16-03-2012, 03:41 PM
Hey Dean - I'm curious what sort of speeds were you running at that you noticed this difference so as to add the 1%?
The force of drag caused by air resistance is proportional to the SQUARE of your velocity...so double your speed, and you quadruple the energy required to overcome drag. This can be mitigated by reducing your drag coefficient (tight clothes...hair cut...hehe)....but can't be avoided.
The exact impact of that as an overall % of force (or proportionally effort/energy) required to run at a particular speed is what matters. At lower speeds I've heard its almost irrelevant...but at middle distance speeds...ie 20kph or faster it starts to hit 15% of overall effort...maybe.
My own personal anecdotal experience is this: When running at about 12kph on the treadmill at 1% incline, when i transitioned to outdoors I found it much easier. Where I found it difficult to maintain 12kph for longer than 20-25minutes on the 1% treadmill, i could do 50minutes at 12kph outdoors.
However now, where i have difficulty doing 15kph for 20minutes on the treadmill at 1%, when i go outside, I have equal if not slightly more difficulty maintaining that pace...I don't know if 3kph is sufficient difference to account for that. It could be other factors like TheEd mentions.
Also, my experience across numerous different treadmills on my travels is that occasionally you get one that is mis-calibrated...I've ran on a few where the incline doesn't work (it says it works, but doesn't move). hehe. Overall though i have found most comparable/consistent from workout to workout, which is probably ultimately more important.
I think the idea that the belt pulls your feet along and thus makes it easy is false though...If you don't push off the belt with the same force as if you were running at that speed, you will eventually fall off the end of the belt. The belt is moving one way at a certain speed - just like the ground. The only way for you to keep going forward at that speed is to exert the appropriate force against the belt to push yourself forward (or more correctly push yourself to a stationary position relative to the machine..hehe).
TheEd - I think the ability to dial in an exact pace is a bonus of treadmill training...It definitely makes it easier to push myself at a certain pace, where as outdoors i might end up slowing down due to a lack of mental discipline. But that doesn't speak to the energy requirements...though, perhaps you're onto something with the different bio mechanics coming into play..if i'm mentally unprepared to push a certain pace i might start flailing around where as i'm pushed at it robotically on the treadmill making it easier....
I wish there was an easy way to check a treadmill to see if its calibrated...
The force of drag caused by air resistance is proportional to the SQUARE of your velocity...so double your speed, and you quadruple the energy required to overcome drag. This can be mitigated by reducing your drag coefficient (tight clothes...hair cut...hehe)....but can't be avoided.
The exact impact of that as an overall % of force (or proportionally effort/energy) required to run at a particular speed is what matters. At lower speeds I've heard its almost irrelevant...but at middle distance speeds...ie 20kph or faster it starts to hit 15% of overall effort...maybe.
My own personal anecdotal experience is this: When running at about 12kph on the treadmill at 1% incline, when i transitioned to outdoors I found it much easier. Where I found it difficult to maintain 12kph for longer than 20-25minutes on the 1% treadmill, i could do 50minutes at 12kph outdoors.
However now, where i have difficulty doing 15kph for 20minutes on the treadmill at 1%, when i go outside, I have equal if not slightly more difficulty maintaining that pace...I don't know if 3kph is sufficient difference to account for that. It could be other factors like TheEd mentions.
Also, my experience across numerous different treadmills on my travels is that occasionally you get one that is mis-calibrated...I've ran on a few where the incline doesn't work (it says it works, but doesn't move). hehe. Overall though i have found most comparable/consistent from workout to workout, which is probably ultimately more important.
I think the idea that the belt pulls your feet along and thus makes it easy is false though...If you don't push off the belt with the same force as if you were running at that speed, you will eventually fall off the end of the belt. The belt is moving one way at a certain speed - just like the ground. The only way for you to keep going forward at that speed is to exert the appropriate force against the belt to push yourself forward (or more correctly push yourself to a stationary position relative to the machine..hehe).
TheEd - I think the ability to dial in an exact pace is a bonus of treadmill training...It definitely makes it easier to push myself at a certain pace, where as outdoors i might end up slowing down due to a lack of mental discipline. But that doesn't speak to the energy requirements...though, perhaps you're onto something with the different bio mechanics coming into play..if i'm mentally unprepared to push a certain pace i might start flailing around where as i'm pushed at it robotically on the treadmill making it easier....
I wish there was an easy way to check a treadmill to see if its calibrated...