Training4cyclists

Cycling Training Tips

power output

The Ultimate Guide to Time Trial Training

by 21 Comments

IT SOUNDS fairly straightforward. You, your bike and the clock, riding in splendid isolation as quickly as you can, away from the rough and tumble of the peloton.

In theory a time trial should be a simple test of your ability to ride your bike as fast as possible over a set distance.

But if only it was as easy as that…

In many ways a time trial is the ultimate challenge for a rider. There is nowhere to hide, no bunching pack to drag you along. And it hurts: in fact the pain will usually last from start to finish.

But whether you achieve a personal best (or a personal worst) you will always be left with the same feeling when you cross the line: you will want to go faster next time. Time trials have that glorious habit of leaving riders hungry for more.

If you’re serious about getting faster, beating your quickest time over a particular course and completing the perfect time trial, getting every little detail right is absolutely crucial, especially with regards to pacing, aerodynamics, preparation and technique.

So before you saddle up, here is my own ”time trial bible” to give you a kick-start”…

Time Trials: Getting the pace right

The first five minutes
Pacing is everything when it comes to time trials. Getting the initial speed correct is the key to achieving your goal time. But the easy trap to fall into  and so many riders do this is to go out too hard so your pace slowly but surely slackens off during the course of the ride.

The end result? You finish meekly when you should be aiming to finish with a flourish.

Patience is the key
Starting at breakneck speed will NOT lead to a better overall time. If you blast out at full pelt you risk blowing up well before the end of the trial, which will lead to you running out of energy and finishing poorly.

So with this in mind, the first five minutes of a time trial are crucial and will almost certainly dictate if you succeed or fail in achieving your goal time.

In addition, your cardiovascular system takes a few minutes to react before it delivers optimally for your desired intensity.

Even if you’ve performed a solid warm-up, you will be at risk of going anaerobic if you try to maintain your target pace right from the beginning of the time trial.

While I strongly recommend the use of power meters to help with your pacing strategy, it is possible to learn how to pace yourself sensibly without using one.

Ups and downs of pace control
The traditional view among the majority of coaches and riders is that a time trial should be tackled by adopting a strong but even pace throughout the whole race. But I beg to differ slightly. I strongly believe that a few judicious and subtle changes to your pacing strategy will yield a faster overall time.

I stress again… it is so vital not to start too fast. Try staying SLIGHTLY BELOW your planned target power for the first five minutes of the time trial. Then after five minutes make sure you ride as close as possible to your target power.

Now here’s one difference to the ride-at-an-even-pace throughout mantra: Try pushing a tiny bit harder uphill, and then ease off slightly on the descents. Do this and you will achieve an overall quicker time.

Try it: it works!

About 20 watts more power riding uphill will save you more time than you will lose by reducing 20 watts going downhill. This is because there is a stronger aerodynamic drag at higher velocities.

When it comes to pacing, one great training tactic is to practise completing the distance you will be tackling at a flat-out pace. If you find that your speed slackens off towards the end, then you have clearly gone out too hard.

However if you feel fresh at the end then you probably haven’t paced it fast enough. Practice makes perfect, so it’s worth practising until you know for certain what a challenging but sustainable effort over a given distance feels like.

Action plan:

So when it comes to judging the right pace try the following tips:

  • Analyse your last time trial (heart rate, power outputs).
  • Develop a new pacing strategy for your next time trial.
  • Perform specific time trial training with your new pacing strategy.

*Obviously if you are taking part in a track pursuit then you will have to use a different pacing strategy.

Advanced Time Trial Training – Aerodynamics

Bradley Wiggins. Silver medal at World Championships in Time Trialling 2011. Image by Training4cyclists.com

Aerodynamics are pivotal to completing a successful time trial. But riders shouldn’t get too hung up on aeros: keep in mind that it is just one part of the overall performance equation.

Yes, aerodynamics play a big role, but they are not the deal breaker when it comes to achieving a goal time.

However some facts are indisputable: one big fact is that 90% of a rider’s power output is used to break wind resistance. In fact wind resistance is the biggest enemy when competing in a time trial.

