Cycling training zones — and Sweet Spot — explained

Training zones have a few purposes. One is strategic: They let you make precise physiological adaptations in your training. Another is tactical: Training zones tell you how hard or easy to pedal in a workout or on a training plan. But the overarching idea of training zones is to measure where you are, do specific work, and improve.

At FasCat Coaching, we use seven training zones. There are two types of basic intensities within those seven: ‘as hard as you can’ (zones 4 to 7) and ‘not as hard as you can’ (zones 1 to Sweet Spot). It’s easy to train in all these zones with a power meter and/or a heart rate monitor, but you can also do without either by using your rate of perceived exertion (RPE).

Here we explain each of the seven training zones, plus Sweet Spot.

Training Zone 1 / Active Recovery / Easy

Training zone 1 is the recovery zone. This means easy riding, conversational pace, low heart rate, low power. The purpose of a recovery ride is to deliver oxygenated blood to tired muscles and carry away by-products of exercise metabolism.

Compared to complete recovery — meaning, not riding — an active recovery ride increases lactate clearance after maximal exercise (Martin, 1998). So by riding easy between intervals, or the day after a hard effort, recovery is improved compared to complete rest.

My rule of thumb for active recovery rides is that they last one hour or less, are over flat terrain, and involve the small ring only. They may be done on the way to a coffee shop and should never be ‘forced’ (i.e., ridden in ‘not fun’ weather).

If you are an athlete with a family and career, don’t stress about finding the time for an active recovery ride. Instead, devote your rest days to other areas of your life, and in the long run, your riding will benefit just as much as it would with an active recovery ride.

Training Zone 2 / Endurance / Base

Training zone 2 is your all-day endurance pace. If you have a power meter, this is 59-75 percent of your Functional Threshold Power (FTP). This zone is extremely valuable for your training. Being able to ride 2 – 6 hours in zone 2 is the first step in an athlete’s training for being able to compete in races or events of similar duration. By riding in zone 2, you can train your body to burn fat in preference over muscle glycogen. (Perry, 2008)

Substrate utilization (i.e., fat vs. carbohydrate) varies individually, but as a rule of thumb, as intensity increases energy supply from carbohydrate increases, while supply from fat decreases. Therefore it is important to not go too hard in zone 2 training. For long zone 2 training rides, often the magic and ‘fat adaptation’ doesn’t begin until the last hour of the ride.

Training Zone 3 / Tempo

Tempo training is prescribed as sustained 7- to 60-minute efforts. An example tempo workout is 3 x 10 minutes on in tempo and 5 minutes off. It’s more difficult than training zone 2 training and therefore achieves more physiological adaptation (see table above). Often times road races begin with a lot of tempo and therefore athletes need to be able to put out 60 – 240 minutes of tempo power while still being able to go harder afterward.

Most fondo and gravel events have normalized power and heart rates that fall in this zone.

• Related: Training and Racing with a Power Meter, 3rd Edition

Sweet Spot

Sweet Spot training occurs between 84 – 97 percent of your FTP and there are many many ways to achieve “the Sweet Spot.” Sweet Spot training achieves more physiological adaptations than tempo (see above table) with less need for recovery than threshold training. The intensity balances training benefits and recovery time, thus ‘the sweet spot.’

While Sweet Spot training achieves less training adaptations than threshold training, recovery is generally easier, and therefore, athletes can do more training as a whole. You get “more bang for your buck.” Prior to Sweet Spot training, riders would perform threshold intervals and be too tired the next day for meaningful training.

With Sweet Spot, you can repeat the next day and therefore achieve more training adaptations over the course of a training block. Like tempo, brisk road races contain a lot of Sweet Spot, therefore athletes need to be able to race at Sweet Spot intensities and then still be able to make higher power — during and — late in a race, for the crux moments.

Training Zone 4 / Threshold / Full Gas

Threshold, as its name implies, refers to the maximal effort you can sustain. Training in this zone is usually done for efforts in the 8- to 30-minute range. For instance, threshold intervals are usually proscribed in blocks like this:

• 3 x 10 min ON, 5-10 min OFF
• 2 x 20 min ON, 5 min OFF
• 3 x 15 min ON, 7.5 min OFF

Threshold intervals are beneficial for all cyclists especially time trialists, mountain bikers, and climbers. It is important to go as hard as you can — but not so hard that you can’t finish as strong as you started. Here, it’s very, very helpful to use a power meter or an interval ‘pacer’ to do intervals properly from start to finish.

