What is the best way to build muscle (core and upper body, especially) when one has fibromyalgia and suffers from 24 to 48 hours of severe spams and pain in the shoulders and neck whenever any lifting (with arms or of the upper torso against gravity) is done?
I have a limited diet due to food allergies, and primarily rely heavily on fruits and veggies, and use chicken or eggs as animal protein. I need to build strenghth and endurance, but the effects of trying are severe.