When you are using a stationary bike at the gym or at home, knowing the distance of your rides is useful for tracking your training load. But how accurate is the distance tracking on stationary bikes really?
The accuracy of the odometer on stationary bikes varies depending on its manufacturer. Different brands of stationary bikes use various algorithms to convert revolutions of the pedals into distance. The distance on a stationary bike is not comparable to the distance on a real bicycle.
Because the accuracy of distance tracking on stationary bikes is so variable, most professional athletes focus on metrics like time, heart rate, and cadence when raining on a stationary bike. Here, we explain the reasons why the distance on a stationary bike is not always accurate.
Can You Trust The Accuracy of the Distance On Stationary Bikes At The Gym or at Home?
When training on a stationary bike at the gym, distance is not really the most useful metric for determining the duration of your workouts and your training load. This is because the distance is not always tracked accurately on stationary bikes.
Theoretically, calculating the distance traveled on a stationary bike is relatively straightforward. All you need to know is the diameter of the bike’s flywheel and the number of pedal revolutions. Multiply these two figures, and there you have the distance traveled.
However, in practice, this calculation is not so straightforward. Different stationary bike manufacturers use various algorithms to convert pedal revolutions to distance.
Therefore, you cannot compare the distances on two different models of stationary bikes, and you certainly cannot compare the distance on a stationary bike to the distance on a real bicycle.
Smart bikes that have a high-quality watt meter and give you the option of entering your weight are generally more accurate at measuring your distance than ordinary stationary bikes. Cycling is all about your power-to-weight ratio, so these metrics must be factored in when the bike calculates your distance.
How Stationary Bikes Calculate Distance
If you cycle for 30 minutes on a Peloton Bike, then cycle for the same period on a NordicTrack Studio Cycle and do the same amount of time on a spin bike at the gym, you will see that the three distances are all different.
This is true even if you do your best to keep your heart rate, cadence, and power or torque the same. Why is this the case?
Different bike manufacturers use different algorithms to calculate distance based on pedal revolutions, resistance, and cadence. None of these calculations are 100% accurate, but they are good enough to give you a reasonable idea of how far you cycled.
If you train on a stationary bike at home, you can use distance as a metric for tracking training load because you are using the same bike consistently (comparing apples with apples). If you train on different brands or models of bikes at the gym, comparing the distances on them is like comparing apples with oranges.
Stationary Bikes At The Gym Are Seldom Calibrated for Accuracy
Another issue that affects the accuracy of distances measured on stationary bikes is calibration (or lack thereof). If a stationary bike is re-calibrated regularly and calibration is done correctly, the distance tracking can be quite accurate.
Stationary bikes at the gym are almost never calibrated. The factory that produces them calibrates the bikes before they are shipped off, and then they are seldom re-calibrated.
If you have a stationary bike (or treadmill, or any other exercise machine) at home, you should re-calibrate it regularly. It’s a quick, simple process. Just follow the bike’s instruction manual.
What Are More Reliable Metrics On A Stationary Bike?
Professional athletes and individuals who are serious about their training do not generally use distance as a performance metric when working out on a stationary bike. There are so many factors that affect the accuracy of the distance calculation, and distance is not really a useful metric, even when it is relatively accurate.
Better performance metrics to track when using a stationary bike are heart rate and time.
The Peloton uses heart rate to calculate the Strive Score which you can use to compare your workout on a Peloton vs Treadmill.
Heart rate is a brilliant measure of your effort and exertion. It is best measured using a wearable heart rate monitor (fitness watch or chest strap). Never trust the heart rate “monitor” on a stationary bike.
Time is the best measure of training load. Keep your heart rate above a certain level for a particular amount of time. 99% of the time, the time tracked by a stationary bike is accurate.
Riding A Stationary Bike Is Nothing Like A Real Bicycle
If you cycle for an hour on a stationary bike and cycle for the same length of time on a real bicycle, you will find that the two recorded distances are drastically different. Depending on the brand of stationary bike, it may track that you cycled a shorter or longer distance than you did on a bicycle.
There are many more variables that affect your speed and distance when you are cycling on a bicycle. Firstly, the weight of the bike and the weight of the cyclist have an effect. So do the type of tires and their diameter.
The type of terrain you cycle on also has a massive effect. If you ride a bicycle for an hour on hilly terrain and for an hour on flat terrain, you will find that you ride further on even terrain because there is less resistance.
Riding on a dirt track has a higher resistance than on a tar surface. You will ride further on the road than on a dirt track in a given span of time.
Do not underestimate the impact that the wind has when you are cycling outside! In windy conditions, you will ride faster or slower, depending on whether you have a headwind or a tailwind. This impacts the distance you ride.
None of these external variables are factored into distance calculations on a stationary bike. This accounts for the disparity in distance measurements on a stationary bike and a bicycle.
Is Distance On A Treadmill Accurate?
The distance measured on a treadmill is generally more accurate than the distance on a stationary bike (provided the machine is calibrated). This is because treadmills simulate the action of walking or running more closely than a stationary bike simulates the action of riding a bicycle.
On a stationary bike, your feet turn the pedals, but instead of propelling the bike forwards, you are turning a heavy metal disk. The power it takes to turn the metal disk for one revolution has no relationship to the power it takes to turn the pedals on a bicycle to propel it forward.
However, on a treadmill, the ground is moving backward below you in the same way it would if you were walking or running outdoors. You have to do the same amount of work to stay stationary on a treadmill as you would moving at that speed on the ground.
Conclusion
The algorithms that different stationary bike manufacturers use to convert pedal revolutions to distance are not always accurate, especially if the bike has never been re-calibrated after leaving the factory.
Rather than focusing on your distance on a stationary bike, look at the time and your heart rate. These metrics will give you a far more accurate idea of the intensity of your workout. If you are going to be using distance to track your stationary bike workouts, make sure you always train on the same bike.
