Due to the way your body extracts energy from fat and glycogen, your brisk walk should (for most people) keep your heart rate around 120bpm for a sustained peri

Due to the way your body extracts energy from fat and glycogen, your brisk walk should (for most people) keep your heart rate around 120bpm for a sustained period of around an hour. This way you'll condition better mitochondria development, oxidise fat for energy and avoid producing damaging metabolic by-products.