This was written up for a friend who asked about how to use heart rate in planning his training. Much of this I learned years ago from material produced by Joe Friel. A near cousin of heart rate based training is training with power originated by Andrew Coggan.

Heart rate training is a method of structuring workouts based on your heart’s beats per minute (BPM). Instead of running, hiking, rowing, cycling, etc  at a pace that “feels hard,” you train within specific zones that reflect how intensely your cardiovascular system is working.  Heart rate training breaks intensity of activities into 5 distinct zones—from easy recovery sessions to high-intensity efforts. Tracking your heart rate ensures each session targets a specific physiological benefit.

Why Train by Heart Rate?

1. Precision Over Guesswork – Environmental and internal factors can mislead your perceived effort. HR data provides objective feedback.
2. Build Endurance Efficiently – Training in aerobic zones develops long-term stamina.
3. Avoid the Gray Zone – Many athletes train too hard on easy days and not hard enough on hard days. HR zones offer clear structure.
4. Track Fitness Progress – Over time, a lower HR at the same pace indicates increased fitness.

Heart Rate Zones

Heart Rate training has identified  5 distinct intensity levels.  A quick summary of these zones:

Zone	Intensity	Focus	Sustainable
1	50–60%	Recovery, warm-up	All day
2	60–70%	Aerobic base	3-6 hours
3	70–80%	Endurance, tempo	2 hours
4	80–90%	Threshold	20-60 minutes
5	90–100%	VO₂ max, sprints	< 20 minutes

Maximum Heart Rate

Determining your maximum heart rate (Max HR) is key to using heart rate zones effectively—but the “right” method depends on your fitness level, goals, and access to equipment. Here are the three primary methods for determining your Max HR:

Estimated Formula (Simple but Inexact)

The most common formula is:

Max HR = 220 − age

Example:
If you’re 40 years old:
220 − 40 = 180 bpm estimated max heart rate

This method is easy but can be off by ±10–15 bpm, especially for athletes or those with unusual cardiovascular responses. Some alternative formulas try to improve accuracy:

Formula	Equation	Notes
Tanaka (2001)	208 − (0.7 × age)	More accurate for older adults
Gulati (for women)	206 − (0.88 × age)	Based on female-only cohort

Important: These formulas give a general ballpark but don’t account for individual variation in fitness, genetics, or medication.

Field Test (Accurate & Accessible)

A field test gives you a personalized Max HR value. Here’s a simple running-based test:

1. Warm up for 15–20 minutes with easy running and some short strides.
2. Run at the hardest sustainable effort for 20 minutes.
3. Use a heart rate monitor.
4. Your average HR over the final 15 minutes is a close estimate of your lactate threshold HR.
5. Your peak HR during the final minute is likely near your Max HR.

This works best for trained athletes and runners. Cyclists can use similar tests on a bike trainer.

Laboratory Testing (Most Accurate)

The gold standard is a VO₂ max test or graded exercise test (GXT) at a sports performance lab:

• You wear a heart rate monitor and breathe into a gas analyzer while running or cycling on a treadmill or ergometer.
• Intensity increases every few minutes until exhaustion.
• Your true max heart rate is recorded at peak effort.

This method is highly accurate, but it requires access to specialized equipment and supervision.

Resting Heart Rate

Your resting heart rate (RHR) is best measured in the morning before getting out of bed. Use a heart rate monitor or count manually for 60 seconds. Repeat for a few days and average the results.

Typical RHR:

• 60–100 bpm for most adults
• 40–60 bpm for trained endurance athletes

An upward trend in RHR can signal overtraining, fatigue, illness, or poor sleep.

Method to Calculate Zones

The simple method (good for untrained individuals) is to use your maximum estimated heart rate (details to follow).

As you become for fit it is better to use the Heart Rate Reserve (HRR), sometimes called the Karvonen Method.

