Here are the following ways by which one can stay physically fit and avoid weight again:
1. Get atleast 10000 steps a day. This can be done by walking up and down the stairs when the opportunity arises, going for a walk during the day and maybe even walking around the house.
2. Reduce consumption of processed foods like sugar, starch etc. Eating plenty of green vegetables and fruits has a lot of health benefits.
3. Find a workout type thay excites you like rhumba, or running. Going to the gym and doing some boring workout will not be sustainable in the long term