Train your base mainly in Zone 2. Zone 2 is aerobic-endurance effort at low-moderate intensity. You can hold it for hours while breathing steadily and talking.
Cycling Unbound calls these sessions FoundationMiles. They underpin faster riding, group-ride comfort, and racing endurance. Base work means prioritizing them before adding much hard intensity.
Table of Contents
- What numbers define Zone 2?
- Why does easy riding make you faster?
- How do you find your personal zone?
- How much easy riding do you need?
What numbers define Zone 2?
Cycling Unbound defines base Zone 2 as about 69-83% of lactate-threshold heart rate in three essential training rides for cyclists every week. The same guide puts it at 55-75% of threshold power and about 5 out of 10 effort. Typical sessions last 1-3 hours, longer for advanced riders. Wattbike Australia frames Zone 2 as about 60-70% of maximum heart rate.
For a 200-bpm maximum, that is roughly 120-140 bpm. The body mainly burns fat at this effort while building aerobic capacity. If your threshold heart rate is 160 bpm, Zone 2 is about 110-133 bpm. Stay near the lower half when tired or new to base work. Move up only while speech stays comfortable.
Why does easy riding make you faster?
TrainingPeaks explains the mechanism in science of aerobic base training. Zone 2 work loads slow-twitch fibers at low intensity and raises aerobic threshold. That process increases mitochondria, capillaries, and fat oxidation.
Stroke volume also grows, so each beat delivers more oxygen. Better fat use spares glycogen for harder efforts. The result is steadier power late in long rides.
How do you find your personal zone?
Velo / Outside recommends a steady 20- or 30-minute time-trial field test to set zones in guide to heart-rate-based cycling training. Threshold heart rate is highly individual, with examples of 140 bpm in one pro versus 190 in another. That is why the source warns against using 220 minus age.
Velo / Outside outlines Coggan-style endurance at 69-83% of threshold heart rate. Tempo sits at 84-94%, threshold at 95-105%, and VO2max above 106%. If conversation fails, you have likely drifted into tempo or above.
How much easy riding do you need?
Elite endurance athletes spend about 80% of training time at low intensity below the first lactate threshold, with about 20% hard. Velo Fast Talk with University of Agder's Dr. Stephen Seiler reports that pattern in polarizing training episode.
For cyclists, that means making most weekly volume easy Zone 2 plus limited intervals. Velo / Outside notes heart rate is an internal response affected by fatigue, heat, and day-to-day variation. Consistent accurate measurement matters. Combine heart rate with power, perceived exertion, and talk-test conversation ability.
- Hold conversation in complete sentences.
- Check effort near 5/10.
- Compare heart rate with power when available.
