If you are used to running in the morning, it is best to do it after the sun comes out, especially in places with more vegetation, and the concentration of carbon dioxide is relatively high at night, so exercising before dawn also has its disadvantages (the advantage is that the environment is cleaner and there is less dust in the air), so many experts now suggest exercising in the afternoon.

If you don't like the sound of keys, you can only take your room key. If there is more than one piece, you can tie it with a rubber band, so you won't fight in your pocket.

Everyone's situation is very different. As you mentioned, such people are generally strong and energetic, and some people like to sleep. They have to guarantee 8 or 9 hours a day, and without them, they will have no spirit. If you can't sleep so little now, I don't think it is necessary to study. Insomnia is bad for most people. Reduce your sleep slowly, make up your lunch break, or take a nap at your desk.

If it rains, I think skipping is the simplest alternative to running in the morning. The intensity and effect are similar to running exercise, and the location is not too limited, as long as it doesn't affect others.