When I spotted an 800-meter repeat workout and progression run scheduled for the first week of my Runna training plan, I immediately tried to figure out a way to get out of it. I wanted to get faster , but gradually, and seeing those two sessions on my plan sent off alarm bells inside my head.

I signed up for Runna—a personalized training app—with a long list of to-dos. Nailing down a solid routine with a mix of speedwork , strength training, and mobility was top priority.

As a newly RRCA-certified run coach, I had an idea of how my next training plan would look: A steady progression of mileage and intensity—one that kicks off with easy runs in the first week, followed by short intervals or strides the next, and then getting into more structured workouts.…