Nothing.
From Kesslers latest book :
A female Secret Service agent on the president’s detail is so out of shape that she literally cannot open the heavy doors to exit the president’s limousine. Instead of removing her from protecting the president and requiring her to pass the physical fitness tests that all agents are supposed to take every three months, Secret Service management told drivers to try to park the Beast so it would be easier for the vehicle door to swing open for her.
If the president were shot, she could not help carry him to safety, an agent notes. Agents know there is no point in complaining to a supervisor: The overweight female agent is a supervisor