Ive been doing strength training for about 19 months. For most of that time I deadlifted sumo-style, and worked my way up to 355x10 about a year ago, then stagnated for many months after that. About 4 months ago I decided I hated sumo deadlifting and changed to conventional.
I was only able to pull 420x1 on my first day, but I made some pretty newbtastic gains and last month pulled 385x10 (I am following 5/3/1 and so using the formula Wendler provides to judge progress, 385x10 translates to 513lb, ie 93lb of progress). That was my last PR. The week after that I made 410x6 and then the week after 440x3 and then deloaded the week after. That was when I suddenly lost deadlift strength.
The next week (i.e last week) the last warm up was hard and it should not have been. I was attempting 410x8 and I made 0. Couldnt even break it off the floor. WTF? Same thing today. I was reattempting the same weight and couldnt break it off the floor. Two weeks in a row my deadlift has been in the gutter. What gives? All my other lifts have been doing fine. I just lost 100lb on my deadlift out of goddamn nowhere.
I apologize for giving you my life story, I wasnt sure how much was relevant. Anyway, my question is how should I approach this sudden strength loss, given that I have no idea what is causing it? As far as I know I am not injured. The only other thing that might be relevant is that the week I pulled 440x3 (ie the last time I pulled anything respectably close to my best calculated 1RM) I tried out the snatch grip deadlift as a new assist exercise.
I only worked up to 315 since my hook grip blows and I dont own straps, but my lower back was pretty sore and stiff for a few days after, which I figured was normal since Id never done the lift before, but I wasnt in any pain.
As of right now, my only plan for approaching this sudden strength loss is to start back at a weight I know I can handle now for at least 5 reps, like 360 lb, and keep adding 10lb a week until I get back to where I was. At that rate I would be back to where I was in 8 weeks.
Other information if it is useful:
-My sticking point is breaking the bar off the floor. If I fail a rep, it will be in breaking the bar off the floor. I have never missed a lockout once the bar is above my knees.
-5'8, 192lb, 20yo
-Other lifts/ current PRs: SOHP: 170x6, Push press: 190x6, Oly Squat: 335x7
-Natural deadlifters build. Long arms, short torso, long femurs.