As a pilot, some days are long. The days were longer at a regional airline but they have improved at the majors. Expect a duty day between 5-12 hours. Sometimes they are longer. This does not include waking up, taking a shower, and the drive to the airport.

My advise would be to eat well, work out when you can, don't drink a lot of alcohol and get a good nights rest.

You also have to be able to adjust your body clock to the am (6am-3pm) or pm (2pm-11pm) shifts.