Training Intensities

The above table is supposed to represent the various intensities commonly used in training by an endurance athlete. It is important to note that these are not “zones,” and are not intended to be viewed as totally distinct entities, but rather as a continuous spectrum. As with many things in physiology, each intensity listed above is probably better thought of as a bell-curve where somewhere in the middle, you will have what elicits the most physiological response for the most athletes, but at the same time keeping in mind that there is a lot of overlap in the effects that each intensity will bring. Any comments, questions, or thoughts you might have or feedback you could offer is appreciated, as I’m always interested in trying to make these materials better in whatever way possible; email me at


Recovery exercise is meant to be easy activity that is not stressful to your body, but loosens you up and warms you up for the next bout of hard exercise. Recovery rides should never leave you tired, but should help you feel good about riding and prepared to go hard in a day or two. Or, if you’re still fatigued from the last hard workout or race, recovery exercise should help you feel a little less so. Often, a second day of recovery will be best if you feel lousy on your recovery ride. In an ideal world, each day you set out to do a hard workout, you should be well recovered and ready to put in your best effort, or very close to it. One of the keys to improving as an athlete is to become aware of how much you can do on your easy days without taking away from your hardest workouts, how many easy days it may require to recover from certain workouts or races, and then to make sound judgments about what to do in between races and hard sessions on the road.

Of course, often the best recovery is just plain rest. Whether it’s physical or psychological or practical, there can be good reasons to take a day or more totally off. You should always go into your hard workouts and race days mentally and physically prepared and anxious to perform, and you should never force yourself to ride on a day when you really won’t enjoy it and it won’t add to the overall pleasure of riding and training.

Aerobic Endurance

General aerobic conditioning is the foundation for the rest of your higher-end fitness. It’s key to an endurance athlete’s development and success to have the endurance to get to the finish line, and to do so fresh enough to finish strong, and hopefully stronger than the competition. For a road racer, that might mean doing 4-5 hour rides on a weekly basis, so that you can get through a tough road race or stage race. For a mountain biker or cyclocrosser, you might not need anything longer than 2-3 hours, because the events are shorter, but the endurance is still key.

Still, in most cases, your long rides on the bike should usually include more than just riding around at a medium pace for 3, 4, or 5-plus hours. It can be much more interesting, enjoyable, and helpful to your fitness to intersperse more intense efforts into almost any long-ride. For that reason, it’s good to include some tempo and threshold riding into an otherwise endurance oriented ride, or to have a few VO2 max efforts and accelerations inserted throughout the ride, for example. If you’re on your bike regularly for 4 or 5 hours, you’re going to have the endurance you need, but doing harder efforts will also improve other aspects of your fitness at the same time, it will build confidence and toughness as well. Besides, if you’re on your bike that long, you’re bound to be tired at the end, so you might as well get tired while trying to improve your endurance and your aerobic capacity… or your threshold… or your sprint. Doing this will increase the effectiveness and specificity of your riding by making your long ride bring about multiple positive changes in your fitness, and by making your long rides much more specific to the demands of racing, which are basically always multi-intensity events.


These kinds of efforts are still basically endurance building, but at a higher effort level. This is generally the average intensity you might ride while in a long break, or chasing down a break in a race. It’s definitely a notch below your time-trial, threshold level of effort, but also a solid level or two up from your natural, endurance pace. In theory, if you could consume and assimilate enough fuel on the bike, you could ride tempo more or less forever. In the real world, tempo riding will be a level at which you can ride comfortably hard and feel your legs, heart and lungs working, but you remain comfortable enough that you fatigue slowly. It will vary based on what kind of athlete you are and where you are in your fitness, but tempo efforts may vary from anything like 10 minutes at a time to a couple of 30-45 minute efforts on some long climbs, going hard enough that you’re working hard, but not so much that can’t wait to finish the effort.

This is the intensity at which your fat burning is taken to it’s highest level in absolute terms. At lower intensities, you will be burning proportionally more fat, but less total fat. Early in the season, tempo can be useful as a means of easing into the more intense threshold oriented workouts that are key throughout the year for fitness development, but those threshold workouts will generally get tougher throughout the season as you build towards whatever events or goals you have.


