MONTREAL, Canada -- Iga Swiatek had a unique practice session ahead of her tournament debut at this week's Omnium Banque Nationale. Fresh off her victory on home soil at the BNP Paribas Warsaw Open, where she captured her tour-leading fourth tournament of the season, she discussed one of her more creative training techniques.

In the days leading up to the tournament, the World No.1 player was spotted on the practice courts with a piece of tape over her mouth. Devised by her fitness coach, Maciej Ryszczuk, the unorthodox exercise helps to restrict Swiatek's oxygen intake to improve endurance. 

"It's harder to breathe when you're only breathing with your nose, and it's easier for my heart rate to go up," Swiatek told reporters during Media Day. "I'm not going to explain it to you perfectly because I'm not an expert. Sometimes I don't get the things they tell me to do, but I'm doing that for a long time now so it got pretty easy. 

Montreal preview

"But for sure you can see the difference in how everything you do on the court is getting more and more hard with that tape on your mouth. So I guess it's the way to kind of work on my endurance by not having me run so fast and do extreme things."

You can add "the tape method" to the unique list of Team Swiatek's preparation. She remains the only player to travel with a full-time sports psychologist. Her team uses medical instruments to measure her brain and heart activity for stress indicators. Then there are the puzzles and mini-games that test the 22-year-old's cognitive speed. 

After a bye in the first round, Swiatek will face Karolina Pliskova in the second round in Montreal. A potential rematch of the French Open final against Karolina Muchova could take place in the Round of 16. 

Last year, Swiatek came into the US Open Series with more insecurities about the state of her game. After going unbeaten over 37 matches, Swiatek took two losses, at Wimbledon and in Warsaw. 

"I remember for sure I had some technical struggles that I focused more in terms of where I wanted to improve, but I was kind of stuck with a few shots that I didn't like," Swiatek said. "This year I don't have that. I feel more confident."

Swiatek has fewer points to defend over the next two weeks -- with losses in the Round of 16 in Canada and Cincinnati a year ago -- than in recent events. But her title defense at the US Open is just around the corner. A win there would give her four successful title defenses this year. 

"I think playing Warsaw on hard court changed a lot the perspective because last year, switching from grass to clay and then to hard court was really tricky," Swiatek said. "This year, I feel like it's a really nice process without any extra obstacles. So it was pretty easy for me to just focus on work.

"I think it's great before the whole swing and before the US Open." 

This will be Swiatek's first-ever appearance in Montreal, but Canada holds a special place in her heart. When the tournament was staged in Toronto in 2019, Swiatek was a qualifier who stunned Caroline Wozniacki in three sets before playing a memorable duel with Naomi Osaka. Swiatek recalled the matches fondly. It was when she found the belief she could hang with the best.

"When we played in Toronto, it was a kind of a breakthrough match for me because I realized that I can win those matches against the best players, the really experienced players. And I remember it was important for me because I lost the first set, 6-0 and then I came back. I was able to shake off all the stress and just focused on the game."

2019 Toronto highlights: Polish teen Swiatek seals Wozniacki in titanic tussle

Wozniacki 'not stressing' over comeback in Montreal

On the topic of Wozniacki, Swiatek says she's excited to see what the Dane can do in her comeback to competition.

"Even though she is not representing Poland, we all know that she speaks fluently, her parents are Polish," Swiatek said. "So she was one of these people that showed me that it's possible, besides, Aga Radwanska obviously. 

"It's great that she wants to still see what she's capable of and to still challenge herself. I just have a huge respect for what she has done before. It's nice for me to see that as a player, even though she's satisfied with her career, she still wants to come back and challenge herself. I don't know if I would have the strength for that.

"So I'm just going to cheer for her. It's been pretty exciting."