This is a hot topic; everyone wants to know how to train effectively with a power meter. What equipment is needed? How much does it cost? What software is best? How do you actually train with your new expensive tool?
I am going to skim the surface on most of these topics, but will go into enough detail that you can go away from reading this with a good idea of how to train with power.
If I were to delve to deep I would just end up writing a book and I don’t have the time or skills to do that. I am going to pull resources from the book “racing and training with power” that is written by Coggan and Allen. both of whom are experts in their fields. Coggan in physiology and Allen in power meters and cycling coaching.

The choice of power meters

Ultimately your purchase will depend on your budget.
At the top of the price range and probably the best is the SRM. These are produced in Germany and have been the benchmark in power meters. They were the first and still are the best. The SRM is a crank based setup that uses your existing crank set and creates a new spider that has the power measuring devices (strain gauges) contained within. The top of the range SRM comes with 4 strain gauges and has an accuracy of 1 to 2 %. All the new versions are wireless and transmit on the ANT+ network.

Next hot on their heels is the Saris group and their unit called Powertap. This is my power meter of choice. It is a rear hub. So if you have 2 sets of wheels and want to get power readings from both sets, then you will need 2 hubs. With most cyclists having race wheels and training wheels the hub based system is probably the biggest disadvantage with the Powertap. It also uses strain gauges and also has an accuracy of 1 to 2 %. A Powertap comes in a few variations that alter cost and weight. Obviously as it is with everything in cycling, the lightest is the most expensive. The new versions of the Powertap also run the ANT+ protocol so it can talk to Garmin devices.

The ergo meter is a bottom bracket based power meter that transmits via a wire. Like with the SRM you can use multiple wheels with it as it is integrated into your bottom bracket. I don’t have any experience with a ergo meter so can’t discuss it any further.

Polar manufacture a chain tension reader that reads the tension and speed of your chain and using the vibration frequency released by the chain it gives you a power number. These seem to take a while to setup and go out of setup quite easily and are susceptible to heavy riding conditions.

Ibike have a very high tech unit. It uses newtons third law to work out your power output. Every action there is an equal and opposite reaction. It’s very tricky and from what I have heard it requires some calibration against another power meter in order to give you accurate numbers. I personally have never used one, so can’t add more than that.

The new player on the market is Quarq CinQo it is also a crank based setup like the SRM but it is a little cheaper. This product is still very new (as of today 17 May 2009) I am yet to see one, but it does promise to be excellent. They also use ANT+ wireless. I think these will be the future of power meters.  It seems to work with any crank set that has a removable spider, making it very versatile
All these have their positives and negatives; I don’t want to get into it too deep. So I will leave the rest of the research up to you.

Once you have chosen your “weapon of choice” then it’s time to start using it

Do the base miles

Best thing to do when you first install your new power meter is to get out and do a few weeks of riding with it. Don’t bother about the numbers too much. But keep a note of what you push up that “normal hill” or what your average power is in your “time trial circuit” make sure that you download all your data into a software application so that you can come back to all of it at a later date. One thing you will notice while you are riding is that the numbers will jump up and down quite erratically. Don’t worry, this is normal. It is very difficult to maintain constant power in normal road riding conditions. Indoors on a trainer or on a velodrome you may be able to hold your power number quite steady. Outside conditions such as wind, small hills, road surface etc make it almost impossible.
Once you have a good understanding of how it works and what the numbers are reading we can start to work out a training plan around your FTP (functional threshold power, we will discuss this later)

Software

There are some great 3rd party applications available on the market. Most power meters will come with name brand software. This might suffice for your needs. I have chosen to purchase the WKO+ training peaks software. It is brilliant. Does all the normal data types but comes with handy add-ons. WKO+ also talks to all power meters and units on the market. So you can simply import your power files from SRM, Powertap, Polar etc without any hassles. I will go into WKO+ in more detail shortly

If you choose to use the software that came with your unit ensure that you know what all the graphs and pages mean. It’s pointless spending all the money buying a power meter to have it on your bike on all your rides and then download the data to computer for it just to sit there. You need to analyse it and see what the ride is telling you. By looking at the graphs available you will be able to see just how many watts where required for that 10 minute 10% climb. Or how many watts you made when you sprinted for the traffic lights against your training partner. These numbers are going to be incredibly valuable for monitoring your performance and your progress and also will help design the best possible training plan to target your week areas.

