Try exercise at home. Most things that are done to attain physical improvement can be done at most places outside a gym. For example running or doing various ab exercises like the plank , bicycles , side twist plank , iron butterfly's etc (really I could go on for a long time on the varied amount of ab exercises) can be done at home or any place with a solid ground. Although I guess if you have a preference on gym equipment being implemented into exercise regiments then you can purchase several pieces of exercise contraptions at decent prices for home usage. I bought a rowing machine myself for 50 quid so yea there are indeed alternatives than going to the gym.