Introduction to Training with Power Meter

BRadley Wiggins using a SRM power meter during time trial. Image by Training4cyclists.comPower meters like SRM, Ergomo and Powertap are very useful if you want to optimize your training and start getting better results. Before you throw away all your pocket money consider how serious you are with your training.

If you find it very difficult to stick to a rigid training scheme, doing specific intervals in heart rate target zones, then a power meter might not be the best choice for you.

If you think that analyzing your performances or registrating your training sessions is a waste of time, then you are probably not ready for cycling with a power meter yet.

If you get excited when you turn on your computer immediately after parking your bike, watching your heart rate file, then you will likely be even more excited about the data from a power meter.

If you like to make training plans or have a cycling coach who works out plans for you, then a power meter will be a very powerful tool, which gives you opportunity to make better training plans.

Power meter training starts a new era

Like the heart rate monitors started a new era back in the 80´s, and got mainstream in the mid 90´s, the power meters started a new one in the early 90´s and are now getting popular among amateur riders here in 2006. The SRM crank system was the one and only power meter system in the beginning, but now there are a couple of other systems on the market. Powertap and Ergomo uses different technologies than SRM´s crank system, but they give a precise measurement of watts. SRM is the most expensive system, while Powertap and Ergomo is less expensive. I will not make further comments on the differences between SRM, Powertap and Ergomo, but instead save my words for a review later.

What you need to know is, that there are different technologies and different prices. Generally they all allow the workload to be measured correctly.

In the first couple of weeks I will recommend that you just continue to train as normal. It will be a very good education for you to spent this time studying how quickly the power meter react to your effort. People get surprised when they accelerate the bike for the first time and discover that they are pushing more than 500W (for a short while, naturally…)

After a few weeks you will be getting more familar with your new equipment. You are now ready to make your first observations with this powerful tool.

Before you can start doing intervals or pacing with your power meter, you have to make a test of your physical performance. To make things easy and time saving, I recommend you do a 5 minutes allout test to measure your wattmax.

You can use the software that followed your power meter or you can a software system like Cyclingpeaks which offers more opportunities. After your 5 minutes allout test you have to figure out what your average power output was. Please notice your body weight since this is an important factor when comparing test results.

You are now able to make your first training program based on test results from your power output.

Make maximum power tests to define your intervals

It is possible to convert your test result to shorter or longer intervals. There will be less accuracy depending on what kind of rider you are. Some people can keep a high percentage of their VO2 max for a very long period of time, and other people who are much better at shorter distances where they can perform impressing high average watts for short intervals.

Therefore this table is only a guideline and the best way to define your target zones is to do a test at that specific distance. If you are a track rider and are training for 1km time trials (anaerobic endurance and strength) you will have to test your power output at that distance.

Power output Training examples
Sprinting200-?? %5×150m (complete rest)
Anaerobic endurance100-130%5x(1+6min)
VO2 max90-105%3x(3+2min)
Threshold85- 90%3x(8+4min)
Endurance50-85%3 hours
Recovery40-50%1 hour

Next time you go to a race, use your power meter to collect data from the race. You will see, that you spend time in all the target zones in the table. Have a look at the interesting parts of the race. This investigation is an important part of having a power meter, and it is here you can discover things you would never have found out. You can see the difference it makes in crosswinds to sit behind a bunch of riders compared to suffering in a long line. When you see that big difference, you will definitely try even harder to keep your good position in the bunch in the crosswinds next time.

Time trialists uses watts for pacing

Time trialists love to train with power meters because they can see exactly how good they perform and make it easier for them to see progress. With a little training it is possible to use the power meter as a pacer during the time trial. In this situation they can compare their physical performance from time trial to time trial. These data files are not affected by the wind, course or equipment, so they are very useful to see how the form changes.

If you have a velodrome in your neighborhood you can make aerodynamic tests to improve your position on your bike. Serious time trialists should consider this and at least give it a try.

Testing in a wind tunnel is very expensive, so testing on a velodrome with your power meter might be a cheap alternative. When you do the tests you will need at least one assistant to take split times for each lap. With a little training in this setup, you can try different positions and equipment, and see which combination saves most watts.

This part of using a power meter is the more challenging part, but I promise, that it is very satisfying when you save a couple of watts.

