Cyclists are notorious for 'just getting on their bikes and riding'. Bradley Wiggins briefly explains the importance of warming up and cooling down.
Warming up and cooling down for cycling
A bit like a car engine, the body needs to be warmed up before it will work properly.
It may take a bit of time management - like getting up ten minutes earlier, or preparing your clothes and bike the night before - but it's not a great idea to leap on your bike and pedal like fury to meet your club mates at an agreed hour, or dash to work at race speed because you haven't left yourself enough time. Your body will be far more responsive if you spend the first 10 minutes of your ride easing yourself into it, rather than putting heavy demands on your muscles, heart and lungs 'from the off.'
Ideally, you should also allow yourself a bit of time to stretch once you are warmed up (see Stretching). You can do this if you're meeting your riding pals somewhere. While you wait for the last rider, you could be doing some stretches to prepare your muscles for the rest of the ride.
The shorter the ride, the more important the warm-up. If you're riding a 200km audax event, then you don't need to spend too much time worrying about warm up. Besides, you won't be riding at maximum intensity anyway. However, if you're competing in a 10-mile time trial, or a track event (or even a hill climb) then the warm up will be absolutely crucial to prepare yourself for the explosive effort.
Prior to racing, you need to spend 10-30 minutes pedalling smoothly, gently increasing the intensity to about 80-85% maximum effort. You ought to arrive at the start line just lightly sweating but without feeling unduly fatigued. In this way your heart rate will reach its 'operating level' very quickly in the race and you'll be riding at your optimum efficiency sooner.
Prior to racing, you need to spend 10-30 minutes pedalling smoothly, gently increasing the intensity to about 80-85% maximum effort
After your ride or race, you should 'warm down'. To let the muscles get rid of the waste products that have been accumulating, you should spin a low gear for a few minutes. If you don't, these waste products will remain in the muscles for too long and you'll feel stiff and sore when you need to get back on your bike.
If you can, find a good massage therapist and take a regular massage after heavy training or racing to speed up the recovery process.