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Rainy day pondering of treadmill running + inclines
Starting assumption: Running on an incline requires more energy. Almost everyone agrees on this, and there us much pragmatic and objective (eg O2 requirement measurements) information to state this as “fact”. My position is : It is not the same as running up a hill. A 1% incline on a tredmil will not be the same as 1% of walking up a hill. The extra energy being put in does not get turned into potential energy by the body / treadmill system. Even considering a reference frame the same as the top surface of the belt, where in that frame the belt is not moving, and you are running forward with the same speed as you would be outside, you are not gaining height and therefore not gaining potential energy. As this reference frame does not gain or loose hight in relation to the gym room / earth reference frame (ie the machine does not move up vertically) then there is no energy epxended in seperating the refernce frames. So where does the energy go? 1/ Into the friction bearings of the treadmill. Or as they have motors it probably needs to do less work. I can imagine a treadmill with a free moving belt at a high incline, only the friction slows the belt. You need to run faster until the friction force matches your propulsion force, then you are stable on the belt. If you increase the propulsion force while the friction force remains the same, then you will move forward. As we know there is more energy going in (pragmatically from many people finding it harder) but your speed is the same, then more energy is given to the motor/friction system in the machine. This probably means the motor works less hard and uses less energy, or the friction device provides more resistance. How about if it was a bycicle on the treadmill? This is purer as it takes the running complexity out of the system and its easier to visualise what is happening. When flat the and the bike is not moving forward or backward in relation to the room, both its wheels and the belt are moving at the same speed. The force that the rider puts in is matched by the resistive system of the belt, some is lost to wheel bearings and the belt end bearings, heat on the belt and what it rubs against. There is so much friction on the belt that a motor is acutally used to drive the system at a constant speed. If the belt is now at an incline of a few degrees does the cyclist need to put more energy in? I have read that the answer is yes from peoples experience. He is not gaining height though, so its not being turned into more potential energy. The energy must go somewhere. I think its still going into the belt drive+friction system, and would be evidenced by the motor using less energy and driving the belt with less force. If we imagine the belt now being raised to a steep angle, we get to a situation where no matter how hard/fast the cyclist pedals, and how fast the belt spins (faster = more friction) we can imagine the bike falling off the back of the belt. I think this would not happen, but the motor would pull more energy out of the system, it would become a generator. It is taking much more energy from the cyclist. If the angle goes higher still the tyres loose traction obviously, but imagining they dont (cogs) and the belt is vertically upright we basically now have the kind of exercise bike that is used in spinning with a friction band. It is obvious that on a spinning bike, all of the energy goes into the band and none to raise potential energy (move mass vertically upward) but this spinning bike is theoretically the same as a running machine at 90 degree vertical incline. 2/ I had thought that the machine might weigh more or less (thinking of reaction forces) but this does not make sense. The mass is the same, and gravity is the same so the machine + body will weigh the same. It will go up and down from impacts, but over time be constant. 3/ Possible mechanical losses in the leg system. It might be harder to run on a none flat surface because of mechanical losses. Considered that the legs might gain height in a strange manner when striding. There is not net gain as your legs and body do not raise overall. 4/ Machine provides an none perfect support for you to push off, later I realised this is the same as point 1. The extra energy put in goes to more friction in the machine (in practice the machine motor using less energy). 5/ Have just realised that although there is no gain in height between the two reference frames, the “belt frame” where we consider belt horisontal and stationary but us moving forward, will be at an increment to the world frame. This will mean that gravity does not point straight down, but back by the same amount as it is inclined. This will produce a retarding force that must be overcome by extra work in order to keep the same speed. It is still different to walking up a hill, as in that case gravity Is still straight down and the extra energy is required to increase potential energy. Point 1 is reminds me of the Airplane on a treadmill thought experiment. Imagine a 747 is sitting on a conveyor belt, as wide and long as a runway. The conveyor belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off? That experiment relies on some unrealistic properties of friction and wheel bearings set up by the statement that the runway exactly matches the speed of the wheels (so the plane does not move). There is a lot of energy with no where to go (so not a realistic situation), I personally think of the energy going to the wheel bearings on the plane and dissipated as heat. Sources http://forums.randi.org/archive/index.php/t-230280.html http://blog.xkcd.com/2008/09/09/the-goddamn-airplane-on-the-goddamn-treadmill/ http://van.physics.illinois.edu/qa/listing.php?id=183 http://www.hillrunner.com/jim2/id110.html – more about wind resistance effects http://en.allexperts.com/q/Weightlifting-Exercise-1549/2008/1/f/treadmill-incline-myth.htm I'm not certain that I'm right, I actually agree partially and disagree partially with almost all of the posts I've read on the matter I Might ask Brian Cox. Nurburgring 2012 Trip 
This is what happens when 2x Ferrari Challenge Stradale and a 360s (not to mention a secret, lemans bread car) take on the Ring. Nurburgring Bi-Yearly photo update complete 
Massive update to the online images, including Midsummers festival in Sweden, A rock festival in Sjenoki Finland, the high defenintion surfing pictures, and a set from a DIY buit knife I've made. Oh! Almost forgot I took a few shots of the Manchester skyline which I think are quite good (I've not doctored the colours it actually looked like that). Click here Sailing + Foo fighters pictures online 
Sailing and Foo Fighters Photos now Online. Yippee! Click here Mani marries Krisha 
It was such a happy day! Full set of pictures. Mani's Engagement Riot 
Due to an excessively high loss of camera rate, this is the first update for a while. Thank god its a good one. Congratulations (or condolences depends who you ask)to Mani for his careful selection of a female - after a thorough interview process and many fitment trial sessions. Anyway it was a great bash and I promise I'll be in a suit for the main event. Some of the photos are quite amazing... I mean charlie had a girl and this time we have PROOF Now if only you fools would send me your pictures from Hamburg I could put those online too :> Strokes & Foo Fighters at the LCC. 
