During a cycling class, have you ever wondered what gear you should be in? How hard you should work? Sometimes, you just shout out “what gear?” Instead of a simple answer, you get a range. “Eight to fourteen!” the instructor might say. Not all that helpful, is it?

Unfortunately, it’s the best any instructor can do, and for a very simple reason. Each person has a different level of leg strength and conditioning. In untrained folk, it is related to your activity level and body weight. In trained folk, it is highly dependent on the amount of work the person has put in, and can still be very different among highly trained athletes of different body weights.

So what gear? A better question is to ask what power zone. Assuming the same cadence (pedaling speed) each rider could be in a different gear, thereby making a different wattage, but all in the same power zone relative to their own fitness level.

In other words, everybody is working equally hard!

The Olympian in the corner is breathing just as hard as the man beside her on his third class. They are both working at a percentage of their relative FTP measurements.

That term again! FTP stands for Functional Threshold Power. It is simply the power level (in watts) where you cross the line from an aerobic effort (one where you can maintain your breath) to an anaerobic effort (an effort that leaves you breathless).

Virtually all serious cyclists use this fitness measure to set the intensity for all their workouts. Once this number is known, the power zones are merely percentages around this power level. Note each power zone can also be approximated by a rate of perceived excretion, and a time that one could be expected to maintain said power zone.

GREY Zone One Power (Active Recovery) 0-55% of your FTP (easy 2/10 effort, breathing normally, no leg sensations, no concentration required, all day riding possible)

PINK Zone Two Power (Endurance) 56-75% of your FTP (easy 2-3/10 effort, breathing while conversing, slight leg sensations, mild attention required to maintain effort, more than four hours riding possible)

BLUE Zone Three Power (Sweet Spot) 76-90% of your FTP (working 3-4/10 effort, breathing punctuates conversation, mild leg sensations, attention required or effort lapses, riding 2-3 hours possible)

GREEN Zone Four Power (Threshold) 91-105% of your FTP (harder 4-5/10 effort, single sentence conversation, medium leg sensations, constant attention to effort level required, riding possible for about one hour with extreme difficulty)

YELLOW Zone Five Power (Anaerobic Power) 106-120% of your FTP (hard 6-7/10 effort, multiple breaths between sentences, strong leg sensations, constant attention to effort level required, riding usually limited to duration of 3-8 minutes)

RED Zone Six Power (Sprint Power) 121-145% of your FTP (hard 8-9/10 effort, conversation ceases, intense sensation in the legs, maximum concentration required, riding usually limited to duration of .5/3 minutes)

PURPLE Zone Seven Power (Maximum Neuromuscular Effort) 141+% of your FTP (hard 10/10 effort, conversation ceases, intense sensation in the legs, maximum concentration required, riding duration in seconds)

Using these zones correctly requires an awareness of your FTP. You can home in on it a few ways… but always remember that it is a moving target! FTP changes a bit day to day depending on your motivation, level of fatigue, and other factors. You can expect our bikes to be accurate to around +/- 5%.

A quick and easy way is to do an FTP test in the studio. If your spivi profile is set to update your FTP automatically, then every time you do an FTP test the software will update your profile in the cloud. We run those tests during the free intro class, and all #cykluscrew are invited to come in and do a three minute field test that will estimate your FTP. Look for it on the schedule or ask your instructor.

Second, you could look at the percentage of FTP in the front display at the end of the class. Compare yourself to the rest of the riders in the room and also consider the effort you put into the class. Did you ride at a displayed 120% of FTP while everyone else was riding at 80%? Then your FTP is likely set too low. A hard effort in a forty minute class is usually going to result in an effort of around 85 to 90% of your FTP.

Check the zones above: a 120% FTP effort would be sustainable for less than three minutes for most people. Clearly it would not be possible to ride a 40 minute class at this level. If this is you, you need to adjust your FTP.

To adjust your FTP, log into your account at spivi.com, and navigate to the account and settings page. Under personal settings you will see a link FTP, LTHR, MHR and RHR. As said, FTP is Functional Threshold Power, LTHR is Lactate Threshold Heart Rate,  MHR is your Maximum Heart Rate and RHR is your Resting Heart Rate.

Two more steps and you are done. First, make sure then the button that says “Automatically set my FTP over time’ is deselected. Then, enter a new FTP value. If you worked a class at over 100% of FTP, try increasing your FTP by the same raw number your class result is above 90%. Or go the other way: if you had trouble keeping up with the zones, you can reduce your FTP a bit until you can.

You can also ask our desk staff to help you do this at any time. Remember to reselect the “Automatically set my FTP over time” button so that when you do an FTP test in class your results are updated automatically.

Once you are aware of your FTP your workouts and the results from them will be a lot more meaningful. You will be able to see yourself getting fitter: all you have to do is ride classes and do your best to stay in the zone requested by the instructor.

Your FTP number in watts is the same gold standard every cycling pro is using to train with. Go ahead, strike up a conversation with your racer friend or roadie colleague: they are going to know exactly what you are talking about. In fact, the power zones above were not set by us at Cyklus, but rather by the inventor of the FTP concept that has changed the way we all train, both the pros and the joes.

Welcome to the crew! See you in the studio.