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Formula, in Recovery

Resting Heart Rate Formula + Interpretation

Resting heart rate is the heart rate at complete rest. Measure morning supine within 5 min of waking, before caffeine or movement. AHA 2019 normal range: 60-100 bpm for adults; trained athletes commonly 40-60. RHR is a sensitive but noisy marker of recovery state — a sustained +5 bpm shift above your 14-day baseline (Lehmann 1998 overreaching study) flags accumulated training stress or illness before perceived fatigue catches up.

4 variables. Published May 14, 2026. By AI Fit Hub.

Education, not medical advice. The result comes only from the published formula and your inputs. How we check our formulas.

Formula
RHR_5min_avg = sum(beats_per_minute over 5 min supine) / 5 baseline = 14_day_rolling_mean(RHR_5min_avg) overreaching_signal = (current_RHR > baseline + 5) for ≥ 3 consecutive days fitness_category (resting HR norms, AHA 2019): Elite endurance: < 50 bpm Trained endurance: 50-60 bpm Trained general: 60-70 bpm Average adult: 70-90 bpm Elevated: > 90 bpm (check with physician)

Variables

RHR_5min_avg

Morning RHR average

5-minute supine measurement within 5 min of waking. Phone-camera apps or chest strap work. Skip caffeine, alcohol, or movement before measurement.

baseline

14-day rolling mean

Stable reference. Excludes alcohol days (sympathetic activation), illness days, and days after very late nights. Forward-fill those for cleanliness.

overreaching_signal

Overreaching trigger

Sustained elevation flags non-functional overreaching or onset illness. 1-day spikes are noise (poor sleep, large meal, stress). 3+ consecutive days is signal — pair with HRV deload (see /formulas/hrv-deload-trigger-formula/) for stronger evidence.

fitness_category

RHR fitness band

Trained-endurance RHR runs 10-20 bpm below population average due to increased stroke volume + vagal tone. Lower isn't always better — sustained <40 bpm with symptoms (dizziness, fatigue) warrants cardiology referral to rule out conduction issues.

Step by step

  1. 1

    Measure morning supine RHR for 14 days. Skip alcohol/illness days. Phone camera apps (HRV4Training, Welltory) or a chest strap both work.

    14-day average: 56 bpm, SD 3 bpm.

  2. 2

    Categorize: <50 elite, 50-60 trained, 60-70 active, 70-90 average, >90 elevated.

    RHR 56 = trained endurance band.

  3. 3

    Set overreaching threshold: baseline + 5 bpm.

    Threshold = 56 + 5 = 61 bpm. 3 consecutive days above 61 = signal.

  4. 4

    Daily check after waking. Compare to threshold. Track 7-day rolling mean alongside daily.

    Mon 55, Tue 60, Wed 62, Thu 64, Fri 63 → 3 days above threshold (Wed-Fri). Trigger fires.

  5. 5

    On trigger: 50% volume deload for 5-7 days. Keep intensity on top sets. If RHR doesn't normalize within 7 days, investigate non-training causes (illness, life stress, undereating, sleep deprivation).

    Deload week: drop running volume from 60 to 30 km/week, lifting volume from 16 to 8 sets/muscle. Day 5 RHR back to 57 — resume normal volume.

Worked example

Trained marathoner with 14-day baseline tracking RHR for overreaching

14-day baseline RHR

54 bpm

14-day SD

3 bpm

Threshold

54 + 5 = 59 bpm

Recent 5 days

53, 58, 61, 60, 62 bpm

Day 1: 53 (below threshold) ✓ Day 2: 58 (below) ✓ Day 3: 61 (above) ✗ Day 4: 60 (above) ✗ Day 5: 62 (above) ✗ 3 consecutive low days starting Day 3 = OVERREACHING SIGNAL

Trigger fires Day 5. Deload week: volume 50% of normal, hold intensity on key sessions, sleep 8+ hours/night. Re-check RHR daily. Expect baseline return within 5-7 days. If RHR remains elevated, look upstream — sleep tracking, nutrition log, stress audit, GP visit if accompanied by fatigue or any flu-like symptoms.

