The point of going to the gym is to get moving and burn some calories while you are at it. There are many other activities that you can engage in outside of the gym. If you do not feel inclined to spend hours inside a gym, you can opt to go swimming instead. It is a great way to burn calories without putting much stress on your limbs.
Another alternative is to walk as much as you can. If you can walk in order to get your errands done, do so! Walking for at least 30 minutes a day can do wonders!
Last, take the stairs instead of the elevator or escalator. This extra effort will also result in more calories burned.