3 pounds is about an hour in the sauna doing light movement i.e shadow boxing. If he's walking round at 133lbs before training then in my opinion he's very light, if he was 133lbs after training, before an evening meal then I'd say he's on course, maybe a little light. Fluctuations are massive depending on the time of day. A formula 1 driver loses a minimum of 8lbs during a race. Fighters have been known to cut 30lbs just a day before the weigh in.