Pictures here. Foo fighters trounce the strokes at Lancashire county cricket ground. ITS A SHAME WE HAVE TO DIE MY DEAR, NO ONES GETTING OUT OF HERE, ALIVE THIS TIME... MASSIVE UPDATE 
Update to pictures section. Sorry about the delay (especialy to charlie who was moaning like a bitch) but I've changed the photos now. Problem is I lost all the ones from nottingham when my memory card went AWOL. I'll stick them on when I find it. Croatia 
Intresting goings on in Croatia? Nathan and Anna investigate! Pictures. Manchester -> Sweden -> Croatia -> Venice -> Croatia -> Sweden -> Manchester!!! Antibes 
Nathan, Charlie, James, James, Geoff, Mike, Shitelle, Jackie and the rest of the crew invade Abromavich's paradise port. Check it!. Rome! 
Have a look!Click!. Old Boys Mk. III 
Fourth version. Oh my god i cant believe it ive never been this far way from home... Oh my god i cant believe it ive never been this far way from home... Oh my god i cant believe it ive never been this far way from home... Oh my god i cant believe it ive never been this far way from home...Oh my god i cant believe it ive never been this far way from home... now. Gym Routine 
Day 1: Chest, calves + forearms. Day 2: Back, legs, abs. Day 3: Shoulders + Biceps Day 4: Chest or shoulders, triceps + other. Cancun 
Charlie, Rudi, Richard and Nath escape to Cancun! Pictures! Please add your comments... Nottingham & Manchester 
Thanks Rudi & Charlie for letting us stay at your houses. Pictures are here. See you all again soon! Reading hat party sept '04 
Check out the pictures! This is the weekend that charlie found the weapons of massed destruction, Nathan beat Mani 1-0, and Tom bought a chandeleir ;) Old Boys 2004 
The Pictures are here. And the videos will be online for a while here. Though some people couldnt make it, I think that we still managed to represent the 01 leavers well! Can hardly believe its been 3 years already. Holiday friends reunion! Check out the new pictures of our latest adventure in London here. I think that everyone was really happy to meet up with old pals. I haven't seen dave since Sanfrancisco in 2002, and rediculously, its almost as long since I've seen Charlie! Respect to charlie for standing up to a bouncer and letting him know that swearing is illegal, and to Mani for taking things so well... Ill let the pictures do the rest of the talking! Barcelona pictures The pictures from our (Tom, Chalrlie, Andi, Manny and Myself) trip to barcelona. I think that everyone had an awsome time and im already looking forward to our next adventure! You can find the pictures here: Barcelona Terrain Visualisation Applet I have updated the page displaying my Terrain visualisation. I used Java and Java3D to make this application, and believe it to be fairly unique. All feedback welcome. Click here to see the program in action. All comments welcome, email me nathan@bowern8.plus.com. Old boys sports day MKII 
Despite a fairly poor turn out this year we still managed to rip it up bigtime. Charlie had an especially impressive performance on Saturday night, managing to destroy two cars, and extract his own toenail. Chunder is still unsure of the reasons for this but we all agree that it made perfect sense at the time. I had to take this monday off to recover from the weekend - when my boss phoned I told him I couldnt walk because I'd been playing rugby with some 17 stone feinds. Impressed doesn't begin to describe his response... Fish and myself will be organising some carnage in london in a month or two. I expect more of you lazy bastards to turn up this time!!! You can find the pictures here. Rudi's Leaving MASH UP pictures now online. I know you boys want to get straight down to business, so here is a direct link to the carnage! Click here. There are also some videos, also awsome - especially finger explaing about the all night wrestling competition. Grab them here. I think everyone had a ballistic weekend, everything was spot on. Props goto fishy for organising it, Ong&Goose for not bashing anyone, Finger for the leopard skins of death, and all you other geezers out there, for making it such a memorable weekend. See you all in a couple of weeks for the old boys session! |
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