Make a list of all of the surfaces your hands touch during the course of a day. Now make a list of the number of times and where you touch your face with your hands. Rubbing eyes, biting fingernails, scratching an itch, propping your face with your hands, sneezing into your hands, covering your mouth to cough, all count toward your total. If you are one of those, and there are many, who correct imbalances created within the filtering mechanism of the nose with their fingers, then this definitely counts. Applying make up, adjusting an ear ring, shaving, or just sticking a finger in your ear count. Placing food into your mouth with your fingers also counts (French Fries! Biscuits! Sandwiches!). Count any occurrence of your hands coming within an inch of your eyes, ears, nose, or mouth. Scratching your head, smoothing your hair, or adjusting a necklace or tie do not count. Now count the number of times you wash your hands.
Few microorganisms are collected by your hands from any one particular surface. The chances of catching something dangerous from touching a surface and then inadvertently rubbing your eyes, cleaning vegetable matter from between your teeth with a fingernail, or even, if you are one of those, correcting an imbalance in your air supply filtering mechanism, is not high in probability. The danger comes when the microorganisms collected from various surfaces decide to colonize. Large colonies can form on hands that go unwashed. If these 'germ colonies' are familiar to your immune system then you probably will not catch anything. Unfamiliar 'germ colonies' can cause sniffles, sore throat, or much, much worse. The much, much worse is something to be seriously concerned about. For normal circumstances, washing your hands before eating, during visits to the toilet, and before consciously touching your face, such as applying make up or working with contacts, prevents large microbial colonies from forming. In short.......washing your hands several times a day will help prevent you from becoming ill. Not washing your hands will certainly contribute to more illnesses during your lifetime.
So! What does hand washing have to do with fitness, exercise programs, and nutrition? ......Everything! People who are sick do not exercise, eat inadequate diets, and their fitness level deteriorates proportionally with the length and severity of the illness. Wash your hands. It is an integral part of being fit.