A medium pair of high heels (i.e. less than 3 inches high) will strengthen and tone the muscles in your calves, thighs and hips, and correct your posture as it tilts the top of the hips forward, curving the back and lifting the chest and stomach.
Yes, you could simply wear flat shoes and remember to stand up straight and walk tall. However, with sedentary lives comes weak abdominals and back muscles, so unless you're a professional dancer... it's probably not gonna last long. Much easier to wear a pair of reasonable heels.
Keep Your Feet Happy and HealthySo, if you want to avoid expensive and painful foot problems, podiatrists and biomedical engineers advise* that you don't walk ( or worse, stand still) in high heels for longer than a couple of hours without taking a break.
Also, try to wear them no more than 3 days a week, alternating every other day with flats or lower heels. This will keep your Achilles tendon (back of your ankle) from shortening to the point where you can no longer wear flat shoes, and will lessen the likelihood of falls due to cumulative muscle fatigue.
If you do yoga, try a couple of Downward Dog stretches after wearing heels all day. Or stand on a stair and gently raise and lower your heels over the edge several times for a maximum stretch.
In essence, if you want to keep your feet happy and healthy, think of your high heels like fine chocolate: an occasional treat, not a daily staple.
* See the final summary of this scientific study on the dangerous cumulative effect of wearing high heels.
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