When it comes to heart rate and exercise, there are five zones.
First is Zone 1, which is a state of rest or very light activity where your heart rate is low.
On the other end is Zone 5—an all-out effort that you can hold for a few minutes at most. In Zone 5 you are close to your maximum heart rate.
Zone 2 is a level of effort that for most people is equivalent to a brisk walk. Experts sometimes refer to Zone 2 as the Goldilocks Zone—not too easy and not too hard.
In Zone 2, your muscles mainly use your fat stores for fuel. This is important because your sugar reserves can only supply a fraction of the energy held in your fat cells.
While your blood sugar can support short bursts of exercise, Zone 2 is your all-day zone!
