Chapter 1: Watt is Power?

Chapter 1: WATT is Power?

What IS Power?

For the purposes of this book, we will focus on how power relates to the world of indoor cycling or Spinning® with the equipment used in most fitness facilities: stationary bikes. While the principles and concepts discussed here will apply to cycling in both forms – the sport of cycling outdoors, as well as our defined indoor environment – power will always be the product of strength and speed, and while the science that surrounds it does not change when we move indoors, it certainly does simplify understanding and working with it.

For indoor bikes, power is the resistance applied to the flywheel in conjunction with the pedal’s RPM (which in bike speak is called ‘cadence’). That’s pretty straightforward.

However, when we move outside, the number of elements that come into play make this a much more complicated equation to wrap our minds around. Take a look at this very handy Power Calculator that some very smart people from Penn State created to estimate power:


















Power = Resistance x Cadence

For the mathematicians out there, things are slightly more complicated, but for the purposes of indoor cycling or Spinning®, this is all we need to know. When we ride inside, we enjoy the perfection of a controlled environment for training, but riding outside is anything but a perfect and consistent environment. Outside, there are many factors that can affect your power – hills, headwinds, rough roads, rain, clouds of gnats, tire tread.

You can see by the counter on the Power Calculator that this page has been visited many, many times. A lot of people are curious about power. A simple Google search can give you a gazillion references to power as it relates to cycling. But all this is information overload! For our purposes, discussion will be focused squarely on how power is measured and used for indoor cycling or Spinning®. Much that’s done indoors can be applied outdoors, so along the way I’ll be pointing out how power work indoors can extend beyond the indoor cycling studio, and help improve your overall fitness and power when riding outdoors.

The indoors/outdoors distinction does not mean that the power generated indoors is different to the power generated outdoors. Watts are watts. It simply means there are different methods used to measure that power due to differences in equipment, environment and cost. There may be disparity between the watts measured indoors and the number of watts measured on an outdoor bike; that’s okay and to be expected. Cyclists who use the same bike in both environments (outdoors on the road and indoors on a bike trainer), with the same power meter will experience differences in their generated power. Overall, these differences are small enough that they should not alter our training or results.

Power meters are one of the best tools for improving fitness and performance to hit the indoor cycling or Spinning® market in a very long time, and the differences between indoors and out will not negate these positive effects. At the end of the day, we are looking for results. Put simply, training with power delivers!

Key Facts About Power Training

  • Power is the best predictor of performance.
  • Power is not necessarily a better method of training than heart rate; it is simply different, with each having specific applications they are best suited for training.
  • Watts represent mechanical feedback, compared to heart rate, which represents metabolic feedback.

The main goal in Power Training is to increase the amount of watts you can sustain for different, defined time periods.

Indoor Power Training Distinctions

  • Indoor Power Training has been designed around the average indoor and outdoor rider, from beginner to competitive cyclist.
  • The foundation for Indoor Power Training is based on the Speed and Power Chart which has been validated by the Performance Lab at the University of Wisconsin. This chart represents the power requirements for each rider based on their weight.
  • Indoor Power Zones reflect a different type of power required for a different interval of time.
  • Your ability to maintain power is always spoken of in terms of the Maximal Sustainable Power (MSP) within each power zone.

“I Don’t Ride Outside…Why Should I Care About Power?”

Before you write power off as just one more toy for the techno geeks, let’s talk about why the rest of us can find a reason to train with power too.

Power Training Helps Prevent ‘Plateaus’ in Fitness Development or in Weight Loss

Just because you sweat and get tired after a workout does not mean you are getting fitter or losing weight. So is it a waste? No. But your body is incredibly smart and it will not work harder than it needs to. It is possible to work out the same way, every day, and feel good while you are doing it, but the results end up in the realm of maintainance, not gain. Without an indication of resistance, even though you think you are ‘turning it up’, in many instances you are not, especially since most non-power bikes will vary in the resistance they apply with the same degree of turn. Without a progressive increase of resistance or ‘gearing’, your body will soon get accustomed to the resistance you apply, and once again, no adaptation will occur. No stress, no adaptation. No adaptation, no change.

