I really did not try and overdo it at the Y, but my back has been horrible for 3 days now. I hope it isnt a kidney stone.....it feels not quite like I hurt my back.
You probably gave yourself a killer case of tendonitis where the spinae erectus muscles insert on your pelvic rim. I did the same thing trying to set a 500m PR on a Concept II rower about a year ago. It took 6 weeks and about a dozen chiro visits to get over it.
