I don't have a tactful way to say this - but perhaps you are exercising too hard? It might be wiser to take a progressive approach - i.e. start with a five min

I don't have a tactful way to say this - but perhaps you are exercising too hard? It might be wiser to take a progressive approach - i.e. start with a five minute walk, the next day/week/month increase it to a ten minute walk or increase the pace.