Canada’s Andre De Grasse competes in the men’s 200m at the Rio 2016 Olympic Games in Rio de Janeiro on August 16, 2016.JEWEL SAMAD/AFP / Getty Images
If the Rio de Janeiro Olympics have proved anything, it's how much can happen in the span of four years.
Consider that the last time the Summer Olympics were held, in London in 2012, Penny Oleksiak was a 12-year-old and Andre De Grasse had just recently given up high school basketball to dabble in sprinting.
Neither was in the conversation for 2016. Now, they are Canada's undisputed stars of Rio. With seven podium appearances between them, Oleksiak and De Grasse have had a hand in nearly a third of Canada's 22 medals.
At 16, Oleksiak's four medals set the record for the most claimed by a Canadian swimmer in one year, and tied her with Victor Davis for the highest Summer Games career total.
De Grasse's three-medal count made him the first Canadian sprinter since 1932 to take home that much hardware in a single year. At 21, he is now considered the heir apparent to the sprinting kingdom soon to be vacated by Jamaican legend Usain Bolt, who turned 30 on Sunday and is expected to retire before Tokyo 2020.
Both are leading hopes for Canada in Japan. And De Grasse is looking to better his performance there. "I hope for my next Olympics that I can do something [Bolt] has done before – win triple gold," he said.
While no one is counting against that, there is reason to exercise caution over exuberance: The remarkable and sudden rise of Oleksiak and De Grasse proves that trying to predict what happens between now and 2020 is next to impossible, given the shifts that can, and most likely will, occur.
Somewhere in a Jamaican sprinting academy, there is a young sprinter looking to inherit the mantle from Bolt. And inside the U.S, Australian, and Chinese swimming programs, those juggernaut countries are almost certainly going to churn out a few Oleksiaks of their own.
Still, De Grasse and Oleksiak give Canada more reason for optimism coming out of these Olympics than the country has had emerging from any Summer Games in recent memory. Both have yet to enter their prime performance years, meaning there is still considerable upside to hone through training.
Swimming Canada officials believe Oleksiak, who is already nearly 6-foot-2, will only get stronger, and perhaps a slight bit taller, by the time the next Olympics roll around. That added strength is expected to make her more of a threat in the pool than she was in Rio, her coach, Ben Titley, said.
"We'll start our building blocks all over again," Titley said of the plan for Oleksiak once she returns to Canada and begins training after a few weeks off.
"Our first building block is going to be working on her underwater work, like her fly kick – where you see people dolphin kicking in some of those underwater shots on the TV. That's an area where she still is nowhere near world-class yet."
Athletes train with the goal of being at their best each year for the world championships. But in the background, there is also an eye to a four-year strategy aimed at Olympic success.
"Because we're now at the start of a four-year cycle, we're going to spend the first two or three months really focused on [improving] her so that within the four years' time, she's been built into a better athlete than what she currently is now," Titley said. "And I don't see any reason why that's not possible."
Meanwhile, De Grasse admits he still has a lot to learn as a sprinter. His emergence, from a guy who was discovered at a high-school track meet running in basketball shorts and borrowed spikes and not knowing how to use the starting blocks to a multiple Olympic medalist, has been remarkable.
"He's a catcher. He can snatch people," Canadian relay coach Glenroy Gilbert said of De Grasse's ability to finish strongly in races.
De Grasse figures there is room to improve, particularly on his starts, where he can be much more explosive.
"It's definitely a learning experience for me," he said. "I think I learned a lot about myself technically [in Rio], because if I can just develop a better start. … If I just work on my first 30 [metres] out of those blocks, I think it's a whole different race for me."
New rivals are emerging as threats for Tokyo already, including the host Japanese sprinting team, which surprised Canada by beating it for silver in the 4x100 relay.
"I didn't even know who they were," De Grasse said, impressed by Japan's performance. "They're peaking at the right time, because now they have Tokyo coming up in 2020, so they're definitely going to be a threat and they're going to have the hometown support for them. So we're definitely going to have to watch out for them."
The other factor impacting how Canada does in Tokyo will be funding. After Oleksiak won her medals, Titley told The Globe and Mail that he hoped corporate sponsors would step up and support swimming more, given the success Canada had in the pool in Rio.
"We've got a girl here who is something special. We've got a team here that could be something special. And I'm sure they've made all of Canada proud – but we need people to invest in these athletes," Titley said.
The 22 medals Canada won over the past two weeks exceeded the 19 medals Canadian officials projected before Rio, and equalled the country's best medal count in a non-boycotted Summer Olympics.
De Grasse and Oleksiak carried the bulk of that load at these Olympics, and they will be looked upon for a similar performance in Tokyo. But Titley figures that's not impossible.
As he put it following one of Oleksiak's last races in Rio – the work for Tokyo begins now.