Apple supports Family Sharing for apps (free and paid-up-front apps). Fitbod is a free to download app so you can share the app between family members however, you cannot share a subscription. While we would support Family Sharing, we aren’t able to due to Apple’s system; our subscription is considered an in-app purchase which is not compatible with Family Sharing.
We are aware that this is what our App Store description says (since Fitbod is free to download), but unfortunately this is something we unable to change on our end.
If you and your family members would like to use Fitbod, please use our Submit a Request form with "Family Sharing" in the subject line for special offers.