Power Meters for Pacing Control

I normally recommend serious riders to use a power meter for optimization of physical performance. The reason for this is that it is possible to control the workload very precisely, securing me that they train exactly what I am interested in.

There are a lot of riders who start out too fast in intervals and then slow down in the last part of the interval. The problem about this is that the first part of the interval requires such a great amount of anaerobic work that they get exhausted too early. They reduce the pace and can’t maintain the power output required to stimulate the aerobic system sufficiently.

The result is that the interval subjectively is a very hard experience, but objectively a poor controlled aerobic interval. If they just know how many watts they can maintain over a given period it is much easier for them to control the pace during the interval.

10 comments… add one

  • Really am hooked by cycling. Riding just under two years and I am 52. Not going to race but presently ride 120-150 miles per week with my group where we ride 20-22 mph for 45-55 miles. I can sprint up to 30 mph not longer than maybe 300-400 yards. Ride with cycling computer, Garmin 705 and want to bet better! Better meaning faster so that I can be an “A” cyclist rather than a “B” cyclist. I really enjoy cycling. Am really hooked so I want to get a power meter. Question is which one—-crank, power tap. Or even iBike! Help!!! What is your recommendation. I own a Wilier Cento Uno with SRAM RED Groupo.

    Thanks.

  • Forget iBike…its a poor man’s power meter. However, if the economics dictate that or nothing, do that! Its just that the iBike depends on too many variables being dialed in to give a truly accurate comparative picture of performance. I’m speaking from experience since I owned an iBike. The choice between SRM vs Powertap…comes down to subjective and convenience issues…if you have multiple frames, go with the PT since its on the wheel. I can’t really make a strong case for going with Crank even if you have 1 frame. I have been a PT user for years, and I love the equipment. I ride with a wireless “ANT+) PT setup with a Garmin Edge 705…its perfect! But, my disclaimer here is I have never owned a crank power system. Hope this helps…
    By the way, I’m 57 and my fitness and performance went vertical when I started training with power.

  • shish

    A vote for the crank based power meters…..like SRM. If you ride several different rear wheels, the Power Tap gets out of hand. you need a new one for every wheel you ride. If you are a TT rider, you need a PT disc or similar aero wheel which to me is not practical. Try selling one after a season or two. With SRM, and considering the ease of crank removal these days, I think it is debatable whether changing the crank is any less difficult than changing a wheel. My $.02

  • Mark

    I went with a Quarq S975 crank based meter and have been very happy with it so far. I do not know if it is any better or wore than the SRM but it seems to read very consistent and is quite a bit less than the SRM.

  • jon berman

    I purchased a QUARQ power meter with ROTOR cranks. IT is ANT a+ compatible. I use it with a GARMIN 705. It is awesome. The nice thing about what I bought is : 52/38 chainrings and 50/34 chainrings. I can use the power meter crank set(s) either in flat Florida(which where I live) or in the hills of Georgia! Great choice. All that I have read suggests that a crank based system is more accurate. Had I purchased a PowerTap rear wheel power meter, I felt I would have had to purchase another front wheel. I already ride ZIPP404′s. I am very happy with the aluminum rim 404′s. The firecrest have had great reviews but I felt economically as well as ergonomically, a crank system was a better choice.

  • One of the reviewers comments on an iBike. We checked and determined that it was purchased in 2006.

    To put the year 2006 in context, computers were shipping with Windows XP or Mac OS9, smartphones were nonexistent, and modems were dominant.

    A lot has improved in the last 6 years, including the technology and performance of the iBike.

  • kfg

    Dear John,

    What is the drag coefficient of my cowboy hat?

  • Pierre Gaul

    I have an ibike I purchased in 2012 and I am happy with it
    The bottom line if you are not a racer and rich then paying over 1000 bucks for power meter is bit overdoing it in my case.
    I am an A rider and do well in mountains so need to improve for big mountain centuries without breaking the bank

  • Eric Meyer

    Sram quark red and training peaks along w following doc Jespers v02 max training yields results period. Currently following his winter training program and am able to see specific results. Well worth the $2k. Absolute no-Brainer

  • hi Jesper !
    I ask about time trial how to perfect time trial? Thank you

Leave a Comment