Why do paramedics need to go through a physical training?
Most places around here run emergency medical services/911 through their fire departments. So in essence to be a firefighter you have to be a paramedic. Thankfully I love the paramedic side as much as the fire side. Most firefighters resent having to be a medic.
Physical ability tests tend to be the most physically demanding 5~10 minutes of your life. They are designed to prove that you can run into burning buildings and not drain you SCBA in 30 seconds. Also helps weed out people who don't want to put in the effort the job takes.