I'd do all of it for 2 weeks and don't cheat on #1. Obviously you need to do a lot of other things to guard your lower back as well such as no lifting, no shovelling, blah blah blah. (I'm sure they told you this.)

After 2 weeks I would keep doing #2 and #3 and I would get in a second ride of moderate duration.


Physical therapy works in many cases, if you can actually adhere to the regimen. I had pretty bad repetitive stress issues in both wrists and both elbows. At the worst of it I couldn't carry a gallon of milk in one hand. Went to docs, listened, changed my desk at work, avoided high stressor activities (like push-ups and chin-ups) and 2 years later I am pretty good.

Unfortunately, wrists & elbows aren't lower back. You have a tough road ahead but it can be done.