Thread is too long to look through. Question: I am 61 years old and looking to regain some upper body strength. I have my routine but am wondering how often to work the same muscle group. Every other day? Every third day? Twice a week? I plan on progressing weight/resistance every two weeks? All advice appreciated.
Based on your 'maturity', I will make a few suggestions.
1. warm up and stretch before and after
2. Get plenty of rest, water, & proper nutrition (this is important for a variety of reasons)
3. Start slowly with light weights and proper form in order to avoid injury and to "break-in" your body again without injury or being overly sore due to getting started again
Everyone's physical abilities are different, but I agree with the above suggestion of hitting each muscle group 2x indirectly per week. Focus on hitting the larger muscles earlier in the week; secondary muscles later in the week.
For example, Chest & Biceps on Monday and Triceps & Shoulders on Thursday. This will allow your shoulders some indirect work on Monday as well as direct focus on Thursday. Everyone has a different recovery rate, but this should give you enough time.
Monday- Chest & Biceps & Traps
Tuesday- Cardio & Abs
Wednesday- Rest
Thursday- Shoulders & Triceps & Traps
Friday- Back & Biceps
Saturday- Rest or Cardio or Abs
Sunday- You can start the cycle over or rest depending on your abilities
Hope this outlines a little of what you were looking for. Ask any questions you may have. There are numerous ways to mix it up. I did not list any leg work as you mentioned upper body only and I'm unclear on what your cardio regimen is.