“Even if I am on vacation, you’re on 24 hours a day. You never can really leave,” says Lior Lewensztain, founder and CEO of fruit bar and snack company, That’s It Nutrition.

And while the nutrition bar industry has exploded into a multi-billion-dollar enterprise in recent years, Lewensztain being willing to sacrifice tranquility at beach trips has been part of what’s helped propel his company through the crowded food space. His company now brings in over $50 million in annual revenue and is on the shelves of 85,000 retail stores, including Costco, Walmart, and Target. 

But just because they got their foot in the door doesn’t mean they can lay off the gas, the 46-year-old says. More success means more eyes watching—and more effort is needed to protect what you’ve built and fend off imitators.

“If you’re hesitant, somebody else will take your spot in a heartbeat,” Lewensztain adds.

Reality check: Work-life balance might kneecap success

Work-life balance is a perk that many young workers prioritize on the job hunt. After all, the ability to log off at 5 p.m. without thinking about work until the next workday is something experts say can have bountiful mental health benefits—and even enhance productivity during the prescribed work hours.

But Lewensztain isn’t the only one who cautions that staying ahead means embracing a grind that doesn’t always fit neatly into work hours. The billionaire Mark Cuban said last month that ambitious people can’t afford to spend time away from being focused on this business. 

“If you want to work nine-to-five, you can have work-life balance,” he told Sports Illustrated. “If you want to crush the game, whatever game you’re in, there’s somebody working 24 hours a day to kick your ass.”

Even former President Barack Obama admitted that “if you want to be excellent at anything—sports, music, business, politics—there’s going to be times of your life when you’re out of balance, where you’re just working and you’re single-minded,” he said on The Pivot Podcast.

Lucy Guo, billionaire cofounder of Scale AI, admitted to Fortune she gets up at 5:30 a.m. to begin her workday bright and early—and typically doesn’t log off until after midnight. 

For Lewensztain, work doesn’t mean locking himself up in the corner office, it’s getting his hands dirty across all parts of his business.

“It’s never a dull moment. I’ll be hopping from literally marketing to operations to finance all within minutes, if not hours. It’s really to fill the gaps where I’m needed,” Lewensztain adds.

“I’m a very hands-on type of CEO, where I am not trying to micromanage, but I really like being involved in the day-to-day. It keeps my finger on the pulse.”

Crucially, it’s not just startup chiefs and Fortune 500 bosses that have to put in overtime to get ahead: Unfortunately for work-life balance-loving young people, experts have stressed that 40-hour workweeks aren’t enough if they want to climb the corporate ladder. In a leaked memo to Google’s AI-focused workers, Sergey Brin suggested that 60 hours a week is the “sweet spot.”