Single-leg sled pushes and pulls involve emphasizing one leg to move the sled on each step, which is especially good if you're trying to focus on a weaker side.
An easy way to implement these single-leg sled push and pull variations is to simply perform half the distance or duration with one leg and do the second half with the other leg.
This six-week program breaks some of the currently accepted rules for workout volume and duration. That's why you'll do more than 20 sets per workout and you'll train for 60 to 75 minutes.
Look around your gym. Most trainees lack the calf thickness to suspend a pair of double striped knee socks, let along balance out the size and symmetry of the lower leg. Now look in the mirror. Are you one of them?