Mark McClusky says for elite athletes today, pushing boundaries and breaking records is all about "the aggregation of marginal gains."
While the hunger strike inside the U.S. detention center at Guantanamo Bay continues, there are separate concerns in other parts of Cuba about conditions at regular prisons.
Cuban prisons are usually closed to outside scrutiny, but foreign journalists were recently allowed through the doors of one prison, for the first time in almost a decade.
The visit comes ahead of a Universal Periodic Review by the United Nations Human Rights Council.
The BBC’s Sarah Rainsford reports that at the entrance to a cell block, the journalists were given paper flowers, handmade by inmates.