Originally Posted by Carbonfiberboy

It's adaptation. The trainer is the perfect place to work on cadence. Warm up for 15 minutes in an easy gear. Then put the bike in a low gear and set the resistance on low. Put your hands on the bar tops, straighten your back and relax your shoulders. Gradually increase your cadence until you start to bounce in the saddle. Drop down just a hair until you aren't bouncing. Hold that. Relax your toes. Keep your feet flat. Concentrate on having a cushion of air between the soles of your feet and your shoes. Try pedaling a little faster.Try to feel like you are pedaling smooth circles. Keep a tight chain. If the chain flaps, try increasing resistance by one gear. Hold that as long as you can. With practice, you'll be able to hold a very high cadence, up to 120 or so, continuously for 45 minutes. But that's with a lot of practice. To begin with, even 2 minutes at 100 is good. For a warmup, do some high cadence practice every time you get on the trainer. When you are doing your usual workout, try to increase your cadence just a little. Don't worry if your speed drops off. It might. You're not trying for maximum speed, you're trying to stimulate your nerves to to fire faster and in the correct order. It's called neuromuscular coordination. It won't really start to pay off for a few weeks, but then it will, big time.

The theory is quite simple. Lab studies have shown that a cyclist can go fastest with the least aerobic effort at about a 50 cadence. The problem is that the legs wear out quickly because the leg effort is high. One can go the furthest with the least leg effort at very high cadences. The problem is that is the aerobic effort is high, and one goes slower. Most people find a happy compromise, with training, at about 90 cadence on the flat and 75-80 climbing.

Did I mention not to worry about your speed? Ignore speed. Never look at it. It's like weighing yourself every 5 minutes all day. It's a waste of time and energy. Just watch your cadence and notice your breathing and leg effort. Legs tiring and breathing easy? Lower gear and pedal faster. Breathing too hard and legs easy? Bigger gear, pedal slower. You're looking for the combination so that when you are breathing as hard as you can, your legs start screaming after a few minutes. That combination will change with training, too.