There are two kinds of cooks in the world. My friend, Tim, is trained as a chef and - without ever consulting a recipe - produces excellent cuisine. He understands the ingredients and how to combine them. And then there's John who, to prepare anything more complicated than a steak, needs a detailed recipe. This column won't give you a recipe for training; rather, it will teach you the ingredients so you can cook like Tim.

A Taste of Physiology
We're each born with a mix of muscle fiber types in a given muscle group. The mix is determined genetically and, if you're reading this magazine, you probably have a lot of slow twitch fibers and relatively few fast twitch fibers. When you're riding easily your leg muscles are working, but only the slow twitch fibers (Type I) are engaged. If you start working harder, say, on a sustained climb, then the fast twitch (Type IIa) fibers will also start firing. And if you start hammering over a short climb, your fast twitch (Type IIb) fibers will also start firing. (Slow twitch and fast twitch relate to how fast the individual motor units fire, not to your cadence.) The differences in muscle fiber types, and the progressive recruitment from Type I to Type IIa to Type IIb, is the reason why the smart athlete trains differently at different times of the year.

Adapted from: Wilmore J. and Costill, D. (1994). Physiology of Sport and Exercise. Champaign, IL: Human Kinetics Publishers.

Slow twitch fibers
The slow twitch muscle fibers can work for a long time without getting fatigued, but they don't have a lot of power. They are for cruising on a century or longer event. The slow twitch muscles metabolize free fatty acids to produce energy. Fat is a great fuel for endurance exercise (and we all have plenty!) but it cannot be processed without oxygen. Thus, slow twitch fibers have a high density of capillaries to the mitochondria, where the fat is metabolized for energy. Most of the time in ultra events, we are using primarily slow twitch fibers.

Fast twitch fibers IIa
These fibers are intermediate and, depending on training, can produce energy via aerobic metabolism (oxidative), like a slow twitch fiber, or from anaerobic metabolism (glycolytic), like a fast twitch IIb fiber. If you do lots of endurance training, these fibers will become more oxidative, more like a slow twitch fiber. If you do lots of speed work, these fibers will become more like the fast twitch IIb fibers.

Fast twitch fibers IIb
These fibers are the strongest, most glycolytic, and fatigue most quickly. They produce energy by metabolizing glycogen anaerobically.

Training implications:
1) because each energy system uses different enzymes to metabolize fuel in a different part of the muscle cell, each system must be trained separately. Slow base miles train the fat metabolism system — the dominant system by day two of an ultra event.

2) because Type IIa fibers can be trained to produce energy either oxidatively or glycolytically, prolonged endurance training will increase their endurance, but at the expense of your sprint!

Our Five-Course Season
With these ingredients, we can prepare a five course meal, dividing the year into periods, each with a different focus:

Base Training
The purpose of base training is to increase aerobic capacity, fat-burning efficiency, cycling endurance and muscle size and strength. During this phase the cyclist is primarily training the slow twitch muscle fibers, and recruiting the fast twitch IIa fibers to endurance cycling. The benefits of this training include:

• improving the fuel supply , by increasing your ability to burn fat during long events and increasing the potential to store carbohydrates within the muscle and liver.
• elevating oxygen delivery to the working muscles, both by improving your respiratory system, bringing more oxygen to the circulatory system, and by increasing the efficiency of the heart, so you can pump more blood per minute.
• raising blood flow to the skin , as a result of improved cardiovascular function, thus helping cooling.
• improving the endurance of cycling muscles by increasing the number of mitochondria, the subcellular structures in your muscles that produce aerobic energy.
• improving neuromuscular efficiency in your pedaling technique. Increased power and endurance is partly the result of increased muscle strength, and partly the result of improved coordination in muscle firing patterns.
• toning core and upper body muscles , to improve comfort on the bike.

The key workout is the weekly long ride, building up to 1/2 to 2/3 of the duration of your target event, e.g., 135 miles if training for a double century or 600 km if training for a 1200 km.

Build Training
The purpose of this phase is to increase the anaerobic threshold, glycogen-burning efficiency, cycling speed and muscle power. During this phase, the emphasis shifts from endurance to power. The rider concentrates on several very hard workouts a week, doing just long rides to maintain endurance. The benefits of this training include:

• raising the anaerobic threshold , the region where the metabolism shifts from oxidative to glycolytic metabolism. This allows the cyclist to ride faster without going anaerobic.
• becoming more efficient , producing more power at any given level of oxygen consumption.

The key workout(s) are one or two weekly hard rides at or above your anaerobic threshold. These can be very structured, e.g., intervals, or free-form - just get your heart rate up there!

Peaking
During this phase you combine your endurance and speed training into specific distance training to peak for the key event(s). By this point, the rider should have sufficient endurance and power to complete the event. Now the focus is on training the brain and nervous system to optimize performance.  The rider does just enough intense riding to maintain power. The rider will increase the volume of endurance riding, not to increase physiological endurance, but to improve cycling performance. The long rides will be as event-specific as possible. The rider training for a non-drafting event will practice riding efficiently on the aero bars. The cyclist will work on focus, the ability to set and maintain a constant level of effort for hours . . . and days. The rider will practice bike handling skills: cornering in the dark or taking hand-offs without wasting time. The randonneur will learn to minimize time off the bike. The benefits of this training include:

• increasing cruising speed , the ability to ride steadily below anaerobic threshold.
• becoming more economical , eliminating wasted time and effort.
• building confidence in your ability to complete the event.

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Taper
The purpose of the taper is to store energy for the big event. At this point, doing more miles won't make you faster, it will just make you tired! The smart rider will do just enough intensity to stay sharp, and a short weekly event simulation ride. After three big courses, this course is light, to refresh the palate to allow us to enjoy dessert!

Racing
Dessert is served! Ultra rides are so rich that it's difficult to digest fully more than a few in any season. Choose carefully which events you want to excel at, preferably spaced a few months apart. Ride the other events for enjoyment and training, but back off the pace a little, saving some capacity for the big desserts.

These are the ingredients. Experiment to see what mix pleases your palate — training is very personal. I hope your next season rates three stars!

References
Burke, E. Serious Cycling, Champaign, IL, Human Kinetics
Tanner, D. "Muscles: Why Ultra Marathoners Can't Sprint", UltraCycling , November, 1998
Tanner, D. & Derchak, A. "Metabolism: Why Ultra Marathoners Must Eat", UltraCycling , January, 1999
Derchak, A. & Tanner, D. "The 'Anaerobic' Threshold", UltraCycling , May, 1999

Preparing for Long Rides
A recipe to use these ingredients to prepare for a 1200 km event is in Preparing for Long Rides, the UMCA handbook which is sent to each new member of the UMCA.