US President Barack Obama is "fit at fifty" after improving his cholesterol readings and kicking his smoking habit, according to results of his latest medical exam released Monday.

A memo from Obama's doctor Jeffrey Kuhlman declared the president to be "in excellent health and 'fit for duty.' ... he is fit at fifty and staying healthy at 50+."

The examination revealed Obama, 50, who works out frequently at gyms in the White House and on the road, has and "ideal" cholesterol levels, weighs 181 pounds (82 kilograms), and has a of 23.9.

His doctor declared him to be "tobacco free" -- after a long struggle to give up the occasional stress-relieving cigarette -- and following a healthy diet, and to be drinking alcohol only in moderation.

The exam showed Obama actually improved his fitness over the year, reducing his from 138 in February 2010 to 110 in October.

The report also revealed that a cut Obama suffered on his lower lip nearly a year ago while playing basketball had healed well and that the president had had some benign skin tags removed from his neck.

US presidents habitually release results of their annual medical checks to assure Americans they are up to the exacting demands of the Oval Office.