It's the price that must be paid for athletic success, but we still shake our heads when we get presented with the gruelling regimes endured by our top sporting stars.
Michael Conlan was on stage at the Web Summit in Dublin this week and he gave a window into the sacrifices that are made to become a world champion and the world's top-ranked bantamweight boxer.
'I think we're more professional than the professionals. We're training four days a week in Dublin, twice a day and the sessions are two-hour sessions so that's four hours a day.
'We're in Dublin four days a week but I train for a full seven or a full six, it depends if I take one day off.'
Here's Conlan's four-day Dublin routine in his own words:
Day 1: First we'll have track in the morning, which is either sprints or a long-distance run. In the evening it'll be hitting bags or pads, which is very high intensity.
Day 2: Strength and conditioning in the morning, either circuits or weights and then that afternoon would be sparring, six or eight rounds.
Day 3: As the week goes on it gets changed around, the run would be in the morning and then sparring that evening, nine or ten rounds.
Day 4: The last day would be five sets of three rounds.
Billy Walsh played a major part in establishing the professional Irish boxing set-up, but while Conlan was disappointed to see him leave in controversial circumstances for a post in America, the 23-year-old reckons those still on the scene are more than capable of continuing the run of success.
'I don't think much will change for me. Zaur Antia is probably the best coach ever based on these shores, and my father is part of the High Performance set-up, and Eddie Bolger, so we had a great team behind Billy and these guys are now going to push us on even more as well.
'We've always wanted to be the best in the world and now we're showing that we can be the best in the world.
'Other boxers are seeing some of the fighters do it, like myself and Paddy, and they are striving to be like us, to be the best. It's in our culture to be the best.'
Being the best places some horrific demands on the rest of his life, and the last year has been tough on Conlan as he has spent so much time away from his young family as he travelled to World Series of Boxing events, and the European and world championships.
'This is my life, it is my job,' Conlan says. 'I just have to give everything I can to it, even though I have a family. They understand and they all get behind me and help me and support me a lot.
'But it's been the best year of my life. From January I had the WSB, which was a 14-week stint and it was very demanding, and during that time I was waiting for my baby to be born.
'When she was born I was actually at home, but I had to fly off the morning after she came home. That gave me a bit more of a drive as well, I was gutted but I went away with a bit of life in me and I went over for my next fight and destroyed the guy.
In between that I had a bit of time with her, but then I've been away, so I've been away for about half the year when you add it all up.'
