Not expensive. Health is more important than anything else. It is a good way to take time out to exercise. Everyone has inertia. It's hard to persist at home. In a different environment, you will stick to it. What's more, if you don't go, you will feel that you are losing money. The subconscious will produce initiative. More importantly, you can make some friends by exercising in the gym. So urge yourself to work hard.