Hi K H. Unfortunately, there is not a way to manually add a workout that you did not do through Grokker. However, I don't have a device such as a Garmin or Fitbit, but I've loaded the FitBit app onto my phone and synced it with Grokker. When I go to the gym, I track my workout through the FitBit app as either a run or walk. Those minutes are then synced to my Grokker account and will show up on my calendar as a walk or run for the day. I also receive wellness minutes for those activities. Does that help? If not, please let me know.