I’m always suspicious when I see someone loading up a lift with more weight than I use. It’s not that my lifts are unbeatable, or even that impressive. What I do know with certainty is what’s possible for someone with my athletic ability (average) and my level of conditioning (excellent); and therefore, the bright line across which proper form collapses and injuries proliferate.
In truth, this guy moved the weight through a much larger range of motion than I expected. He began the lift by letting his legs go nearly limp, smashing the sled against the bottom of the track and bouncing halfway up, then re-engaging his thighs to finish each rep.
Imagine the actual progress he could have made by cutting his weight in half, and bending his legs in a slow, controlled fashion.
1 Some old school gyms have a few 100 lb plates lying around. I’ve used them a couple times trying to look cool, and have nearly broken my back trying to maneuver the massive plate onto a shoulder-high leg press carriage. I can’t imagine creating such an unwieldy arrangement by choice.