LISSLow-intensity steady-state

LISS is low-intensity steady-state cardio: continuous exercise held at an effort you could sustain for a long time and talk through comfortably. Walking, easy cycling and gentle rowing are the usual forms.

It matters because it delivers real aerobic and metabolic benefit at almost no recovery cost, which makes it the one form of cardio that can be added to a hard training week without taking anything away from it. It overlaps heavily with what endurance coaches call zone 2, though LISS is often a touch easier still.

In practice its role in a fat-loss context is often oversold — the calorie burn per session is modest, and 'the fat-burning zone' misreads a fuel-mix chart as an outcome. Its genuine value is as accumulated aerobic volume and daily movement, which is a different and more durable argument.