So to counter the elements finding the optimal body position is crucial as it minimises the aerodynamic drag, so requiring fewer watts to ride quickly.

Pole Position
The position of the body is also where riders can make the biggest improvement to overall aerodynamics.

And if your bank balance won’t stretch to purchasing a dedicated time trial bike and all the expensive accessories built for brilliant aerodynamics then nurturing a good body position is even more important.

There is even a growing view among some experts that the most aerodynamic position for a rider can actually lead to a decrease in pedalling efficiency, and a rise in the metabolic rate of effort. Subsequently, this can lead to a cut in the average power output of the cyclist.This reduction in power can be between 10-20%, say some experts.

The body position can also become so extreme that it actually limits your performance even though it is more aerodynamic. However I believe that with targeted uphill training while maintaining the aerodynamic position it is possible to cut down on this loss of power caused by aerodynamic body position.

Aero Test
Wind-gallery tests are also extremely useful but are expensive. However there is one simple test to gauge the aerodynamic advantage of different bike positions.

All that’s required is a 300m descent, with a gradient to allow a 50 km/h speed without effort on the pedals, followed by an ascent to slow down and stop the cyclist within a fairly short time: the further the cyclist goes up the hill, the more aerodynamically efficient the body position.

This can take a few attempts to eradicate statistical errors, and conditions such as wind speed/air temperature have to be taken into account but, in the end, you will find the results are reliable.

In terms of body position the frontal area is the most vital aspect.

Most coaches agree that riders should try to minimise their chest’s bagginess and keep their arms and shoulders as closed as possible. Other strong aerodynamics tips include:

  • Make your aero extensions as long as the rules allow
  • Handlebar height is not as vital as reach
  • Wear an aero helmet

Get Your Kit On
The last point above is a good one. An aero helmet (app. $150) is a good place to start if you have some spare cash to splurge. There is no doubt that an aero helmet will make you significantly faster so it’s a solid investment. Experts estimate that an aero helmet alone saves a rider 10-15 watts of power at time trial speeds.

You could also try lowering the front of the bike, which could be as simple as flipping the stem, and fitting some tri-bars, which cost as little as $50. After an aero helmet, you could start thinking about adding aero drinks bottles, overshoes, skin suits, deep-section wheels. But it is wise to spend any money you have on making sure you get into a good body position first.

And while all this expensive equipment is useful, pricey kit won’t make you go faster if your body acts like a huge air brake.

So if your budget is limited, keep in mind that body position should be your main priority. Focus on improving your body position on your current bike and invest time and energy on the areas where you can make the biggest gains.

Remember: cut wind resistance and you’ll go faster.

Take action:

  • Perform aerodynamic tests with your current bike.
  • Reduce your frontal area. Make a “longer” position on your bike.
  • Perform an aerodynamic test with optimised set-up.
  • Repeat above steps until you see gradual improvements.

Interval training for time trials: No pain no gain

In cycling your training should always be targeted to your goal. So for time trials you will have to train at a very high intensity if you want to improve your time over a given distance.

To sustain a strong pace for the duration of a time trial, your training sessions need to be explosive. So interval training is the key, with a combination of sub-threshold, threshold power and VO2 max intervals.

Professional riders target their time trial training towards improving their threshold power. But developing a large aerobic engine will not happen overnight. It demands a huge amount of training and effort, and the adoption of the highest quality training principles over several years.

But one thing is certain: time trial riders (just like sprinters and climbers) do need a fantastic threshold power as a strong performance at threshold power is obligatory for winning any race. And another thing is certain: training with a very high intensity will boost your ability to continue riding without accumulating lactic acid.

VO2 Max Intervals

VO2 max intervals are a brilliant stimulus for your aerobic system. They also provide a great boost to your threshold power. VO2 max may not be the most crucial power output but the advantages of learning this skill are immense because the physiological adaptations to VO2 max training are the same as the ones you achieve when training at lower intensities.

Also bear in mind that threshold power is only a percentage of your VO2 max. The physiological skills you train with during threshold power intervals are also stimulated at VO2 max intensity.

