I know a bit about this stuff and I work out heavy with 30 min cardio warm up 4 days a week (alternating with shoulders, arms, traps with legs back, core) and 45 min strong cardio the other 3 days. At age 75 my goal is to slow down muscle loss and I have pretty much plateaued last few years with weights, push ups etc but have kept up decent muscle definition.
My 5K's are decreasing a bit each year and, as with everyone guy I know who are past their 40's, there is not much that can be done as all of this is to expected IMHO, as telomeres shorten every time a cell divides (there is a lot of division between birth and old age).
Just look at the formula for max heart rate as it is a direct function of age. BTw, it decrease not because of slower heart contractions but r
esult of
slowed relaxation (where the heart chamber fills back with blood. An example you can see is pinch your skin and see how long it takes to become smooth again - loss of elasticity.
Anyway, to make a long story short, the problem I have with the site you posted is this:
"When we think about HMB’s primary mechanism of action –
inhibiting muscle protein breakdown and decreasing muscle damage – that makes sense. "
However, the mechanism for building muscle is not "decreasing muscle damage" but actually stressing the muscle fibers to cause muscle damage. Muscles don't get stronger the day you work out
but the next day when the stressed and damaged muscle fibers from the workout repair and add some additional muscle in the process.
I'd like to see some studies (with placebo control groups compared to those taking HMB.)