I admire your dedication to your body and health, I have heard many times that if you don’t feel pain then you are not doing enough, however consider that you are 79 years old and you should limit yourself, if your shoulders are hurting then it could mean that you’re maybe over exerting, to sustain an injury at our age is not worth it because it takes more time for our bodies to heal and therefore it will set you back for a long time, keep up the good work and always remember moderation is the best way to get there.

@frannee I am 78 and had shoulder pain limiting my exercises - turned out it was an impingement. There are good exercises to address impingement if that is what it is. I followed an appropriate routine for several weeks and am now able to continue my workouts.