Practical execution rules. Dates, recent data and targets belong on the plan page.
The dashboard uses effective-dated Karvonen (heart-rate reserve) bins. Current constants: maximum 203, resting 44, reserve 159. They describe observed/configured values, not measured ventilatory or lactate thresholds. The zone names do not establish a physiological threshold.
| Zone | Current bpm | HR reserve |
|---|---|---|
| Z1 | ≤ 139 | Below 60% |
| Z2 | 140–155 | 60-70% |
| Z3 | 156–171 | 70-80% |
| Z4 | 172–187 | 80-90% |
| Z5 | ≥ 188 | 90% and above |
The report fills these markers from hr_config. Each run retains the version in force on its date. Comparisons across versions need that context; do not move zone boundaries to make an intensity target pass. A short race may enter high zones, but easy training should not chase them.
Comparing heart rate relative to speed between comparable steady segments can flag a change in internal effort. It is a descriptive check, not a test that locates your aerobic threshold or clears an entire run as easy. The old less-than-5% pass and greater-than-10% failure labels are not diagnostic rules.
Compare similar terrain, temperature, wind, hydration and sensor quality. Exclude warm-up, stops and any deliberate fast finish; avoid comparing different pacing strategies. Heat alone can change HR. Negative drift during an accelerating run may reflect pacing or HR lag rather than aerobic improvement. A poor number does not identify heat, fuel or fatigue as the sole cause, and a good number does not rule out tissue overload. Do not retroactively relabel Z3 as easy solely from this metric. Heat and cardiovascular drift.
Use the dashboard's personal percentiles as prompts to reduce load, not a licence to override how you feel. HRV depends on measurement and context; a single high value is not always better. The seven-night baseline overlaps successive days. Morning data precedes that day's run. HRR60 depends on finishing effort and how recovery was measured, so compare like sessions and conditions. Neither proves that a session was absorbed.
Persistent fatigue, illness, poor sleep and local pain matter alongside the watch. Stop running for recurrent or increasing pain or altered gait, and arrange assessment if symptoms persist or recur. Do not use a green HRV signal, a painkiller or disappearance of discomfort after warm-up to clear hard running. Severe pain or inability to bear weight needs urgent help. Subjective monitoring evidence; NHS hip guidance.
Strength can support longer-term training, but its dose depends on familiarity, soreness and recovery. Low mean HR does not mean low muscle or tendon load. Near an event, avoid new exercises, maximal lifting or work that changes the next run's mechanics. Comfortable familiar mobility is optional. Cycling, hiking and sightseeing load count even when absent from running kilometres.
For runs and racing lasting about 1-2.5 hours, practise 30-60 g carbohydrate per hour, using familiar products and checking their labels. Start toward the lower end if this is new, and build only as tolerated in rehearsal. For example, a 25 g gel every 30-40 minutes provides about 38-50 g/hour while sustained; count carbohydrate in drinks too. Begin early, around 20-30 minutes, rather than waiting until depleted. These are examples, not a compulsory brand or dosing schedule. AIS carbohydrate guidance.
Use a familiar pre-run meal and normal hydration. Plan access to fluids; drink according to thirst, conditions and what you tolerated in rehearsal. A fixed 500 ml for every two-hour run can under- or over-shoot individual needs. Do not force large volumes or try to drink away every change in HR. Familiar electrolyte/carbohydrate drinks can be useful; no new supplement strategy on race day.
Use familiar shoes, clothing, breakfast and fuel. Start the first 3-5 km controlled, roughly RPE 4-5/10 with breathing settled. Through the middle, aim for sustainable effort (roughly 5-6/10), and reassess around 15-16 km. Increase only if you still feel controlled and symptom-free. Pace must adapt to weather, hills and actual endurance; there is no validated absolute HR band or cadence that applies throughout this runner's race.
Planned brief walk breaks at aid stations are a valid strategy. Do not accelerate to recover seconds lost taking fluid. A gradual warm-up is appropriate; it need not turn into another tiring training run. Stop for returning hip pain or an altered stride. A finish-time target is subordinate to safe execution.
The Riegel formula, T2 = T1 x (D2/D1)^1.06, is an illustrative race-equivalence model. It assumes appropriate endurance preparation and comparable all-out performances and conditions; it is not a guarantee. Extrapolating a short race to a half marathon can be optimistic, while applying it to a comfortable training run misuses a non-maximal input. Use recent longer-run endurance, effort, fuelling, terrain and symptoms alongside the race result. Do not choose whichever input yields the desired target.
Reduce volume in the final one to two weeks while keeping a little familiar faster running if well. Research in competitive athletes supports substantially reducing volume while retaining some intensity/frequency, but the exact percentage is not a rule for an individual novice or a runner with symptoms. Avoid last-minute endurance tests or making up holiday mileage. Taper evidence.