I am in somewhat the same situation - I'm a beginning runner, a BIG guy (214 lbs and over 6"), and have been running for 8 months. I've lately gone up to 3x/week, 4 miles per run, and two weeks ago finished a run feeling fine, but woke up with some pain and incredible stiffness in my lumbar area. It's been gradually loosening up, and I can stretch, but I still have tightness and discomfort and have not bee able to run these last two weeks (though I can walk, but need to stoop over just a degree or two.)

I'm assuming it has something to do with NOT cooling and stretching properly at the end of the run, or my shoes. I'm also assuming it's a pure muscle problem and not a damaged inter-vertebral disc (it's not really painful, just stiffness and soreness, though it does seem to be right on the lumbar part of the spine.)

I could use some advice on how to avoid this in the future.

Thanks in advance to anyone who can offer advice.

Now that you mention it - the pain is a dull, constant one. And it's not really all that painful. The lumbar area burns a bit sometimes, but mostly it's very, very stiff. When I stand straight, I find my knees automatically buckling to take some pressure off. Very wierd.

I'm beginning to suspect that running uphill may be the culprit. I have long uphill sections in my runs, and noticed when walking around today that going uphill or downhill beyond a mild gradient puts dramatically more pressure on my now sensitized back.

If it doesn't clear up in one more week, I'll see a doctor. Hopefully it's not disc damage, I REALLY don't want to confront something so detrimental when I've really only just begun.