What to see on your watch at each marker. Changing the strategy keeps the finish time identical — the pace ramps and is then rescaled so the splits still add up to your target, because a race plan that quietly moves the finish is no plan at all.
| Marker | Split | Pace | Elapsed |
|---|
A race result implies a VO2max, and each training zone is a fraction of it. These are the paces that result — the same race time, read as a training prescription rather than a ranking.
| Zone | per km | per mile | what it is |
|---|
One finish time gives pace, speed and the reverse, so entering a target pace works just as well. Type 5:30 or 5.5.
T₂ = T₁ × (D₂ / D₁)1.06 projects a time to another distance. The 1.06 was fitted to world records (1977, 1981); cycling and swimming use gentler, less rigorous exponents, disclosed as such.
Your time placed on a log-normal model of finishers at that distance, calibrated so the Average tier is the 50th percentile and Beginner the 15th.
Riegel suits the half marathon but is optimistic for the marathon: in a 2016 study of 2,303 recreational runners it predicted at least 10 minutes too fast for half of them.
Excess over 1.00, where pace would hold perfectly steady. Nobody holds 5K pace for a marathon: glycogen, heat and fatigue compound with distance. At speed cycling is limited by aerodynamic drag, not fatigue, so its speed degrades far more gently.
A 60th-percentile time means you are faster than 60% of a general finisher field, which already includes plenty of first-timers and walk-runners. It is a population comparison, not a verdict on your fitness.
The swimming benchmarks here reflect pool conditions. Open-water swims are commonly 10–15% slower because of sighting, currents and having no walls to push off and glide from.
It was derived from — and validated against — running race results specifically. Cycling's aerodynamic drag dominates its energy cost in a way running's air resistance doesn't, and swimming's water resistance scales differently again, so this tool uses gentler, less rigorously sourced fatigue estimates for those two sports rather than borrowing running's constant wholesale.
It's the estimated fraction of all finishers at that distance who are slower than your time — a 75th percentile 5K means you'd finish ahead of roughly 75% of a typical race field, based on a statistical model of the population, not a specific race's actual results.
Published "average" race times include the entire finisher population — first-timers, charity participants and run-walkers alongside serious amateurs — which pulls the average well below what a regularly-training recreational athlete would post.
Riegel's formula (and its cycling/swimming analogues here) assumes equivalent training for both distances — a fast 5K only predicts a fast marathon if the underlying endurance base actually supports it. Vickers and Vertosick's 2016 study of 2,303 recreational runners measured it: Riegel was well calibrated up to the half marathon, but gave marathon times at least 10 minutes too fast for half of the runners. Race predictions are most accurate between distances that aren't too far apart.
Releases in which this page changed, newest last. Derived from the archived copy of every release, not from notes written afterwards — so it reflects what actually shipped. Site-wide passes are left out; they are in the full changelog.