When setting up a training plan, one of the key elements to look into is the intensity of your workouts. Training at the proper intensity will make you faster. However, it’s important to understand the different intensities and how to use them in training.
There are three ways to measure intensity: heart rate (HR), rate of perceived exertion (RPE), and power. For the purposes of this article, only HR will be discussed. HR is a direct measure of how many times your heart beats per minute. As the intensity increases, your body requires more oxygen and nutrients to keep it going. Your body responds by increasing your HR to pump more oxygen and nutrient saturated blood.
To properly use HR to measure intensity, there must be an understanding of your current fitness level. The best measurement of the fitness level for endurance athletes is lactate threshold (LT). The lactate threshold is the point where more lactate is produced then can be removed or reused. This results in an increase in lactate in your body that continues to rise unless you lower your intensity. This point is crucial because once you go over it, lactate begins to accumulate and your body eventually shuts down. However, staying just under your LT, you can ride for much longer. Many of the riders in the Time-Trial stages of the Tour de France are typically hovering right at or above their LT. They know exactly where that level is and how long they can hold it. A properly designed training plan will involve testing and constant evaluation of where this LT is throughout the year. Ultimately, the higher your power at LT, the faster you will go.
Finding your HR at LT is the next step in determining the intensity of your training. This involves testing. There are several ways to measure this level. One is to hire a coach/professional and have it tested. A coach/professional typically charges around $100.00 per test, but he/she can provide invaluable information in regard to your current fitness level. The second method is a field test. This test involves a 30-minute time trial on a relatively out-and-back course. The field test should include the following:
• A solid warm up for a minimum of 20 minutes.
• An out-and-back, 30-minute time trial on a flat road(10-minutes within the Time Trial, push the button that starts a new interval)
At the end of the TT, record your average HR for the last 20 minutes. The average HR for the last 20 minutes is a good estimate of where your lactate threshold HR is.
Now that you have determined your HR at LT, you need to determine your zones. Plug your lactate threshold heart rate into the following chart to determine your zones:
Training Zones % of LT Lower % of LT Higher
1 Active Recovery <80%
2 Endurance 80% 89%
3 Tempo 90% 93%
4 Sub-Threshold 94% 99%
5a Supra-Threshold 100% 102%
5b Aerobic Capacity 103% 105%
5c Anaerobic Capacity >105%
Zone 1 Active Recovery: When training in zone 1, you ride at a very easy pace, too easy for many cyclists, which is why many tend to neglect this zone. After a stressful workout, it is important to fully recover as soon as possible. The faster you recover, the sooner you will be able to do another intense workout and the faster you will improve. Training in Zone 1 will result in the release of growth hormone and will increase circulation of blood throughout the body. Both are very important in removing toxins from the body and rebuilding muscles. However, keeping your training in Zone 1 on rest and recovery days is crucial. Going higher will result in more stress on your body and possibly insufficient recovery.
Zone 2 Endurance: For the endurance athlete, zone 2 is where majority of your training should occur. This zone maximally stresses your Slow Twitch (ST) muscle fibers, the muscles responsible for most of your power and energy for exercise lasting longer than 4 minutes. In addition to working your ST fibers, training in zone 2 will result in your body’s ability to burn more fat and less carbohydrates at higher intensities. This is crucial because as your body loses glycogen, or the stored form of carbohydrates, it becomes less and less efficient. It is important to note that training at this intensity maximally overloads the ST fibers, and training at higher intensities will not be as beneficial for that purpose.
Zone 3 Tempo: Zone 3 is a brisk pace that is neither hard nor easy. Typically, cyclists like to stay in this zone during group rides. It feels relatively fast, but is slow enough to have a conversation and still ride comfortably. Training in this zone should be minimal. This zone is too high to maximally stress your ST fibers and too slow to build your lactate threshold. Often times it is used to prepare yourself for higher intensity workouts early in the year
Zone 4 Sub-Threshold: Training in zone 4 will result in the most bang for your buck. Zone 4 training specifically targets improvement s in your LT. You are teaching your body to remove more lactic acid and produce less at a given output. At this intensity your body is removing lactic acid faster than it is being produced, which allows you to ride at this intensity for a long period of time prior to being forced to stop. If you increase the intensity to zone 5 or higher, lactic acid will begin to accumulate and eventually force you to stop. In addition to this, training at higher intensities will require longer recovery periods between workouts. This is why it is very important to include interval training at zone 4. Typically, you can sustain an interval for about 20-60 minutes at the lower end of zone 4 and can hold a steady pace for about 12-30 minutes at the higher end of zone 4. A good part of your training should involve training in zone 4, but remember, more is not always better. It is crucial to schedule enough recovery time between workouts and blocks of training, especially when you begin training in zones 4 and higher.
Zone 5a Supra-Threshold: When you are training in zone 5, lactic acid is slowly beginning to accumulate in the body. In most Time Trials that are around 40k, you will be hovering right around this zone. Training in this zone will increase your body’s ability to tolerate lactic acid. More specifically, you will be able to continually produce power and speed with more lactic acid in your system.
Zone 5b Aerobic Capacity: Training at this intensity can be a very effective tool to increase your endurance performance. This training also requires very little time. But, training at this intensity also requires a lot of rest and recovery between workouts. Without the proper recovery, you run the risk of overtraining, resulting in decreased performance. It requires around 48-72 hours of recovery between interval workouts of this level. The types of intervals range from 1-6 minutes and have periods of equal to double the amount of recovery time between them. Be careful when training at this level. It can be very useful, but it can easily send you over the edge.
Zone 5c Anaerobic Capacity: Training in Zone 5c involves very short bursts of high-speed training. The benefits result in improved performance above your aerobic capacity. Situations such as sprints and mass starts in mountain biking are both examples of where this type of training may benefit you. In addition, training at this intensity will result in improved efficiency and economy of work, resulting in less wasted energy. Once again, this intensity requires sufficient recovery prior to your next important workout.
To sum things up: Training with intensity is one of the most important aspects of a training plan. With a well-designed training plan, you will see continuous improvements throughout the year, and your race results will dramatically improve. However, it is also very important to remember that, although intensity is very important, a proper training plan involves not only the right intensity but also the right amount of volume and frequency of training.
Stay tuned for my next article, which will talk about being mentally prepared for training and racing.
