Exclusive | Shoeless Long Island runner has put best foot forward through 6 marathons shocking everyone from cops to top athletes: Just keep going

It keeps him on his toes.A Long Island ballroom-dance instructor doesn’t know the meaning of de-feet — running six marathons barefoot, including four in New York City.“I do get, periodically, a little shard of glass or something in my foot, and what I say is that that’s what the bib pins are for,” quipped 57-year-old shoeless sensation John Mazzei of Lindenhurst to The Post.“I could perform minor surgery on my feet now.”Mazzei is used to getting looks, including during training, stomping on jagged roadside pebbles and other debris while running on the island’s bustling streets.“I actually one time got pulled over by a police officer while I was running barefoot training for the [NYC] marathon,” the quirky runner recalled. “I guess they thought I robbed somebody, but I said, ‘Actually, I was doing an 8-minute mile.’ ”Mazzei won’t be running this year’s Big Apple 26.2-miler — but only because he’s working to qualify for the Boston Marathon.He has already heard it from marathon-route onlookers and folks in honking cars over the years, such as one Big Apple race fan who recognized him and yelled, “Barefoot John!” from a fire escape as he ran along. “People say, ‘Hey! You forgot your shoes! And I’ve come up with the line back – ‘I just forgot to tie them and ran right out of them,’ ” he said.Before going barefoot in the park while trotting through Manhattan for the New York races, Mazzei would run the conventional way — with socks and shoes.He first got into running around 43.But after just three months, his sneakers were ironically causing more pain on his knees than being barefoot ever has.So he stepped away from running for a few years.It was only after reading Christopher McDougall’s “Born to Run,” which focuses on the sports science behind barefoot running, that Mazzei gave it another crack — sans shoes and socks.“I think because I’m a dancer, I love teaching technique,” said Mazzei, who “has...