Simple solutions to hard problems seem to be falling out of favor.

Actually, exercise lowers cGMP (and low cGMP is what Viagra reverses) so your "simple solution" is actually totally wrong.

Have done regular exercise to improve my Long COVID state for 6 months now. It has helped, but it has its limits too. If I overdo it, I get worse, but I can't always tell until later. And other health issues are limiting what forms of exercise I can do.

Hard problems rarely have one simple solution, or they wouldn't be hard, would they?

> The OxHARP trial was a meticulously designed double-blind, placebo-controlled study involving 75 participants who had experienced a minor stroke and showed signs of mild to moderate small vessel disease.

I mean, I think if going for a walk were a magic bullet for stroke rehabilitation, someone would have noticed by now.

I'm not knowledgeable about stroke rehabilitation specifically, but the benefits of walking are extremely robust. Especially if you're talking about the difference between a totally sedentary lifestyle and one which includes a substantial amount of walking.