Penny Oleksiak’s high school coaches are surprised but proud that their tenth-grade student has won not one but four medals in Rio de Janeiro – a record haul for a Canadian at a Summer Games.

Bryan McAlpine, head coach at Monarch Park Collegiate in Toronto, told reporters Friday that he and fellow teachers thought she Oleksiak was incredible, but despite seeing her build “more and more momentum” before the Games, they “never would have predicted anything like this.”

“I thought … maybe Tokyo?” he said, referring to the 2020 Olympics host city. “But gold in Rio is mindboggling.”

Oleksiak tied for gold in the 100-metre freestyle Friday, after earlier taking a silver in the 100-metre fly and bronzes in the and bronzes in the 4x100 and 4x200 freestyle relays.

While he didn’t predict the medals, McAlpine said he was astonished by Oleksiak’s endurance when training at school. He said the girl once held a plank so long he had to stop her because they ran out of time.

Oleksiak would train with her national coach in the mornings and McAlpine said he worried intense fitness training at school might hurt her, but Oleksiak’s father told him “she can take it -- push her.”

McAlpine described Oleksiak as well-grounded and humble, and described how she blushed when her classmates applauded her for setting a new Canadian record at a meet.

Jenna Grezela, who coaches the swim team at Monarch Park and serves as Oleksiak’s guidance counsellor, told CTV News Channel that watching her swim was like nothing she had ever seen before.

“It’s almost like she floats on top of the water as she motors across,” she said.

Grezela added that Oleksiak made time for her high school swim team even though she spent mornings training with the national team in another part of the city.

Grezela said her student also managed to balance her social life with school and athletics.

“She’s a high school student as well as competing at the Olympics. That doesn’t happen a lot,” she said. “To make that work shows how humble and amazing she is.”