Burpees are a good fast-paced exercise that strengthens the chest and core. It's also an excellent movement for aerobic conditioning.
Get into the starting position by squatting down with your hands in front of you on the floor. Next, kick your feet back to a push-up position. Perform one push-up and immediately return to the squatting position.
Now, leap up as high as possible pushing your arms in the air up over your head. Repeat the full movement as quickly as possible.