Anyone experiencing and mid back problems with this workout? I did it Monday about 6AM and was fine until about 8PM when my back suddenly was very tight. Then I did it again this morning and noticed the tightness in the back muscles after starting the warm up punches. I went through the routine Ok but I was wondering since I'd done it without problems before and didn't feel like my form was off this time??? I was OK doing PUB yesterday so it's not slowing me done as much as bugging me.
Thanks

Thanks