I have been biking to work for the past week because I’ve lost use of the car I was driving and don’t like walking forty minutes when I can bike it in twenty.
Since the terrain between my home and my place of work is slightly hilly and I am biking again for the first time in ten years, I let my bike coast whenever possible to give my knees some relief.
Does this impact the amount of calories I might otherwise be burning by walking or am I getting the same amount of exercise either way?
Even if you pedal the whole way, you’re getting less exercise cycling than walking.
Cycling is more efficient than walking. Therefore cycling a given distance consumes less energy (= burns less calories) than walking ithe same distance.
If you coast part of the way you’re getting less exercise again, since for that part of the journey you’re not doing any work at all.
Aha. I assumed since I was out of breath while biking but not when walking, that I was getting more exercise.
Can anyone tell me the differences in calories burned over four miles?
I don’t know if I agree with UDS’s analysis. Cycling is certainly more efficient, but you’re also going a lot faster. Surely the energy you expend to maintain sufficient speed more than makes up for the efficiency difference. I sure know that I feel a lot more tired cycling a long distance vs. walking.
There are many who know more about this than me, and hopefully one of them will be along shortly. What I say may be partly or completely wrong.
Work is a function of mass and distance. The work done in moving Mass M through Distance D is the same, regardless of the time taken.
Of course, when we cycle we move a greater mass than when we walk (because we move the bicycle as well as ourselves), so strictly speaking cycling a given distance does involve more work than walking it. However as already noted walking is inefficient; when walking, the human body burns more calories than is theoretically necessary to move Mass M through Distance D. Cycling improves the efficiency by more than enough to offset the extra mass of the bicycle.
If you throw time into the calculation, what you are measuring is power, not work. The less time you spend moving Mass M through Distance D, the more power you are exerting. Hence cycling to work does require more power than walking (unless, of course, you cycle at walking speed).
That may leave you breathless, but that doesn’t necessarily translate into more calorie consumption.
It may do, in the long run, if you exert sufficient power often enough to alter your metabolism, causing it to burn calories faster in order to give you the power output you are demanding of it. It will continue to burn calories faster even during the intervals when you are not exerting power; hence exertion in exercise is an important factor in developing fitness and (if you are aiming for that) weight loss.
Twenty minutes steady exertion (i.e. enought to make him short of breath) twice a day, five days a week, probably is enough to affect Aesiron’s fitness level, if sustained for some weeks, and so may in the long run lead to a greater calorie consumption. But it is the metabolic change which is burning the extra calories, not the actual work of moving himself and his bicycle.
The effect is diminished if he spends time coasting, since he is clearly not exerting himself. I’ve heard it suggested that, as a rough rule of thumb, you should be aiming to make yourself short of breath for twenty minutes to half an hour, continuously, three or four times a week in order to be having any positive effect on your metabolic fitness. Regular vigorous sex would be ideal, but we are not all so fortunate, and we have to resort to running and similar less enjoyable pastimes. Cycling will do it but, precisely because it is so efficient, commuting cycling or leisure cycling doesn’t always make the sustained power demands on your body that are needed.
Yep
No it isn’t. If this were true, there would be as much work involved in moving a kilogram 10 metres by sliding it across ice as there would be in dragging it across sandpaper.
Work is a function of force and distance.
The force involved in moving you and a bicycle is a function of mass (because it takes more force to accelerate a greater mass) and friction. Mass is not that significant unless your route is very hilly or very stop and start.
Friction is highly relevant.
Generally speaking, a bicycle has little of it. So all else being equal, a bike will get you to where you are going with less work than walking.
However, bikes also go faster. Wind resistance increases as a square of speed. That is, it increases very rapidly with speed.
So while a bike is much more efficient than walking, if you go at the type of speed that it is easy to go on a bike (as opposed to a walking pace) you may actually use more energy (do more work) going the same distance on a bike as you would on foot.
As UDS says, with increased speed comes increased work and vice versa. So if you were to ride to work on a bike at walking pace you would use less calories (bikes being more efficient). If you ride to work very fast you may well use more.
If you coast you will go slower than if you pedal. So the more you coast, the less calories you will use.
Probably but not necessarily. If you cycle at a high enough speed, you may create enough friction to increase the force required over the distance involved to push the work done to a level beyond what you would expend walking.
It depends upon your speed in both cases (cycling and walking) and it is beyond my capacity to calculate.
What does sufficient speed mean? I gaurantee you that I can cycle at 10 km/hr (double walking pace) all day. And I would barely feel it, since 10km/hr on a bike is so slow my major effort would be in avoiding dying of boredom. If I walked for the same length of time I’d go half as far for a lot more effort (but have a less sore arse).
You’ve got to be kidding. I think this is only true because you’d cycle a lot further. I’d go the same distance on a bike in a bit over an hour as it would take you to walk all day.
I did 232km in a day last week on a bike. To do the same distance would have taken me a week, walking. [Yes, this whole post is a thinly disguised pretext for making this boast. Sorry]
Sufficient speed means speed sufficient to keep the bike from falling over. Which in my experience is faster than a walking pace. But then, I’m a big stupid gorilla and I walk pretty slow.
I have both walked and biked the four miles to my old job and back, and the bike definitely took a lot more out of me. But that’s just my experience.
Let me boil this down.
Biking uses less calories than walking the same distance over the same terrain. There is another thread on this recently; biking is the most energy-efficient form of human-powered transportation.
You feel more tired if you cover 15 miles by biking it in a half hour vs. walking it in 4 hours because the effort is more intense, not because you’ve used more energy.
Almost.
Biking uses less calories than walking the same distance over the same terrain at the same speed.
A distinction must be made between fitness and burning calories, which are not the same. If you walk or run 5 miles you will burn basically the same number of calories (not quite due to internal factors), but you will get your HR up higher jogging, running, or running fast, and the faster you run the higher the HR. It is this (increased HR) which will lead to more fitness. Walking may burn more calories per a given distance than biking, but biking at any reasonable speed will get your HR up higher (coasting doesn’t count).
According to this site
Check it out on the About.com calorie counter.
I honestly think I’ve gotten in better shape due to biking. I used to walk to and from work, approx. 20 mins. each way. In the early spring I got a bike and started biking there and back, which cut my time down to 10 mins each way. But, I noticed that over time I didn’t get out of breath as easily, my heart actually felt stronger, I had more energy, I lost some weight, and my legs became more toned and smaller. So I must be getting some benefit from biking vs. walking. I do live in a hilly area though, so that might have something to do with it, as I never switch to the easiest gear when I take hills (my gear shifts are kind of finnicky so I try not to touch them).
If you eliminate efficiency of the human engine and air resistance as variables, then physics says you will use the same energy to move a mass through a distance at constant velocity regardless of speed.
I am open to the possibility that human efficiency and air resistance could make a measurable difference but I can’t believe that biking distance x can ever cost more energy than walking the same distance, no matter what speed you are cycling.
Gotta cite? (The thread I referred to has cites for my point.)