Twenty years ago, a rugby player's physique was not anything to write home about. For many athletes of that era, bulk was as much the product of beer as barbells, and players could get away with being a little on the scrawny side.
These days, every man on the pitch, from scrum-half to full-back, is a powerful, lean, immaculately-oiled machine. To survive 80 minutes in the professional game, you have to be incredibly fast, built like a tank and be able to use your strength as skillfully as a gymnast.
It is a brief that perfectly describes 23-year-old Cork native Peter O'Mahony, who is only too aware of his responsibilities as the new Munster skipper.
In Dublin to launch the Snickers 'Who Are You When You're Hungry?' campaign, you would expect him to be wolfing down free chocolate bars, but he is keeping a close eye on his diet, even on his day off.
"They're for the heavier fellas!" he says, laughing. "I'm a lean athlete at the moment, so I have to stay away from that kind of stuff. Maybe on treat day, on a very rare occasion, I'd have one or two."
Clearly, Peter has willpower to burn – how much of a rugby pro's day is taken up with dietary dilemmas like this one?
"It's very different from player to player," he says. "Everyone's body reacts differently. Some guys are blessed with a phenomenal metabolism and can eat whatever they want whenever they want, and other guys balloon out if they do that.
"I have to keep an eye on things a little bit. I'm lucky, I have a fast metabolism, but I still have to stay on top of it.
"The way rugby has gone now, everybody has to be quite lean and eat well. Your body is your job, so you have to look after it well."
For Peter, looking after his body means feeding it lots of fruits, vegetables, lean meat and whole grains –and he really means lots! The average rugby player needs to consume between 4,000 and 5,000 calories a day during pre-season training.
"It all depends on what kind of a training day we've had," he says. "If you've had a heavy enough session, normally on a Monday or a Tuesday, you need a good bit to keep you going."
With the amount of food it takes to fuel Peter for a match, it should come as no surprise that a large percentage of his waking hours is taken up with eating.
"In fairness, our nutritionists really look after us," he says. "Sometimes, if it's too much for us, they'll give us a couple of shakes to make up the difference. Obviously, the best source of energy is your meals, but sometimes that's simply not possible.
"Rugby has become very technical in regards to conditioning and nutrition," he adds, before outlining his typical training schedule, a head-spinning mix of on- and off-field conditioning, weight training and traditional rugby drills. "The big thing in rugby is mobility, it's stretching and rolling, all these kind of things," he says.
"It's become the fourth part to the rugby player – your speed, your strength, your rugby skills and now you've got your mobility as well, which kind of adds to everything else, keeps it ticking over."
Is there any part of training that he particularly loathes?
"I'm sure a lot of the lads would say running, the conditioning aspect, the long-distance running, that would be the one thing that would break a few fellas!" he says.
"It's obviously very important because it's tough going when you're one match down and you have another five or six to go, but yeah, it's a great feeling when you've got that done."
For a player who regularly carries the expectations of a passionate fanbase on his shoulders, the mental workout is every bit as important as the physical, which is why you'll find Peter swimming, fishing or taking his dog, Roxy, out for a walk, before an important game.
"Those things are great for getting your head right," he says.
"I think part of rugby is leaving it on the field, and it's nice to do something outdoors. I like the outdoors – I like going for a fish, or a walk with the dog rather than being in front of the television. I'd rather be outside, especially with the nice weather.
'Ithink it's very important for guys to have something that they can do to switch off from rugby, and maybe just park it for an hour or two a week, just to get out and get away from it.
"It can be overwhelming at times, especially around the big games. You need to take a step back and take a bit of down time for yourself."
As Munster captain, Peter is setting the example for an entire squad of athletes, but he is adamant that nothing about his playing style or attitude changed when he became skipper.
"When you look at rugby, the great captains don't really care," he says.
"I've always obviously looked up to Paul (O'Connell), a big player for Munster and Ireland for many more years to come – he wouldn't carry on differently, really.
"He wouldn't carry on any differently in a dressing room. When Dougie (Howlett) was captain, he still carried on as he always did.
"I think the best ones don't change. It's not like when you're captain you've gotta play 10pc better or 10pc worse. You've got to work your hardest every time you go out."