Do you have the Velcro straps on the shoes cinched to tight and restricting circulation in your foot/feet? It could even be a circulation problem beginning up at your seat. Ensure you seat height and angle is adjusted properly. Also, every few miles stand up on the pedals for a few seconds to get a little blood flowing.

I have the same problem, but my shoes fit great and are not too tight. It depends on the type of riding I'm doing. My toes go slightly numb if my feet are wet, but when I'm nice and warm, they are fine. I have also discovered they will go numb when I'm only pushing and not pulling up on the pedals (sometimes I forget I have cycling shoes on!) It is really a circulation thing. It doesn't bother me because mine is so slight, and I can get the blood flowing and they are fine.

Kelli

I agree with Flipster...

Try loosening the shoes. I know that when my shoes are fastened too tightly, my toes start to go numb. On long rides, since my feet swell, as will yours too, I have to loosen the shoes a notch or two. Last Sunday during Ironman Coeur d'Alene I had to loosen a few times on each foot. Within a minute the numbness goes away.

If that doesn't work, I'm guessing the shoes don't fit right. Or you need orthodics. Or ?