I've run a few marathons between 3:13 and 3:30 before, but I'm running a marathon alongside my wife in October and will be running 10:30-11 min pace as opposed to my usual 7:15-8 pace. I assumed I'd be fine since it's so much slower, but I just realized that I'll be running for 60-90 minutes longer than I've ever run before and was curious if anyone else has been in this situation before, if you trained differently and how it went. I'm going to run one or two long runs with her one weekend soon, but should I be worried my legs will give out at some point? Do I need to train for time instead of distance?