Sproing Fitness has a product similar to what you are describing. It was on Shark Tank:
Sproing Fitness has a product similar to what you are describing. It was on Shark Tank:
killermike wrote:
zzzz wrote:
When I looked into it in the past, the effect of no wind resistance was more along the lines of 17-20 seconds per mile, and didn't change that much as the pace slowed through common running speeds. Yes, the effect of wind resistance decreases as pace slows, but 17-20 seconds per mile becomes a smaller percentage of the pace. For instance 17-20 seconds at 4:00 pace is 8%, while 20 seconds at 8:00 pace is 4%. My source was those VDOT calculators with additional factors that you could input. The ones I can find now have removed the wind input though, just having altitude and temperature effects.
The formula for kinetic energy is 1/2mv^2, which means kinetic energy is cut by a factor of 4 when velocity is cut by a factor of 2. Going from a 4 minute mile to an 8 minute mile cuts the wind resistance by 4x, so we should see the amount of time saved on each mile cut in half when the mile time doubles.
I'm sure there were reasonable formulas that were used to spit out what saw from that wind factor calculation. I'm probably tested a narrower range of paces, maybe from 4:00 to 6:00 or something like that.
My main point is, based on what I've seen wind resistance at those faster paces has a cost of more like 17-20 seconds per mile than 5 to 10. 4:00 pace is 15 mph, and its quite noticeable wind.
zzzz wrote:
My main point is, based on what I've seen wind resistance at those faster paces has a cost of more like 17-20 seconds per mile than 5 to 10. 4:00 pace is 15 mph, and its quite noticeable wind.
There is absolutely no possible way the wind resistance has a cost of 17 to 20 seconds. Are you saying a solo runner running a mile in 4:30 could run a 4:10 if he was able to tuck in behind a couple pacers?
Even my experience shows you would need to be running into winds of 20 to 30 mph to have a cost of 17-20 seconds per mile. Even at 5 minute pace, that is only 12 mph. 8 minute pace is only 7.5 mph.
Another way to put it is if you ran into a 10 mph wind for 5 miles and turned around and had the wind at your back, you would be able to run 30-40 seconds per mile faster at the same effort. That is just not possible.
Forgot to say, How many runners are running 4:00 pace on a treadmill?
Virtually zero
The important point here is to square the factor increase in mile time to get the inverse of the change in wind resistance. So going from a 4:00 to a 6:00 mile (a 1.5x increase) would result in a 2.25x decrease in wind resistance per unit of time. So if there is 20 seconds of wind resistance "slowdown" at 4:00 per mile, there would be 8.88 seconds of total slowdown over four minutes of running at 6:00 pace. Stretched out to six minutes of running at 6:00 pace, we arrive at 13.33 seconds of wind resistance slowdown. I am pretty sure I have these calculations correct. This assumes no change in running form as it relates to aerodynamics.
The big question of course is the starting values. 20 seconds at 4:00 sounds like a lot, but 4:00 is quite fast.
At the speeds a treadmill can produce, lack of wind resistance is negligible and more than offset (negatively) by heat retention due to that same lack of wind. Even at slower speeds, a "cool breeze" works the same - because it's moving, it's lower pressure and easier for sweat to evaporate into.
You can compensate for that by using a big fan to blow air at you. But that's another treadmill physics question! If you put the fan in front of you, does the air act the same as wind resistance outdoors? I say no; it's not enough to move you backwards and the treadmill will not slow down either.
Bad Wigins wrote:
At the speeds a treadmill can produce, lack of wind resistance is negligible and more than offset (negatively) by heat retention due to that same lack of wind. Even at slower speeds, a "cool breeze" works the same - because it's moving, it's lower pressure and easier for sweat to evaporate into.
You can compensate for that by using a big fan to blow air at you. But that's another treadmill physics question! If you put the fan in front of you, does the air act the same as wind resistance outdoors? I say no; it's not enough to move you backwards and the treadmill will not slow down either.
I agree that wind forces are probably negligible at the speeds most treadmills produce.
The question regarding the fan all depends on the amount of air moved by the fan. Running on a windless day at 6:00 pace, or 10 mph, functionally produces 10 mph winds against the body. That isn't enough to move you backwards either. To really answer this question, you would need to calculate the surface area of your body as it runs and then use that to determine the volume of that is being forced against that surface area in a 10 mph wind. A fan may or may not be able to produce that. If we are talking one of those 6' tall fans that can really get cranking, yeah, it probably can. A fan that can only create wind against 25% of your body would need to blow at 40 mph, though, and even then the mechanisms of the human body running with a 40 mph wind against a small portion of the body would throw things off.
Should be easy to get a big fan linked to treadmill that matches wind speed to belt speed. More comfortable too -- anyone who has ridden a trainer vs biked outside can attest.
Test
Sometimes I'll toss a broomstick on the belt to simulate running near Brenda Martinez.
jamin wrote:
With real running,....your arms have to more work to cut through air resistance.
Congratulations, this must be the stupidest comment ever posted on LRC. Even if you hadn't left out the word "do."
At least it's funny.
You know that you're supposed to move your arms while running and they are generally swinging back and forth. If you are running outside and there is a strong head wind it's going to be net zero energy expenditure due to the wind because the arms are moving back and forth. In fact there might be more arm swing wind resistance on a treadmill since the air is stationary.
