Got 10 minutes? Try interval walking

Learn your levels
Level one (intensity level 4–5 out of 10)
Walk at a comfortable pace and focus on your posture by lifting up through the centre of your body, relaxing your shoulders and swinging your arms in rhythm with your stride.
Your arm swing should be from the shoulder, rather than the elbow, and your arms should swing out in front of you rather than across the centre line of the body.
The length of each stride should be comfortable and on planting your heel, the toes should be raised towards the shins. The foot then rolls from heel to toe before pushing off.
Level two (intensity level 6–7 out of 10)
Walk briskly, bending your elbows to 90 degrees and swinging them in time with your stride.
Keep your elbows close to your body and concentrate on their forward and backward movement. Your legs should never be straight – the aim is to produce a smooth motion and a locked knee can cause a bouncing action.
As speed increases so will your hip rotation, but allow this to occur naturally rather than wiggling your hips artificially.
Increase your forward lean, making sure that you lean from your ankles, rather than the waist, as this could lead to back ache.
Level three (intensity level 8 out of 10)
This level is all about speed, so walk as fast as you can! It’ll be hard to maintain, so do it in bursts.
Concentrate on increasing stride frequency, not stride length, and pumping your arms by lifting your elbows high behind you.
To help increase speed, narrow your stride width a little and add a strong push off with your big toe with each step, moving the foot in a continuous heel-to-toe motion.
Lean forwards from your ankles to give yourself a feeling of being able to push against the ground harder. Leaning will also avoid over-striding, which can slow you down.