Athletes have come and gone throughout the duration of his career, but he has defied studies that suggest sprinters peak in their mid-to-late twenties.
At 40, the runner from Saint Kitts and Nevis will be the oldest sprinter at this month's Rio 2016 Olympics, and is already the oldest male to have competed in the IAAF World Indoor Championships -- finishing eighth in the 60 meters in Oregon in March.
In May, he ran a personal best of 9.93 seconds in the 100 meters in Germany, making him the first 40-year-old to go under 10s. It beat his previous record of 9.96 from London in 2014, when he was 38.
"I've been trying to retire for the longest while, but each time I think about that I keep running faster -- and you think that the best is yet to come," Collins told CNN.
"I felt good and confident. The body just takes over and says, 'Hey, this is what we've been training for. This is what we've been working towards. And we're going to get it right today.'
"I'm looking forward to getting it right many more times."
Collins made his Olympic debut in 1996 when his Caribbean island nation made its first appearance at the Summer Games.
At Sydney 2000 he was the first athlete from St. Kitts and Nevis to reach a final, which he repeated at Athens 2004 in the 100m and Beijing 2008 in the 200m.
Collins is still working with his wife Paula, and says "she's doing a fantastic job."
"I listen well, and I'm a good student and she's a good teacher -- it makes a good recipe."
Collins has never finished higher than sixth at the Olympics -- indeed, his country has yet to win a medal -- but he was the world 100m champion in 2003 and claimed gold at the previous year's Commonwealth Games, with several silvers and bronzes from international competitions.
He has the ninth-fastest 100m time outdoors this year, so making the eight-man final in Rio will be an achievement -- but Collins has higher hopes.
He'll be up against the likes of Usain Bolt -- seeking to complete a "triple triple"
-- and American Justin Gatlin.
"Gold, silver, bronze, fourth, fifth, sixth, seventh, and eighth; all things are possible. But I think it's going to be a great event regardless and the competition will always be tough," he says.
"You just have to think about running the race that you've been training for and just hope for the best."
Keep going and going
When asked about the secret to his longevity, Collins told CNN: "If there was a secret, I wouldn't tell it. I would sell it."
The secret -- if there is one -- seems to lie in his motto: "You just keep going and going and definitely you're going to go until your body cannot go anymore."
And that's exactly what he's going to do.