Training Zone 5 / VO2 Max / Full Gas

These are very intense efforts, characterized by maximal power ranging anywhere from three to six minutes. Wattage-wise, they are 106 to 120 percent of FTP. These efforts are extremely hard, generate fatigue, but are also some of the most beneficial and race-specific. VO2 Max intervals are full gas, max efforts, and should follow rest days on one’s training calendar. Our classic VO2 interval workout is:

• 2 sets of 3 x 3 min ON, 3 min OFF; with 6 minutes of rest between sets

Training Zone 6 / Anaerobic Capacity / Full Gas

Anaerobic intervals are critical for racers of all cycling disciplines especially mountain bikers, criterium racers, track, and road racers. Often times the difference between a ‘cyclist’ and a ‘bike racer’ is their ability to deliver short bursts of power anaerobically. Fortunately, with this training, a cyclist can become a good bike racer by incorporating anaerobic intervals.

Similar to threshold and VO2 intervals, anaerobic intervals are maximal, full-gas efforts performed greater than 121 percent of your  FTP. Here is what zone 6 interval workouts look like for different levels of riders:

• Beginner: 3 x 1 min ON, 1 min OFF
• Intermediate: 2 sets of 4 x 1 min ON, with 5 minutes OFF between sets
• Pro: 3 sets of 7 x 1 min ON 1 min OFF, with 5 minutes OFF between sets

I have done the latter and to this day remember the hill, time of year, and taste of lactate in my mouth! In between the beginner, intermediate, and pro-level zone 6 interval workouts, there are several possibilities, each one specific to the athlete.

Over six weeks athletes may progress from beginner to intermediate, or intermediate to pro with a dedicated training plan. The term ‘capacity’ comes from the athlete’s ability to do more and more anaerobic efforts. The more anaerobic capacity you possess, the better you’ll perform.

As a coach, I strive to improve an athlete’s anaerobic capacity measured by their ability to complete and improve from one anaerobic workout (3 x 1 min = 3 min total), and to a greater anaerobic capacity workout (like 2 sets of 4 x 1 min = 8 minutes).

Training Zone 7 / Neuromuscular / Full Gas

This zone is about sprinting, and efforts up to 20 seconds. This is the absolute highest intensity. I prescribe them as sprints or 20-second Tabata intervals. Sprint training forces the physiological adaptations to increase neuromuscular power, recruit more motor units, hypertrophy of more type II muscle fibers, and improve recruitment synchronicity (Linossier, 1997; Lucía, 2000).

Also, sprinting is a technical skill, so sprint training is a two-for-one workout.

Summary: Train in all the zones

Interval training is highly effective training for bike racing. It should be custom-tailored to the type of events you are training for. We call that race specificity. However, sometimes you just can’t design workouts to achieve everything you will face in a race and that’s why racing is the ultimate form of training.

Bike racing is not done in one zone; most races are a combination of all zones 2 – 7. Therefore, do your Sweet Spot and base training but also incorporate anaerobic and sprint intervals. Make your training well-rounded. In addition to structured zone-based intervals, group rides and motor pacing round out the best training plans.

REFERENCES
Linossier, M. T., Dormois, D., Perier, C., Frey, J., Geyssant, A., & Denis, C. (1997). “Enzyme adaptations of human skeletal muscle during bicycle short‐sprint training and detraining.” Acta Physiologica Scandinavica, 161(4), 439-445.

Lucía, A., Hoyos, J., Pardo, J., & Chicharro, J. L. (2000). “Metabolic and Neuromuscular Adaptations to Endurance Training in Professional Cyclists. A Longitudinal Study.” The Japanese Journal of Physiology, 50(3), 381-388.

Martin, N. A., Zoeller, R. F., Robertson, R. J., & Lephart, S. M. (1998). “The Comparative Effects of Sports Massage, Active Recovery, and Rest in Promoting Blood Lactate Clearance After Supramaximal Leg Exercise.” Journal of Athletic Training, 33(1), 30–35.

Perry, C. G., Heigenhauser, G. J., Bonen, A., & Spriet, L. L. (2008). “High-intensity aerobic interval training increases fat and carbohydrate metabolic capacities in human skeletal muscle.” Applied Physiology, Nutrition, and Metabolism, 33(6), 1112-1123.