Last updated: May 25, 2016

Lawyer turned fitness guru Robin Arzon has so much swagger, it oozes out of her pores, especially when she’s, you know, casually running five marathons in five days. (Exactly.) We chatted with Arzon, author of the new book Shut Up and Run ($19, amazon.com) about her top running rules.

1. Claim the title

"If you are putting in the effort, you are a runner. I don’t have enough middle fingers for people who say that those who aren’t fast or aren’t doing a certain mileage aren’t runners. To me, this sport is measured in hustle: Did you actually move your body today?"

2. Don't overcomplicate things

"People get into these crazy debates: 'What Garmin should I wear?’ ‘What are the most expensive shoes?’ It’s almost an excuse to avoid the actual training and grittiness of the sport. Just shut up and run!"

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3. Broadcast your goals

"If you want to stay accountable, you have to tell someone. Don’t be ashamed to take that running selfie. When you make your goal public, it’s hard to backtrack. Let that pride drive you."

4. Find your fast

"Besides your long run, speed work is the linchpin to a training plan; do it once a week. It can be just a fartlek, where you are running hard for two blocks and then jogging for two. Listen, 30 seconds of a fast run done repeatedly can be a game changer."