(CNN) -- The legendary Bjorn Borg fueled his success with a daily diet of steak and potatoes.
Hell raising stars of the recent past were not adverse to sinking more than a few beers after a tough match.
But the modern tennis star is more likely to be teetotal and to stick to a gluten free diet -- avoiding the red meat and carbs which five-time Wimbledon champion Borg apparently ate every day.
Doubles stalwart and ATP Player Council member Eric Butorac should know.
He's been on the circuit for nearly a decade and rubs shoulders with the likes of Roger Federer and Novak Djokovic both on and off the court.
"I think the top players have cut alcohol completely out of their diet and the rest of the players to stay competitive have mostly followed suit," Butorac told CNN's Open Court program.
"It's funny because actually our tour sponsor is Corona -- so there are Coronas available wherever we want, in the locker room and in the players' lounge but it's surprising that at the end of the week they are often not even touched.
"For the most part guys treat their bodies like a temple and take it very seriously."
Butorac believes the established "Big Four" of Rafael Nadal, Djokovic, Andy Murray and Federer have permanently raised the bar as regards fitness and diet issues and there is no going back.
With the rewards for success so large -- $31 million on offer at the 2014 season opening Australian Open -- any small margins gained can be worth a small fortune.
"If you look at the amount of money that can be won at the top of the sport or any major sport so you know that line between No.1 and No.5 in the world is worth millions and millions of dollars so I think you see these guys doing every little thing they can to achieve that," added Butorac.
Former Wimbledon champion Pat Cash said that the move to a great emphasis on fitness and diet started during his glory years in the 1980s and 90s, but his predecessors were not so careful.
"I heard stories that the old Aussie greats used to play hard and drink hard and used to have steak and potatoes," said Cash.
"I once asked Bjorn Borg 'what did you eat?' and he said 'every day I had a steak and I had potatoes' and he used to play five sets of practice every day and back it up day in day out with steak and potatoes!"
Modern superstars such as Djokovic would not dream of that approach and it was the Serbian who started a trend with his gluten free diet, cutting out wheat and treats such as chocolate.
"This particular diet changed my life really in a positive way and affected positively my career and my overall feeling on and off the court," Djokovic said.
As he charged to No.1 and went through 2011 with just a handful of defeats, others took notice and followed suit.
"Novak really made that popular when he really rose to the top," said Butorac.
"I don't know if it's a fad or if it's here to stay but it's definitely a thing that a high percentage of the guys on tour now are gluten free or almost primarily gluten free.
"I watch them taking strolls around the breakfast bar in France, bypassing the croissants and the pain au chocolats, all the different tempting things and actually staying away from it. It's pretty impressive to see them do it!"
They are helped by the more healthy offerings available at the ATP and WTA's official tournaments and with players on the road for half of the year, maybe more, this is vital.
"Players are looking to eat a lot of salads, a lot of fruits, pastas and then white meats, chicken and fish are really popular," Butorac said.
"The cuisine can vary tournament to tournament but also normally what the tournaments week in week out provide is some really healthy options that allows us to stay very fit."
But with this austere regime -- fat free and alcohol free -- has the sheer joie de vivre gone out of the game?
"I believe the fun on the tour has dropped," said American Butorac. "There is very little alcohol consumed as players take their matches and practice very seriously.
"But the tour is still a great place to be and there is plenty of fun to be had, though the stories we hear about what it was like 'back in the day,' it isn't even close nowadays."
The 1987 Wimbledon champion Cash, who retired in 1997, said in his era there was still a high degree of professionalism but the difference has been advances in sports science.
"You know more about nutrition. In my day it was all about carbo loading and I think it's slightly different now, it's not just about having carbohydrates because you need protein for your muscles to recover as well," said the Australian great.
Butorac, who is 32, has had to battle to earn a living on the ATP Tour and establish himself as the No.3 American doubles player behind the incredible Byran brothers (Bob and Mike).
A recent victory in the doubles at the Malaysian Open with Raven Klaasen was proof he is still a force at the top level and aside from attention to diet, Butorac, like many others, is training smarter.
"I have become more attuned to listening to my body, when it needs rest, icing, stretching, massage and addressing minor injuries.
"Almost every player on tour is hurt or dealing with some sort of minor injury. However, players have all become great at managing these niggles."
Butorac takes inspiration from the likes of Tommy Haas -- "playing some of his best tennis in his mid thirties" -- not to mention the 32-year-old Federer, who is the long-time president of the Players Council.
Butorac is a vice president on the 10-member board and the group meet about half a dozen times a year to address issues such as prize money, draw sizes and the tour calendar.
Player "burn out" has been a hot topic in recent years, making attention to diet and fitness all the more important with the increased demands placed on them.
"Players are taking their health very seriously," said Butorac.
"Fitness programs have reached new standards and along with that players' diets have become very healthy.
"I haven't seen actual chefs with players yet, but I have seen nutritionists who are getting the food for the player out late at night buying specific products that they want to have in their players' body the next day.
"And a physiotherapist is often in charge, making sure you have the protein shakes right after the match and also a specific diet that has probably been pre-arranged by a chef or nutritionist."
Tennis is not alone in this obsession with fueling the body with the right stuff.
"I think this is a trend in all sports though. I hear Steve Nash is a vegetarian and Kobe (Bryant) takes incredible care of his body," said Butorac.
At 39 and 35 years of age respectively, the LA Lakers basketball stars serve as a powerful reminder that careers can be prolonged in the most demanding of sports by taking care what you eat.