I thought I'd been progressing slowly with these, but during the past six months on SLS/SE>iM's 3, 4 and 5, my hamstring tendons seem to get increasingly sore post workout. There's usually a bit of tenderness during the first set, but then it goes away. It's nothing serious yet, but it does feel like the initial stage of tendonitis.
I'll take a break from the iM's, and then back down to the shoulder bridge leg curl for at least four weeks to see if it takes care of the problem.
I suspect the reason is that I've never done any specific hamstring work in the past, and consequently they're weak. Another deficit revealed by Foundation, I guess. I've also gone straight for 5x5 on these, which is kind of foolish, when they're really strength exercises of the same caliber as the SE's. When I resume them, I'll work back up using the 5x5 template instead.
Anyway, if you're like me, take your time with these.