'Within arm's length' is an interesting book by Dan Emmett, a former Secret Service Agent (SSA). The books is about his life as a SSA protecting the most powerful person on earth, the US President or what they call, POTUS (President Of The US).
The book, for obvious reasons, doesn't delve too much into the different incidents that happened in life as a SSA, except for a brief account of what happened when President Bill Clinton took a stroll on the Bridge of No Return diving North Korea from the South. The book is more about the practical challenges faced by a Secret Service Agent like traveling extensively with the President across different countries and time zones with little or no rest and yet having to be alert all the time and protect the POTUS from any impending danger.
The book talks extensively about the physical training that goes into making a SSA to ensure their physical fitness and alert reflexes to guard their most important person they are out to protect.
What caught my attention more than anything else was the fitness levels of the US Presidents. Many of them were in the habit of running and the SSAs, entrusted with the task of being by the President's side at all times, had to run with them too.
Former President Bill Clinton took just about 9 minutes to run a mile while President George HW Bush, surprisingly, took just 6 minutes to run a mile, leaving the SSAs puffing and panting for breath. I compared that with my 10-and-a-half minutes per mile distance and am still looking for a place to hide my face.