PARIS — Perhaps it was the “pain and exhaustion” of swimming in 13 races over  the course of the gruelling Paris Olympics meet.

Perhaps it was the fact that freestyle sprinting isn’t the strongest in 17-year-old Summer McIntosh’s incredible competitive arsenal.

Or, maybe she was just run down by some of the best in the world over 100 metres as her breakthrough Olympics came to a close.

Whatever it was, the Canadian swimming sensation was unable to punctuate her historic Olympics with a relay medal, fading to fourth in the final leg after her three teammates had got them to second place through 300 metres.

As a result, the Canadians finished fourth in the 4×100 medley relay here at La Defense Arena on Sunday night, the final dash in an exhilarating meet.

“Going into today, I just tried to leave everything I had left in the pool,” McIntosh said, not reaching for excuses for her effort. “No one is feeling fresh on Day 9. Everyone is in the same boat there.

“Of course, you’re going to get tired, nine days of Olympic racing, but at the same time, I’ve trained years and years and simulated this kind of pain and exhaustion way greater than this right now. I really just try to trust my training and trust that I’ve put in all the work I can to prepare for moments like this.”

The agony of a near-miss aside, McIntosh knows what she’s done in Paris over the previous nine days, swimming her heart out for three golds and a silver medal. It will go down in history as the greatest collective work by a Canadian summer Olympian in one Games.

“Obviously, I’m pretty happy with my results,” McIntosh said, despite not being able to finish it off for Kylie Masse (backstroke), Sophie Angus (breaststroke) and Maggie Mac Neil (butterfly) who had set the stage for her to close it out. “It’s been some of the craziest days of my life this past week and a bit. Just trying to soak in this moment. I’m already thinking of L.A. (and the 2028 Games) to be honest. I’m really excited.”

With her freestyle leg clocked in 53.29 seconds, McIntosh saw the Aussies and Chinese pass her in the final 100 metres as the Americans cruised to gold in world-record time. The Chinese closer, meanwhile, swam in a blistering 52:11.

With the narrow-miss, the Canadians finish these Games with eight total swim medals, a nice boost from the breakthrough six they captured at Rio 2016 and matched in Tokyo three years ago.

Speedskater Cindy Klassen’s five medals at Turin 2006 remain the most in one Olympics by a Canadian. McIntosh’s four medals match Penny Oleksiak’s record in Rio eight years ago as the most by a Canadian swimmer.