Trump says that when he looks in the mirror he sees 'a person who is 35 years old'
Trump insisted on the show that he's in good health and said he has the stamina of a much younger person.
At one point, Dr. Mehmet Oz asked Trump, "When you look in the mirror, what do you see?"
Trump responded: "I see a person who is 35 years old."
He noted that he has stayed active and enjoys playing golf.
The health of the two major-party presidential nominees has taken center stage in this election. If Trump was elected in November, he would be the oldest person ever to be sworn in as president.
Also on Thursday, Trump released a letter from his doctor summarizing his latest physical examination. Trump's physician, Dr. Harold Bornstein, wrote that Trump was in "excellent health."
Trump was hospitalized only once in his life - to have his appendix removed when he was 11 years old.
The renewed scrutiny over each candidate's medical history and physical health comes after Democratic presidential nominee Hillary Clinton abruptly left a 9/11 memorial service on Sunday for overheating related to previously undisclosed pneumonia.