FINALLY STARTED CROSSFIT!

I started CrossFit today. Finally gathered the courage to do it. Did 133 Kettlebell swings (was supposed to do 150) with 35 lbs and 5 situps every one minute between the KB swings. On the 133rd swing felt a sharp pinch in my lower back and dropped the weight and stopped immediately. Had lower back strain from squatting 315 lbs about 10 days ago and I think this is a re-lapse of that. Have to be more careful in the future. I almost collapsed at the end of todays workout which only lasted 9 minutes but boy was is intense! I am ready for tomorrow but I hope my back doesn't keep me from doing XFit. Wish me luck!