Most infectious disease exposures in health care providers occur due to:

In healthcare providers, most infectious disease exposure occurs due to sharp injuries caused by penetration of blades, needles, scalpels, into the skin. These instruments when contaminated with an infected patients' blood, can cause more than 20 diseases including HIV, and hepatitis. These injuries are also called as percutaneous injuries. Following such injury, the wound should be held under running water,  dry, and cover with waterproof dressing. The person should also consult a medical advice on an urgent basis.

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)