I'm also on the school team.

You can try skipping rope, once every 5 minutes, in about 6 groups. Now I continue to insist every day.

Tie sandbags to your legs. Frogs jump, you think it's boring to turn around. Try the stairs or something. 10 minute grouping. Do three groups.

Twice a day, between 6 am and 7: 30 pm, 9 am and before 10: 30 pm. This is the most effective. Leg pain means the effect is coming.

No barbells or anything. It is not good for height development. There will be a hunchback ... If you are over 22 years old, you can try a barbell with 0. 60 to 80kg on your shoulders.

Jump in place.

Once every 5 minutes, rest for about 3 minutes and do 4 groups twice a day. The time is basically the same as above.

I think the most effective method is leapfrog.

I think so myself. I hope you can keep exercising.