Sloane Stephens reveals the data and insights that take her game to the next level

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NEW YORK—Back in one of her favorite tournaments, Sloane Stephens kicked off her US Open campaign with a victory—overcoming an early wobble against Greet Minnen and raising her level to complete a 1-6, 6-3, 6-3.

That's been kind of a theme throughout Stephens’ career: the wobble, and the comeback.

In 2017, the American was on crutches with a broken foot—and a few months later on Arthur Ashe Stadium lifting the US Open trophy. After struggling with consistency in 2020 and 2021, Stephens is back with a vengeance this year after clinching the Guadalajara title, her first tournament win since 2018.

“Having gone through a major foot surgery in early 2017, I know that there are no guarantees in a career,” Stephens told us.

“I’m grateful every day to be out here doing what I love to do. That’s success to me.”

Before the tournament, Stephens caught up with Baseline to talk self-care, daily rituals and how she and her team use WHOOP data and insights to take her game to the next level:

Q: Athletes measure “success” in so many different ways, whether that’s in trophies or prize money figures or intense emotions. What’s your personal metric for success, and what does that word mean to you?

Sloane Stephens: Success is being proud of who I am and the effort I put in every day. Having gone through a major foot surgery in early 2017, I know that there are no guarantees in a career. I’m grateful every day to be out here doing what I love to do. That’s success to me. When you believe that for yourself, results follow.

Q: As a professional tennis player who prioritizes self care, how do you balance the demands of the job and the sport—plus, your work on projects like the Sloane Stephens Foundation—with making sure you’re also meeting your own needs?

I rely on my calendar, Slack, and my team to keep everything organized and running smoothly. Part of being a leader is being able to communicate my vision for different projects and trust that they can keep progressing when I’m focused on what I need to do for my tennis.

I always take the time for self-care rituals like face masks and body scrubs, and consistently check in on my mental health through therapy. I’m vocal about what I need and what I’m feeling so people know and we can make a plan.

Q: You’ve been using WHOOP for a while now, even before it became the official fitness wearable for the WTA Tour. Is there anything new that you’ve learned about yourself through WHOOP that surprised you or that you didn’t expect?

Consistency is key for me, so I’ve learned what my usual routine equates to in terms of strain, recovery, etc. The WHOOP journal has gone through a lot of upgrades and is very quick to complete, so that’s a great tool for keeping yourself honest about everything you did the day before.

I would also remind people that strain scores are individualized, so you can’t compare your 9.0 to someone else’s 11.0 or 12.0. Just focus on the routines and practices that produce the best results for you.

Q: Let’s talk about periods, a topic that has been receiving a lot of attention in women’s sports, including tennis. As a part of the Women’s Performance Collective, you’re helping to research the links between menstrual cycles and performance/training. Can you share more about your involvement and some of what you’ve been discovering in the process?

There is a lot of insight to be unlocked when people acknowledge that women’s bodies are dynamic throughout our cycles. The Women’s Performance Collective is focused on exactly this—how do we take our shared experiences as women athletes, and move the conversation forward through data and research?

These conversations are becoming more common in society, and I’m encouraged by that.

Q: In the past you’ve mentioned using WHOOP to fine-tune your daily routines, both at home and on the road. What are some of your most reliable daily rituals that you’ve created through those insights?

The nature of professional tennis is that I’m traveling every week, and often switching up time zones, environmental conditions, altitude, etc. With all of this extra stress on my body, my recovery can frequently be in the red. When that happens, I acknowledge it, and I focus on how I can get back into the green as quickly as possible.

This comes down to being consistent with my morning alarm time and focusing most of my intense training and practices in the morning and early afternoon. After 4 p.m. or so, I shut things down to recover and shift focus to running my businesses while getting a massage or wearing my Normatec boots.

Q: How does your coaching team use your data, if at all? Have you guys adapted any training sessions or pre-match/recovery routines based on what you’ve learned through your fitness tracking?

We use my data on a daily basis to optimize my schedule and training. Especially with the rigors of our travel schedule, it’s helpful to know how my body is actually performing and recovering versus what we suspect is happening. Knowing my match strain helps my team plan practices that either replicate the intensity and conditions of a match or help me taper and have a lighter session.

Q: Break down your stats for us: What does a full-intensity, three-set WTA battle look like in terms of Strain? How intense are your pre-match warm-ups and practices? And how do you achieve an “ideal” Recovery afterward?

My matches are always at least a 15.0 strain, but I’ve had several matches that have maxed my strain out for the day at 21.0. My team has tracked themselves watching my matches and categorized it as “high stress work”—they’ve gotten 10.0s on that before. Wild.

My daily practices are at least a 12.0, that is pretty consistent. On a match day, I’ll warm up for 20-30 minutes and typically hit a 5.0 strain or so—just something light and quick to get a rhythm.

I wish I had more to say about an “ideal” recovery, but it comes down to the schedule. I’ve been playing a lot of night matches or late day session matches recently, so once I cool down, do press, and whatever else I need to handle on-site, I’m trying to eat quickly and go to sleep.

Q: With the US Open just kicking off, can you talk about how you’re feeling ahead of the last Grand Slam of the year, and how you’re mentally approaching this part of the season?

This is one of my favorite stretches of the season. I love playing on home soil, and there’s nothing like the New York crowd. Even though I grew up in Florida and California, this feels like a home tournament in many ways because I have so many family and friends come out to support me.

Q: In addition to your already impressive professional career, your tennis has an impact off the court as well through the Sloane Stephens Foundation. Tell us more about your foundation, and the work you do for youth around the L.A. area?

It’s hard to believe, but next year is our 10-year anniversary. I started my foundation when I was 20 because I recognized that tennis could be an incredible lifelong sport and open so many doors, but it has a lot of barriers to entry that make it inaccessible or unapproachable for a lot of youth, especially in under-resourced communities.

Tennis has made strides in terms of representation and diversity, even within my lifetime, but we still have a long way to go. I wanted to create the opportunity for kids to have an amazing first interaction with the sport, and I want tennis to be the hook that keeps kids healthy, safe and thriving in school.

We have programs in over 20 schools within the Compton Unified School District, and work with over 10,000 youth each year. For example, we have recess tennis programs in every elementary school in the district. Within those schools, every single child touches a racquet during recess, and every child has the opportunity to work with academic tutors and mental health/social work professionals. That makes me really proud.