"Some have a higher level of testosterone, I feel smaller than them": Marta Kostyuk claims Sabalenka and Swiatek stand out for a reason

Marta Kostyuk has offered an honest reflection on what sets Aryna Sabalenka and Iga Swiatek apart from the rest of the WTA field. As the 23-year-old Ukrainian concluded her 2024 season with a first-round loss to Karolina Muchova at the Wuhan Open, she took time to analyse why facing the world’s top two players presents a unique challenge — one that goes beyond rankings or tactics.

Currently sitting at No. 28 in the world, Kostyuk has struggled to find a breakthrough against either player, holding a 0-4 record against Sabalenka and 0-3 against Swiatek. In her view, the difference lies not only in talent, but in the combination of physicality, power, and mental fortitude that defines both champions.

The Ukrainian, who has steadily climbed the rankings with her aggressive baseline play, recognises that the gap she faces is as biological as it is psychological. While she has the skill and variety to trouble most opponents, she admits that against players like Sabalenka and Swiatek, she is forced to rely on effort and precision rather than pure strength.

“Against Iga (Swiatek), when I have played her, I wasn’t ready to play her at all,” Kostyuk said in an interview with Tennis 365, when reflecting on her previous meetings. “I played her over a year ago and she was very strong. With Aryna (Sabalenka), I know it is a tough battle. I have my own skills, but at the end of the day, they are all much bigger than me, much taller than me, much stronger than me.”

That physical disparity, she explains, has a natural origin. “We all have our own biological structure. Some have a higher level of testosterone, some have lower. It’s just natural and that definitely helps. I feel smaller than them. I try to see how I can beat these players with the tennis skills I have, but I have to work harder to win the points. I have to run a lot more than them to win points.” Her awareness of these differences doesn’t come from resignation but from realism — a recognition that she must approach each match strategically, maximising every shot and every movement.

Kostyuk doesn’t shy away from her physical disadvantages; instead, she embraces them as part of her identity as a player. “I cannot make myself 10kgs bigger or five centimetres taller,” she said. “So I have to use everything I have at 100 percent. For other players, they have more of an advantage in other things. This is just the way I am.”

Despite often appearing smaller than her opponents, the Ukrainian views that as a challenge rather than a setback. “I look at the photos when we shake hands at the net and I look so much smaller than some of my opponents. It’s just part of the sport and a very cool challenge for me to take on these players.”

Her mindset reflects a blend of humility and quiet determination. Instead of focusing on what she lacks, Kostyuk channels her energy into sharpening the aspects she can control — movement, anticipation, and mental consistency. The gap in power between her and the top players becomes, in her own words, “a cool challenge,” one that pushes her to innovate rather than imitate.

Beyond strength and size, Kostyuk believes that confidence is what truly separates champions like Sabalenka and Swiatek from the rest of the field. “Their confidence is just different,” she explained. “I have played some close matches against Aryna and you see how she plays the break points. She just doesn’t care. She has no doubt that she will save them. She hits a big serve and hits the forehand. No doubt.”

That fearless approach, Kostyuk said, comes from experience at the highest level. “She is No. 1 in the world, she has played a lot of finals and she has that confidence. That helps her to have no doubts. For me, it is not so easy for me to play without doubt.” It’s a candid admission that underlines the psychological difference between contenders and champions — a gap that is often invisible but decisive when it matters most.

Still, Kostyuk remains undeterred. “It is an interesting sport and I’m enjoying the journey of trying to figure it out,” she added. Her willingness to learn from her defeats and to analyse the very traits that define her rivals shows a maturity that could serve her well in the coming seasons.