Cardio:
Sprints, Calisthenics, Swimming,Long Distance Runs
SWIMMING AS AN ALTERNATIVE TO RUNNING
Swimming is great because it doesn't bang up your knees and elbows like heavy running and lifting do. With swimming you can have a heavy workout comparable to sprints or you could keep a steady pace and have more of an endurance workout.
Calisthetics
Box Jumps,Jump Rope Cardio, Burpees, Stair Sprints,Up Hill Sprints
Doing cardio is always good but if you have been on the treadmill a lot lately; you might be looking for different ways to get those daily 45 minutes of exercise in.
One way that works on explosiveness is calisthenics.
The only equipment used are boxes like the ones shown and an occasional medicine ball.
Overall these type of workouts allow you to intensly engage your muscles while giving you a good cardio workout.
Something like a walk or jog will be good for your heart but you won't really use those explosive movements.