hi, thank you for providing the brief history of you. since you mentioned this all aches started after going to gym then the mechanism of injury is the impact to the spinal muscles. first let me begin with this. for going to gym many people avoid the 3 basic steps as per me. 1. clearance from a cardiologist 2. clearnace from a Orthopedic 3. clearance from a neurologist. now many people wonder why I say to meet three people before going to gym . well, the answer is here and common for all irrespective of the age. 1. the cardiologist has to give cardiac clearance for undergoing cardiac training as anything unknown can be traced and help the individual perform better in a gym. 2. the orthopedic has to check the bony or muscular issues if any is present. Once he asseses he will be able to say what should be done and what should be avoided. since most injuries in gym are muscular, soft tissue and bony. he may even guide to an physical therapist for rehabilitation exercise plan to undergo in gym. 3. The role of a neurologist is to check your motor and sensory behaviour. if there is a lack of concentration and coordination there might be a chances of fall and landing the individual in a hospital. now coming to your case. as per the symptoms you mentioned it looks like you have a nerve entrapment. it may have occurred due to running on a treadmill as when you run on a treadmill you hit your heal hard to the hard surface beneath and that s where the Newton s third law comes - ever action has equal and opposite reaction. so the harder you hit your heal the harder the hit comes back. it will straight away travel upto the spine. This was just a simple example.. coming to focus on your issue, I will request you to meet an orthopedic and get an MRI done to check any soft tissue or bony injuries in the lower back and neck region. as mentioned by you, it appears that you have a radiating symptoms of pain which is a appearing to be a soft tissue Damage and nerve entrapment. your orthopedic may advice you to undergo physical therapy sessions for the same. for which you should definitely try out. as the physcial therapist will re-asses you and figure out your physical capacity to undergo the stress and strain in future. also to mention , that you should first stop the gym and not ignore this symptoms. It can get worsen and one has to say only one sentence - did all what doctor said but nothing worked well? well, injury starts by a mistake. so correct a mistake one needs to be focused on the self always. with the grace of God I wish you a good health