No need for long-distance running. You can choose jogging 10 minutes and walking 10 minutes alternately, and 40 minutes is enough.

You can make some musical instruments if you don't have the easiest way.

Lie on your back with your hands like you did, fill the drink bottle with water and hold it in your hand. One of your legs is bent on the ground as before, and the other leg is straight, making an angle of 45 degrees with the ground.

This makes it more difficult to do sit-ups