Remember, intensity is one key to this program. If you could ride 200 to 400 miles per week, sheer volume would guarantee a high level of fitness. But you can't. Instead, make up for missing miles by including intense efforts. Mix short, hard efforts like sprints with longer, steady efforts on hills or into the wind. Spirited group rides raise intensity, too. Aim for efforts at or above your lactate threshold.

Lactate threshold is also called "anaerobic threshold." It's the exertion level beyond with the body can no longer produce energy aerobically, resulting in the buildup of lactic acid. This is marked by muscle fatigue, pain, and shallow, rapid breathing.

The key is varying the intensity during the week. If you always go at a medium pace, your fitness will be mediocre. So, when you go hard, go really hard. When you go easy, go at a pace that Colorado cycling coach Skip Hamilton calls "guilt-producingly slow." You must learn to go slowly.

A second key is sufficient rest. Intense workouts boost your speed and power, but this increased fitness comes at a price. Put the hammer down too often and soon you'll be tired, irritable and slow — all the hallmarks of overtraining. This is why I recommend staying off the bike at least 2 days each week. Lift a little, take a relaxing walk, prop up your feet and read a good book. When the time comes to train hard or to beat up your friends on weekend rides, you'll be rested and ready.

Don't forget to squeeze in some resistance training. Cycling is great in many ways, but it doesn't do much for the upper body. Maintaining muscle volume is crucial as we age. So, cheat on the 7-hours-a-week maximum and find 15 minutes 2 days each week for some basic upper-body exercises. Pushups, pull-ups, crunches for the abs and a low-back exercise (such as back extensions) are all you need. Knock off a couple of sets of each to complement your saddle time. A good time to do this simple-but-effective resistance program is right after easy rides when you're warm.

Are you so busy that finding even 7 weekly hours looks like mission impossible? The trick is to examine your daily schedule and look for small segments of free time. For example:

• Can you get up early and ride before work? With modern lighting systems, pre-dawn rides are safe. It's cooler, less windy and traffic's often lighter, too.
• How about a lunch-hour workout? With a little planning, you can change, get in a brisk 60-minute ride, clean up and be back at the desk in 70 to 75 minutes. Eat half your lunch at your midmorning break and the rest during the afternoon.
• Late evening is a good time for many people to exercise. Dinner is over, you've had some family time and a great workout is a lot better for you than slouching on the couch in front of the cardiac tube. Again, modern lighting systems make after-dark rides a snap.
• Ride indoors. If you don't like riding in the dark or nasty weather, consider pedaling on a trainer. An hour passes quickly if you vary your workouts, use a big fan for cooling, drink plenty of fluids and watch race videos as you pedal.
• Commute. A 5- to 10-mile ride to work with a longer loop home provides an automatic 1 or 2 hours of cycling each day. Why sit in a car and stress about finding time to ride when you could use your bike for daily transportation?!

Finally, ride smart. Is there a negative to this 7-hours-a-week program? Of course. In lengthy events such as centuries or week-long tours, you won't have the endurance of riders blessed with more training time. The solution is to realize your limitation and ride accordingly. Sit in a paceline, back off a bit on climbs, eat and drink often. You'll do fine.