Threshold Power Intervals

These are the most popular way to boost threshold power. The key is to know your power output or heart rate at threshold power and then use these to pace yourself throughout intervals at the same intensity. The best tactic is to tackle a time trial as a yardstick or reference.

The toughest part of these intervals is to stay at the right intensity throughout. Setting off a tiny bit too fast will make it impossible to maintain the right intensity. Starting too slowly, and you won’t benefit from the adaptations you are training for.

Threshold power intervals are extremely tough but really effective in creating a better aerobic capacity and they are brilliant for any rider want to become a better time trial rider.

Sub-Threshold Intervals

High intensity interval training is only beneficial if you complete them. So while VO2 max and threshold power intervals are the most effective ways of training for a time trial, they will be rendered ineffective and meaningless if you don’t complete the actual intervals at the required speed/intensity.

So physically and mentally you will undoubtedly achieve a better training result for a time trial if you opt for an intensity with a higher success rate. This is where sub-threshold power intervals come into their own as they can offer major improvements.

Some experts also argue that there is a physiological sweet spot as you can train at a high oxygen consumption without going anaerobic, with a positive knock-on effect on your aerobic system. So for time-trialling, they are excellent for training.

I would strongly recommend that you track your training progress using a series of physical performance tests. For example if you train for a 25km time trial then measure your average power output for such a distance in training.

But do remember that the beauty of hard interval sessions is that as you begin to increase the size of your aerobic capacity, you will also boost your power output for that distance. This will allow you to monitor your physical performance and, more importantly, separate these improvements from other improvements caused by improved aerodynamics.

One thing is for sure: the magic formula is out there waiting for you.

Take action:

  • Sub-threshold intervals, e.g. 2x20min.
  • Threshold power intervals e.g. 3x12min.
  • VO2 Max intervals e.g. 3x(3+3min).

Other top time trial tips

Food

Many cyclists with a race or time trial on the horizon see it as a perfect excuse to gorge on a mountain of food. But while carb-loading is recommended to a degree, moderation is advised when it comes to time trials. For an event like a 10 or 25-mile time trial, a meal rich in carbs, such as pasta or rice, the night before the race is probably sufficient. There is no reason to eat food high in fat.

On race morning focus on carbs again. Jam on toast is a good choice while if you prefer cereal ensure it’s low in fat and fibres. En route to the time trial, it is worth sipping an energy drink while a dose of caffeine (up to 200mg) may also be advisable. Stay euhydrated during warm up.

For a short time trial of 10 or 25 miles don’t bother with a drinking bottle as time lost sipping the fluid will outweigh the benefits of taking on mid-race fluid. After the event make sure you have a recovery drink ready.

Warm up

Failing to warm up properly will mean you won’t benefit from all those tough hours of training. One warm-up strategy is to ride comfortably for 10-15 minutes and then perform three 10-15 second bursts (not all-out sprints) with a couple of minutes of recovery in between. Slightly increase the intensity so you raise your oxygen consumption in small steps. This protects you from going anaerobic.

Aim to warm up for at least 20 minutes and there is rarely no reason to spend longer than 45 minutes. If you’re in a hurry, check out this quick warm up.

Mental preparation

While psyching yourself up may seem the obvious thing to do, staying calm is probably more important. Get too worked up and you may be tempted to go off too hard. Stay calm and stay in control of your effort. Remember if you go off too fast, there is no chance to recover.

Ride the course

Familiarise yourself with the course if possible. This really helps and makes sure there are no nasty surprises on the day. It is better to know where any killer hills (or potholes) are lying in wait. And even on well-marshalled courses, cyclists can still take a wrong turn in the heat of battle.

So do you feel motivated? Are you now ready to complete the perfect time trial?

If you have enjoyed reading this post why not share it with your friends on Facebook or Twitter?

Here is the link: http://www.training4cyclists.com/time-trialling/

Best of luck!

SRM Live from Tour de France 2009

by Leave a Comment

Tour de France 2009 begins tomorrow and this year we get an even better chance to follow the strongest cyclists in the world. Several riders share their data from the SRM Cranks Systems (power, heart rate, cadence, speed) and GPS position with us.
SRM data are transmitted directly so you can watch them live along with the television transmission.

