Zone 2 (aerobic base)
Zone 2 is the aerobic intensity between 60 and 70% of heart-rate reserve, sustainable for a long time and low enough to hold a full conversation. It is where the aerobic base is built, and it is where most of an endurance plan's volume should sit, because it leaves little fatigue relative to the adaptation it produces.
Zone 2 is the aerobic intensity between 60 and 70% of heart-rate reserve, sustainable for a long time and low enough to hold a full conversation. It is where the aerobic base is built, and it is where most of an endurance plan's volume should sit, because it leaves little fatigue relative to the adaptation it produces.
Also written as: zone two · aerobic base training
In practice
For a client lifting as well as running, it is the zone that interferes least: low-intensity aerobic work coexists with strength training far better than high-intensity intervals do.
The common mistake
Running it faster than it is. Most people execute it in zone 3, where it stops being easy without becoming an intensity stimulus: it accumulates fatigue with neither adaptation.