WKO+

This is the best power based training software on the market. It has a multitude of add-ons that the others don’t do. It can give you all the graphs and pie charts you could ever want. You can customize graphs based on any of your data over any period of time. WKO+ has also employed some handy new features to help judge your performance. Some of these include IF (intensity Factor) TSS (training stress score) NP (Normalized Power). All of these I will explain later.
The software will also automatically tell your peak 1second (s), 5s, 10s, 20s, 1minute (m), 5m, 10m, 20m power numbers. Having these numbers can help you gauge whether your training is paying off. For example if you have been doing hard sprint training for 2 weeks you should notice that your 1, 5, 10 and 20 second peak power should be increasing. Because ultimately, power produced during sprints will be in those time zones. If you have been hard climbing up hills at your V02Max you should see and increase in your 10 and 20 minute peak power numbers. Don’t be too concerned when you come home from a V02Max training session and see that all your 1, 2 and 5 second peak powers are really low. That’s not the training you were doing that day so naturally you won’t be making 1000 watts for 10 seconds, unless of course you did some sprinting on the way to or from your VO2Max  session.
It also has a nifty way of working out just how much effort you are continually putting into your training. It runs a total called CTL, so day after day of training will slowly move this number higher and higher. A few days off will let it drop slightly. This comes in very handy when you have to decide if you are training hard enough or too hard.

Acronyms Explained

FTP: Functional Threshold Power, the power that you can maintain for a 60 minute time trial
IF: Intensity Factor & TSS: Training Stress Score both of these were coined by Coggan for use in WKO+. They quantify how much work was done in a training session. Your FTP is used to get these results. Here is an example. A TSS of 100 and IF of 1 would mean that you did as much work as hard as a 60 minute time trial. So that’s 1 hour of effort at your lactate threshold
NP: Normalized Power is worked out using a fairly complicated formula. I won’t go into it in too much depth. NP is a better number to note than average power. For any given ride you will most likely notice that NP is higher than average power. In a mass start event or race NP is often a good indication of what a riders FTP is. In hard rides that have an IF close to 1 you should see it up around your FTP. Again it is just another number that can be used to gauge the stress for any given work out
If you want to read up on these in more depth go here

Calculating Your FTP

In another post I have already explained how to do this. But I will go through it again.
After a suitable warm up you should ride flat out for 20 minutes. This needs to be an all out assault you should have nothing left in your legs when you are done. Try and do it on a criterium track or piece of open road so that you don’t have to stop or slow down for anything. It’s pointless having to stop every 5 minutes for red lights.
Don’t go out too hard. Just pedal solid and hard. Don’t look at your numbers too much cause that will most likely just put you off. Build up to the last 5 minutes making sure you give it all you have. After your 20 mins you’re done. Cool down for 15 to 20 minutes and then head home to look at your numbers.
Coggan and Allen provide another test in their book that will test all your power levels. 1s, 5s, 1m, 5m and FTP. Today we are just concerned with FTP. So we won’t do the other phases.
When you get your data onto your computer we need to select the 20 minute all out session and work out the average power for that segment. If your computer has a lap function, as most do, then I suggest you use that when you are out testing. When you have that average we need to take off 3%. The final answer is your FTP. The reason we take off 3% is because FTP is a number that relates to a 1 hour time trial power figure. But we have only ridden 20 minutes. On average most people’s difference between a 1 hour test and a 20 minute test is about 2 to 5 %. Here is an example. Let’s say I averaged 315watts. My FTP would be 305. This number is very important. In fact it is the most important number for power training. You will need it every day.
It’s also important to retest your FTP at least once every 6 weeks preferably every 4 weeks. Hopefully your training between tests will pay off and you will see an increase in the numbers. Try and do the test on the same piece of road under similar conditions each time
What do we do with this number?
Now that you have your FTP we can begin to train in very specific ranges. We will use the hypothetical FTP of 305 that was worked out above. Using the Coggan power levels we come up with the following training levels. There is a spreadsheet available here that will let you fill in your number to automatically work out your training zones

Active recovery             less than    168    watts
Endurance                                   171    229    watts
Tempo                                           232    275    watts
Threshold                                    278    320    watts
Aerobic Power                           323    366    watts
Anaerobic capacity    more than    369    watts

You might notice a few rounding up/down errors in the sample above, but you can fix that later. If you are using WKO+ then these levels can be worked out on the athlete home page.
Creating workouts that target each level will help improve your overall cycling ability.

