Caroline Wozniacki studied Dwyane Wade's sock range, while Garbine Muguruza is currently investigating the business interests of Roger Federer and LeBron James.
Johanna Konta, meanwhile, has been reading up on the careers of Chip and Joanna Gaines - the home makeover reality TV couple from Texas.
The three WTA stars are all past or present students of a three-month course at Harvard University, which gives athletes the chance to develop business skills by working alongside current MBA students.
The programme, now in its fifth year, has also been completed by two-time Grand Slam champion Victoria Azarenka, former NBA player Chris Bosh, and Olympic and World Cup-winning footballer Heather O'Reilly.
The course allows athletes to timetable sessions around their playing careers, with Muguruza and Konta - who are part of the 2021 intake - relishing a return to (online) schooling.
"Once I commit to something, I'm pretty intense about it," Spanish two-time Grand Slam champion Muguruza told BBC Sport.
"I like to study and do the exams. It's exciting, it's an adrenaline - I've always loved school.
"I consider myself decent a studying person, I had good notes. History was my best subject, I loved it. The wars, I was very good at studying dates and what happened in this country and that country, why did they fight?
"I was always very curious at what happened before I was born."
Konta, the British number one and three-time Grand Slam semi-finalist, nominated history and maths as her two best subjects.
"I liked maths for the fact there was going to be a wrong or a right answer. I liked that predictability of it," she said.
"And then I've always loved history, I love stories. I loved learning about Greek mythology, or ancient Mesopotamia, or ancient Egypt.
"I always enjoyed the process of learning and I think that translates into my tennis career. Starting to study a little bit again has been a bit nerve-racking, a bit intimidating, but also really fulfilling."
With help from three current Harvard students - Sam, who has a media background, Mike, who was in the military, and Mark, a former dancer - Konta has been working on various case studies.
One focused on which tennis players should receive the main share of the appearance budget at the ATP tournament in Rotterdam a few years ago. Konta had to analyse decisions made based on the funding available, and the audience demographic.
But not all the subjects are so close to home.
"I don't know if you know Chip and Joanna Gaines," she continued.
"They have a show called Fixer Upper on HGTV. They were leaving, they'd finished that show, and it was basically about Discovery wanting to keep them and therefore offering them the opportunity to set up their own network within the Discovery umbrella."
Muguruza has recently been studying the Argentine football club Boca Juniors, and some of 20-time Grand Slam champion Roger Federer's business decisions.
"He's a very ambitious person," she said.
"I think that he is super focused on what is coming next for him, his legacy. I feel like he wants to be very involved in everything he does. Everything he touches, he wants to be very successful and sophisticated."
Wozniacki, the 2018 Australian Open champion who is now retired, was among the first group of WTA players to sign up for the Crossover Into Business course in 2019.
Her final project focused on the sock collection the former Miami Heat star Dwyane Wade launched with the company Stance.
The former world number one says the course offered her a very different perspective on the business world.
"As an athlete [when you start working with a company], you see the numbers or you know that you are wearing a patch on your shirt.
"But to look at it from the other side and why is it beneficial for the company, and why do brands want a certain person to represent them - there's a lot of things that go on behind the scenes that I thought were very interesting."
Of the three, Konta was the most forthcoming about what a future business career might entail.
The 29-year-old is a keen cook, and has already established a dog-walking business with her partner, Jackson.
"I love dogs, and I really want to do right by them in this world," she said.
"So I'm passionate about happy canines - it's very much in the infant stages, but it's something I'm definitely looking to how I can grow.
"And I'm passionate about food in a lot of different ways: from the general consumption of it to the really charitable side of it in food waste and hungry people. There's so many different things I want to do with that."
First though, Konta needs to graduate, and has the support of a one-time rival in Wozniacki.
"I think tennis players in general, being in an individual sport and having to think a lot on our own and make a lot of decisions in a quick amount of time, are well equipped to do this," she said.
"I think Jo will do a great job."