Solving the mystery of numb feet

Xtenex laces can help your shoe conform to your foot without cutting off circulation. David Lawrence/ESPNHS

Have you ever had your feet go numb when you're exercising?

If so, your good ol’ bunny ears knot may be twisting things out of proportion.

"If the top of your shoe is cinched too tight, you’ve basically created a restrictive point that blood can’t pass through,” says Darcy Norman, a sports conditioning specialist with Athlete’s Performance in Phoenix, Ariz.

Try a smart, stretchy lacing system, like Yankz ($7.50) or Xtenex ($14.95), right, that conforms to your foot without cutting off your circulation.

Or consider a pair of kicks featuring Boa technology, like the Scarpa Corsa Boa trail running shoe, which dials in to give you a glove-like fit ($115).