I am absolutely baffled how people can run one, two or more miles. How do you do it?

I bring this up because even when I was in shape in my teens, it took me 15 to 20 minutes to run a mile. And when I say run, it was more of a jog.

I could sprint all day long but when it came to long distances, running was not my strong suit.

Over the last year, I've gotten back into exercising on a regular basis. Now, when I try to run (and again, it's more of a jog), I can last about a minute or so. And just that minute turns my calves to rocks and legs to jelly.

I get there is a lot of training involved in long distance running. Training that I don't have. I get that because I'm 40, exercise isn't the easiest of accomplishments. But shouldn't I have a bit more stamina to run for a longer distance?

I'm no exercise guru so I'm asking if there is someone who is a runner that might be able to help me with this conundrum.

But then, it could be just as simple as I'm out of shape. If you can help, let me know below.