Power in Motion: Using Watts to Amp Up Indoor Cycling Drills

Are participants maximizing calorie burn or just spinning their wheels? A simple physics equation can help you (and your riders) do the math.

by Krista Popowych

We have all seen “those riders” who pedal super-fast on their indoor cycles with little or no resistance. They’re smiling, sweating and bouncing around in the saddle, brimming with an unbridled enthusiasm that we love. Their workout appears intense and productive, but is it? How do you know? (Spoiler alert: It’s not. More on that later.) And how do you convince these riders to literally change gears to improve their performance? For an indoor cycling instructor, one of the many challenges is knowing which cues will enable participants to reach their workout goals. Gym members aren’t snapping into the toe clips of their bikes with the object of burning as few calories as possible. Yet, without the correct ratio of gear to revolutions per minute, riders may be doing just that.

The key to helping indoor cycling enthusiasts turn up their burn lies in two buzzwords you’ve surely heard sweeping the group indoor cycling scene: power and watts. Here’s a quick brush-up on physics, power and watts—with tips on how to help members use the bike’s digital display to get the ride of their lives.

A Powerful Equation

Generally speaking, POWER is a function of FORCE multiplied by the VELOCITY at which the rider is pedaling:

Generally speaking, POWER is a function of FORCE multiplied by the VELOCITY at which the rider is pedaling:

In the case of cycling, wattage (power) is equal to gear (force) multiplied by revolutions per minute (velocity):

Wattage = Gear × RPM

As this equation illustrates, power is not a reflection of either gear or rpm by itself. An increase in both velocity and force will result in a higher intensity than an increase in either of them alone.

Many exercisers think of power training as something that happens in a weight room and involves relatively high-speed, high-load exercises that are performed with an explosive intention. But we can extrapolate that same concept to the cycling studio.

A Powerful Connection

In the scenario of those furiously pedaling, seat-bouncing cyclists using a low gear, velocity is high, but force is low, so wattage will be low, too. We can infer a similar outcome for riders pedaling at very challenging loads but barely turning the crank arms—a habit called “mashing” the pedals. For pedal mashers, force is heavy, but velocity and, in turn, wattage are also low. These riders, like the bouncers, appear to be working hard as they struggle to complete a revolution. But in both cases (bouncing and mashing), the riders are not truly maximizing their power output. What’s more, riding at high speeds is often compromised by poor technique, and using heavy gears and low cadence can set the stage for knee injuries (Young 2016).

While you may be able to spot these issues (and cue riders so they can correct them), the display on an indoor cycle offers a concrete crosscheck that is easy to see quickly and objectively. In fact, this is precisely why power training has become the gold standard for outdoor cyclists, who once tracked progress with mileage and heart rate. Whereas heart rate training can vary greatly—based on the body’s physiological responses to temperature, hydration, exercise duration, caffeine, endorphins, overtraining and other factors—training with power is a mechanical response. It measures how hard you can push at what velocity, regardless of whether you’re jacked up on caffeine or had a bad night’s sleep. And the only way to manipulate power outputs, unlike heart rate results, is to do the work.

Power is a great tool for setting goals and measuring improvement. If a rider usually averages 130 watts per hour, for example, and a month later is averaging 150 watts per hour, he or she is definitely getting stronger.

If you have riders who can’t seem to move out of the middle of the pack on the club’s leaderĀ­board, regardless of how hard they are pedaling, encourage them to focus on their own gains, not on their rank.

Using Watts to Boost Workouts

Riders who are familiar with wattage only in terms of lightbulbs may know little about how watts work. But participants don’t really need to understand the physics to see how they can manipulate variables to raise or lower their average watts. In short, higher watts means greater calorie burn! Use these steps to show riders how variations in force and velocity affect power:

  1. HOLD SPEED STEADY AND INCREASE GEAR. Ask riders to hold a specific cadence (e.g., 80 rpm) and then gradually increase gears. Tell them to note that wattage rises following each gear increase.
  2. HOLD GEAR STEADY AND INCREASE SPEED. Cue participants to drop a few gears and then gradually increase rpm while leaving the gear alone. Again, cue riders to watch their watts on the display; they will go up.
  3. SELECT A FAST SPEED AND DUMP THE GEAR. While riders are pedaling at a high rpm, have them quickly drop gears, or “dump the gear” down to a very light resistance. They will see their watts drop drastically even though they are pedaling fast. They will also experience how their riding technique starts to fall apart at high speed and low gear, thus emphasizing the importance of cycling with some resistance. This is a good time to point out how they can use physical cues to determine when it’s time to switch gears.

Giving Riders More Control of Their Training

Focusing on watts provides an individualized approach to monitoring intensity. For example, let’s say you cue an interval drill with a goal to increase watts by 40 from one interval to the next. In this scenario, riders have three choices:

  • Stay at their current cadence and add gear.
  • Stay at their current gear and speed up.
  • Adjust both gear and cadence.

How each rider hits the wattage goal is a matter of preference: Increase speed, increase gear, or do both. Having this control is particularly beneficial for riders who prefer a certain cadence and don’t want to deviate much from that speed.

Helping Riders Get in the Zone

Wattage goals will vary from person to person. No exact watt number is appropriate for all riders.

Generally speaking, a beginner cyclist may average around 75–100 watts in a 1-hour workout. A fit participant will average more than 100 watts, and pro cyclists can reach 400 watts per hour.

Establishing a rider’s wattage goals can be done through power testing, which can also be used as a basis for power zone training.

FUNCTIONAL THRESHOLD POWER is the highest power a rider can maintain in a quasi-steady state for 1 hour without fatiguing (Allen & Coggan 2010). When power exceeds FTP, a rider will tire more quickly than if he rides just below his FTP. Power zone training uses a rider’s baseline FTP to establish specific individualized watt ranges (zones) for goals such as active recovery, endurance, tempo, anaerobic threshold and more.

Some instructors lead riders in a 20-minute test during class with a correction factor of minus 5% (so it correlates with the 1-hour test). Or, with the benefit of today’s technology, riders can perform their own FTP test using a guided app on their smartwatch or smartphone. Of course, none of this is necessary if your facility has gamified leaderboards that track watts and project them on a screen behind the instructor. Just remind participants that their rank doesn’t tell the whole story. They should compare their watts to their watts, not someone else’s.

Go Ahead: Harness the Power

Just about any favorite drill can be rejigged to focus on power (see the sample workout below). Training with power in the indoor cycling setting adds a new dimension to group classes. At the end of the day, group exercise participants want variety, individualized workouts and, most of all, results. Power training can pave the way to effective and inspiring rides and measurable improvements that can keep you and your class riding high.

REFERENCES

Allen, H., & Coggan, A. 2010. Training and Racing with a Power Meter (2nd ed.). Boulder, CO: VeloPress. Young, C. 2016. 7 common indoor cycling injuries, Slide 14. Accessed Jan. 22, 2018: reference.medscape.com/features/slideshow/indoor-cycling-injuries#page=14.

Meet our experts

AFM_Author_Popowych KRISTA POPOWYCH , is the global director of education at Keiser. The 2014 IDEA Fitness Instructor of the Year and a multi-award-winning presenter. She can be reached at kristap@keiser.com.

The information provided is without warranty or guarantee and NASM disclaims any liability for decisions you make based on the information. Learn more