"Float" your legs during hard pedaling.

This is a neat technique that dates to Jacques Anquetil, the great French time trialist and five-time Tour de France winner. It's also recommended by legendary coach Eddie B.

Use it when you're pushing a big gear or going against a tough, consistent resistance. A good example is that strong headwind that Jeffrey and Fred were just talking about. In situations like that, the constant force of pedaling makes your leg muscles tight and fatigued.

Here's how to relax them without losing speed.

As you're grinding along, "float" your right leg for one stroke. Another term for this is "soft pedal." Just let your leg come around without any force. Four strokes later, do it with your left leg. Then your right leg again four strokes after that, and so on.

You'll feel less leg muscle fatigue as the ride wears on, but amazingly you won't lose speed. The trick is to ingrain this technique and use it whenever you have to push hard for an extended time.