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Old April 1st, 2005, 04:02 PM
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Default Re: Ridiculously OT: Bike vs Walking

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geoschmo said:
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Slick said:
I have to disagree that walking is "the better choice". Yes, bikes are more efficient for getting from point A to point B, but they are comparable when you excercise for the same length of time. Your mathematical example is based on distance when it should be based on time.
No, you are wrong. The question was regarding which mode of transport would be better exercise given a fixed distance, ie his distance form home to work. So by definition the mathematical equation has to be based on distance. If he were asking which would be better exercise for a person with one hour a day to exercise, then you could do a time comparison.


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Slick said: I suspect that a calculation based on time would show that you expend more energy per second on a bike.
I'm not sure this is correct, but it's not relevant for the reason I've explained above. Obviously a person walking at a leisurely pace will expend less energy per second then a person riding a bike briskly. But I suspect that given an equal pace on both you would expend an equal amount of energy at both per second. This is why I mentioned the pace as a factor in my previous post. But the rate of energy expended per second isn't relevant. If you expend 200 calories per minute riding and get there in 10 minutes you've expended 2000 colories. If you expend 5 calories per minute walking and take 20 minutes to get there you've expended the same 2000 calories. This is assuming your bicycle give you no mechanical advantage. But you do get a mechanical advantage on a bike because of the gear ratios. That's why you get more work out with the same energy input.

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Slick said:
That's not to say that biking is "the beter choice" either. Either can be appropriate to an individual's needs. There are tons of articles on the subject.

THis is true, but irrelevant to the paramaters of the original question which was which would be better exercise over a fixed distance.
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Slick said:
You'll get your heart rate up higher on a bike and you will also exercise more muscles in your body. Cyclists also build up more coordination skills as a side benefit. You probably stand a higher chance to get injured, or more severely injured on a bike also.

Walking is better for low impact, low heart rate excercise. Older people, people with certain problems, etc. would find walking better. Doctors often prescribe walking because of its high benefit/risk.

This is all wrong except possibly the part about the coordination. Your heart rate and musculature gains are dependant on the effort you put into it and the resistance you get to that effort. Given an equal briskness of pace your heart rate should be the same regardless of whether you are walking or riding. Your muscle tone might actually be better walking since you don't have the previously mentioned mechanical benefit from the bike.

Bikes are wonderful exercise, but given the same amount of work effort they are no better exercise then walking. And given an equal travel distance, equal amount of work effort and unlimited time, walking is the better exercise. I stand by that. But they will get you farther faster. If transportation time is the deciding factor, or if you bore easily, biking is the way to go.
I stand corrected on the original problem statement of a given distance, not a given time.

I stand by my other statements as I have done minor testing on myself, and with doctor's advice. Under normal circumstances, my heart rate would always be higher during cycling than walking, given equivalent "pace". Leisurly cycling has creates heart rate than leisurly walking. I've checked my heart rate many times under different excercise conditions cycling is always greater than walking; again with other things being "equal".

It's not simply a matter of calories per distance per time. A bike can be a more efficient mode of transportation, BUT, you are also bringing along the wieght of the bike. Hills are harder going up and much easier going down. The point is that energy expenditiure is not linear. Far from it. It's actually very close to a cubic function. i.e. double the pace, and you need to expend approximately 8x the power (2^3 = 8). Also, faster speeds (bike vs walking) cause other factors to become significant, like wind resistance - which isn't linear either. I think wind resistance rises as the square of speed, but it's been too long since I looked at that stuff.

Regarding using muscles. Cycling requires much more effort from arms, back, abdomen, even neck muscles than walking. The leg muscles used in walking and cycling are different. It matters if the cyclist is using "clips" which allows him to pedal on the upstroke.

I don't mean to turn this into a big discussion, and like I have said there are NUMEROUS articles by various "experts" on this very subject; each with its own conclusions. [not to mention throwing in jogging/running, which is another whole can of worms]

All I'm saying is that they are very different and each provides different advantages and disadvantages for people. Each could be the best or totally wrong for a given individual.
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