscle mass in elderly individuals during periods of weight loss.
Therefore, if you are looking to cut body fat while maintaining muscle mass, adding HMB supplementation to your regimen may be beneficial. However, it is important to note that while HMB can help to preserve muscle mass during cutting, it is not a substitute for proper nutrition and exercise. A well-rounded fitness and nutrition plan that includes HMB supplementation may help you achieve your goals of cutting body fat while maintaining muscle mass.