When a boy asks me to go to the gym, invite him to work out with you. He has a good impression on you, wants to work out with you, or wants to accomplish his fitness goals with you. In addition, he also hopes to establish a deeper relationship with you through the same interests and hobbies, and enhance mutual understanding and interaction.

If you have a good impression on this boy, you can try to invite him to exercise together and support and encourage each other during the exercise. If you don't like this boy, you can choose whether to invite him to work out with you according to your own wishes.