Frequently Asked Questions

About RaceX Technology

The time improvement you’ll realize from RaceX’s optimized race execution is significant and depends on the type of race you’re doing.

The examples of improvement below assume that you’re already racing with bike power. If you’re not, your improvements will be far greater.

At a high level, there are three ways that optimized pacing improves your race times:

  1. Avoid setting your Target Power/Pace too low. (5-7 min improvement) Being overly conservative will cause you to leave your performance potential unrealized. Pacing yourself just five watts lower than what you’re capable of can cost you between five and seven minutes on a full triathlon bike split.
  2. Avoid setting your Target Power/Pace too high. (30-60 min improvement) Being too aggressive can cause you to blow up toward the end of your race. On a standalone bike or run event, Target Power that’s too aggressive can cost you several minutes at the end of your race. In a triathlon, it can be even more devastating. Pacing too aggressively on the bike leg can cause you blow up for the majority of your run leg not just the last few miles. The time cost here can be 30 minutes to an hour or more.
  3. Distribute your effort optimally. (8-12 min improvement) Even if you’ve set your Target Power correctly given the race environment and your ability, how you distribute that effort throughout your race has significant performance impact. Properly increasing your bike power on climbs and decreasing it on descents can save you as much as 8 to 12 minutes on a full triathlon bike split. Time savings are similar for the run when using run power or grade-adjusted pacing. Additionally, optimal distribution helps you avoid exerting too hard on climbs causing you to blow up later in the race.

More difficult to quantify is the benefit of being able to train and conduct race rehearsals using your exportable power file. This allows you to learn how to manage your efforts and experience what it feels like to execute your race-day power plan well ahead of race day.

Typically, the cumulative improvement for an athlete from using RaceX to optimize their race execution for a full triathlon is between 20 and 45 minutes. But don’t take our word for it. Run your own race simulations and see for yourself.

RaceX simulations are virtually 100% accurate. As for predictions, it depends on you and the dynamic race-day conditions.

Simulations use precise input data for variables such as weather, terrain, aerodynamic drag based on your riding positions, and your power output throughout the course. Based on these data, your simulation results are 100% accurate. If the input data were different, the results would be different but still 100% accurate.

Predictions are simulations that use anticipated future inputs as variables. These values are based on the best information we have, but we recognize that they will never be exact. i.e. The forecasted weather and wind will not precisely match actual race-day conditions. You are unlikely to stay in your aerodynamic riding position or transition to your climbing position precisely as anticipated in the simulation. Despite your best efforts, you will not be able to manager your power output precisely to the watt as is the case in the simulation. The closer your race-day variables are to the anticipated values, the closer your actual time will be to your predicted time.

The purpose of predictions is not to be a crystal ball that precisely reveals unknowable future conditions and events. The purpose of a prediction is to produce your plan. Regardless of how close forecasted weather is to race-day weather or how well you are able to maintain your riding position or manage your pacing strategy, following your optimized race plan to the best of your ability will produce proportionally better results than you’d otherwise realize.

Consider the case of having a predicted bike split using your optimized plan of 5:45 compared to 6:10 with a non-optimized plan. If on race day it was a little warmer and windier than expected and you had to come out of your aerodynamic riding position for several minutes throughout the course, this might result in a time somewhat slower than predicted such as 5:55. The variance between the predicted time of 5:45 and the actual time of 5:55 is not what’s important. Rather, what matters is that your actual time was 5:55 using the optimized plan versus the likely time of about 6:20 without it.

When optimizing a triathlon bike plan, you may choose to modify the RaceX recommended bike plan settings. If you chose to do so, Bike Impact on Run Time (BIRT) shows you the expected incremental impact on your run time of the bike modifications, if any. i.e. Your bike split may be 5 minutes faster by increasing your Target Power, but this may also cause your run split to be 7 minutes slower. BIRT helps you determine if the net effect of a modification is positive or negative.

Absolutely. With RaceX, you can upload any bike or run route, select a date & location, and your pacing predictions and optimal pacing will be generated.

