HMB is a well-established sports supplement, with a lot of research showing that it increases both strength and muscle in athletes doing strength training (1).

Over more recent years however, we have seen mounting research on the impact HMB can have on endurance performance. Below are three ways taking HMB could improve your performance as an endurance athlete.

Not sure what HMB is? Read about the basics:

Researchers from the University of Connecticut studied runners over a 12 week period taking either HMB or a placebo. Throughout the study, they found that muscle damage was significantly lower in the HMB group (1).

These results were not the first time this had been observed. In a more extreme study carried out at Southern Illinois University muscle damage was reduced dramatically in athletes running at least 48 kilometers a week, preparing for a 20km race (2).

On a more subjective note, another study shows that subjects who took HMB for 28 days ahead of a 30 minute downhill running routine reported less soreness; maintaining strength for a longer period of time. (3)

As an endurance athlete, less muscle damage means that you'll need less recovery time in-between your training sessions. As a result, you will be able to train more frequently / put in more miles per session.

HMB has shown to maintain muscle mass consistently across a number of different situations, including: caloric restriction, aging, inactivity through injury and even disease conditions. Endurance training is no exception to this list. (4)

Even with limited research, it consistently suggests that HMB will help you maintain your composition - this is especially relevant when it comes to higher levels of training volume where it becomes difficult to maintain caloric intake and bodyweight.

Conclusion: Take HMB as you are piling on the miles and also if you are an older or injured athlete. Creatine could also help with increasing muscle mass and maintenance, learn more here.

Where research can be notorious for “suggesting” things, the studies on HMB and endurance are getting pretty conclusive. Good quality, published, independent studies have shown that HMB improves aerobic capacity (VO2 max or peak) in runners, cyclists (5) and rowers (6).

As an example, a study at Sherbrooke University found that 5 weeks of running training resulted in significantly higher increases in VO2max and respiratory compensation point (when you start to breath harder) compared to a placebo group. (7)

1. Kraemer et al. (2009): Effects of Amino Acids Supplement on Physiological Adaptations to Resistance Training. Read the research

2. Knitter et al. (2000): Effects of HMB on muscle damage after a prolonged run. Read the research

3. Byrd et al. (1999): Changes in Muscle Soreness and Strength Following Downhill Running: Effects of Creatine, HMB, and Betagen Supplementation. Read the research

4. Park et al. (2013): HMB Attenuates Muscle Loss During Sustained Energy Deficit Induced by Calorie Restriction and Endurance Exercise.Read the research

5. Vukovich et al. (2001): Effect of HMB on the onset of blood lactate accumulation and VO2max in endurance-trained cyclists.

6. Durkalec-Michalski et al. (2015): The efficacy of a β-hydroxy-β-methylbutyrate supplementation on physical capacity, body composition and biochemical markers in elite rowers: a randomised, double-blind, placebo-controlled crossover study. Read the research

7. Lamboley et al. (2007): Effects of HMB on aerobic-performance components and body composition in college students. Read the research