I was also doing exercise on regular basis but my diet was not proper due to which I was obese. DM ran in my family so I was an ideal candidate for that. But for last 5 years, I have controlled my weight and diet. To me exercise should be taken as something we enjoy doing, it should not be taken as liability.
You should have join the 100k push up challenge of OGnasty, IMO it would have been fun doing your exercises. If push up would be hard for you, then planking would be better just like philipma1957. I observed them doing it for the fun.
That is a superb challenge and a good activity. As I already said I am focusing on my diet and along with that I do walk/jog in the evening. Things are now under control with that.
Those who are fit and have good intake of Protein must enroll in that push-up challenge.