Another thread about exercise

[Doggy Styles]

It'll make you pretty ill if you don't have sufficient calorie intake to fuel the exercise. (nb; this is not an encouragement to eat more pies if you go for a 15 minute cycle ride each day)

True. But overweight people are overweight because their calorie intake is much higher than they use. So they can either reduce calorie intake, increase usage, or perform some combination of the two.

There was a health campaign slogan in one of the broadsheets a few years ago - 'Move more, eat less'. Quite snappy I thought.

[Mich the Tester]

But burning fat only kicks in after 20 minutes or so - that is once you run out of more immediately available sources of energy like glucose, so no matter what, you still have to spend at least an hour (warm-up, cool-down etc) for it to be a sensible fat burning effort...

Or spend a month doing 20 minute jogging/cycling sessions to get basic fitness, then do this.

Much more effective than long slow exercise sessions for getting rid of fat.

Not very pleasant; involves being out of breath several times. But it works and only takes 20 minutes or so a few times a week.

[Doggy Styles]

Before my knees died, I used to walk up a hill (steeper than the one I'm halfway up at the moment) every day.

At the top, just after I'd collapsed on a seat, my heart rate would be a nice consistent 180.

The walk back down was more pleasant.

And of course there was the hand-to-hand combat with war criminals...

[xoggoth]

As an engineer I used to know all this once, long ago. Erm. As you are transporting the same weight over the same distance they are theoretically the same but there will be differences in efficiency of energy conversion between running and walking. If I could find the blurb that came with my pedometer I could give a figure.

Before my knees died?
Can't giant lizards just eat a few children and grow new ones?

[d000hg]

But burning fat only kicks in after 20 minutes or so - that is once you run out of more immediately available sources of energy like glucose, so no matter what, you still have to spend at least an hour (warm-up, cool-down etc) for it to be a sensible fat burning effort...

Well a 20-min run might take 45min to walk (guessing) so my body is active for a longer period. I mean a brisk walk, enough you get warm even in the cold weather

[ThomasSoerensen]

As an engineer I used to know all this once, long ago. Erm. As you are transporting the same weight over the same distance they are theoretically the same but there will be differences in efficiency of energy conversion between running and walking. If I could find the blurb that came with my pedometer I could give a figure.

Before my knees died?
Can't giant lizards just eat a few children and grow new ones?

Don't forget that you are not transporting the weight the same distance. When you run you push off the ground much harder and actually have a phase where you are not touching the ground at all. So you might cover the same horisontal distance, but I think if you track the actual distance of your body as in running /\/\/\/\/\/\/\/\/\/\/\ vs walking ----------- you will find that the distance is longer when running. When running you also, because you push yourself into the air, work harder against gravity.

As a rule of thumb I have read somewhere to use the formula of (kms covered * bodyweight in kg * 1.04) for running and (kms covered * bodyweight in kg * 0.76) for walking.

How does that sound for you?

[TimberWolf]

If you walk for X miles does this burn more or less calories than running the same distance? You're active for a longer period but less energetic. It must come down to biological efficiency I think. Anyone?

There's probably an optimum speed and gait for different species. Efficiency losses occur when you bob up and down I'd suggest most of that won't be recovered by humans, so I would guess walking at a relatively brisk pace would be best for us as you don't jump as high in the air when walking as with with jogging. Looking at people migrating (or exploring) vast distances might be illuminating. I doubt many of those people would be running around unless there were some other (e.g. time) constraint. Wildebeest run everywhere like mad things it seems, but they are likely more efficient at running and need to get places quickly for reasons other than efficiency alone.

The real long distance experts seem to be the fliers and swimmers, who don't do the bobbing up and down malarkey, and humans are tulip at both of those. Something like 5% efficient at swimming IIRC. At walking pace we use around 3.56 kWh per 100km (or 6.5 kWh including resting (basal) energy), but I don't have a figure for running. On hard flat surfaces and with training not to bob up and down and recovering more energy per bounce, I wouldn't be surprised if a slow jog might match or even exceed walking efficiency in the fit.

[manclarky]

There was a health campaign slogan in one of the broadsheets a few years ago - 'Move more, eat less'. Quite snappy I thought.

That sounds like the Radio 2 diet, "Eat less, Exercise more"

[d000hg]

On hard flat surfaces and with training not to bob up and down and recovering more energy per bounce, I wouldn't be surprised if a slow jog might match or even exceed walking efficiency in the fit.

I'm sure I've read somewhere that humans are well-suited to a loping run for long distances... as you walk fast that itself becomes pretty tiring so I imagine that an efficient loping jog could be efficient - as you say you need to be accustomed/trained to it though.

[TimberWolf]

I'm sure I've read somewhere that humans are well-suited to a loping run for long distances... as you walk fast that itself becomes pretty tiring so I imagine that an efficient loping jog could be efficient - as you say you need to be accustomed/trained to it though.

Yeah, I gather we are pretty good at endurance compared to most animals, but much of that may be down to our outstanding heat regulation abilities, as we are the best sweaters on the planet. The animals we can hunt down on foot usually succumb to heat exhaustion.