Training Pace Zones Calculator

Training pace zones are specific pace ranges that target different energy systems during running. Each zone produces distinct physiological adaptations: easy zones build aerobic base and mitochondrial density, while harder zones develop lactate threshold and VO2 max. Running at the right intensity for each workout — rather than always going moderately hard — is one of the most important principles in structured endurance training.

Most training systems use 5 zones, though some coaches prefer 3 (easy, moderate, hard) or 7 (used in Garmin and Polar systems). The 5-zone model — Easy, Aerobic, Tempo, Threshold, and VO2 Interval — is the most practical for recreational and competitive runners. It aligns with Jack Daniels' VDOT framework and is widely supported by sports science research on optimal training intensity distribution.

Easy runs (Zone 1–2) should feel genuinely comfortable — you should be able to hold a full conversation without gasping. They are typically 60–90 seconds per kilometre slower than your 5K race pace. Many runners make the mistake of running their easy days too hard, accumulating fatigue that compromises quality in hard sessions. True easy running is slower than most people think, and it is where the majority of your aerobic adaptations actually occur.

The 80/20 rule, supported by research on elite distance runners, recommends spending approximately 80% of training volume in Zones 1–2 and 20% in Zones 3–5. This polarized approach produces better results than training at moderate intensity most of the time. A typical weekly structure might include 3–4 easy runs, one long run, one tempo session (Zone 4), and one interval session (Zone 5) — all in the right zones, not just hard effort.

Lactate threshold pace (Zone 4) improves most effectively with weekly tempo runs of 20–40 minutes at a comfortably hard effort — the pace you could sustain for roughly one hour in a race. As your body adapts, it clears lactate more efficiently, allowing you to run faster before accumulating fatigue. Adding one threshold session per week for 8–12 weeks typically produces measurable improvements in 10K and half marathon race times.