after dinner (which does happen). I am a firm believer that people who work 20 hours a day accomplish less than those who work 14-16 hours. I've done both. I've seen others do it. You might be able to pull off a highly focused 20 per day for a few days in an emergency situation. But that's about it.
I believe BYI's coaches put in at least 80 hour work weeks during the season.