Nearly 30 percent margin of error
Congratulations! Have you been 10 000 steps today? Or are many of those steps, in fact, perhaps from the bus trip? According sports physiologist Michael Mattson, do not rely blindly on your tränings apps pedometer that can show as much as 30 percent wrong.
– It’s pretty hard to tell the difference between different movements.
More and more use of fitness apps to measure both everyday exercise, as calories burned and hard ice sessions. But how much can you really trust them?
– Roughly one can rely on apps, says the sports physiologist at the Gymnastics and Sports Academy, who performed several tests on most activity bracelet and fitness apps.
They say that there are built-in accelerometer, ie motion sensors, found in pedometer, activity bracelet and now even smartphones. The accelerometer signal is then filtered so as to have produced data including number of steps.
– But it’s pretty hard to tell the difference between different movements, which is the main reason why it is wrong, says Mikael Mattson explains that a bus trip, for example, may encounter counted as steps.
– It is relatively similar signal man sitting on a bus that regularly bobbing a little up and down, as if walking.
So is there any idea to have these apps? Yes, to get a general idea. There is a saying that you should walk 10,000 steps a day to maintain good health and 15 000 steps for weight loss.
– Then it’s teaching to be good if it turns out that it only goes 2000 steps per day. Although there is a margin of error that says it’s a lot if you go for a bit.
They have compared different apps and has concluded that it can differ as much as 30 percent between them even though it gone just as much.
– The meters measure the movements, and then a certain signal converter to information about what is and what steps are not steps, he says, and explains that different applications have different algorithms for this.
– In some cases it will be harder to get a step – and then you get a lower estimate, he says and explains that apps often has an error margin of about 15 percent down or up. But in some cases, this resulted in a 30 percent margin of error.
The meter can display 10,000 steps though you actually just now 7 000th
They believe that apps certainly do benefit, but that you should be aware of the problem and that there is variation between apps.
– Some are worthless, the good ones are pretty evenly matched and they are getting better and better and algorithms are constantly updated.
Traditional pedometer is better
But a better alternative to the apps are really traditional pedometers that it attaches to the hip.
Then you often get a more accurate result than a watch on your arm. But if you have a smartphone in your pocket, it’s safer than a watch on the arm, says, and explains that it is because it is easier to detect a step on the meter sits close to the body’s center of gravity.
– The arms one can move very different even if you walk.
But even if the number of steps is correct then the apps today do not recognize what kind of steps it is, for example, if it is on a flat surface, or if you go up the stairs. And energy consumption which is the course different.
Necessary fitness apps then?
– There is a huge win with them, such that one can measure over time, giving a better overall picture and mean that there may be good both educational for the individual and for doctors who can gain valuable information about the patient’s habits and lifestyle.
– If one is to provide some physical activity on prescription, it is huge advantage if you have an app to start from. Although it measures a little wrong and you have a different track than before.
But the bottom line when it comes to stage monitors: You can rely on your app – in principle.
– You get a good estimate but one should not think that’s exactly true. I think there is great potential in it, but you do not need to exaggerate the benefits of having it on the hour.
A bigger problem is in energy metabolism. Apps are not as reliable when it comes to figuring out how much calories you made of.
– It can be quite a disaster. As for energy metabolism can vary 50 percent wrong, so if you trust blindly on what it shows as the consequence may be that you eat too much or too little.