A Personal Record or PR (sometimes known as a Personal Best or PB) is when a runner has run a first road race, then he or she has attained a PR, or a “Personal Record”. It refers to a runner’s best time in a race of a specific distance. So, if a runner runs a 5K race in 29:31, that’s his or her PR for the 5K distance. If the runner then runs faster than 29:31 in a subsequent 5K race, then he or she set a new PR for that distance. Runners usually have PRs for different race distances, from a one mile run to marathons.