At What Age Should Athletes Start Taking HMB?

HMB (beta-hydroxy-beta-methylbutyrate) helps reduce muscle breakdown, limits exercise-induced muscle damage, and supports muscle maintenance.

These benefits make it particularly relevant for athletes over 40 because maintaining muscle mass and recovery become harder with age. However, younger athletes can benefit too, during demanding training blocks or when recovering from an injury.

So, the question isn’t when you should start taking it. It’s why you might benefit. Let’s look at what the research says.

Why HMB Matters More After 40

You don’t suddenly lose muscle mass when you turn 40. But for most athletes, this is the age when maintaining muscle becomes increasingly important. Muscle loss tends to peak between 30 and 40, with losses accelerating each decade.

Even if you continue training, holding on to muscle mass becomes more difficult. Training more isn’t an answer either, because recovery also gets harder with age.

HMB can help with both.

HMB is a compound your body produces when it breaks down leucine, an amino acid involved in muscle protein synthesis. It helps regulate muscle protein turnover, helping reduce muscle protein breakdown, limiting exercise-induced muscle damage, and speeding up recovery.

Here’s what the research tells us:

• Muscle maintenance: The International Society of Sports Nutrition (ISSN) position stand on HMB reports potential benefits for muscle strength, function, and quality in aging populations. HMB may be particularly useful taken with creatine alongside resistance training.
• Muscle damage and recovery: The original 2013 ISSN position stand concluded that HMB can help reduce exercise-induced muscle damage in trained and untrained people. Studies have found lower levels of creatine kinase, a blood marker associated with muscle damage, and reduced soreness in some circumstances.
• Muscle loss during inactivity: HMB has also been studied during periods of illness, injury, and inactivity, when maintaining muscle becomes more difficult. This may be particularly relevant for masters athletes who need to preserve muscle during a break from training.

HMB won’t magically help you maintain muscle or power if you stop lifting or don’t get enough protein. And the evidence isn’t equally strong across every population. But for athletes over 40, it is a particularly useful tool for holding on to what you’ve built and staying in the game.

Read about how HMB works and the research here.

Can Younger Athletes Also Benefit from HMB?

HMB isn’t just a supplement for masters athletes. However, for athletes under 40, the focus is less about age-related muscle loss and more about supporting your muscles through hard training.

Hard training blocks or ones with lots of new eccentric exercise can cause muscle damage, soreness, and temporary drops in strength and performance.

Much of the original HMB research was actually done on college-aged men and women in their 20s and 30s, not older populations. Those studies found less muscle damage and soreness after hard training.

The research also shows a pattern: HMB helps younger athletes most in these situations:

• Preseason, when training volume and intensity ramp up quickly
• A new training block, such as a switch to heavy strength work or a jump in mileage
• Return after a break, when muscles are deconditioned and damage easily
• Injury layoffs, to help limit muscle loss during inactivity

But there’s an important catch here. HMB hasn’t consistently been shown to improve recovery or performance in well-trained athletes. If you’re already training consistently, eating enough and recovering well, adding HMB may not make a noticeable difference.

Outside these periods, a well-recovered athlete in their 20s or 30s may notice little difference. That’s the key contrast with athletes over 40, for whom the age-related decline never takes a break.

What about teen athletes?

The evidence in teenagers is limited, so caution is the default. The main study is a 2011 randomized controlled trial in elite national-team volleyball players aged 13.5 to 18, all in late puberty. Over seven weeks of preseason, 3 g of HMB a day led to greater gains in muscle mass, strength, and anaerobic power than placebo. It did not change growth hormone, IGF-1, testosterone, or cortisol.

That’s encouraging, but it’s one small study in physically mature, elite athletes. There’s no research in children or younger teens still going through puberty. For most young athletes, recovery is better served by enough food, protein, and sleep, plus sensible training loads. Teens training at a high level should only consider HMB after consulting with their physician or nutritionist.

Resources

1. Volpi, E., Nazemi, R., & Fujita, S. (2004). Muscle tissue changes with aging. Current Opinion in Clinical Nutrition and Metabolic Care, 7(4), 405–410. https://doi.org/10.1097/01.mco.0000134362.76653.b2
2. Wilson, J. M., Fitschen, P. J., Campbell, B., et al. (2013). International Society of Sports Nutrition position stand: Beta-hydroxy-beta-methylbutyrate (HMB). Journal of the International Society of Sports Nutrition, 10, 6. https://doi.org/10.1186/1550-2783-10-6
3. Rathmacher, J. A., et al. (2025). International Society of Sports Nutrition position stand: β-hydroxy-β-methylbutyrate (HMB). Journal of the International Society of Sports Nutrition, 22(1), 2434734. https://doi.org/10.1080/15502783.2024.2434734
4. Wu, H., Xia, Y., Jiang, J., et al. (2015). Effect of beta-hydroxy-beta-methylbutyrate supplementation on muscle loss in older adults: A systematic review and meta-analysis. Archives of Gerontology and Geriatrics. https://pubmed.ncbi.nlm.nih.gov/26169182/
5. Knitter, A. E., Panton, L., Rathmacher, J. A., Petersen, A., & Sharp, R. (2000). Effects of β-hydroxy-β-methylbutyrate on muscle damage after a prolonged run. Journal of Applied Physiology, 89(4), 1340–1344.
6. Deutz, N. E. P., Pereira, S. L., Hays, N. P., Oliver, J. S., Edens, N. K., Evans, C. M., & Wolfe, R. R. (2013). Effect of β-hydroxy-β-methylbutyrate (HMB) on lean body mass during 10 days of bed rest in older adults. Clinical Nutrition, 32(5), 704–712. https://doi.org/10.1016/j.clnu.2013.02.011
7. Nissen, S., Sharp, R., Ray, M., et al. (1996). Effect of leucine metabolite β-hydroxy-β-methylbutyrate on muscle metabolism during resistance-exercise training. Journal of Applied Physiology, 81(5), 2095–2104. https://doi.org/10.1152/jappl.1996.81.5.2095
8. Rowlands, D. S., & Thomson, J. S. (2009). Effects of β-hydroxy-β-methylbutyrate supplementation during resistance training on strength, body composition, and muscle damage in trained and untrained young men: A meta-analysis. Journal of Strength and Conditioning Research, 23(3), 836–846. https://doi.org/10.1519/JSC.0b013e3181a00c80
9. Sanchez-Martinez, J., Santos-Lozano, A., Garcia-Hermoso, A., Sadarangani, K. P., & Cristi-Montero, C. (2018). Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials. Journal of Science and Medicine in Sport, 21(7), 727–735.
10. Jakubowski, J. S., et al. (2020). Supplementation with the leucine metabolite β-hydroxy-β-methylbutyrate (HMB) does not improve resistance exercise-induced changes in body composition or strength in young subjects: A systematic review and meta-analysis. Nutrients, 12(5), 1523. https://pmc.ncbi.nlm.nih.gov/articles/PMC7285233
11. Portal, S., Zadik, Z., Rabinowitz, J., et al. (2011). 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. European Journal of Applied Physiology, 111(9), 2261–2269.