This probably really belongs on the 65-85 thread, but that's turned into another Addiction thread, blather, no info, so I'm posting it here. I'm 76.
I've been really frustrated for the past year by my inability to maintain/get into decent riding shape. I think this is mostly due to slower recovery after workouts. My muscles hurt all the time, even after ordinary moderate rides on my rollers. I had to let 2-3 days go by between any moderately hard workouts. My resting HR was up several beats over what it was just a couple years ago. I also have another problem which seems to happen to older riders, namely saddle sores. My skin just can't take the pressure from a saddle anymore. It seemed to me that all these things might be connected.
I messed with my diet, changed timing, carbs, and added protein. Adding more protein helped noticeably, but my recovery still wasn't good enough to build up to doing serious rides again. As is my practice, I hit the google, looking for wound healing (for the saddle sores), sarcopenia (muscle wasting in the elderly), and osteoporosis (I have that, too). I ran across a few studies and recommendations. One, for wound healing, involved adding 3 supplements, 2 of which I don't think do much, but one seemed worthy of more study: HMB, see:
https://en.wikipedia.org/wiki/Beta-H...ylbutyric_acid
I started taking 1g of HMB 3Xday only 10 days ago, and bingo. My metabolism is back on track, my resting HR is back down to where it should be, I'm recovering normally, and my wife and I got 7 Strava PRs on our tandem ride yesterday. The saddle sore is a little better, but a minor change compared to my restored ability to recover. I don't know how much it will help my osteoporosis, but I ran across a study where it prevented bone loss in pregnant mice
. Maybe so.
The main effect of HMB is to reduce muscle damage from exercise, just what I need. So if your recovery ability has gone sharply downhill as you've hit one of those aging drop-offs, give it a try.
A thorough look at HMB is here:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2245953/