Power Training Increases Muscular Strength

The more resistance you put on the indoor bike’s flywheel, the more power you will produce. The problem, however, is that most indoor bikes don’t have gear indicators, so you really don’t know from workout to workout whether you’re increasing the resistance and there is no assurance that you are stressing your leg muscles. I often describe my strength classes as ‘leg day in the gym’, only we are using an indoor bike instead of leg machines. Would you go to your leg press machine, close your eyes and pick a weight stack? Would you ask someone to hand you a long bar with ‘surprise’ weights for squats? Of course not! But with no gear or consistent resistance indicator, and with such variability from one bike to the next, that is basically what many indoor riders are doing.

Power Training Improves the Toning of your Legs

If you want better-looking legs, you need to tone your muscles, rather than bulking them up. Strengthening them while in motion, instead of doing leg presses and squats, will deliver toned muscles.

Power Training Improves your Cardiovascular Fitness as a Natural By-product of Focused Training at Higher ntensities

We often speak of Power Training and Heart Rate Training as if they are completely separate. In many ways they are, yet the body remains an integrated unit, an organic ‘machine’ where the systems commingle and complement each other. Generally, if you train one, you improve the other, just not as specifically or as dramatically as when you target each one individually.

Power Training Adds Variety and Motivation to your Existing Workout Routine

When newbies decide to start working out or wanting to get serious about training, I’m often asked for how long they should train. My answer is simple, if not direct. It’s about consistency, not volume. Finding a way to eventually do this (running, riding, working out) five or six days per week will make fitness a part of your life, instead of one more ‘to-do’ item to check off your list. Nothing will kill consistency quicker than boredom. Your workouts need to be challenging, motivating and even entertaining where possible. You need to look forward to training, and variety is one of the key components in keeping the whole process fresh, challenging and engaging.

Power Training Will Make you a Better Runner

While I’m not a runner, I’m going to throw this out there and see if anyone can find fault with the logic. We often find runners as regulars in our cycling classes because of how beneficial it is for their cardio fitness. They report how they can run for longer, easier after a winter of indoor cycling. However, until the power bikes, we didn’t have a distinct and measurable way to improve their leg strength. With power, they can begin their winter training at an established power level, and begin a plan of increasing that to a higher level by the time they start running outside again in the spring.

“I Ride Outside…What’s the Big Deal About Power?”

When it comes to those who ride outside, whether it is mountain biking, road cycling, or even vacation touring, power can be the catalyst to new experiences on two wheels. You’ll be able to ‘hang with the faster group’, climb the hills you used to walk, climb with speed where you used to get dropped, or just feel fresh throughout a touring ride while your companions are suffering.

Let’s define power just a little more precisely. It is not simply the amount of work you are doing – that’s a different measurement. Although many people say “I worked hard today in class”, and you are admonished by instructors to “Work it!”, when it comes to power, in terms of work, it is the RATE of performing that work that matters – how fast you do it.

The easiest example is walking up a set of steps. Whether you walk or run up the steps, you have done the same amount of work. However, running will require a different amount of power. Performing the same work faster requires more power. So to make a bike go faster, you need more power. The same concept applies to climbing – the same hill will require the same work for a given individual, but if they climb it faster, it will require more power.

There is however, an additional wrinkle for power. The steeper the hill, the more work required to move the bike up that hill and essentially overcome the forces of gravity (which, while constant, seems stronger as you climb steeper hills). Thus, the amount of power required for climbing will also change as the pitch of the hill changes.

So if you haven’t already drawn a rather obvious conclusion, let me draw it for you. If you just ride Rails to Trails, or only on flat terrain, with no concern for speed, then you really don’t need to train with power for your outdoor riding. You may be interested in training with power for all the reasons mentioned earlier for ‘non-cyclists’ – leg strength, toning, fitness, and so on. But as it relates to cycling, this is, plain and simple, a technique for improving your speed or ability to climb better.





















Outdoor Riding—Why to Focus on Power

Power Training will improve climbing, possibly more than any other method or technique.

