Heart-rate zones,
tuned to you
Enter age, resting HR, and your 2K time. Get a 7-zone Karvonen heart-rate model with target splits per zone — from Z1 Recovery through Z7 Peak Power.
Quick answer
Karvonen target HR = (MaxHR − RestHR) × zone% + RestHR. If you don’t provide a max HR, we use Tanaka: 208 − 0.7 × age. The seven zones run from Z1 Recovery (60–70% HRR) up through Z7 Peak Power (102–110% HRR), each with a target 2K-derived split when you provide your 2K time.
Methodology
- Max HR. Use your provided value, or fall back to Tanaka: 208 − 0.7 × age.
- Heart-rate reserve (HRR). HRR = MaxHR − RestingHR. This is your dynamic range.
- Target HR per zone. HRtarget = HRR × zone% + RestingHR. Zones use rowing-typical %HRR ranges.
- Target split (when 2K provided). Splitzone = Split2K × splitFactor, where splitFactor ranges from 1.20 (Recovery) down to 0.92 (Peak Power).
Frequently asked questions
What is the Karvonen method?
A heart-rate-reserve (HRR) approach to prescribing training intensity: target HR = (max HR − resting HR) × intensity% + resting HR. It accounts for individual fitness — two athletes with the same max HR but different resting HRs end up with different target HRs at any given intensity. More accurate than fixed % of max HR for endurance prescription.
Why 7 zones instead of 5?
The 5-zone rowing pyramid (UT2, UT1, AT, TR, AN) is the canonical pace-prescription system anchored to your 2K split. The 7-zone system adds Recovery (below UT2) at the bottom and splits the top into Anaerobic Capacity vs Peak Power for sprint training. Both work — pick the one that matches your coaching framework. The 7-zone is more granular for power-focused or sprint-event programming.
How is max HR estimated when I leave it blank?
We use the Tanaka formula: Max HR ≈ 208 − 0.7 × age. Tanaka is more accurate across age ranges than the older "220 − age" rule, particularly for masters athletes. If you have a measured max HR from a graded exercise test or a hard 2K finish, enter it directly — measured beats estimated by 5–10 bpm in either direction for most people.
How do I measure my resting HR accurately?
First thing in the morning, before getting out of bed, ideally before checking your phone. Take three consecutive mornings and average. Avoid days after caffeine, alcohol, or hard sessions. A chest-strap or wrist-based HRM gives a stable reading; manually counting for 30 seconds × 2 also works.
How do the target splits relate to the zones?
When you provide a 2K time, each zone gets a target split derived from your 2K split via empirical multipliers: Recovery 120% (slow), Aerobic Base 113%, Aerobic Threshold 107%, Anaerobic Threshold 102%, VO2 Max ~100% (race pace), Anaerobic Capacity 96%, Peak Power 92%. These are anchors, not hard limits — pace varies with stroke rate, drag, and fatigue.
Can I row in zones above 100% HRR?
Briefly, yes. Z6 (98–102%) and Z7 (102–110%) are short-burst zones — your HR can momentarily exceed your measured max during sprint efforts and post-exercise drift. Treat the upper zones as power prescriptions rather than HR prescriptions; the splits matter more than the bpm at this intensity.