I am too ill to do physical training today.
So how to honor my duty as a martial artist?
I can study the techniques, review notes, and work on the terminology so that I can better understand and lead the class.
I can do mental rehearsal, a form of guided imagination used by Olympic athletes, dancers, and many others: Picture every exact move in the technique/form/sequence, and run through it slowly, then faster and faster in my head.
Instead of pushing my boundaries physically and prolonging the illness, hydrate, rest, and recover so that I can get back to training ASAP!