Walking faster begins by walking with the right technique at any speed. This technique will ensure your body is properly aligned and your legs and arms are working together to transmit energy and power to your stride. You won't have any wasted motion that doesn't translate into speed.
You may need to slow down at first and concentrate on good technique before you let the right technique take you to new speed.
Using the right technique may also help prevent injury.
You can expect to be stiff in some new places as you learn a new technique. This should work itself out, but you can also use the stretches to get looser.
Be sure to include the warm-up and cool-down phases in each workout. Pain (beyond stiffness) that doesn't go away should be checked out with your medical provider.
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