Here are some of the things to look for:

Power Output and Tactics
How much power a rider needs to provide in the lead, in the middle of the bunch or in a break away. If you are lucky you might notice differences between riders effort in the same break away.

Aerodynamics and Pacing in Time Trials
Notice how constant workload the bet riders deliver in time trials. Also you might be able to notice differences in aerodynamics. In this year’s Tour de France you also have the chance to wath power meter data from team time trials. Who push the highest watts on Team Saxo Bank?

Absolute or Relative Power Output
This is also commonly referred to as watts or watts per kilogram. Who generate the most watts in the flat terrain? Who get first up the hills/mountains? Probably not the same riders, so take a closer look to their watts per kilogram when you compare power output in the mountains.

Soy Milk or Semi-skimmed Milk as Recovery Drink?

by 5 Comments

This article is a guest post from Shim Ravalia who studies a master in sports rehabilitation at the University of Kent (Gillingham, Medway). Now she is proposing a study on the effects of soy milk and semi skimmed milk in the recovery period after exercise on trained male cyclists by looking at the time to exhaustion. Participants who are regular readers here on Training4cyclists.com are included in this project.

Enjoy her detailed review of the current knowledge about recovery drinks.


Is soy milk a better recovery aid compared to semi-skimmed milk after exercise?
Does it increase time to exhaustion in trained cyclists?

The efficacy and importance of a recovery drink when balanced with training has to be deeply considered. The body is in a state of stress and needs a lot of nourishment after exercise (Carlson, 2008). The body is dehydrated, the blood insulin levels are low and cortisol and other hormones levels would be high; more importantly, the glycogen stores would be low or completely depleted and muscles would be breaking down (Ivy & Portman, 2004). This should be reversed by the nutritional strategy implemented.

Milk has been seen to be an effective recovery drink simply because of the components it has. Milk contains both whey and casein protein; whey is considered as to be a high quality protein and is more soluble than casein protein which also has a higher quality rating. Around 20% of whey is found in milk and 80% of casein is also found in milk (Pasquale, 2008).

Research has shown that the adding of protein to a carbohydrate drink is just as effective as a carbohydrate based drink for recovery after exercise; although carbohydrates is unquestionably of major importance, proteins is now considered to be of larger importance than previously thought (Niles et al, 2001).

A study by Saunders, Kane & Todd (2004) looked at the effects of a carbohydrate protein drink on cycling endurance and also looked into muscle damage. The main aim of the study was to see if cycling endurance performance changed and post exercise muscle damage changed when the carbohydrate protein drink was ingested in comparison to a carbohydrate only drink. The results showed that with the first ride at 75% of V02 peak, the participants rode for 29% longer with the carbohydrate with protein drink than the carbohydrate drink. In the second ride, at 85% V02 peak, the participants rode for 40% longer with the carbohydrate protein drink; to add to these findings, the level of muscle damage was 83% lower with the carbohydrate protein drink.

To support the above, Niles et al (2001) looked at the effects of a carbohydrate with protein drink improving time to exhaustion after recovery from exercise. With the ingestion of a carbohydrate protein drink or a carbohydrate only drink, the overall results showed that the carbohydrate protein drink gave higher insulin levels within 90 minutes into the recovery period and time to exhaustion was also longer in comparison to the carbohydrate only drink.

A very important study by Karp et al (2006) looked at the effects of chocolate milk as a post exercise recovery aid. By using 9 male endurance trained cyclists, the study compared chocolate milk, a fluid replacement drink and a carbohydrate replacement drink. The participants went through a glycogen depletion trial followed by a 4 hour recovery ending on an endurance trial. The results showed that the time to exhaustion and total work performed during the endurance performance trial were greater with the chocolate milk (15 minutes greater) and the fluid replacement (16 minutes greater) trials than the carbohydrate trial. The participants rode 49% and 54% longer with the ingestion of chocolate milk and fluid replacement trials despite the carbohydrate content in the drinks.

