NEW YORK (AP) — GOP front-runner Donald Trump marked President Joe Biden ‘s 81st birthday on Monday by releasing a letter from his physician that reports the former president is in “excellent” physical and mental health.

The letter posted on Trump’s social media platform contained no details to support its claims — measures like weight, blood pressure and cholesterol levels, or the results of any test. Dr. Bruce A. Aronwald, a New Jersey physician who says he has been Trump’s doctor since 2021 and most recently examined him in September, reported that Trump’s “physical exams were well within the normal range and his cognitive exams were exceptional.”

He added that Trump’s most recent lab results were “even more favorable than prior testing on some of the most significant parameters” thanks to recent weight loss he credited to “improved diet and continued daily physical exercise, while maintaining a rigorous schedule.”

The doctor concluded the 77-year old is “currently in excellent health” and “will continue to enjoy a healthy active lifestyle for years to come.”

The report comes as age has emerged as a key issue of the 2024 election, which could find Trump and Biden, the country’s oldest president, facing off once again.

While Trump isn’t all that much younger than Biden, polls consistently find t hat Americans view age as more of a liability for the president. An August poll from The Associated Press-NORC Center for Public Affairs Research found that 77% of U.S. adults, including 69% of Democrats, viewed Biden as too old to be effective for four more years, while only 51% of adults — and just 28% of Republicans — said the same about Trump.

Still, Trump’s rivals have tried to highlight his age by pointing attention to his own recent flubs, including mixing up the city and state where he was campaigning.

“The presidency is not a job for somebody that’s pushing 80 years old,” Florida Gov. Ron DeSantis, one of Trump’s rivals, said on CNN Sunday, casting himself as a man “in the prime of my life.”

Attestations of Trump’s rigor by his doctors have become a genre of their own.

In late December 2015, during his first campaign for the Republican nomination, Trump’s campaign released a glowing letter from the late Dr. Harold N. Bornstein that claimed Trump, a known fast food aficionado who eschewed vigorous exercise, would “unequivocally” be the “the healthiest individual ever elected to the presidency.”

Bornstein later revealed that Trump had dictated the glowing assessment himself, calling it “black humor” and admitting that he had written it in five minutes while a limo sent by the then-candidate waited outside his office.

“I just made it up as I went along,” he told CNN in 2018. “It’s like the movie ‘Fargo.’ It takes the truth and moves it in a different direction.”

While in the White House, Trump’s doctors offered a more complete picture of his health following annual physicals that included numbers and test results.

His physical in 2019, for instance, revealed that he was officially considered obese, while his 2018 exam revealed he had a common form of heart disease.

Still, then-White House Dr. Ronny Jackson offered a glowing report during a lengthy press conference about the exam in which he extolled Trump’s “incredible genes” — “it’s just the way God made him,” he said — and joked that if the then-71-year-old president had eaten a healthier diet over the previous 20 years, “he might live to be 200 years old.”

Jackson also said Trump had performed “exceedingly well” on a surprise cognitive screening test designed to detect early signs of memory loss and other mild cognitive impairment. Trump continues to brag about the results to this day.

Aronwald did not immediately return a message left with his office.