Running pace is the time required to cover a standard distance (typically 1 km or 1 mile). It's expressed as "minutes:seconds per unit distance." For example, a 5:00 pace means 5 minutes and 0 seconds per kilometer. Pace is more intuitive than raw speed because runners naturally think in terms of "how long does this distance take" rather than "how many kilometers per hour."

Pace is fundamental to race preparation and performance analysis. Elite marathoners maintain paces around 2:50-3:00 per km, while recreational runners might work at 5:00-6:30 per km. Understanding your current pace and target pace guides training intensity and helps predict race outcomes using formulas like the Riegel predictor.

There's a nonlinear relationship between pace and speed: running 1 km/h faster typically reduces your pace by 20-30 seconds, not 1 minute. This is why pacing strategy in racing is critical—small pace adjustments significantly affect total race time over long distances.