MN/PE2>iM Jefferson Curl

Build up weight slowly on this movement. Depending on your background and the health of your back, you may want to start with as little as just bodyweight. Work up to 45#/20kg for mastery. 

After achieving mastery, it is advisable to keep the movement in your warmup: slowly build up to performing the movement with 1x bodyweight. 

Jefferson Curls benefits :

Coach Sommer said:

Jefferson Curls work the fascia (the long primary strip that runs from the top of the head down to the bottom of the feet), ligaments between the veterbrae, discs, traps and spinal erectors, the upper hamstrings, lower hamstrings and also quite possibly the 'kitchen sink' - although that last is still conjecture at this time.  

Jefferson Curls are not intrinsically dangerous.

Mark Collins said:

The Jefferson Curl is a controlled exercise that is to be done pain free. It is safe if done correctly with the appropriate load for you. The spine is designed to flex and extend, not to be locked in neutral all the time and only relying on the hips for mobility.

Is there scientific proof? No, as it would be too hard to research. Just as McGills theories have no randomized controlled trials as it is too hard to research.

You will just have to trust Coach that in his many years of experience it is a beneficial exercise. If it caused injuries he would not expose us zombies to it. Also there is a lot of people on this forum who are older and stiffer than young gymnasts and we are going well. No disc injuries from the Jefferson Curls that I have heard of.

Be careful and progress slowly. I started on 2.5kg and am now up to 45kg. This took 6-9 months. I use it in my warm ups twice a week as it really helps improve flexion mobility. I increase by 1.25-2.5kg when I feel ready.

Could we have a point of reference to how much weight the average individual should start on and then move to mastery?

I did 3 kg start, and I think I read mastery should be 20kg.

Maybe I'm wrong but I thought mastery for this is not about the weight. Its about performing the movement right and then slowly increasing the weight until you get 1 x body weight. 

Nicholas Cooper said:

Maybe I'm wrong but I thought mastery for this is not about the weight. Its about performing the movement right and then slowly increasing the weight until you get 1 x body weight. 

Mastery requires performing correctly with ~45lbs of weight. A bit more or less if you're particularly large or small. After mastery you should work up to bodyweight.