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.
"Back in the days of being 297 pounds, every workout was brutal; there was no other alternative. That's not the case any more. Have I become soft, like a former all-star playing out a multi-million dollar contract?"