A healthy person can respond to pressure and enjoy the stimulus. However a person who has been under intense pressure over a long period is unlikely to have sufficient coping reserves to manage cumulative stress. The first signs that they are not coping will inevitably show up in their work performance, in their behaviour and, ultimately, also in their appearance and persona. It is rather like a car trying to run on an empty tank.
Stress management is basically one long battle, where mental resilience needs to be supported by physical resilience. Yet one of the most serious pressures is the extreme difficulty of arranging regular exercise, when your workload is made up of one panic after another.