The Complete Guide to Running Heart Rate Zones
How to calculate your heart rate zones, what each zone means for your training, and how to use them to run faster without overtraining.
Heart rate training takes the guesswork out of easy runs and hard efforts. Instead of wondering "am I going too fast?" you look at your watch and know. Most runners train too hard on easy days and too easy on hard days. Heart rate zones fix both problems.
Finding your max heart rate
The old formula (220 minus your age) is unreliable, with an error margin of plus or minus 12 beats. The Tanaka formula (208 minus 0.7 times your age) is better. But the best method is a field test: warm up for 15 minutes, then run 3 minutes as hard as you can uphill. The peak number on your watch is close to your max HR.
Use the HR zone calculator to get your zones. Enter your max HR (or estimate from age) and optionally your resting HR for more accurate Karvonen-based zones.
The five zones
Zone 1: Easy (65-79% max HR)
This is your conversational pace. You can talk in full sentences. Most of your weekly running (60-80%) should be here. This builds your aerobic base, develops fat-burning efficiency, and promotes recovery. If it feels too easy, it's probably right.
Zone 2: Marathon (80-85% max HR)
Steady effort. You can say a few words but not hold a conversation. This is where you practice marathon-specific sustained effort.
Zone 3: Threshold (85-90% max HR)
Comfortably hard. This is your tempo run intensity. You're at the edge of what you can sustain for 40-60 minutes. Threshold training improves your lactate clearance.
Zone 4: VO2max (95-100% max HR)
Hard. Short intervals of 3-5 minutes with recovery between. This maximizes your oxygen uptake and is the most efficient way to improve speed. Think 800m and 1000m repeats.
Zone 5: Repetition (100%+ max HR)
Max effort. Short bursts of 30-90 seconds. Develops neuromuscular speed and running economy. Think 200m and 400m sprints.
The 80/20 rule
Elite runners spend 80% of their training in Zone 1-2 and only 20% in Zones 3-5. Recreational runners typically invert this, going too hard on easy days and too easy on hard days. The fix: use your heart rate monitor to enforce easy pace on recovery days.
Why resting heart rate matters
If you add your resting HR to the calculator, it uses the Karvonen formula, which accounts for your heart rate reserve (the difference between max and resting). This gives more accurate zones because a fit runner with a resting HR of 48 has a very different training range than someone at 72, even with the same max HR.
Get your personalized zones with the HR zone calculator, then match them to your pace zones from the training paces calculator.