 

To add to the concept of using milk as a recovery aid, there has been new and limited research done on the possible benefits of using soy milk; although research is still limited in terms of the use of soy milk in endurance exercise, research has shown some interesting results with resistance exercise. Pasquale (2008) expressed that soy protein has the protein quality of 1.00 meaning that that it is equal in the quality of protein that it exists in other diary and egg proteins. To add to this point, Paul (2005) also stated that soy protein contains 2 high performance amino acids; Arginine and Glutamine which have a vital role in muscle recovery.

Bos et al (2003) cited by Roy (2008) looked at the increase in protein net balance and muscle protein synthesis which was defined by the consumption of 500ml of fat free milk compared to an soy protein beverage. The findings were that the soy based beverage was digested more quickly which led to an increase in blood concentrations of amino acids carrying it to plasma protein and urea synthesis. The rise in blood amino acids in the fat free milk however, was a lot slower and continued rising for a longer time providing more amino acids for muscle protein synthesis, but however, Bos et al (2003) used resistance exercise, not endurance exercise.

The proposed study has extracted the methology from Karp et als study (2006) using chocolate milk as a post recovery aid. With each participant undergoing a V02 max test with a gas analyzer to determine an individual’s maximum oxygen consumption and maximum power output.
Test bike
The participants will also do a glycogen depletion trial starting from 90% maximum power output riding for 2 minutes and then 2 minutes onto 50% recovery; this will be carried out onto a lode bike; the intensities would decrease by 10% every time the participant s can no longer keep up with their cadence. This is then followed by a 4 hour recovery where 355ml of a drink would be administered straight after the glycogen depletion trial and also another 355ml 2 hours into the recovery stage. The last section of the test is the endurance trial where participants have to ride as long as they can at 70% of their maximum power output. Blood lactate measurements will be taken before and after the glycogen depletion trial, 2 hours into recovery and before and after the endurance trial and analysed; body hydration status will be taken before and after both exercise trials using the bio electrical impedance equipment.

References
1.Carlson, A. (2008) Protein Nutrition for Peak Performance, Peak
Performance, P2P Publishing, pp65 ”“ 74.

2.Ivy, J & Portman, R. (2004) Nutrient timing: The future of Sports Nutrition,
Ed:Illustrated, Basic Health Publications.

3.Karp, R.J, Johnston, D.J, Tecklenburg. S, Mickleborough, D. T, Fly, D. A, &
Stager, M.J (2006) Chocolate milk as a post-exercise recovery aid. Journal
of Sport Nutrition and Exercise Metabolism, (16), pp. 78-91.

4.Niles, S.E, Lachowetz, T, Garfi, J, Sullivan, W, Smith, C,J, Leyh, P.B &
Headley, A.S. (2001) Carbohydrate-protein drink improves time to exhaustion
after recovery from endurance exercise. Journal of Exercise Physiology, 4
(1)pp. 46 ”“ 52.

5.Pasquale, D.G.M. (2008) Amino acids and proteins for the athlete The
Anabolic Edge, 2nd Ed. CRC Press Taylor & Francis Group.

6.Paul, G.L. (2005) Soy protein and Performance Nutrition New Evidence ”“
New Opportunities. The Solae Company Nutrition Brief, pp. 1-8.

7.Roy, D.B (2008) Benefits of milk consumption with resistance and endurance
sports. Director, Centre for Muscle Metabolism and Biophysics, Faculty
of Applied Health Sciences. Brock University, St. Catharines, ON. CANADA.

8.Saunders, J.M, Kane, D.M & Todd, M.K. (2004) Effects of a carbohydrate ”“
protein beverage on cycling endurance and muscle damage. Medicine &
Science in Sports & Exercise, 36 (7), pp 1233 -1238

9.Williams, M.B, Raven, B.P, Fogt, L.D & Ivy, L.J (2003) Effects of recovery
beverages on glycogen restoration and endurance exercise performance.
Journal of Strength and Conditioning Research. 17 (1), pp. 12 ”“ 19.

Optimal Bike Training: Threshold Power vs VO2 Max

by 9 Comments

In the last couple of weeks I have covered the importance of VO2 max intervals. Even though VO2 max is an important physiological skill, threshold power is even more crucial. The absolute power output at your threshold power is often a lot more important than the absolute number at VO2 max. That also explains why the athletes with the highest VO2 max values not per definition are the strongest performing riders in the peloton.

