26. Sports Shoes: The Danger Underfoot
Just like finding the proper formula for nutrition and exercise, it’s
up to you to find the right shoes for your feet. That may sound sim-
ple, but the truth is most shoes — even the ones in the impressive tel-
evision ads — can be hazardous to your health. Most modern exercise
shoes offer too much support, are too heavy, and have too-thick soles.
What’s more, many people are wearing the wrong size. The result is
a formula for injury.
Biomechanically incorrect shoes can cause physical stress
throughout your body, and contribute to injuries from the foot, ankle
and knee to the hips, spine and other areas. Scientific studies show
that the so-called protective features found in many shoes, including
shock absorption and motion control, actually increase the likelihood
of injury. For instance, some support systems can weaken your
ankles, and soft, cushioned shoes can potentially lead to instability of
the knee joint and other areas. Furthermore, the thicker the sole, the
more unstable your foot and ankle become.
Many of these oversupported shoes are also overweight. The
seemingly insignificant weight added to your feet, in the course of the
day or workout, produces large negative effects in the economy of
locomotion. For example, for every 3 ounces of shoe weight, a 1 per-
cent increase in oxygen uptake is required for the same performance.
The soles of your feet have millions of nerve endings that sense
the gravitational stress of standing and each step you take. This infor-
mation is sent to the brain, which works together with your body to
adapt to this stress by constantly adjusting your body during move-
ment. This normal protective mechanism is meant to keep you from
accumulating excess wear and tear, and from being injured. When
you cover the foot with a shoe, you risk interfering with this adaptive
mechanism by preventing the nerve endings on the bottoms of your