Power for Triathletes 3/3: Training and Racing to Power

You have just bought a power meter and installed it on your bike; then what?

I know my first thought when I got my power meter was this:


Once you have overcome the initial excitement of buying a power meter you need to consider what to do with the new found data recording to your cycling computer.
Initial setup and riding

Once the power meter is installed it needs to be paired with your Garmin. Many power meters require you to complete a calibration before every ride to ensure – it is important to do this if advised. The calibration steps are slightly different for each head unit but it is a simple task to do pre ride and takes about 10 seconds.

Once you’re out riding it’s actually good to do very little with the power data for the first few rides. At first it can be quite tempting to frequently look at the power data during rides. I encourage the opposite – just keep riding as you normally would for the first couple of rides. Set up the power display on a secondary screen on your Garmin and check it every now then to make sure your new toy appears to be functioning correctly. You will soon discover that instantaneous power data fluctuates noticeably even at a stable speed/cadence. This is due to the constant variations in riding conditions. Most riders will look at instantaneous power by either the 3 or 5 second moving average display to smooth out the readings.

You will also notice how much power varies when riding over hills. Riding uphill you will notice your instantaneous power rapidly increasing and riding downhill it can rapidly fall, even at a relatively high perceived effort. This effect is similar to the lagged trends of heart rate when travelling over hills. It becomes important once you start training and racing to power to understand the natural fluctuation in the data over hills. You should always see increased power output up hills but it is important to regulate your effort so that your power is not too high. Similarly down hills your power will drop, but ideally by not too much. Varying your power output will be discussed in a later blog.

During and after reviewing data from a few rides you will start to notice approximately what sort of power you are able to sustain at certain intensities. If you use a heart rate monitor whilst riding you will also be able compare the corresponding heart rate zones to power readings. Once you have done a few rides you are ready to find your Function Threshold Power (FTP) through an FTP Test.


FTP Test

The FTP test is a similar concept to a threshold heart rate test in that it allows you to find the power you are able to ride to over an extended period of around one hour.

The gold standard for threshold testing (either running or cycling) is a ramp test. This test typically involves gradually increasing your running pace or cycling intensity to find the point when the anaerobic threshold (AT) occurs. In these tests the athlete’s blood lactate levels are measured by collecting small blood samples throughout the test. The increasing blood lactate level is tracked and thus the AT can be been found. From the test we can accurately estimate your zones through power and corresponding heart rate bands.

Outside of the laboratory test setting there are several ways to find your FTP, each is similar to the method used to find threshold heart rate. The tests involve you riding flat out for at least 20 minutes and at the end of the test your FTP is 95% of the average power you held for the 20 minute period. You will notice when reviewing your Garmin data post ride that Garmin Connect calculates your 20 minute average maximum from every ride, so if you are going to do the test on the road then it will automatically find the maximum 20 minute period for you. You can also conduct an extended test over 60 minutes and your FTP will be the average power you can hold for that hour.

Just like any good test an FTP test should be conducted in a controlled environment which allows you to ride at a constantly high intensity. This becomes difficult when you are on the open road with changing conditions, roads, traffic, etc. The best FTP tests are therefore on a smart trainer or in a race situation time trial. Smart trainers such as a Wahoo Kickr can be controlled by various computer programs or smart phone apps. These programs have built in FTP test protocols that will get you warmed up and ready to hit that 20 minute effort as best as you can. Whilst many may think the indoor smart trainer is harder to push yourself than the open road, it allows you to ride at an optimum cadence/heart rate, and thus power, without any variation in conditions. There are no undulations, corners, changing winds, etc., so your average power for the 20 minute section is a true representation of your ability. The power values from your bike’s power meter will vary slightly from the indoor smart trainer so make sure you to take note your power meter’s numbers as these are the ones you will be riding to on the road.


Interested in ramp or indoor FTP test? Details on Front Runner testing are at the end of the blog.


The best alternative to an indoor FTP test is to race at an organised time trial that is approximately one hour or less. If you finish the TT in around the hour you can take the power average from race. If the TT is less than one hour you take 95% of your 20 minute average maximum power output from the race. The benefit of doing a time trial over simply riding on the road by yourself is that in a race environment you are likely to push yourself a lot harder and the traffic wardens on the road allow you to ride the course hard without worrying so much about traffic. Again it is important to know that variations in the course and conditions will impact your result, so the best results are achieved on flat, non-technical courses.

FTP can also be estimated. Many coaches and online training platforms have developed equations to estimate power based a number of factors including weight, gender, altitude and training load. These equations are often based on historical evidence and may be a good initial estimation for curiosity. However, it is far more accurate to do an FTP test as the data from the test is personal for you.


