iPod Which data is more accurate, treadmill or Nike+ Kit?

I'd bet the treadmill would be more accurate since it knows the size of it's rollers and has only to count revolutions of the roller to know exactly how far the belt has gone (assuming no slipping). The Nike system as I understand it would be measuring your stride length so if that varies on pavement vs treadmills it could easily be off for treadmill running.

Did you calibrate the Nike+ sport kit?

Still - that is a huge variance.
How exactly does it measure your strides? The treadmill has to be more accurate IMO.

Treadmill should be fairly accurate. It measured based on how many times the belt turned, a constant. Whereas the Nike+ thing is based on strides alone. If you take different length strides then the Nike+ will be off. I think in general you will tend to take longer strides on a tredmill becasue you don't have to worry about what is coming up on the path.

I would believe the higher number, because it would make me feel better.

To play devils advocate...

A treadmill doesn't exactly have to be accurate. Sure, it can do a great job of counting the number of times the tread has gone around and get a good idea of that distance. But the way that someone runs on a treadmill can make a difference in how much of that distance is actually "ran," if that makes any sense.

The Nike kit doesn't just count the number of strides and multiply it by a constant; it is not a pedometer. It is an accelerometer that can measure different distances in stride.

All that said, I'd still expect the treadmill to be more accurate.

tobefirst said:

To play devils advocate...

A treadmill doesn't exactly have to be accurate. Sure, it can do a great job of counting the number of times the tread has gone around and get a good idea of that distance. But the way that someone runs on a treadmill can make a difference in how much of that distance is actually "ran," if that makes any sense.

Click to expand...

It really doesn't.

The Nike kit doesn't just count the number of strides and multiply it by a constant; it is not a pedometer. It is an accelerometer that can measure different distances in stride.

Click to expand...

I'm pretty sure this is not even physically possible.

nice bump

tobefirst said:

To play devils advocate...

A treadmill doesn't exactly have to be accurate. Sure, it can do a great job of counting the number of times the tread has gone around and get a good idea of that distance. But the way that someone runs on a treadmill can make a difference in how much of that distance is actually "ran," if that makes any sense.

Click to expand...

Explain. I'm still trying to wrap my ahead around this and can't.

Policar said:

Explain. I'm still trying to wrap my ahead around this and can't.

Click to expand...

holy thread bump batman

but as to your question, if someone took a stride, then sat idle while their foot moved towards the back of the treadmill before taking another stride, the distance ran would be less. in reality, nobody on a treadmill would actually do this.