How to Train by the Numbers

Running is full of round numbers that got repeated until they became facts. 220 minus your age. 2,000 steps to a mile. Each of these tools replaces one of those with something that actually accounts for you.

General training tools, not medical advice — if you have a heart condition or are returning from injury, that conversation belongs with a clinician.

Pace is the foundation

The Running Pace Calculator turns a distance and a finish time into pace per mile and per kilometre, with speed in both units.

Start here, because every other number in this guide is expressed in pace. Knowing your real pace for a distance you have actually run is the only honest input the rest of it has.

Predicting the next distance

The Race Time Predictor uses Riegel's formula, and the useful part is not the predicted time — it is that it shows how much your pace is expected to slow over the longer distance.

People plan a longer race by holding their shorter-race pace, which is the standard way to blow up at two-thirds distance. The slowdown is expected, it is quantified, and planning for it is the difference between a good race and a walk to the finish.

Predict from a race you genuinely ran, not from a good training run.

Heart rate: 220 minus age is the weak one

The Heart Rate Zone Calculator uses the Tanaka formula rather than 220 minus age, and factors in your resting heart rate — so that "easy" comes out as a number you can actually hold.

220-minus-age is a rough population fit with a wide spread around it, and it drifts further at both ends of the age range. Using it to set zones produces an "easy" zone that is genuinely unholdable for some people and pointlessly slow for others — and since easy pace is where most training volume lives, getting it wrong distorts everything.

Take your resting heart rate properly: first thing, before getting up, several mornings, averaged.

Steps: the 2,000 rule describes a tall man

The Steps to Miles Calculator converts using your height rather than the "2,000 steps per mile" rule — which quietly describes someone 6 ft 4 in tall.

That is a real gap. Stride length scales with height, so for most people 2,000 steps is meaningfully less than a mile, and a daily step target converted with the rule of thumb overstates the distance covered. If you are tracking mileage from steps, this is worth ten seconds to fix.

Walking: speed does not change what the walk cost

The Walking Calorie Calculator completes the picture the steps tool starts. Steps give you distance; this gives you what that distance cost — and separates it from what you would have burned sitting still anyway.

Walk 5 km at 70 kg and change nothing but the time taken:

Time	Pace	Net calories	What a tracker shows
40 min	7.5 km/h	186	235
60 min	5.0 km/h	186	259
90 min	3.3 km/h	186	296

The net figure is identical all three times. Walking energy cost is weight × distance; speed does not enter it. What changes is only how long you were also existing during the walk — which is why the slowest walk makes the tracker number the biggest while the walk itself contributed exactly the same.

That is the whole reason the tool separates net from gross. Going 7.5 km instead of 5 takes the net from 186 to 278; carrying 100 kg instead of 70 takes it to 265. Distance and weight move it. Pace does not.

Putting them together

1. Get your real pace from a real effort.
2. Predict the longer race, and plan for the slowdown rather than against it.
3. Set zones from Tanaka + your resting HR, then do your easy running actually easy.
4. Convert steps with your own height.
5. For walking, add distance — pace does not change what the walk cost.

The short version

• Pace first — everything else is expressed in it.
• Riegel tells you how much you'll slow. Believe it.
• Tanaka beats 220-minus-age, and resting HR makes "easy" usable.
• 2,000 steps per mile assumes a 6 ft 4 in stride.

Each has a printable — the zone sheet is the one worth keeping, since those numbers only change when your resting heart rate does.