Maybe we could invent arm wings that allow runners to use wind to provide a slight lift to reduce the downward force on the runner's feet.
Hahahaha
killermike wrote:
Running on a windless day at 6:00 pace, or 10 mph, functionally produces 10 mph winds against the body. That isn't enough to move you backwards either.
by "move backwards" on the treadmill I mean the fan causing deceleration of the body relative to the treadmill belt, in an analogous way to how the air decelerates it relative to the ground outdoors.
But on second thought, it should do precisely that, as long as the body is airborne at least part of the time. It does move you backwards.
Let noone claim I never admit to being wrong! Only rarely do I have the opportunity.
your numbers are too high.... wrote:
zzzz wrote:
My main point is, based on what I've seen wind resistance at those faster paces has a cost of more like 17-20 seconds per mile than 5 to 10. 4:00 pace is 15 mph, and its quite noticeable wind.
There is absolutely no possible way the wind resistance has a cost of 17 to 20 seconds. Are you saying a solo runner running a mile in 4:30 could run a 4:10 if he was able to tuck in behind a couple pacers?
Even my experience shows you would need to be running into winds of 20 to 30 mph to have a cost of 17-20 seconds per mile. Even at 5 minute pace, that is only 12 mph. 8 minute pace is only 7.5 mph.
Another way to put it is if you ran into a 10 mph wind for 5 miles and turned around and had the wind at your back, you would be able to run 30-40 seconds per mile faster at the same effort. That is just not possible.
That 10 mph out and back actually seems kind of reasonable to me,
A solo 4:30 runner wouldn't be getting 17-20 seconds benefit behind pacers. The drag reduction isn't that high.
maybe at 2:30/mile...... wrote:
Forgot to say, How many runners are running 4:00 pace on a treadmill?
Virtually zero
I think I've watched two videos of Famiglietti doing sub-4s on treadmills. Of course he's a 2x Olympian, but he was probably only 4:high-teens shape for one of them.
I don't think you can ever really simulate uphill running on a treadmill. While increasing the angle will simulate bio-mechanically the different posture which you adopt while climbing, you aren't actually increasing your potential energy, the amount of energy required to run on the belt remains the same regardless of the angle. If there was resistance on the belt, then that might go part-way to simulating the increased force required for the legs to produce, but as treadmills are powered, this is impossible. I suppose if you had a chronically under-powered treadmill ramped up to a steep-ish angle, and while running you were forcing the belt to run faster than the motor was driving it, then this energy would be dissipated by the motor, but in reality I can't see this ending well, and you would just fall off the front of the belt.
I would think that using a bungee to hold you back would be similar to dragging a tyre around, another way of increasing run resistance. The elegant thing about a bungee is the force is proportional to the amount of extension, so that faster you try and run, the more the bungee will stretch, and the more resistance it will produce to pull you back. Assuming you could adjust it to get a sweet spot in the middle of the treadmill it might work quite nicely.
I will caveat all of the above by stating that I utterly detest treadmills and avoid them like the plague, only climbing on for VO2 max tests!
While that Sproing might mimic running, how many people would actually want to use it for more than a few minutes? Absolutely no feedback on how intense the workout it or how fast you are going - basically running on the spot. That would be even more mind-numbingly boring than a standard mill - how much self-discipline would it require to keep going at a reasonable work rate? It would be nice to combine that harness with an actual treadmill though.
cotton shirt wrote:
jamin said: your arms have to more work to cut through air resistance.
lol
you've finally explained it. the air resistance on my arms is clearly why I don't run faster. maybe that's why elites wear those compression sleeves, to reduce the air resistance on their arms. can we please start a thread on the diet required to make you lose weight off your arms to reduce the air resistance. are there special exercises I can do to make my arms thinner?
you know Jamin, I think you're on to something.
either that or you're on something.
cheers.
Jamin is just making excuses why he doesn't do curls for the (Ukrainian) girls every day at the gym.
turboferret wrote:
While that Sproing might mimic running, how many people would actually want to use it for more than a few minutes? Absolutely no feedback on how intense the workout it or how fast you are going - basically running on the spot. That would be even more mind-numbingly boring than a standard mill - how much self-discipline would it require to keep going at a reasonable work rate? It would be nice to combine that harness with an actual treadmill though.
Lol, yes. When I saw the link, my first thought was “what an expensive way to bolt a bungee to the wall behind a treadmill”. Then, I saw what I THOUGHT was a deck was just a cushioned pad, and just started laughing. (Brought back memories of Grass Drills at football practice back in the day... I won’t be paying $X,000 to do grass drills anytime soon.)
Don’t forget to electrocute your left pinkie whilst running with the bunnies. Then clap three times.
That's utter nonsense. While it's true that the heat retention makes the treadmill harder, overall running on a treadmill is significantly easier and you can do workouts on it that you can't do otherwise. Running close to 5 minutes per mile or 12 mph, which you can run on a treadmill, produces quite significant wind resistance. I have done 5M tempos on the treadmill even at 1% under 26 minutes, while my pr is forty to fifty seconds slower and so on, and I will typically go well under current 10k pace for 5 miles@1%.