Calculator

Romney J. Hogaboam I returned to running in 2018 following a nearly 20-year hiatus after high school. A friend talked me into trying to qualify for the 2020 Boston Marathon. I followed the Daniels' Running Formula marathon training plan to prepare. In order to assess my likelihood of qualifying, I needed a good way to create a fairly uniform metric. I used the Jack Daniels' VDOT Running Calculator to convert distances and times to a marathon time. Unfortunately, I didn't find a calculator which accounted for account elevation profile to my satisfaction. Therefore, I decided to write my own converter :-) It's been useful for me. If it's useful to you too, that's great!

This converter operates in three separate steps.

  1. 1. Sample race distances of each type (uphill, flat, downhill) are adjusted to compensate for elevation.
  2. 2. Forecast race distances of each type (uphill, flat, downhill) are adjusted to compensate for elevation.
  3. 3. The time in the sample race is scaled to the forecast race to compensate for distance.

Elevation compensation is done by adjusting the effective distance based on elevation profile. The effective distance is reduced to account for downhill portions and increased to account for uphill portions. Richard A. Lovett authored an article titled Downhill All the Way in Runner's World in 2007 which sites to research performed by Mervyn Davies to calculate the effect of gradient on running speed. In it, he reports approximately a 1.8% increase in speed per % downhill gradient and approximately a 3.3% decrease in speed per % uphill gradient. This calculator uses the Rigel Race Time Prediction formula to compensate for distance.

Sample Race Distance Gradient Time
Uphill  
Flat    
Downhill  
Total  

Forecast Race Distance Gradient Time Pace
Uphill    
Flat      
Downhill    
Total