Your lactate threshold is roughly that level at which you come up against your maximal aerobic consumption of fuels, and above which, you increasingly are unable to sustain the effort for long. Roughly speaking, threshold is the hardest you can ride for about an hour, but not much longer than an hour. If you can keep it going for longer, then you’re moving more into tempo territory. If you can’t keep it up for at least 15 or 20 minutes, then you’re doing aerobic capacity work.

These workouts are some of the best for improving high-end aerobic fitness, fuel efficiency, smooth pedaling under power, breathing and rhythm on the bike, self-awareness and pacing. Assuming a decent level of general fitness, doing 2 or 3 x 20 minute efforts on a 3-4 hour ride will be great for building up a lot of aerobic enzymes in your muscles to aerobically consume carbohydrate as quickly as possible, but not anaerobically. You’ll also be contributing to an increase in your heart’s stroke volume and how fully it can empty with each beat. And as with any sustained hard effort, your body will be forced to become more efficient by reducing wasted motion and inefficient effort… all of which builds both confidence and fitness.

Aerobic Capacity/VO2 Max

VO2 max workouts are performed at an intensity that is not sustainable for more than 10 minutes, and often are done at intensities that cannot be sustained for more than 5 minutes. These workouts are meant to take your heart and lungs to their upper limit, in order to expand those limits, as well as your brain’s awareness of those limits. Often, it may not be a physiological limit you come across in a workout, but just an awareness limit of how hard your body can actually go. If you haven’t had your heart beating above 160 beats per minute for a solid 5 minutes somewhat recently… or 170, or 180 or 190, as the case may be… your brain may be hesitant to allow you to do so. More often than not, the first few concerted VO2 max efforts of a training cycle feel the worst and have the lowest power outputs of any you’ll see, even compared to efforts done when you’re more fatigued later in the year. Largely this is because you don’t have the enzymes and neuromuscular training to do as much work (i.e. produce as many watts) as you will later in the season, but it is also a matter of your brain’s comfort zone, and it may prevent you from going as hard as you can, until it’s totally confident that you can safely go that hard.

These types of efforts should be done with some regularity throughout the year, to maintain or improve your maximal aerobic output and maximal aerobic metabolism (how much oxygen your lungs can absorb, how much blood your heart can pump, and how much fuel your legs can burn aerobically). Early in the year’s training cycle, these efforts are fewer and more modest, but they will become more frequent and intense in preparation for the competitive season or key events. A couple of efforts may be included each week whenever it sounds good or fun during the off-season to keep things fun and interesting and to maintain fitness, but structured workouts and maximal efforts will be included every week or two during the racing season in preparation for key events or competitive periods.

Anaerobic Capacity

These brief, all-out efforts are more liberally included in the training cycle to prepare for the more anaerobic requirements of racing. These efforts may not be included for some of the year, because too much anaerobic work will limit aerobic development. But, if your goals include events that demand a level of anaerobic fitness, these workouts will obviously be necessary for proper preparation. Most cyclists participate in road races and crits that both require a good deal of anaerobic fitness, and often anaerobic fitness is what makes the difference between placing well or not. Generally, most people competing have enough aerobic fitness to get to the finish line, but only the ones with good racing know-how and anaerobic fitness will win the race, most of the time.

This is probably the quickest type of fitness to get for a lot of athletes, and a relatively small number of key workouts or races should prepare you well for goal events or seasons. Even just 1 or 2 sessions a week (including races) in the month before a key event may be adequate for some athletes. For others, whose events are highly anaerobic, more workouts may be included.


Though not an intensity level in the sense that it requires a certain level of fitness or suffering, speed and neuromuscular training is important to improve efficiency and force production. This type of work is less of an intensity than it is a variety of drills, such as low-gear sprints, high-gear sprints, in-the-saddle efforts in big or low gears, etc. Including these types of efforts can improve in-the-saddle efficiency and force production without necessarily wrecking the legs from doing VO2 max intervals or long, hard threshold efforts. Sprint drills like this can improve sprinting technique without the demands of an anaerobic capacity workout, which focuses more on race fitness and speed under pressure, rather than just speed and technique. Both are key, but this can be worked on throughout the year without compromising aerobic development.