The result is that many people find themselves having an emergency episode and end up in hospital.

BBC: Where next for the NHS?

In the second episode, Roach's brother, a former boxer named Pepper, suffers a medical emergency not long after sparring with a young pupil.

WSJ: Jason Gay: On the Periphery of Boxing Madness; Freddie Roach, Manny Pacquaio; Floyd Mayweather Jr.