Hi - I am a new member and therefore still learning about Grokker's offerings, but I did see that Grokker offers two programs for those aged 50+:
yoga: https://grokker.com/yoga/seniors/program/yoga-for-50-with-sherry-zak-morris/56df3bd9c5bf9b585631c7dd
strength training: https://grokker.com/fitness/program/basic-training-with-keith-lazarus/5f0f80feeff320188fd50306
The Jane Fonda walking video is fun for all ages. It's "Part One" of a two-part series. I hope Grokker will add the second "Level Two" Jane Fonda walking video someday! Good luck!