Could be the best 3 hours you ever invest in anything your whole life.
Could be the best 3 hours you ever invest in anything your whole life.
That's what I do, i'm quite muscular, but I do work on my shoulders with 4kg weights, no more. But my rep lasts a good 20 seconds (or more, the slower, the better). PER rep. I can tell you you'll feel it very quickly, you certainly don't need a ton to get a serious workout!
And and I'd like to concur, 15 years ago I had massive back/neck pain, and doing the weights on a regular basis completely cured that. Same 3 exercises.
I had crippling back pain [literally, it put me to the floor, unable even to crawl] in the lower back that seems to have been guarded against with weekly Shotokan karate sessions - my hypothesis is that my sacroiliac joint was "tight" and that the emphasis on low stances and hip-rotation has loosened/strengthened it sufficiently to avoid damage. I did manage to damage my hamstring setting off to run though, now I warm up before I warm up!
What DLs do as a side effect is teach people how to pick up things properly. Most people are too tight in the their ankles, hips, and rest of their posterior chain so they are picking things up incorrectly all day long. This sets them up for injury. Learning to DL properly is a great way to teach how to properly pick thing up, and I agree it will likely help with most people's back pain. But, doing anything improperly can cause injury.
Buy Starting Strength by Mark Rippetoe and read it front to back. Then watch his videos/DVDs. Then execute the movements per the book and video them.