Workouts

The following 5 workouts have been adopted from the example workouts in the book “Training and Racing with a Power Meter” and have been setup for a cyclist with an FTP of 265 Watts.
I will also supply all 5 workouts in Garmin format. So you can upload them to your Garmin 605 or 705 GPS (they may also work with older Garmin units that support advanced workouts) contact me if you want more. I have a full 16 week plan

Workout 1 – Level 7 Neuromuscular Power
Warm up for 20 mins with power below 150 watts
Repeat the following steps 20 times
…..3 minutes with power between 200 and 235
…..10 seconds power above 350 (flat out)
do 30 minutes with power between 130 and 210
cool down for 15 minutes with power below 150 watts

Workout 2 – Level 2 Medium Endurance Ride
Warm up for 20 mins with power below 150 watts
ride for 45 minutes with power between 200 and 235 watts
cool down for 15 minutes with power below 150

Workout 3 – Level 4 Lactate Threshold
Warm up for 15 mins keeping power below 150
repeat the follow steps 10 times
…..ride for 1 minute cadence between 100 and 120
…..ride for 1 minute with power below 150
ride for 10 mins with power between 210 and 235
repeat the following steps twice
…..ride for 10 mins with power between 260 and 270
…..ride for 5 mins with power below 150
cool down for 15 mins with power below 150

Workout 4 – Sub Lactate Threshold
Warm up for 15 mins power under 150
ride for 5 minutes with power between 260 and 270
ride for 5 mins with power between 160 and 170
repeat the following steps twice
…..ride for 10 minutes with power between 250 and 260
…..ride for 10 minutes with power below 150
cool down for 15 minutes power below 150

Workout 5 – Level 2 Endurance
Warm up 20 minutes power below 150
ride 2 hours power between 170 and 190
cool down power under 150

download all the files here in .zip format

Racing with your power meter

Some of your best data is going to come from racing. During criterium or road races you will always be pushing that 5 or 10 % harder than you normally would in a training session. Along with getting great post race data you will also have great in race data. Knowing exactly how much power you are putting out during the race is priceless and I will explain why.
Let’s say you find yourself on the back of a 5 man break away that has 30 seconds on the bunch. You start to pull turns on the front. You keep a close eye on your power figures and notice that even when you are in the recovery train you are still putting out 320 watts. This is 15 watts above your FTP, you will be able to maintain this for a short amount of time but it will not be long until you pop and drop off the back. Not wanting this to happen you tag on the back and remove yourself from duties off the front. You might catch some stick from the other 4 guys but at least you won’t get dropped. They might begin to tire to drop their output to somewhere within your range and then you can start to pull turns again.
You may even find that in the break you are below your FTP even when off the front. If you know your limits and just how hard you can push you can pull away from them and go it alone solo.
If you find yourself alone off the front and there might be 15 minutes left in the race. Knowing your limits based on your training and your numbers you will know you can pull 350 watts for 10 minutes. So you could pace yourself until 10 to go and then step it up in the hope the pack does not get to you before you get to the finish.
Knowing your power is a huge advantage, knowing your peak power outputs over certain time frames is an even bigger advantage. It could be the difference between winning the race and getting dropped by the pack.
In a recent criterium I raced I was dropped with 2 laps to go. Up to that point I was involved in 3 separate breaks, all of which were away for a while but ultimately got picked up by the bunch.
Unfortunately I was on my Zipp wheels that don’t have a Powertap installed. However if I had my power meter I would have been able to avoid getting dropped or would have been able to pace myself better in the breaks.
Post race I could have come home downloaded the data and then looked at the exact spot that I popped to see why. Obviously I was producing more power than I could handle over a given distance, but just how much was too much? That is the answer I could have worked out if I had chosen to race with my power meter

Conclusion

If used correctly your power meter will be the best cycling tool you own. There is no truer indication of just how much effort you are putting in. Watts don’t lie; the effort you put in will be displayed in the numbers you see on your computer. If you have a coach he will quickly be able to see if you have been “cheating” your workouts. You won’t worry about heart rate ever again…