Line jumping is a great cardio workout in the pool. Cardio just means that you get your heart rate up, and you burn a lot of calories, so line jumping is great if you do want to lose some weight and burn some calories.
To start off with line jumping you want to pretend that there's a line right next to you. You can jump over and jump back to make it a little easy. To make it harder you can do both legs at the same time. So you pick up the pace. It's a little tricky. You burn a lot more calories.
You can also do the same thing if the line was horizontal in front of you. You could step over, step back, step over, step back. Use your arms, and that will give your arms a really good workout as well. Or you can pick up the pace, use both legs and jump forward and back.
So this is line jumping. I would do it for about two to three minutes. You could also do intervals, which is the basic for about 30 seconds, and then you could do it for a minute back and forth, and I would repeat that about 3 times. So that's line jumping, a great cardio workout.