I do agree with all you guys. But I would like to add more thoughts of mine. The gym exercises will bring you in to a good shape. It is 100% true. But you can also try Swimming. I recommend you this by my personal experience. Also it is not like gym exercises. You don't need to lift heavy weight and also you will definitely have fun while swimming. You can continue this as a hobby also. Hope you will try this.

ALL THE BEST