Conditioning for a sport takes a lot of hard work. A big part of all sports is jumping. Jumping is essentially doing squats. Power is used to push your lower body up off the ground and into the air and ending in a squat again. Practice this by squatting, encouraging your lower body to push you up and land in a squat position to prevent intense impact on your joints. Once your strength is up you will notice that you can jump higher, sprint faster, accelerate quicker and perform better in sports. You need a lot of strength for most sports.
Medicine balls aren’t just a big help with this; they also help with balance. To practice with this try getting a partner and, while standing on one foot, throw the ball back and forth. Then of course you have basic exercises like running, sit-ups, jumping jacks, pushups, lunges, crunches, etc. These help with strength and getting yourself used to running and working hard, which gets you into shape. Then of course we can’t forget about stretches, which should be done first just to be on the safe side. It gets all of your muscles good and ready to go. It also helps with flexibility which can improve your sports performance. For example, in tennis, if you are more flexible and have greater range of motion it will increase the force on the ball. Make sure you do all of this thoroughly and I guarantee you will make the team!