President Joe Biden got a clean bill of health from the White House doctor on Friday after undergoing an extensive, routine check-up during which his powers were briefly transferred to Vice President Kamala Harris.

"The President remains a healthy, vigorous, 78-year-old male, who is fit to successfully execute the duties of the Presidency, to include those as Chief Executive, Head of State and Commander in Chief," Kevin O'Connor, the White House physician, wrote.

The detailed report said that Biden did have "perceptibly stiffer and less fluid" motion while walking than a year ago, and suffered "increasing frequency and severity of 'throat clearing' and coughing during public speaking engagements."

However, these two symptoms were not considered of immediate concern and did not appear to result from serious conditions, O'Connor's letter said.

On a raft of tests, Biden came out with high marks.

He has "no signs of heart failure," "no dental issues," has no "suspicions for skin cancer," and his eye health "is reassuring."

One reason for that solid report may be the doctor's finding that "the president does not use any tobacco products, does not drink alcohol, and he works out at least five days a week."

Biden, who turns 79 on Saturday and is the oldest president in US history, takes three common prescription medications and two over-the-counter medicines, as well as wearing contact lenses, the letter revealed.

He measures five feet, 11.65 inches (1.82 meters), weighs 184 pounds (83.46 kg) and has a body mass index of 25.

A smiling Biden returned to the White House from his checkup at Walter Reed hospital earlier, saying "I feel great."

"We're in great shape," he said, wearing his trademark aviator sunglasses.

Historic 1.25 hours

While the annual visit to Walter Reed hospital was routine for a president, the requirement for Biden to transfer power while sedated during a colonoscopy exam made history.

For one hour and 25 minutes, Harris was the first woman to hold presidential power in the United States. She is already the first female vice president.

The White House press office said that official letters to Congress declaring the temporary transfer of power were sent at 10:10 am (1510 GMT). "The president resumed his duties at 11:35 am," (1635 GMT), the White House said in a statement.

"Today that was another chapter in that history for many women, young girls across the country," Press Secretary Jen Psaki said, noting Harris' trailblazing role.

Harris made an unsuccessful bid for the Democratic Party nomination in 2020, before being picked as Biden's running mate. While holding the temporary presidential reins she continued to "work from her office in the West Wing," Psaki said.

Psaki noted that a similar temporary transfer of power, "following the process set out in the Constitution," had been carried out when president George W. Bush underwent the same procedure in 2002 and 2007.

The details on Biden's health were being closely watched, given speculation on whether he will stand by his stated intention to seek a second term in 2024.

Crucial moment in presidency

The positive medical assessment mirrored an earlier letter from Biden's physician during his election campaign in December 2019, when he was described him as "a healthy, vigorous, 77-year-old male, who is fit to successfully execute the duties of the presidency."

He was vaccinated early on against Covid-19, and received a booster shot in September.

The health check comes at a crucial moment in his presidency, with the House of Representatives voting to send Biden's huge "Build Back Better" social spending agenda to the Senate for approval. Earlier this week, Biden signed into law another package to fund the biggest national infrastructure revamp in more than half a century.

The twin victories come after weeks of falling approval ratings for Biden and setbacks for his Democratic Party ahead of next year's midterm elections when the Republicans are widely predicted to take control of at least the lower house of Congress.