Not All Intervals Are Created Equal! Why You Need to Learn More About Cycling Intervals

How much do you really know about the training goals for indoor cycling intervals? Do you realize that the intensity, duration, and recovery amounts should change depending on your goal and the benefit you want to achieve? Take this quiz to see how much you really know about interval training.

Not all cycling intervals are created equal

Cycling intervals are fun—they get your riders excited and engaged and leave everyone with a feeling that they worked hard. Intervals are also the trend—every fitness magazine, and almost every training “guru” lauds the benefits of high-intensity interval training (HIIT). Some even go so far as to say steady-state exercise is a waste of time. While I agree that intervals are an excellent training method to increase fitness and can even improve fat burning, I also know that the fitness industry and the media tend to way oversimplify fitness claims.

It’s not an either/or situation. The pendulum doesn’t need to swing all the way over to the opposite side, ignoring the wonderful intensity range between the lower-intensity so-called “fat-burning” zone and the high-intensity 1- or 2-minute intervals.

Studies show that fat utilization can be improved with longer-duration sub-threshold and threshold intervals and steady-state work. Fitness instructors should offer students a blend of training methods that include some steady-state work at various intensities as well as different types of intervals to activate different physiological adaptations. Don’t fall into the trap of “all HIIT all the time”!

The Indoor Cycling Association has a cycling interval education series that highlights the fact that not all intervals are created equal.

Cycling intervals can be very confusing to new instructors and students, but even longtime instructors can get the equation wrong. Many “experts” claim the work-to-recovery ratio should be at least 1:1, but this general rule doesn’t always apply. There are too many considerations that determine how hard you should go, how long you should recover, and how many total intervals you should perform before they become unproductive. 

Knowing when to stop your intervals (or back off and ride easy) is one of the more important things to learn about interval training because there are diminishing returns with too many high-intensity efforts. There can also be some negative consequences.

Instructors should also know what physiological adaptations are taking place with each type of interval. I have often heard instructors make a blanket statement like, “These intervals will improve your VO2 max.” While it may be true, it also may not be true; it depends on the duration and intensity of the work effort, as well as the fitness level of the participants. It is common to see this statement in the Spinning® profiles submitted by instructors to the Spinning monthly profile newsletter. But, upon examining the profile, you’d see there was nothing they were doing that has been proven to improve VO2 max. Don’t fall prey to spouting off “scientific-sounding” information that is not true.

Could that be you? Might you be making claims that sound good, but you aren’t 100% sure if they are  true or not? 

Here is a self-test that you can take to determine if you need to know more about interval training:

  1. What is the difference in intensity level between a 1-minute and a 3-minute interval? Should there be an intensity difference at these two durations?
  2. Does each duration require that you go as hard as you absolutely can for that duration? In other words, should you wring yourself out for 3 minutes every time your interval is 3 minutes long?
  3. How much warm-up is needed for intervals? Is it the same regardless of the type of interval?
  4. Are “aerobic” efforts considered intervals?
  5. One often sees a recommended recovery ratio of 1:1. What if you do an 8-minute interval; does that mean you should recover for 8 minutes? What if the duration is 30 seconds; should the recovery be only 30 seconds? Why or why not?
  6. What happens when the duration falls below 30 seconds—what energy system is being utilized? Should everyone do these types of intervals?
  7. What are VO2 max intervals? What types of intervals are unlikely to elicit changes in VO2 max? Why not?
  8. What are lactate tolerance (or acid tolerance) intervals? What do they do for you? Are they only for athletes, or can your moms and non-cyclists benefit from them?
  9. What is the difference between aerobic capacity and anaerobic capacity intervals? Which ones are longer? Harder?
  10. How long should a threshold interval last? How many should you do?
  11. Is it ever OK to have insufficient recovery periods? If so, how many, how long, and how often should you do these?
  12. Should everyone in your class do every interval? If not, how do they know when they shouldn’t continue and how do you convince them to back off?
  13. Should every interval class target the same energy system? When can you mix them up, and how?
  14. What are Tabata intervals? If a few are good, are more of them better? Who should do them and who shouldn’t? How would you employ them in an indoor cycling class?
  15. What are the dangers of too many intervals?
  16. What is the danger of intensity that is too high?
  17. Should your older students do intervals? Should your less fit students do intervals? Why or why not?
  18. How often should you do an interval workout in one week?
  19. What if your students are training for a long-distance event like a century ride or a marathon? Will high-intensity intervals help?
  20. Should you mix “interval” and “endurance” workouts in one class? Do you even know what that means? If you are a “Spinning®” instructor, it might mean one thing, but to a cyclist, it means something entirely different. Do you know why?
  21. What is overtraining? How do you avoid it? Is it caused by too many intervals?
  22. Are heart rate monitors helpful when doing intervals? Why or why not?
  23. Should you, as the instructor, do all the intervals with your students? Why or why not?

If you could not answer all of these questions with 100% confidence, then you should learn more about interval training so you can lead your students and yourself to the best fitness (and performance if they are athletes) of their lives!

If you realize that you need to know more about cycling intervals and you are not an ICA member, please consider joining!

I also want to invite all ICA members to submit their specific interval questions so we can cover them in our Ask the Expert series.


  1. I am happy you are delving into this Jennifer, because it is too often misunderstood. Can’t wait for more!!!

  2. Looking forward to the series. Intelligence & training work well together.

  3. These types of questions are what separate those instructors who do the ‘aerobics on the bike’ and the instructors who understand and use intervals as a training tool.

    I don’t mean to sound elitist, however, fact is fact.

    Looking forward to the series, Jennifer.

  4. I can’t wait to read up on all the information that’s on it’s way. It will be so helpful to get answers to those questions (and see how right or wrong I was 🙂 I believe that we get such good quality advice here, it allows me to up my game, and help me be a better coach. I like to have the science behind the “why” – thanks Jennifer

  5. excellent as always and love the thought provoking questions to get us thinking and evaluating our interval profiles. i look forward to the answers to the questions you provide to guide us in developing more appropriate and effective interval training.

  6. Thank you! I always learn somthing new from you. I have been doing what I thought were intervals for a couple of years now. It will be good to really learn how to do them right.

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