I Have Been Having Muscle Contractions, Stiffness In Hands, Arms

I have been having muscle contractions, stiffness in hands, arms and also in legs. At times the stiff contractions are severe and produce a tingling, weakness in both arms. These symptoms have been increasing in severity, lengthyness and frequency. As an 84 year old former gymnast, runner and weight lifting athlete since high school, college and beyond -- even today at 4 days / week in the gym these symptoms seem to be making my arms, chest and legs weaker.