HRR = Max HR – Resting HR
Target HR = (HRR × % intensity) + Resting HR

Devices That Support Heart Rate Training

To train effectively by heart rate, you need reliable tools to monitor and interpret your data. Options include:

Chest Strap Monitors

• Most accurate for measuring electrical heart signals
• Brands: Polar H10, Garmin HRM-Pro, Wahoo Tickr

Optical Wrist Monitors

• Built into many smartwatches; more convenient but slightly less accurate
• Brands: Apple Watch, Garmin Forerunner, Coros Pace, Suunto, Fitbit Sense

Arm Band Monitors

• A middle ground: more accurate than wrist-based, more comfortable than chest straps
• Brands: Scosche Rhythm+, Polar Verity Sense

Notable Programs,  Gyms, and Software That Use Heart Rate Training

There are a number of training programs and gyms which use heart rate to guide intensity level of exercise.   There is a growing number of software systems which will build and adapt a training program based on individual variability that is determined by your heart rate data.

• Morpheus Training System is fairly new, but promising looking system informed by current science that is simple to use.
• Garmin & Polar: Smartwatches and training apps offer adaptive HR-based training plans.
• TrainingPeaks, Zwift, Peloton are software systems (largely focused on cycling) which train and analyze your heart rate data to determine optimal training.
• Orangetheory Fitness: Heart rate zones are central to every class, targeting time in the “orange zone” (84–91%) for metabolic boost.
• Maffetone Method: Zone 2-focused training aimed at maximizing aerobic function and fat metabolism.
• 80/20 Endurance: Backed by science, this system advocates 80% easy (Zone 2) and 20% hard (Zone 4–5) for sustainable performance gains.

Lessons Learned doing Heart Rate Training

Common Pitfalls and How to Avoid Them

• Ignoring Individual Variation – Max HR formulas are just estimates. Use personal testing if possible.
• Overtraining in Zone 3 – Avoid the “gray zone” unless it serves a specific goal.
• Neglecting Rest and Recovery – Use RHR and HRV to track readiness.
• Misusing Devices – Optical monitors are convenient, but ensure tight, consistent placement for accuracy.

Why So Many Training Programs Emphasize Zone 2

Zone 2 (60–70% MHR) is where foundational aerobic fitness is built:

• Enhances mitochondrial function (energy production)
• Improves fat metabolism and energy efficiency
• Builds stroke volume—your heart pumps more blood per beat
• Low stress, high benefit—ideal for recovery, endurance, and volume

Most elite endurance athletes spend 70–90% of their training in Zone 2.

When Time Is Tight: The Power of Intervals

High-intensity interval training (HIIT) in Zones 4–5 delivers strong results when time is limited:

• Boosts VO₂ max (your body’s ability to use oxygen)
• Improves lactate threshold and metabolic capacity
• Time-efficient—15–30 minutes of intervals can rival much longer workouts
• Promotes EPOC—your body burns calories long after the workout ends

What Is HRV and How Can It Help Training?

Heart Rate Variability (HRV) measures the small fluctuations in time between each heartbeat. Unlike simple BPM, HRV reflects the flexibility of your autonomic nervous system—your body’s balance between stress and recovery.

Why HRV Matters:

• High HRV: Indicates good recovery, readiness to train, and parasympathetic dominance (rest-and-digest).
• Low HRV: Suggests stress, fatigue, or poor recovery—time to take it easy.

How to Use HRV:

• Use apps like WHOOP, Oura Ring, or HRV4Training
• Track morning HRV for baseline trends
• Adjust training intensity based on daily HRV insights (e.g., back off when HRV drops significantly)

Further Reading and Tools

• VO2Max
• Health and Fitness in One Page
• Heart Rate Zone Calculator – TrainingPeaks
• “80/20 Running” by Matt Fitzgerald
• Maffetone Method – Official Site
• HRV4Training App
• Garmin HR and Recovery Metrics
• Running Training Zones
• HRV: A Beginner’s Guide to Heart Rate Variability – Measuring Recovery