Re: How often.
I try to do some exercise every day for 20mins in addition to my 3 daily walks which are restricted at the moment due to flooded fields.
I bought a Yoga mat earlier in the year fully intending to join a class when the problem I had with mobility due to Vitamin D deficiency improved and my injured knee healed. Although and pain/lack of mobility due to the deficency has improved greatly , as soon as one knee gets better the other becomes a problem again. I think maybe once a knee is damaged it develops a weakness .
Although I have yet to join a class I manage to do some basic Yoga stretches with the help of You Tube videos.
I still hope to make it to a class one day, inactivity is the enemy of mobility and fitness.