You want a strong core – who doesn’t? But the typical crunches and sit-ups you’re used to aren’t the way to go. There’s a much better way, and you’ll probably enjoy it a whole lot more than endless crunches.
If you’re practicing jumps as a “cardio” exercise, you’re missing out on the power and precision you can gain from training them as a skill. Learn how to improve your jumps and about the immense benefits to be gained.