Recently came to the conclusion I needed to take my back and leg training more serious and focus on developing them more. So I started going heavier with squats and deads, and added them into my routine every week. A few times I got some light pain/soreness in the mid/lower back but only a day or two after training, never during, and it always subsided within a day or two. I train 3 days a week, Thursday back, Saturday legs, and Monday chest. So, anyway, training this past week and was just feeling overall tired but trained anyway (probably the source of the problem) didn't go real heavy on deads, skipped squats on Saturday, and did chest on Monday, and on Wednesday I started feeling pain in my thoracic area on my right backside near my ribs, and this morning, I was scared to turn in my sleep from the pain. Now that I'm up and moving it's a little better but there's no way I'm training today. I just don't know how I should address this and if anyone has ever experienced anything similar. Do I need to do some more specific core work? Because I don't do any. Also, I think what pushed this over the edge was a certain chest move I've been doing, where I hook up long cables to a pulley system and stand out in front of machine and do chest presses. I've had shoulder issues in the past and using benches for press or fly movements can bother me, so I eliminated that by standing using the cables, but now my body has to take all the pressure standing upright instead of a bench supporting me and I know that was taxing my core pretty hard. Sorry if I just wrote a book. I'm just sore as fcuk and want to get back to training asap.