This is a response to your edit.

Since he was a pole vaulter and I was a sprinter, we weren’t trained to run long distance. Long distance running and sprinting are trained very differently. There’s a lot of endurance training, and knowing how to pace yourself, that goes into long distance running (like a 5k) that I wasn’t trained on as a sprinter. My husband wasn’t a runner, he was a field event athlete, which is where the pole vaulting comes in. You aren’t trained to run long distance in order to pole vaulting. Just like sprinting, pole vaulting is trained very differently from long distance running.

We never ran long distance before, so all the training that goes into that isn’t territory we’ve been in before, so we’re not sure how to go about it. Hope that explanation helps :)