What it is
Zone 2 is low-intensity aerobic work — the pace where you can still hold a conversation. It builds mitochondrial capacity and metabolic health.
What is currently understood
High volumes of low-intensity work underpin the training of endurance athletes and are well supported for improving fat metabolism and aerobic base in humans generally.
What is not established
Exact zone boundaries from wrist heart rate are imprecise, and popular prescriptions of exact weekly hours are conventions rather than established thresholds.
Regulatory status
Not applicable — this is a lifestyle and behaviour topic, not a regulated product.
How it comes up in coaching
It is usually the largest training block in a client's week once we establish the baseline. Coaching sets the volume you can actually recover from and progress it. Nothing here is a recommendation.
This page is educational. It is not medical advice, not a recommendation, and not an offer to supply anything. Whether any intervention is appropriate for you is a decision for a licensed provider.