VO2 Max intervals improves your threshold power

Even though VO2 max is not the single most important power output, it still needs lots of training because the physiological adaptations to VO2 max training are the same as the you receive from threshold training. The biggest difference is the time needed to train to achieve the same progress.

Intervals close to VO2 max is a really potent stimulus for your aerobic system. Actually, it there is scientific evidence indicating that well trained athletes must have intervals close to their VO2 max to continue further progress. VO2 max intervals not only improve your VO2 max power, they also give a great lift to your threshold power.

Remember that threshold power is only a percentage of your VO2 max. You don’t train specific physiological skills with threshold power intervals that don’t get stimuli at VO2 max. If decide to train at lower intensity than VO2 max, you have decided to train your aerobic system less effectively. Bump.

VO2 Max Intervals are better than threshold intervals

I know that there are circumstances where intervals at lower intensities are handy, but from a strict theoretically point of view, VO2 max training is the most effective.

There is a common myth that training exactly at threshold power is the most optimal way to train. Let me make it clear:

There is nothing magical about training exactly at threshold power. Training a little above or below threshold power improves performance in exactly the same ways.

Conclusion: Training exactly at your threshold power is great, but slightly below or above threshold power is just as great. Well trained athletes need training close to their VO2 max, because it helps them to further progress of both VO2 max AND threshold power. From a strict theoretically point of view, VO2 max training is the most effective way to improve your performance in endurance disciplines like road cycling. Both VO2 max and threshold power training can be beneficially for riders at all levels.

How To Optimize Your Aerodynamic Position Using a Power Meter

by 5 Comments

If you are a time trialist or triathlete one of the benefits using a power meter is that it enables you to optimize your aerodynamics. Better position on the bike supplied with aerodynamic equipment can help you to save seconds or even minutes in a time trial.

Now I will show how you can use a power meter to optimize aero position on your bike through a simple testing procedure.

Wind tunnel aero testing: Gold standard but expensive

Wind tunnel tests are referred to as the gold standard of optimization of aerodynamics.

These wind tunnel tests are expensive and therefore we only see professional riders use these tests to optimize their position on their aero bikes. It’s logic that professional riders have a great advantage being able to do wind tunnel testing. Often it is only the classement-riders who get the chance to do these tests due to the high cost.

Don’t worry, here comes the good news. A power meter can help you optimize your aerodynamic position without ever visiting a wind tunnel or spending extra money!

Power meter: Great performance and affordable

If you are the lucky owner of a power meter like SRM or PowerTap you can perform your own aerodynamic tests. It’s essential to have a precise measuring of power output.

Currently I think SRM and Powertap are the two best power meters on the market. Using cheaper and less precise power meters is not recommended. If you don’t have a power meter, then buy one or try to borrow one.

A power meter is the single best investment for a serious rider who wants to improve performance. The fact that it enables you to make aerodynamic testing, precise analysis of power output in races and training situations and finally is a solid training partner/coach makes the power meter an easy choice.

Best of all, the power meter presents objective data that are not influenced by weather, hydration, stress or any of the many parametres that affect your heart rate.

Use a power meter to optimize aero equipment

Maybe you remember how I last summer used a power meter to investigate how much bike weight costs on Alpe d’Huez? The U23 rider who performed these trials had to maintain a power output around 275w on all four rides up Alpe d’Huez. The test bike was a Pinarello Prince equipped with Shimano Dura Ace and SRM crank.

Afterwards I could compare the finishing times to see what price you pay if you carry extra weight. It’s obvious that you can make more precise trials than we did here, but it shows the principle of using a power meter to optimize your equipment.

Thus, after these trials we had a picture of how much weight matters in the Alps.

When you ride up Alpe d’Huez, aerodynamics don’t play a big role because you ride relatively slowly. In time trials the speed is much higher and many serious riders perform average speeds above 40km/hr.

Thus, optimization of aerodynamics should be the major concern if you want to improve performance without spending more time struggling with your threshold power.

Find a good location

You will need a circuit where you can ride fast and still maintain a constant speed/power output. This is best done on a velodrome.

