Daily. Most of us go up and down stairs, walk to the market, play with our kids. Why not just jump on your bike and go for a vigorous ride? Activity (not just ‘exercise’) is something, if we’re so blessed, we do everyday. Clearly intensity, duration and type of activity need to be considered. Recovery and proper nutrition are essential following vigorous, exhaustive exercise. But I think that being as active as possible every day is important.
As often as their recovery state allows and they want to exericse (or are willing to exercise). I teach a series of CEC courses on recovery called Recovery Essesntials. Check out my website, www.hawaiifitnessacademy.com , if anyone is interested.