From May 15, 2017: Trump's theory about exercise
"Other than golf, he considers exercise misguided, arguing that a person, like a battery, is born with a finite amount of energy," writes Evan Osnos in a piece entitled "How Trump Could Get Fired" that appears in the May 8, edition of the New Yorker.
That's far from the first time we've heard that Trump and exercise aren't friends. This, from a February 6 piece in Axios: "The only workout Trump gets is an occasional round of golf. Even then, he mostly travels by cart.
On the campaign trail he viewed his rallies as his form of exercise."
In their revelatory book "Trump Revealed," the Washington Post's Mike Kranisch and Marc Fisher wrote more extensively about Trump's "battery" theory of energy:
After college, after Trump mostly gave up his personal athletic interests, he came to view time spent playing sports as time wasted.
Trump believed the human body was like a battery, with a finite amount of energy, which exercise only depleted. So he didn't work out. When he learned that John O'Donnell, one of his top casino executives, was training for an Ironman triathlon, he admonished him, "You are going to die young because of this."
http://www.cnn.com/2017/05/15/politics/donald-trump-exercise/index.html