Training zones
for running

50-60% · Very easy

Recovery

Active recovery, walking or very light jogging

60-70% · Easy

Aerobic

Conversational pace, training foundation

70-80% · Moderate

Tempo

Sustained pace, aerobic threshold

80-90% · Hard

Threshold

Anaerobic threshold, 10K-half marathon race pace

90-100% · Maximum

VO2max

Intense intervals, sprints

Cardiac efficiency

Strengthens the heart and increases the volume of blood pumped per beat

Fat burning

Teaches the body to use fat as fuel, sparing glycogen

Mitochondrial density

Increases the number of mitochondria, improving energy production

Base for intensity

A strong aerobic base enables more efficient quality workouts

Heart Rate

Accounts for external factors (heat, stress, fatigue). Ideal for easy and long runs. Prevents overtraining.

Best for: Easy runs, long runs, recovery

Pace

Immediate feedback, ideal for quality workouts. Easy to control during races.

Best for: Intervals, tempo runs, races

By Max HR

Use your actual max HR (from a test or race) and apply each zone's percentages

By Anaerobic Threshold

More accurate. Use your threshold HR (30min all-out test) as reference

By VDOT

Based on your recent race time. Our calculator does this automatically

By Perceived Effort

Z2 = can hold a conversation. Z4 = can say 2-3 words. Z5 = can't speak

Always training in Z3

The 'gray zone' develops neither speed nor base. Too intense to recover from, too easy to improve.

Running easy too fast

If you can't hold a conversation, you're going too fast. Z2 should be truly easy!

Ignoring HR on hot days

In the heat, respect your HR even if pace drops. Internal effort is what matters.

Not recalculating zones

Your zones change as you improve. Recalculate every 2-3 months or after races.