Warm Up and Cool Down
Warm up for five to 10 minutes before your workout to prepare your muscles for exercise. Also be sure to cool down for the same amount of time at the end of your workout.

Boost intensity
Unlike fartlek, where the distance between objects is key, pyramids let you gradually increase or decrease intense activity. Because you're constantly changing your pedal cadence from moderate to fast, your heart rate accelerates, which improves your aerobic capacity.

Choose from the routines below (ascending or descending), or combine them if you're advanced. Ride on flat terrain so you can concentrate on speed. During the high-intensity portions, pedal quickly—you should feel you’re working your hardest, and holding a conversation will be difficult. You can also go to a higher gear at this time, but make sure you can maintain a rapid cadence. Pedal slower during the lower-intensity segments; they allow you to catch your breath.

Build strength
Change from a seated to a standing position while climbing hills to give your thighs more of a workout, plus strengthen the upper body and abdominals. After biking steadily for a few minutes, switch to a low gear, where you can pedal quickly, and tackle a hill. Pedal rapidly while seated to target your buttock muscles. Return to an easy pace. For your next hill, switch to a harder gear, and charge up the hill "out of the saddle" (standing) to hit your quads and hamstrings. Repeat for a total of four hills.

Indoor option: When using a stationary bike, pedal quickly for two minutes at a high level of resistance. Switch to a low level, and pedal easily for two minutes. Then return to the highest level, and lift yourself out of the saddle, pedaling hard for two minutes. Return to the lowest level, pedaling easily. Repeat both hill sequences.

Improve flexibility
Be sure to stretch the following muscles, which tighten during cycling. Hold stretches for 20 to 30 seconds.

Shoulders: Stand with feet shoulder-width apart, and bring arms behind body, clasping hands. Bend at waist, bringing torso forward as you raise arms up toward sky until you feel the stretch in your shoulders.

Hamstrings: Bend over as you do above, but let your arms hang so your torso lowers farther, until you feel the stretch in the backs of the thighs.

Quadriceps: Stand next to the bike, holding it with your right hand, and bend left leg as shown below. Grab ankle with left hand, and pull toward your buttocks. Switch legs, and repeat.

Indoor option: If you're using a stationary bike, add a seated twist, which stretches your lower back. While you're still sitting, look over your right shoulder, and twist your torso gently to the right side. Hold for 20 to 30 seconds, then switch sides.