Plank leg raises, Plank jacks, Plank arm raises and finish off with Plank jump ins.
These HIIT workouts can be done to get into shape for playing tennis and other sports.
Disclaimer: Do not perform these exercises if you have any injury, get rehabilitation first. If you get short of breath, feel fatigued or tired during any of these workouts, stop and take a break. Consult a doctor/trainer if necessary before starting any workout session. Children should do them under supervision of an adult.
These workouts are taken from the Darebee 30 days of HIIT program.