What can I do to stop getting numb feet when cycling?

"Dear Gary, I get very cold feet while cycling. They go so numb that I can not feel them. I have tried everything, including new shoes, warm socks and getting my bike setup changed. Nothing has worked....This winter has been really bad for me." "J" _________________________________
Gary Moller comments:
Dear "J",
I empathise with the discomfort you are suffering. I think this is a problem most cyclists come up against at some time and I am no exception: The main cause of numb feet while cycling is that the blood is squeezed out of the foot when you press down but fresh, warm blood is unable to flood in because, unlike running, there is no relief of the pressure. The result is a kind of iscaemia, including cold feet. It can be painful as well as numbing and can cause most unpleasant chill blains. The solutions are as follows:

• Your shoes should allow space in the forefoot but able to be firmly laced at the ankle to prevent excessive movement
• Wear thin socks. Thick socks do not allow the foot to decompress with each cycle stroke.
  Use an exterior cycling booty over the shoe if it is really cold and wet. Have a quite hard innersole that will not compress. I personally use Formthotics Low Profile in all of my cycling shoes. You can get these from http://www.myotec.co.nz/
• Do not have your shoes too tight over the forefoot - fasten the ankle portion of the shoe to prevent too much movement.
• Work on your cyling technique. If you are a thighy pedaller, you will have constant pressure on the soles of the feet and you will get numb and painful soles.
• Correct cycling techniques has you pulling back and up with the hamstring and butt muscles with the back stroke. This takes a lot of practice and concentration to get right. Get it right and you take the pressure off the sole of the foot with each stroke, thus allowing fresh warm blood in.
• Keep your trunk (core) warm while exercising. if you do not keep your core warm, your periphery (arms and legs) will not receive warm blood because the arteries to them shut off to conserve body heat. If you keep your core warm then your feet will stay quite warm; even in very cold conditions.

I trust that this is helpful.