Swimming is an amazing way to burn calories and tone your muscles. Doing laps can burn anywhere from 540 to more than 700 calories per hour — more than going for a run! But swimming isn’t the only way to use your pool to get fit. Use the natural resistance of water to add variety to your routine by incorporating these calorie-burning exercises into your repertoire. Do as many reps as you can of each exercise before moving on to the next. Repeat the circuits and increase the repetitions as your fitness level grows. K-Treads Tread water while making circles with cupped hands. Lift your right leg to hip-level while stretching the left leg to the bottom of the pool and holding the position for five seconds. Switch legs using fast motions to alternate sides. Jumping Jacks This move is particularly effective in the water because you have to push…