Originally Posted by Garrett Smith
A machine leg curl is extremely different, neuromuscular patterning-wise, than a GHR. Being strong at one does not make someone strong at the other one (but I'd guess that strength in a GHR transfers a heck of a lot better to a machine leg curl than the other way around).
Also, if you watch the video from Coach Sommer above, his GHR is a compound movement that incorporates a back extension as well. Far thing from a leg curl.
The movement of a low-bar BS and a DL may look similar (minus the bar placement), but their neurological patterning is very different as well.
About the GHD sit-up, the need to consciously "kick" the legs straight to return to the upright position always seemed contrived to me. Yes it works, but my thought is, shouldn't the well-trained athletic person do it naturally? I've never seen anyone do it right their first rep without coaching.
To play devils advocate on the thing you said last, I don't know many people that were able to just hop onto a GHR and knock out reps correctly?
"And for crying out loud. Don't go into the pain cave. I can't stress this enough. Your Totem Animal won't be in there to help you. You'll be on your own. The Pain Cave is for cowards.
Pain is your companion, don't go hide from it."