If you could be 5 percent better at your job -- with a small, albeit slightly painful, adjustment -- would you do it?
For Steve Johnson, whose success is measured in hundredths of seconds on a tennis court, the answer was, emphatically, yes.
That's why the 27-year-old Californian summoned the discipline to blow off those late-night burgers and fries, and in three offseason months he remade his 6-foot-2, 198-pound body into a taut, sinewy 183 pounds.
"This is my career, my profession," Johnson told ESPN.com from Delray Beach, Florida. "I just want to get better as a tennis player -- that's the short-term and long-term goal. I need to turn over every stone possible, do everything in my power."
Less, at least in terms of today's tennis, usually means more.
It's a basic law of physics. The less baggage you're dragging around from side to side, from baseline to net, the quicker and stronger you'll be as the points, games and sets play out. Novak Djokovic came to the Australian Open looking, to some, painfully thin. Even Rafael Nadal, who looked like an NFL safety in his glory days, seems to be down a few quarts. Thin is undeniably in.
So how did Johnson do it?
More exercise and less food, he said, sort of joking. But in essence, that's about right.
Johnson had been considering the idea for some time, but after three years of plateauing in the ATP World Tour rankings -- at Nos. 37, 32 and 33 -- he decided to change things up in a number of areas.
Johnson was still at USC, in the process of winning four national team titles, when American professional Mardy Fish underwent knee surgery in 2009 and struggled on his return in 2010. With the help of physiotherapist Christian LoCascio, Fish lost 30 pounds and, more important, trimmed his body-fat percentage to 7 percent from 21 percent.
Johnson, who lives in Los Angeles and counts Fish as a friend, reached out to LoCascio and got on a program. For the first two weeks after the 2016 season, when he didn't pick up a racket, Johnson hit the gym hard and limited his daily calories to around 2,000. Sunfare, a company that delivers personalized, healthy meals, handled the food. When Johnson started practicing again, he upped his daily intake to 3,000 calories.
"The trick is to hold hard to a ratio between protein and carbohydrates," Johnson explained. "It's a formula that works with my body type. I'm a sucker for dinner rolls, but now that I have a better understanding of how it works, I just say no.
"Really, there's nothing more to it than me not doing it. As I've gotten smarter, it's gotten a lot easier."
It takes a village to make over a tennis player's body.
Working with trainer Andrew Morcos, Johnson began working at Proactive Sports, on the recommendation of Tommy Haas. With coach Craig Boynton, Johnson navigated his way through all the changes in nutrition and training.
So far, the results have been inconclusive. He made the semifinals at Auckland, losing to fellow American Jack Sock, but he lost in the second round of the Australian Open to Stan Wawrinka. After going 1-1 a week ago in Memphis, Johnson has another date with Sock in Friday's first quarterfinal match at Delray Beach.
The Americans are a tight group and, according to Johnson, the competition makes them better. There are five U.S. men -- Sock, John Isner, Johnson, Sam Querrey and Ryan Harrison -- currently within 23 ranking spots.
"It's a great thing," Johnson said with enthusiasm. "We all want to push each other to get better -- that's the goal. Hopefully, we can turn it around and get a positive light in the media, get some people behind us."
Tennis just might be the most physically demanding of sports. Soccer features 22 players and one ball -- tennis has two combatants. Unlike football, basketball and baseball, there are no teammates in tennis -- or substitutions. There isn't a lot of running in boxing or mixed martial arts.
Johnson measures his offseason success not in terms of pounds, but in improved fitness.
"I feel like I've added this tool to my game and it's given me another outlet, another way to win," he said. "The good news is, I feel like I haven't played my best tennis yet -- not by a longshot."
Johnson, driven by the daily demands of practice and matches, has now upped his daily calorie count somewhere beyond 3,000. His playing weight is currently 187, so he's down 11 pounds from last year, about 5 percent.
"I feel quicker, lighter on my feet," Johnson said. "I'm getting to balls earlier, not getting tired. When I play the long points, the other guys are huffing and puffing, and I'm like, 'Let's keep playing.'
"I was in good shape, but now I'm in better shape. Now, if the tennis is not there, I know I can run and run and go figure it out on the fly."