The ability to climb, and climb with speed, is one of the easiest ways to separate competitive and recreational riders. Your VO2 (the maximum volume of air you can take in to produce energy) and Threshold Heart Rate (the heart rate where your body changes from aerobic energy which burns primarily fat for fuel, to anaerobic energy which uses primarily glycogen) will limit the upper limits of your power. However, VO2 is not something you can easily monitor. Your Threshold Heart Rate can be monitored, and you could do periodic field tests to see if your threshold has increased from time to time, but you would still not have such an easy task of measuring VO2. Thus, you have performance limiters that can’t be regularly monitored, meaning you will find improving these a bit elusive. Enter the power meter. Now you can see if you are able to generate more power, one riding session after another. From short, timed interval tests, to entire workouts, your power numbers will be a great predictor for how well you will be able to face steeper climbs once you begin your outdoor riding.

Power Training Will Help You Target Very Specific Types of Riding

Training specificity is a powerful training principle that we will speak about from time to time. If you want to get better, stronger, or faster at something, you need to practise. Of course, you need a solid fitness base beneath this sort of specific training, and each rider should be able to identify their weaknesses or objectives, and train specifically for their improvement. ??

As an example, if you often need to get off your bike on a certain hill, you can train indoors on a bike with power in order to improve your ability to generate power. By using Cycling Fusion’s Power and Speed for Climbing chart, you can find your required watts/lb to either get up the hill without having to stop, or conquer it with greater velocity (you can get the grade of the road from a variety of online sources, or your own altimeter).?Similarly, if you are a time trial specialist, you know that maintaining a given wattage throughout your trial is key to improving your times. Knowing how many watts you’ve generated in past races will allow you to set specific power goals for improvement. Sprinters also require a different type of power, utilizing predominantly fast muscle twitch fibers, and power in much higher ranges for much shorter periods of time. Keeping precise records of where you start, and setting higher goals is the key to training specificity.

Power Training Will Add Variety to your Workouts

It goes without saying we would all prefer to be riding on a great road or mountain trail in the sunshine with our friends or family, rather than riding indoors. Putting aside issues of safety and convenience, this is the general preference. But when weather conditions and so on make outdoor riding impractical, we ride indoors. Without suitable variety, we will grow tired of this, diminishing our workouts or discontinuing them altogether. It can be a downward spiral.

Break-Away Take-Aways

Power Training really is for everyone. While it’s a given that the outdoor cyclist should be thrilled to begin training with power, the indoor-only rider should also find lots of reasons to fall in love with power. First and foremost will be the ability to keep oneself challenged and motivated and avoid the dreadful fitness plateau.

Power Notes To Instructors

The main point of this chapter is that Power Training really is for everyone. While it’s a given that the outdoor cyclist should be thrilled to begin training with power, the indoor only rider should also find lots of reasons to fall in love with Power. First and foremost, will be the ability to keep oneself challenged and motivated to avoid the dreadful fitness plateau.[5]



  1. Does this book and the upcoming 2nd edition contain power meter workouts?

    Our club just got power meters; maybe one or two instructors know how to train using power meters; both are cyclists/racers, but don’t teach daily. It would be nice to have some power meter workouts to use on my own.


  2. I’ll reiterate what Gene said….rewriting anything is very time intensive. It can take as long, perhaps even longer than the original writing! I am in the process of rewriting Keep it Real after almost 6 years of being in print. I’m in the same boat!

  3. Author

    It will be my great pleasure Renee. I’ve just completed the 10th chapter in a rewrite of that first manual. I suspect that more than 50% will be new and everyone that bought the first one will get 50% off of the second edition. This time it’s going to be an iBook also – so it will be interactive also.

    Thanks for the encouragement to keep plugging till I get to the end – even the re-write is taking me more than 6 months. SOOOO much to keep up with 🙂

  4. I have my personal copy of Gene’s Power Training Manual and continually refer to it. Great manual that guided me to bringing Power Training as a specialized class to our facility for the first time and “taking the cycling program in a new direction” as one client commented. I will have to ask for it to be autographed when i someday have the opportunity to meet Gene.

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