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.
Sticking points are much like those really talkative, naked old men in your gym's locker room: you'd rather avoid them! Nothing's more frustrating than making good progress overall but failing to improve on the "big lifts" (bench press, squat, deadlift, military press, etc.)
Dan John is Testosterone's Yoda, wise as hell but with better skin and a heckuva' lot higher PR in the snatch than the original. However, our Yoda has had his share of Yodas to learn from. Read here as he shares his most valuable weight-lifting lessons.
Bodybuilding legend Vince Gironda called it the "perfect curl". Christian Thibaudeau says it may be the best biceps-building exercise ever. With street cred like that, you just gotta' try it!