Short answer.I REALLY try to never be over-tired as it’s poison, but if that happens and it does, despite myself, I quilt, make papercuts, chat on skype, email or simply take a short nap. You think you need more exercise? exercise only means movement, not heavy gym workouts so if you are sitting or standing do something...rearrange your pantry as a 5 lb bag of sugar in your pantry or a a half gallon jug of milk weigh the same as a 5 or 8 lb free weight. WHY are you fatigued? Disease process? Answer honestly with a focused solution...bored? not enough sleep? Why? Overworked yesterday? Meds issue? take a SHORT nap followed by a walk with a friend, walk around a mall or offer a neighbor with a baby to push the stroller (having something to hold on to assists your walking, thus increasing your endurance), go to your garden and pull a few weeds /re-pot your plants, do some balance exercises while standing at your sink , clean your house😖, rearrange your closets, IOW ...MOVE! Change your perspective, remember to rest before feeling exhausted and that rest doesn’t always mean sleep. If you are tired of standing, sit and if you are sitting, stand, but always to YOUR tolerance.