Running a new PR in a race is one of my favorite things. As I've become a more experienced racer PRs get more difficult to achieve. In order to get PRs I would spend time obsessing over choosing the best pacing strategy for a race. The pace calculator apps out there assumed I would run perfectly even splits like an automaton, regardless of hills, wind, or human psychology. That was unrealistic. I started making spreadsheets in which I could calculate a finishing time with paces that varied for each mile. I learned from a wise running coach that you often want to run "negative splits" (running the second half of a race faster than the first half). This worked well for me, because it preventing me from going out too fast, and it allowed me to enter the deepest part of the pain cave when there was a manageable distance yet to run. I quickly became annoyed with my clunky spreadsheets--as a long-time professional app developer, I knew that I could make something that would do the calculations I wanted while making the data entry clean and painless. True Pace is the result of that effort. I made it to scratch my own itch, and I'm hopeful that other runners will find it useful as well. Along the way I added other planning features, a "pace line" graph for visualizing pace during the race, duplicating saved races to allow for pace strategy tweaking without losing previous plans, and sharing races with friends! True Pace is a free app--all features can be used without paying. It does limit you to saving 2 races unless you make a one-time In App Purchase which removes any limits. If you use it and find it valuable, please make the purchase to make it as slick to use as possible; if you're an infrequent user feel free to use it without paying and just delete races as needed so you can continue to create new ones!

FWIW, I pulled off a half marathon PR (1:34:15, I realize, not that great but I’m a desk-bound app engineer) a couple of years ago with a pacing plan that involved starting out in a 7:15-7:10 minute/mile pace and gradually ratcheting that pace up every 3 or so miles, with the goal of finishing the last mile or two at 6:55-6:45 pace. Worked pretty well, but I had some fueling issues and by the last 2 miles I was off pace and holding on for dear life. The results of just such pacing plans can easily be computed with True Pace.