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The science behind

Learn about the science behind GRASPOR. What exactly is muscle oxygen, and why does it matter?

The science:

GRASPOR is a training device, similar to your power meter and heart rate monitor. All 3 devices help you control your intensity on the bike.

When you control your intensity on your rides based on power or heart rate, there is often a big mismatch between what intensity your think you ride with, and what the intensity really is because the powermeter measures externally, and it really olny measures how hard you push on the pedal.
In other words: you lack a metrinc measuring how hard your body is actually working.

Therefore, we developed GRASPOR. We wanted to remove all the guess work, and let you train based on the vital performance marker, Oxygen.

The big difference between GRASPOR and the two other devices (heart and power) is that GRASPOR measure how hard your body is working to sustain your current effort, while the powermeter is just measuring your external output.



GRASPOR emits light from two different sources and measure the returning light at three different sites.

The light sources shine through your muscle and measures the intensity of the light returning to the sensor.

The intensity of the light is then used to calculate your muscle oxygen level. This calculation is made 10 times per second, allowing you to rely on live data throughout your workout.

What do we measure?

GRASPOR measures the oxygen level inside your muscles. This gives a clear understanding about exactly how hard you are pushing your body at a certain intensity. Having this data available gives you the possibility to train based on an internal, local performance indicator, as opposed to power or heart rate which are either external or systemic. 

When using power as a performance marker, you put all your trust in an external measurement. Simply put, the power meter only measures how hard you’re pushing the pedal. It doesn’t tell you anything about how much you’re stressing your body to apply the force into your pedals.

This is what GRASPOR can tell you.

GRASPOR gives you a clear understanding about what happens inside your body when on the bike. You can see exactly when you’re pushing too hard, or not hard enough, ensuring that you train the most optimal way for effecient training.

What is muscle oxygen?

GRASPOR measures the number of oxygenated hemoglobin cells in your blood, compared to your total amount of hemoglobin cells. This means that if you have a Muscle Oxygen level of 54%, 54% of your hemoglobin cells carry oxygen at that moment. Your body requires oxygen to perform, as oxygen is a part of the process to create the energy your muscles use as fuel.

So, the harder you work, the higher the demand for oxygen, and therefore a lower Muscle Oxygen.

How it works

Muscle Oxygen has similar applicability to the blood lactate level. You can use Muscle Oxygen to measure the intensity of the work the body is performing in real time.

The major difference is that you can measure it without poking a hole in your finger to analyze the blood. This is because GRASPOR uses infrared light, that shines through your leg to measure your muscle oxygen value.

The intensity is impacted by the amount of oxygenated blood cells. The more oxygen present in the muscle, the more intense light is returned.

Book a GRASPOR expert

If you have any questions, or just want to learn more about the science behind or about GRASPOR in general, you can book a timeslot with our product manager below.