Hello, Thank you for using HCM. By what you explain it seems there are three main things I am considering. 1. a muscle strain- this is very common with weight lifting and you will need to take pain killers, use local warm compresses, soft massage and careful exercises that move that muscle that it hurting 2. Disc hernia- between the back bones there are discs, parts of which can move to the sides and hurt. This is treated the same as the muscular pain but in this case physiotherapy also might be needed. If you have low back pain and you have no neurological symptoms (no weakness, no numbness in the legs, no numbness or tingling in the groin area, and urine and bowel control is normal) you can try first pain killers, warm/cold compresses (some patients get better with warm compresses some with cold ones- you have to try and find what helps you) and do gentle exercises for the back (slowly banding forward, backward, and at the sides as much as the pain allows). If no better in 4-5 days or any worse you will need to see a doctor. 3. Abdominal Hernia- the bowel may find its way through the muscles of the abdomen and come out as a sac that is tender. In this case you will mostly notice a lump in your groin but not always so if the pain is located in the low part of the tummy you need to see a doctor to rule out hernia. If heria is the cause of the pain you will need surgery. Hope this is helpful and answers to your quesiton