Training Pace Calculator

Why each training pace exists

Easy pace builds aerobic capacity with minimal fatigue, threshold pace raises the effort you can sustain before lactate accumulates, interval pace develops VO2 max, and repetition pace sharpens speed and economy. Each band targets a specific adaptation, and running them at the wrong pace blunts the benefit.

The most common error is running easy days too fast, which adds fatigue without adding fitness and leaves you too tired to hit the hard sessions that actually drive progress.

The 80/20 principle in practice

Research on endurance athletes repeatedly points to spending roughly 80% of training time at easy intensity and 20% hard. The pace bands here make that split concrete: keep the bulk of your week in the easy range, and reserve threshold, interval, and rep paces for two or three quality sessions. Polarising your training this way produces more improvement than running everything at a moderate, grey-zone effort.

A worked week, using one runner's numbers

Take a runner who has just raced 10 km in 50:00, an average of 5:00 per kilometre. Feeding that into the calculator returns roughly 6:00-6:30 per km easy, about 4:45 threshold, and near 4:20 for intervals.

Their week then writes itself. Tuesday is the threshold session: 15 minutes warm-up, 2 x 10 minutes at 4:45 with three minutes jogging between, then 10 minutes easy. Thursday and Saturday are 40-50 minutes at 6:00-6:30, genuinely conversational. Sunday is 70 minutes at the same easy pace. If a fifth day fits, it is 6 x 800 m at 4:20 with two-minute recoveries.

Notice the spread: about 80% of the week's minutes sit in the easy band, and the two hard sessions are separated by at least one easy day. The paces are not arbitrary targets to hit heroically; they are guard rails that keep the easy days easy enough to make the hard days possible.