Training to power

Once you have your FTP it’s time to start using those power numbers for training and racing. As with running, your power zones are calculated based off the threshold test (the FTP test). For running, Front Runner uses the Critical Velocity test and creates the 5 pace zones that govern training and racing paces. For cycling, Front Runner uses the FTP test or a time trial to govern the power zones for cycling training and racing.


The Front Runner Power Zones

In the world of cycling there are seven zones that have been created by multiple coaches who are at the forefront of cycling to power. Zones 6 and 7, the highest zones, correspond to sprinting power. At Front Runner we ignore the sprinting zones because these zones are not applicable to triathlon. Instead we focus on the zones 1-5 which are applicable. Each zone corresponds roughly to a race distance and represents what intensity you should be able to sustain on the bike in those races. Note that every athlete is different and athletes will find themselves sitting at different parts of the five zones depending on factors unique to them.

Front Runner Power Zones
Zone % FTP Description
EASY / Recovery <55% Light spinning of the legs at a moderate to high cadence with little resistance felt in the gears. There should be very little intensity felt at this pace. Exertion should be relative to fatigue felt at the time. If you’re very tired and fatigued, the % of FTP should be lower than 55%. There is little to no concentration required to maintain pace in this zone.
STEADY / Ironman 55-75% Long, slow and steady riding that is sustainable for ironman distance ride. This pace will start out easy but as the duration increases and fatigue sets in the concentration required will increase. You should be able to hold conversation in this zone although as fatigue sets in you probably won’t want too.
TEMPO / Half ironman 75-90% The intensity you will associate with a half ironman, long distance triathlon ride or any firm group ride. You will notice the concentration required in this zone is far greater than the previous. Your breathing will be far more laboured and you won’t want to talk.
THRESHOLD / Olympic 90-100% The pace typically found when racing an Olympic distance triathlon and efforts between 60-90mins. This pace is difficult to sustain over the distance. A high level of concentration over a relatively long period is required and fatigue will set in well before you have completed the bike leg.
VO2 / Sprint 100-110% Shorter races, typically well under an hour for triathlon that will be around your FTP. The intensity is similar to fast sections of group rides. Given the demands of triathlon you will notice you power output is slightly lower than expected when transitioning to the bike in a sprint race. High concentration is required to maintain this zone.


Mine is bigger than yours
Your power readings are unique to your personal circumstances. Factors that can alter these power readings are weight, training age and current fitness, bike setup and components, type of power meter used and power meter calibrations. It is therefore important to avoid comparing your power output and power zones to other athletes without considering these factors. The power and power zones alone of two different athletes will not indicate who is the stronger or better rider. For example a rider who weighs 100kg may have an FTP of 300w, but the rider who weighs 75kg and has an FTP of 280w is more likely to be a stronger cyclist because their power output per kilo of body mass is greater. The two riders may also use two different power meters with different factors of error, one may be riding a road bike and the other a TT bike, one may be in heavy training for ironman the other targeting sprint triathlons; and the list goes on.

In summary, try not to compare your power to others because it won’t help you to become a better cyclist. It is human nature to be curious about what others are doing, but the power numbers of another person are specific to them. Focus on improving your own power numbers and watch your own performances improve.

Other power measurements

Normalised Power (NP)
Normalised power is a weighted average of power across a time set that takes into account the variations in riding conditions and predicts the average power that would have been sustained had the ride been in completely stable conditions. Large spikes in power will cause the normalised power average to increase. For triathletes, the more consistent the bike leg is, the closer the average power for the ride will be to the normalised power value.  The less variance between average and normalised power indicates the ride was very consistent and very well executed.

Intensity Factor (IF)
Intensity Factor indicates how hard you have worked in a ride compared to your FTP. It is calculated by the normalised power divided by your FTP. For example, you might complete a particular training session with a normalised power of 200W when your FTP is 250W. This will give an IF of 0.80. You might then complete the same session later on the year but this time your normalised power is now 210W but your FTP has recently increased to 270W. The IF for the second session will be 0.78, indicating you worked slightly harder in the first session.

Training Stress Score (TSS).
Training Stress Score uses NP, IF and ride time to generate a number that reflects how much stress you have put on your body for that particular ride. TSS can be a useful tool to help monitor your training load as you mix volume and intensity across your training blocks, particularly when analysed over multiple rides.


Racing to power

As mentioned previously, riding to power is invaluable for triathletes. By riding to power the guess work can be taken out of your cycle leg to ensure you do not ride too hard and then run poorly. A well-executed bike leg is often evidenced after the race, when little variation is seen between the average and normalised power values. Aside from draft legal races and races where you must respond to a competitors move on the bike (to be discussed in later blog), triathletes should be regularly checking their power data during the rides to ensure they are in the correct zone.

Front Runner Sports Coaching offers both the ramp test and time based FTP tests using indoor smart trainers to ensure the test is as accurate and controlled as possible. For online bookings, please follow the coach heading here.