If you’re using RaceX to optimize your race pacing (which is the vast majority of users), then getting your bike profile values as close as you’re reasonably able is totally sufficient. Small variances in values might account for minor differences between your predicted bike splits and race-day actuals, but the impact on generating your optimized pacing plan generated from simulations will be negligible.

Selecting the most appropriate components and getting an accurate bike weight is relatively simple. If you’re unfamiliar with a bike profile item, just leave it as is.

If you’re using RaceX simulations as an elite athlete to make highly informed equipment decisions, then it may make sense to get your drag coefficients measured in a wind tunnel at the listed yaw angles for both your standard racing and climbing positions.

(For a better understanding of Simulations and Predictions, please see the related FAQ.)

About Using RaceX

RaceX optimizes your race-day performance through many different features and functionalities. Below is an equipment list and the various features and functionalities that each item unleashes to make you faster on race day! No equipment required: Get your predicted times/splits and target power/pace identification based on your fitness and the race environment and terrain. Use bike route segmentation to discover effort levels and durations of key climbs and descents. Run simulations to understand the impact of different bike equipment and position options. Plan your hydration & nutrition appropriately. GPS-enabled watch or Run Power Foot Pod (such as Stryd): Use optimized target grade-adjusted pace (GAP) or run power to nail your run pacing. Your target GAP or power will be adjusted base on your unique Bike Impact on Run Time. Smart trainer and/or cycling power meter: Make your race rehearsals more productive by exporting your power segments and using them on your smart trainer. Rehearse at the right intensities. Establish the feel of your race-day efforts. Monitor your heart rate response and dial in your nutrition. Optimize your bike and run pacing when competing in virtual environments and events. Cycling power meter: Implement your optimized power segments on race day with a cycling power meter. Use the power segment cheat sheet to monitor and adjust your power output. Cycling power meter & compatible head unit: Upload your optimized power segments to your cycling computer for easy execution and spot-on pacing.

About Terminology

Listed races in RaceX are pre-loaded upcoming major races with verified route files. They include most IRONMAN® and Challenge Family triathlons as well as other major endurance events. You can easily select these races for predictions, optimization, and analysis.

Custom races are unlisted races that you create and for which you can upload your own route files.

Adding a race as either “Sim Only” or “Scheduled” allows you to predict, optimize, and analyze the event. The difference is only whether or not you are intending to do the race. Select “Scheduled” if you’re registered or planning to register for this race. If you’re not sure if you’re doing the race but still want to run a race simulation, select “Sim Only”.

If you use TriDot to optimize your training, selecting “Scheduled” will add the race to your training schedule. It is possible to change a race from “Sim Only” to “Scheduled” if you decide to do the race at a later date.

Your aerodynamic drag referred to as CdA values is your drag coefficient (Cd) multiplied by your exposed frontal area (A) causing drag. Reducing either your drag coefficient or frontal area will decrease your aerodynamic drag and allow you to go faster at a given effort. An object’s shape has the most impact on its drag coefficient. Objects shaped like an air foil have very low drag coefficients relative to objects shaped like a sphere or square.

Your aerodynamic drag increases the faster you are moving. It is further increased by wind.

Yaw angle refers to the angle at which your aerodynamic drag is causing resistance. A direct headwind would have a yaw angle of 0° while a tailwind would have a yaw angle of 180°. When in motion, your effective yaw angle is calculated using your velocity, the wind velocity, and the wind direction relative to your heading.

As a cyclist, you will rarely experience yaw angles greater than about 20°, because your forward velocity is generally greater than the wind velocity which causes the “effective” yaw angle to draw closer to 0°.

Your “threshold” refers to your Functional Threshold Power or Pace (FTP) and is the baseline intensity metric used for most endurance training and competition. It’s been most commonly used in cycling and is defined as the maximum power (in watts) that you can sustain for an all-out, one-hour effort.

In swimming, this value is most commonly a pace per 100 meters or yards. In running, this can be expressed as either power or grade-adjusted pace per mile or km. Training and racing intensities can be effectively determined and managed as values relative to your FTP.

You train too hard to let poor pacing rob you of your performance potential!