The main principle is to eliminate everything that is not related to aerodynamic drag. That is why wind tunnel testing of cyclists has become the golden standard procedure. Nevertheless, outdoor testing is still important because that is where you are going to compete when you race (corners, small hills etc.)

If you don’t have a velodrome in your neighbourhood then you have to be a little creative to make a good course for your tests. It’s still possible, but there are more factors that can influence on your ride. Though, it gets more difficult to show small differences.

Write a protocol

Write down all the tests and numbers you want to collect and in which order. That could be the different aerodynamic materials you would like to test and/or different body positions on your bike.

It’s a good idea to start with a standard upset of your bike e.g. Standard frame + standard equipment + standard body position. When you want to test different set-ups, change only one parameter at the time. Otherwise it gets difficult to identify what set-up change actually resulted in reduced aerodynamic drag.

Make two rides of 1-3km with each set-up. The more rides you do, the better chance you get to show a small significant difference.

Constant power output method

When you ride on a flat road with a constant power output differences in speed are primarily due to your aerodynamics. If you decide to use the constant power output method, you have to keep your power output as constant as possible and keep your desired aerodynamic position on your bike.

When you have finished one lap on your circiut, notice your average speed and power output. Hopefully you get power outputs there are so close to each other that differences in average speed can be accepted as due to altered aerodynamics.

Constant speed method

When you ride on a flat road with a constant speed, differences in required power output are primarily due to your aerodynamics.

If you decide to use the constant speed method, you have to keep your speed as constant as possible and keep your desired aerodynamic position on your bike. As you can see, this method is much the same as the constant power output method.

The difference is that you here try to keep average speed so close to each other that any difference in power output can be considered due to altered aerodynamics.

Constant power output or speed?

Decide whether you use constant wattage or constant speed method. Both are good methods, but if I have to pick one I will choose the constant speed method. I recommend it because it gives you the possibility to use an iPod in your ear to keep a constant pedalling frequency.

When you’ve found the right gear combination, this little trick makes it easier for you to ride at the decided speed in all tests. You just follow the rhythm from the music just like when you are at a spinning lesson. Thus you can concentrate 100% on holding your aerodynamic position on your bike.

Riding at speeds close to your race speed is the most optimal since it is here you can see how many watts it’s possible to save. There is, however, a little risk that the workouts with standard setups can become quite hard intervals. This will not happen with the constant power output method.

If you use the constant power output method there is a risk that you loose focus on holding your aero position. The positive thing is that the result is directly shown as increased speed/saved seconds.

Thus you can immediately see how much faster you will go if put on e.g. an aero helmet instead of your standard helmet.

Collecting data

It’s a good idea to have an assistant to help you e.g. your cycling coach, a friend or family member to keep track of the data stream. Assistants can be helpful throughout the whole process.

As I said previously we need data from two rides with each setup at a speed close to race speed. Doing tests with a distance of 1 to 3km gives you a fair chance to notice significant changes in aerodynamics.

I recommend that you do more of these tests instead of longer tests because weather conditions might influence on the results (temperature, changing winds).

It is also recommended to do a few tests at lower speeds e.g. 80 and 90% of race speed. This increases the power of your data and gives you the chance to spot trends at an early stage.

Analysis of aerodynamics

This is the really interesting part of this process since this is where you find out what works for you. You will be amazed how much time you can save with an optimized body position on your bike. Also you have the chance to figure out how much time can be saved if you use a rear disc wheel.

Remember to look at both material and body position savings because they can add up. I know that it is expensive to buy aero gear for your time trial bike, but using the principles above you can find out where you get the best value (watts or seconds) for money.

Share power meter data

Feel free to share your experiences with the readers here at Training4cyclists.com. If you have some interesting observations, let us hear about them. How many watts did you save using the principles described above?

Conclusion

There are many benefits of using a power meter. It enables you to do aerodynamic testing without extra cost and still offers a qualified alternative to an expensive wind tunnel test.

Doing aerodynamic tests using a power meter can help you to optimize your aerodynamic position on your time trial bike and/or selecting the right combination of aerodynamic wheels/frame/helmet etc.