It's a confuddled mix of them moving fast and them actually slowing time. Kind of interesting though, if that's how QS is when he's moving fast, imagine how long it would feel for him to run across the country. He'd be normal speed jogging for the mental equivalent of weeks, but it would take place in a matter of seconds.
More like why dont the insane G forces from such acceleration doesnt rip them apart. You just gotta turn off the logical part of your brain bro.
For the Flash, it's been explained his speed has zero to do with metabolic processes, but everything to do with tapping the speed force. He expends way more energy than he can eat at super speed.
Already established, the Flash has a force field that gets more powerful the faster he runs. It also extends to people that he might carry at super speed.
Their running at the speeds they do are a complete fiction. At a certain speed, it becomes much more efficient to bound than it does to run, and we're talking less than 100 kph, like a cheetah. Running works well for slow speeds, but there's a lot of upward force that speedsters completely disregard. Hulk gets it right. He simply jumps everywhere.
I'd say we are all lazy and didn't read the comics by the questions stayed above that you answered.
Now you know why quicksilver is douche. This is the exact reason the comics give. I think he says something like imagine waiting in line at the bank and having the line not move for hours. That's his life
It was an 00s animated series.
