We all like to ride at medium speeds - we've practised a thousand times, and of course that's why we're good at it. But what's the point of getting faster? Not much. So put an end to it. In the last few weeks of the season, concentrate on the area that makes you fast, the red area of maximum oxygen uptake (VO2max) - and above. In between, ride nice and slow, i.e. really slow. This mixture of up and down will get you going, guaranteed. The training plan below is an example of what such a programme with intensive intervals can look like.
Riding fast means minimising air resistance: Head down, back flat - if you fold yourself onto the bike like a time trialist, you offer the wind less surface area to attack, which can be seen directly on the speedometer in the form of more speed. Rule of thumb: You are sitting flat enough when the front wheel hub is in front of the handlebars from your (rider's) perspective. Sit frontally in front of a mirror on the bike and try to minimise your silhouette. The longer you can stay in your ideal position, the more this will affect your average speed. You can practise this: try to stay in the aero position for longer and longer on your home lap - until you can hold out flat and stretched for the whole lap. The lower handlebar position is often not the fastest. The racing handlebars allow for many grip variations, which can be used for more speed. The brake grip position with arms as close together as possible has proven to be more favourable in the wind tunnel.
You can achieve a better average on undulating roads if you learn to accelerate over smaller obstacles. The top rule: keep your speed up. Always. So don't arrive at the top of the hill on the very last groove and let your legs hang, but accelerate at the crest and pick up speed again straight away. Only take a deep breath when the speed is up again. You have to practise this. The trick is to move the imaginary finish line. The finish line is not on the crest, but in the flat section behind it. By accelerating hard for short periods of time, you will also increase your short-term energy stores, which will benefit your overall performance.
Quality training requires full tanks. This is all about speed - so never set off with empty tanks, but always well fuelled. Energy in liquid form, for example a carbohydrate drink, helps to keep your energy levels high when you are on the move. This allows you to push your muscles to the maximum and achieve greater progress in less time. And don't worry about putting on weight due to the more substantial training food: The afterburn effect of an intensive session is greater. You will feel how your anaerobic energy stores increase and how you can stay on the gas for longer if you regularly empty your stores and always replenish them with sufficient energy.
... or: Every little helps. You get faster if you turn a lot of screws. Preferably all of them. Therefore: clean the chain and trim it to speed with the finest oil (or wax). A clean drive releases one per cent of power reserve. Fit proper tyres - the TOUR tyre tests are a good guide for this. Adjust the tyre pressure to the track. The tyres should roll quickly and smoothly, but not bounce. Leave flappy clothing in the wardrobe. What fits tight and wrinkle-free makes you fast.