Ryan Reynolds helped design the shirt for this year's Terry Fox Run and the response has been 'overwhelming'

The Terry Fox Foundation has announced that  the design for this year's shirt honouring one of Canada's most inspirational figures was picked by Ryan Reynolds – and the response has been "overwhelming."

Reynolds posted a photo of himself Saturday, wearing the shirt and alluding to his involvement with this year's fundraiser for cancer research.

"I’ve been taking part in the Terry Fox Run since second grade and can’t think of a more enduring and lovely legacy for one person. Terry Fox inspired millions in life and death," he wrote.

After a flood of people asked how they could get the shirt themselves, the charity posted online saying "Secret's out" and announcing that it had been working with Reynolds on the design and that the shirts would be available on April 12 – the 43rd anniversary of the start of the Marathon of Hope – to registrants for the annual run. 

But that didn’t seem to satisfy people who wanted to get their hands on Reynolds' favourite pick while contributing to a good cause.

On Sunday morning, the Terry Fox Foundation announced that it would be selling the shirts early, an unprecedented move made due to the overwhelming demand.

"We’re excited to see the early response from supporters and have launched our first-ever pre-sale," a spokesperson told CTV News in an email.

"We are aiming to engage iconic Canadians in our annual launch to reach broader audiences and spark early excitement for the Terry Fox Run. Terry’s story and legacy resonates so profoundly with people of all ages, backgrounds, and abilities in Canada and beyond."

The shirt itself shows Fox set against a background of the phrases "Dear Terry" and "Cher Terry." The text looks handwritten and the design was inspired by "the countless messages Terry received from the millions of people he continues to inspire," according to the foundation's website. The back of the shirt shows actual letters received by Fox. One reads simply: "Run, Terry, run." Another says, "You are my greatest hero ever."

In the years since Fox set out to run across the country to raise funds and awareness, the annual event honouring his legacy has raised more than $850 million for cancer research.

This year's Terry Fox Run is scheduled for Sep, 17. Information on how to participate is available online.