Serena Williams says success needs grind: “28 hours out of 24” disciplined humility

Serena Williams’ “secret” is less magic than math. In a 2025 interview with CNBC Make It, she says, “Tennis is [played] every day, you have to do it every day. You have to train, and business is the same,” adding, “It is exactly the same. You have to be very disciplined.” And when Williams talks about what founders must do to win in the real world, she goes even harder, telling Fortune that “as a founder starting a new company, you have to show up 28 hours out of 24.”

That grind message matters because Williams is not just still playing tennis. She has spent years building a business platform through Serena Ventures, and she is actively mentoring the people running the companies she backed. She’s won 23 Grand Slam titles across 27 years, stepped away from the sport in 2022 to focus on her business work, and then doubled down by investing in founders through her capital fund, Serena Ventures, launched in 2014. In parallel, she’s returning to competition at the 2025 HSBC Championships, where she will compete in doubles with Canadian athlete Victoria Mboko in London. The headline takeaway is simple and loud: in Williams’ view, consistency is the differentiator you can’t delegate.

If you run a company, you already know the language of perseverance. The sharper part of Williams’ framing is that she treats humility as an operational tool. She told CNBC that the “main value” instilled in her is “just humility,” explaining that it “keeps you grounded” and “keeps you respectful, and it keeps you just like everybody else.” That is not motivational wallpaper. In a startup or growth setting, humility changes who gets heard, what gets questioned, and whether a team updates its assumptions before the damage is irreversible.

Williams also makes it clear that her coaching isn’t generic. She told Fortune she is drawn to founders with a personal connection to the problem their company is trying to solve. Then, when mentoring founders, she repeats a core pattern: “dust yourself off and don’t stop.” She ties the reality of founder life directly to repetition and recovery, saying, “You win a few, you lose a few. You get knocked down, and you get right back up.”

Now bring those principles back to the investment business, where incentives often reward showmanship over endurance. Serena Ventures raised $111 million during its early-stage fundraising and, as of 2025, announced that her portfolio included more than 14 billion-dollar companies and several decacorns. Earlier, she highlighted that Fund 1 investments were 79% underrepresented founders, including 54% women founders, 47% Black founders, and 11% Latino founders. Executives should notice the second-order implication here: if you build a venture platform that is explicitly structured around underrepresented founders, then “grind” cannot mean identical advice to everyone. It has to show up as mentorship, access, and staying power when the path gets longer, not shorter.

Williams’ own career reads like the proof-of-work behind that philosophy. With 367 career wins, 319 consecutive weeks as the number one tennis player, and nearly $95 million in total prize money, the numbers say dominance. Yet the humility and “dust yourself off” language suggest she is trying to prevent the most common failure mode after success: believing you can coast because you used to be right.

The broader ecosystem is crowded with versions of the same lesson, but Williams adds a specificity that founders and boards can translate into policy. She tells Fortune that she is excited to talk with mentors about the determination she showed in her past career and “bring it out to this new career.” That is relevant for decision-makers because mentoring programs often become one-time events rather than an ongoing system. Williams’ “every day” logic, plus her insistence on discipline, implies mentorship should track behavior over time, not just deliver inspiration at the moment of fundraising.

Her perspective also sits comfortably alongside other major leadership statements in the source. Serial investor Mark Cuban has recommended “work like there is someone working 24 hours a day to take it all away from you.” Steve Jobs, starting working at Hewlett-Packard at age 13, said the factor between successful and unsuccessful entrepreneurs is “pure perseverance.” And Brian Niccol, CEO of Starbucks, stays grounded by being curious, telling Fortune in 2024 that the best business advice he received was, “Don’t be afraid to ask questions,” adding that even as CEO there are moments where he “don’t totally get what they’re talking about.” In other words, the competitive edge is not just effort. It is effort combined with learning loops.

For executives and boards, the strategic stake is straightforward: perseverance is expensive, but so is miscalibration. The lesson from Williams is not “grind forever.” It is that training, recovery, and humility need to be built into how the business runs every day. If you are a founder, you hear “28 hours out of 24” and ask what your team must do to make discipline real. If you are an investor, you hear it and ask whether your portfolio support actually helps founders stay standing through the ups and downs. A version of this story was published on Fortune.com on June 30, 2025. This story was originally featured on Fortune.com.