What is Running Economy?
Running economy (RE) is the oxygen cost of running at a given speed, expressed in milliliters of oxygen per kilogram of body weight per kilometer (ml/kg/km). A lower number means better efficiency — you use less oxygen to cover the same distance. It is one of the key determinants of endurance running performance alongside VO₂max and lactate threshold. See also our Estimated Finish Time — Half Marathon Pace.
How do you calculate Running Economy?
Running economy is calculated using the formula: RE = (VO₂ × 60) / Speed, where VO₂ is in ml/kg/min and speed is in km/h. This converts the per-minute oxygen consumption into a per-kilometer cost. For example, a runner using 45 ml/kg/min at 12 km/h has a running economy of 225 ml/kg/km.
Why does Running Economy matter?
Running economy determines how efficiently you translate aerobic capacity into speed. Two runners with identical VO₂max values can have very different race performances if one has better running economy. Improving economy can be as impactful as raising VO₂max, since it dictates how close you can run to your aerobic ceiling for extended periods.
What is a good Running Economy score?
Elite male distance runners typically show values of 180–200 ml/kg/km, while elite female runners range 185–210 ml/kg/km. Recreational runners generally fall between 220–270 ml/kg/km. The lower the score, the more economical the runner. World-class athletes like Eliud Kipchoge have been measured well below 200 ml/kg/km. You might also find our calculate Total Trail Distance, Estimated Hiking Time & Time (hrs & mins) — Trail Distance useful.
What factors improve Running Economy?
Key factors include running biomechanics (stride efficiency, cadence, arm swing), strength training (especially plyometrics and resistance work), flexibility, footwear (lightweight or carbon-plated shoes), altitude training, and overall training volume. Even small improvements in form and strength can meaningfully reduce oxygen cost per kilometer.
How is Running Economy different from VO₂max?
VO₂max is the maximum rate at which your body can consume oxygen — it sets your aerobic ceiling. Running economy, by contrast, measures how much oxygen you actually use at a submaximal pace. An athlete with a moderate VO₂max but excellent running economy can outperform someone with a higher VO₂max but poor efficiency.
Can I use this calculator to reverse-calculate VO₂ from a known economy score?
Yes. Switch the calculation mode to 'Running Economy + Speed → VO₂' and enter your known running economy (ml/kg/km) and speed (km/h). The calculator will derive the corresponding VO₂ in ml/kg/min, which is useful when you have lab economy data and want to estimate oxygen demand at different speeds.
How does speed affect Running Economy?
Running economy is always measured at a specific speed — it is not a fixed physiological constant. As speed increases, oxygen consumption rises and the economy value (ml/kg/km) typically increases too, meaning higher oxygen cost per kilometer. This is why economy comparisons should always reference the speed at which the measurement was taken.