Hi welcome to HCM Swelling and pains in arms after exercise and weight lifting is normal as you just started working out after months off . . Exercising while dehydrated can cause greater damage to muscles and reduce the body’s ability to repair itself . A balanced diet which include all essential nutrients is equally important . Lemon juice with warm water helps a lot in energising Turmeric powder a level spoon with hot milk at bed time is great antioxidant & healing agent for swelling . Massage with warm olive oil gives relief to sore muscles . Plan to rest for a day or two is very wise . Avoid processed foods carbs , sugar , fried ,fast foods , Tea , coffee ,alcohol and smoking , stress , sleeplessness and Constipation all will produce biochemical and metabolic conditions in your body that will decrease your immunity. So avoiding is definitely the first step in the right direction to detoxing the body, boosting the immune system . As you haven t been active lately, always start slowly and increase gradualy . Check with your doctor before restarting an exercise . Hope this helps solves your query .Take care .All the best .Get well soon. Don t hesitate to come back in case of any further query .