Previously, I've covered the evidence surrounding supplementation for older adults

with protein or amino acids like leucine.

What about a metabolite of leucine, known as beta-hydroxybeta methylbutrate, known as HMB. Adding HMB to an exercise regimen fails across the board to improve muscle mass,

muscle strength, or physical performance among older individuals,

and since everyone should be exercising, that pretty much takes HMB off the table.

But there are circumstances when you're laid up, for example, recuperating from a broken hip.

Researchers in Spain randomized about 100 men and women over the age 65 in rehab, recovering

from a hip fracture, to a nutritional supplement with about 3 grams of HMB, and they suffered

less loss of fat-free

mass compared to the control group who didn't get the supplement.

Unfortunately, the supplement provided other components, so it's impossible to tease out

the HMB effects, but regardless, there was no significant change in muscle strength or muscle

function.

This was roughly consistent with a 10-day bed rest,

study of straight HMB versus placebo, in which the HMB group similarly lost less lean mass,

but only when an outlier was excluded, which isn't really kosher, and there was no apparent

improvement in strength or function.

This is what meta-analyses of all such studies have found.

An improvement in fat-free mass in older sedentary adults with no change in strength or function,

and no benefits for any muscle parameters when combined with physical activity.

Since we all should be exercising, and there's a questionable benefit of lean mass

for lean mass's sake, combined with the fact that HMB activates the engine

...