My t spaces his clients out by 10-15 minutes (50 minute sessions, 10 minute breaks). I'm always very grateful. My son's t sees clients back to back, with no break (45 minute sessions around the clock). I can't imagine how son's t does it--how he doesn't get burnt out or need a break. My t has told me he finishes his notes after every client--I can't imagine how backed up son's t must get.