Donald Trump Jr. almost burst a blood vessel in his temple over a Washington Post article detailing President Joe Biden's exercise regimen.

In his latest rant concerning Biden, Trump Jr. railed over a reporter who asked White House Press Secretary Jen Psaki about the 78-year-old President's physical fitness efforts.

On Monday, the journalist wanted to know what kind of weights the President was lifting and if he had a personal trainer.

Psaki responded:

"I have nothing to read on the President's private exercise regime."

"But I can tell you traveling with him a fair amount, sometimes he's hard to keep up with."

The next day, Trump's eldest son fretted in a lengthy video post.

"Really, Jen? He can't walk up the stairs of Air Force One without falling over!" he said, referring to Biden's stumble while ascending the steps to Air Force One at Joint Base Andrews in Maryland on March 19.

At the time, Don Jr. posted the footage of Biden's stumble and tweeted:

"I remember the press bashing [Donald] Trump for touching the rail once. Biden falls repeatedly but I'm sure he's the picture of health. No wonder all our enemies are pouncing simultaneously and mocking him publicly."

The incident fueled concerns from many conservatives who questioned his health and called his stumble "scary" and "sad."

White House communications director Kate Bedingfield assured then the President was "fine" and attributed the fall as "nothing more than a misstep on the stairs."

Don Jr. continued his grumbling over Psaki's response to the reporter.

"Now, if you said that he's hard to keep up with because you have no idea what the hell he is saying when he's speaking, that I would understand."

"But if you're going to tell me that he's hard to keep up with physically when we don't see him doing anything early, we see lids being called in the middle of the day, you don't see him doing anything late."

He continued rambling about Psaki's answer.

"I mean, does anyone really believe he's hard to keep up with? You and I and any reasonable being with a brain has no idea what he's saying."

"But these are the hard-hitting questions from the media. I mean, oh, we're blowing it out. This is journalism. They're asking all the tough questions! What the hell are you asking about?"

You can watch the video, here.

Don Jr. was not done.

He urged his fans to speak out against the septuagenarian taking care of his physical health.

"The President rides a stationary bike. Oh, that's wonderful! You think that would happen with Trump?"

"The world is on fire and we're pretending everything is just fine. Joe Biden is riding a bike and he's weightlifting! He's a strong and viable leader! You can't make it up, folks. So we've got to push back. We've got to call it out."

Twitter shaded Don Jr. by reminding him of his father's own physical shortcomings in comparison to Biden's clean bill of health.

Trump critics scrutinized former President Trump's health after he seemed to struggle with walking down a ramp after delivering a speech at U.S. Military Academy at West Point in New York in June 2020.

Trump Sr. also drew concern when he used both hands to raise a glass of water to his lips during an interview last October.

Biden made headlines last year after sharing his workout routine included riding a Peloton bike—which White House staff expressed security concerns due to the equipment's use of a camera and mic.

In an interview with governor Gretchen Whitmer last year, Biden detailed his early morning fitness program.

"It's hard to get into a really regular schedule, but for me, I've been sticking to a routine and it helps. It helps me deal with my day. I try to get out of bed by eight o'clock in the morning and I have a gym in my house upstairs."

"I have a treadmill and a Peloton bike and some weights. And I try to work out every morning for me. That sort of gets me going. And then I take a shower and go down, have some to eat."

"I usually have a protein shake and then what I do is my day starts and the day starts usually with a, somewhere between 40 minutes and an hour and a half meeting with the medical staff dealing with [the virus]."

Biden's physician Kevin O'Connor—who became the new White House physician in January—declared in December 2019 that Biden was a "healthy, vigorous, 77-year-old male" who was fit to "execute the duties of the Presidency."

Fit and Well said Biden frequently uses the treadmill and an exercise bike.

The article cited Harvard University and said in addition to improving mental health, cardio exercise was especially important for seniors in order to prevent diseases like cancer and diabetes in later life.