Adaptive, not rigid.

Tell us your threshold pace (the pace you can hold for 1 hour flat-out) and every metric unlocks:

• Friel rTSSper run — duration × intensity factor squared, the running equivalent of Coggan’s power-TSS.
• Pace ranges for every zone: easy, tempo, threshold, interval, repetition — as mm:ss per km ranges, not Zone numbers.
• HR cross-checkwhen threshold HR is also set: if you’re hitting the pace but HR is drifting high, the Sunday review notices.
• No threshold pace set? We fall back to HR-based TRIMP, flag it, and suggest a threshold test as a future workout.

A typical build week for a 4:00 min/km threshold-pace runner, 50 km/week target, marathon 10 weeks out:

• Mon — Rest.
• Tue — Intervals: 6 × 800m at 3:40–3:50 pace, RPE 8, 90s jog recovery. You can say 2–3 words between breaths.
• Wed — Easy run: 50 min at 5:00–5:20 pace, HR under 145. Fully conversational.
• Thu — Tempo: 20 min at 4:10–4:20 pace, uncomfortable but sustainable.
• Fri — Rest or 30 min shakeout.
• Sat — Long run: 110 min at 4:50–5:10 pace, progressive last 30 min.
• Sun — Recovery: 40 min easy or cross-train.

Every run has a pace range, an HR target (if your LTHR is set), and an RPE + feel cue. You don’t decode anything at the trail-head.

Running injuries don’t come from single workouts — they come from compounding load without variation. Rules we enforce:

• 80/20 polarization check:weekly zone mix reviewed. If Z3 (“grey zone”) exceeds 40%, the coach flags it and adjusts the next block.
• Long-run progression cap: no single week adds more than 15 min to your longest recent run.
• Hard-easy spacing: Tuesday intervals and Thursday tempo, 48h apart. Never two quality days back-to-back.
• Monotony watch: every week of identical easy runs starts flagging at monotony 1.5, escalates at 2.0.