During a workout your feet may swell. Your feet may become sore, tingle, and grow numb. Tingling and numbness mean pressure on nerves, or reduced blood circulation. Runners should purchase shoes later in the day or after a workout to be sure of the fit.
Cyclists often like to buy tight shoes for maximum power and control.
You should look for shoes that give good support around your arch and instep, but don't put pressure on your toes. Shoes with Velcro closures and bikes with short toe clips can both put pressure on your feet. Clipless shoe and pedal designs avoid these problems. If you loosen your shoes or toe clips, numbness should disappear at once. If it doesn't, you may have nerve damage.