If you’ve got a Swiss ball and a mat, you can perform this exercise to help develop powerful hamstrings.
Swiss Ball Hamstring Curl:
Lie on your back with your heels on the Swiss ball. Your legs should be straight at the start of the movement, with your butt off the floor. Keep your abs tight.
Roll the Swiss ball towards your butt with your heels.
Contract your hamstrings at the end of the movement. Release the tension and roll the Swiss ball back out to the staring position.