Common variations

Manual pulse-count vs wearable: morning pulse-count at the wrist for 60 sec is ±2 bpm accurate. Wearable (Garmin, Whoop, Oura, Apple Watch) reports overnight low. Garmin's resting HR averages last 30 min of sleep — runs 5-10 bpm lower than the manual morning method.
RHR alone vs combined (RHR + HRV + sleep): single-metric overreaching detection has ~70% sensitivity. RHR + HRV + perceived sleep quality combined (Eatough 2023) jumps to ~85%. Use this formula as one signal in a multi-metric framework.
Trained-athlete confound: extremely low baseline RHR (<45) reduces signal-to-noise for the +5 threshold rule. Switch to a percentage-based rule: +10% above baseline (45 → 50) instead of absolute +5.
Aging adjustment: maximum HR drops with age (Tanaka 2001: 208 − 0.7 × age). Resting HR rises modestly with age (~1 bpm per decade) due to reduced parasympathetic tone. Compare to your own baseline, not population norms.

Run the numbers next

  • Recovery Heart Rate Zone Calculator

    Calculate personalized training zones with the Karvonen method.

  • Recovery HRV Deload Trigger

    Decide whether to deload from 7 days of HRV vs 30-day baseline using the Plews 2014 method.

  • Cardio VO2 Max Estimator

    Estimate aerobic capacity with the Cooper 12-minute run or Rockport 1-mile walk field tests.

  • Cardio Zone 2 Heart Rate Calculator

    Calculate your Zone 2 heart rate with Maffetone, Karvonen, % Max HR, and lactate threshold methods compared side by side.

Questions people ask next

How do you calculate resting heart rate?

Average your beats per minute over a 5-minute supine measurement taken within 5 minutes of waking, before caffeine or movement: RHR_5min_avg = sum(beats per minute over 5 min) / 5. A phone-camera app or chest strap both work. Repeat for 14 days and take the rolling mean to get a stable baseline.

What is a normal resting heart rate?

Per the AHA 2019 ranges, normal for adults is 60-100 bpm, with trained athletes commonly running 40-60 bpm. This formula bands it as <50 elite endurance, 50-60 trained endurance, 60-70 trained general, 70-90 average adult, and >90 elevated (check with a physician). Endurance-trained RHR runs 10-20 bpm below population average due to higher stroke volume and vagal tone.

Can resting heart rate detect overtraining?

Yes, it is a sensitive but noisy marker. A sustained rise of more than +5 bpm above your 14-day baseline for 3 or more consecutive days flags non-functional overreaching or onset illness (Lehmann 1998). One-day spikes are noise from poor sleep, a large meal, or stress; 3+ consecutive days is signal. Pairing it with HRV and sleep quality raises detection sensitivity from about 70% to about 85%.

What should I do when my resting heart rate is elevated for several days?

When the +5 bpm trigger fires, run a 50% volume deload for 5-7 days while keeping intensity on key top sets, and sleep 8+ hours per night. Expect baseline to return within 5-7 days. If RHR stays elevated, look upstream at sleep, nutrition, and life stress, and see a doctor if it comes with fatigue or flu-like symptoms.

Why does my wearable show a lower resting heart rate than my morning measurement?

Wearables like Garmin, Whoop, Oura, and Apple Watch report an overnight low rather than a morning supine average. Garmin in particular averages the last 30 minutes of sleep, so it commonly runs 5-10 bpm lower than the manual morning method. A 60-second wrist pulse-count on waking is accurate to about plus or minus 2 bpm; pick one method and stay consistent for comparisons.

Sources

  1. Tanaka, Monahan & Seals (2001). Age-predicted maximal heart rate revisited. , Journal of the American College of Cardiology — Tanaka formula
  2. Lehmann, Foster, Dickhuth & Gastmann (1998). Autonomic imbalance hypothesis and overtraining syndrome. , Medicine & Science in Sports & Exercise — overreaching RHR-shift evidence
  3. Aubert, Seps & Beckers (2003). Heart rate variability in athletes. , Sports Medicine — RHR + HRV combined-marker review
  4. American Heart Association (2019). All About Heart Rate (Pulse). , AHA — official resting HR normal ranges

General fitness estimates, not medical advice. For a medical decision, ask a doctor.