Two people can do an identical session. One is settling a debt for the weekend. The other is finding out what their legs can do. Same sweat, entirely different transaction.
Honor rules out the first one. You don't punish something you respect, and you don't judge it exclusively on how it looks from outside.
Grit points at the last mile of a run nobody watched, the rehab nobody applauded, the years a body kept going through things it was never consulted about. None of that is aesthetic. It's a record of service, and a workout is one reasonable way of acknowledging the record.