I am not an expert in the slightest, but doesn't a lot of this depend on how fit you actually are and what is your maximum heart rate?

There must be other variables involved which you would need to state before giving a definitive answer.

However, I still reckon it would be option 1.

Too many variables to say.
Someone will say it's the same. They're wrong 🙂

Being stuck in a mine in Chile knowing you cant be a fat bastard and get out should help burn a few calories.So shifting rocks for 4 months should do it

What temperature is the water?

Ok I'll bite. The 1 hour session will burn more calories.

I am not an expert in the slightest, but doesn't a lot of this depend on how fit you actually are and what is your maximum heart rate?

no

since drag is proportional to the cube of the speed I'd say the 20 minutes would use roughly 27 times more calories than the 60...

The person who takes an hour must be pretty unfit, so I reckon they might, their either very unfit, or they have a very inefficient technique.

If it if the same person I'd guess at the 20 min being more - after all, water resistance increases with the cube of speed I think, or maybe the square, can't remember, meaning that you put in way more than three times as much energy to go three times as fast.

Exercising hard will be partially anaerobic so will be less efficient. Probably.

geoffj - bite all you want, I was just thinking it over in the sauna after I had done it in 20 mins.

i'm niether fit or efficient. though another guy carried on for an hour and I was counting as he swam and we did roughly the same amount of lenghts

Lower effort means more fat burned, but I would imagine the same amount of calories. When you're working hard you're burning carbs rather than fat.

This of course assumes the same person doing the work (same level of fitness!)

simonfbarnes - Member
I am not an expert in the slightest, but doesn't a lot of this depend on how fit you actually are and what is your maximum heart rate?
no

since drag is proportional to the cube of the speed I'd say the 20 minutes would use roughly 27 times more calories than the 60...

To the square of the speed isn't it?

You also have to take into account that over 50 lenghts you are stationary 50 times, the person who completes it the quick accelerates the most

But if you're in the water an hour, you'll be colder, so surely burning loads off 😉

If you trod water for an hour you'd still burn calories but do no lengths.

So this needs to be added to the energy required to do the lengths.

Let's say you use up 800 calories an hour when really going for it. That'd mean swimming slowly would have to use less than 266 calories per hour, which is pretty low. I therefore reckon option 2.

isn't it just a function of distance like walking an running? In which case it doesn't matter how long it takes?

All depends on the temperature of the water.

What if the pool is on a conveyor belt?

isn't it just a function of distance like walking an running

However, if you slow down, you take longer to complete the distance. Because simply being alive takes energy, the slower you go the more of that energy you use.

It's quite complex.

To the square of the speed isn't it?

no, that's kinetic energy, which isn't relevant to constant velocity through a draggy medium

I think it's a function of how hairy your legs are over the square route of the bagginess of your swimwear.

Okay, my understanding is that the sitting human tick over has a sufficient overhead per minute that the duration of the hours swimming would probably eclipse the extra effort put in by doing it quickly.

Research also shows that people use the same amount of energy to walk at 5mph as they do to jog at 5mph which means that the actual increase in energy used between slow and fast will not be as significant as getting out of your chair in the first place.

So, speaking with utter conviction from my armchair sports physiology standpoint, I reckon the hour is going to burn lots more calories.

Research also shows that people use the same amount of energy to walk at 5mph as they do to jog at 5mph which means that the actual increase in energy used between slow and fast will not be as significant as getting out of your chair in the first place.

uh, it proves nothing of the sort. 5mph is quite different to stationary - all it shows is the the gait doesn't matter if the speed is the same

Either one is better than sitting on your ass eating pies.

Depends what stroke your doing!

between slow and fast

Sorry, that was a mistake but I did state that 5mph was the speed in both cases so I wasn't being that misleading. Jogging does require more calories that walking but negligibly so at the same speed is the point I was making.

[b]To the square of the speed isn't it?[/b]
no, that's kinetic energy, which isn't relevant to constant velocity through a draggy medium

Of course the other erroneous assumption is that Cd.A is constant for the two scenarios - I'd suggest it's far higher for the swimmer going slowly, if only because the body will be hanging a lot lower in the water.

Research also shows that people use the same amount of energy to walk at 5mph as they do to jog at 5mph

The power required is proportional to the cube of the speed

quote, yes, you're correct 🙂

I'd suggest it's far higher for the swimmer going slowly, if only because the body will be hanging a lot lower in the water

Oh yes, good point. When swimming fast you have to adopt a much more streamlined position and more of your energy proportionally would go towards going forward than merely keeping your head out of the water... Below a certain speed you have to change your style a fair bit.

[i]I'm amazed. Don't suppose you have a link to that? Certainly from experience of perceived effort and HR it takes a lot more effort to run than to walk.[/i]

Could well be right at the speed given though. 5mph is a very very fast walk, but a very very slow jog, so they could well work out pretty similar.

Swimming speed isn't really linked to fitness/ energy used as running is. With swimming speed is all down to technique. In my experience you have a certain speed that you can increase slightly by putting more effort in but after that slight increase your technique suffers and there is no further increase in speed. The primary reason why you are faster is because of your vastly improved technique. The other chap probably has an inefficient technique that wastes most of his calorific input by fighting the water instead of slipping through it hence he will burn more calories.

Iain

Lots of other variables too, like stroke for instance. Was he a 'floater' ie hovering along in the water doing breast-stroke with just his head visible, making barely a ripple? At 1/3 your speed, he must've been.

Hmm interesting. I think the technique point holds most water (excuse the pun) As a learning swimmer I really noticed how I went faster when I slowed down what I was doing and concentrated on form. Thrashing yourself left me knackered doign the same morning swim across the beach and round the the little island (approx 1km). Doing it everyday for 2 weeks I went from about 40-45mins down to 20-25ish but was feeling less tired at the end by the 2nd week.

Research also shows that people use the same amount of energy to walk at 5mph as they do to jog at 5mph

[url= http://walking.about.com/od/calorie1/a/calorieswalkrun.htm ]Article I read here...[/url]

I started counting how many strokes it took to do a 25m length (without a push and glide). I started at 23 strokes, then went and read up on technique on teh internetz and got it down to 17 immediately.

molgrips - Member
Lots of other variables too, like stroke for instance. Was he a 'floater' ie hovering along in the water doing breast-stroke with just his head visible, making barely a ripple? At 1/3 your speed, he must've been.

Yes he was, and he probably didn't need too much help floating.

I did 30 lenghts front crawl and 20 lenghts breast stroke.

What if the pool is on a conveyor belt?

I think the electric shocks would skew the results somewhat

Which ever is the most intensive will burn the most cals.
After approx 10 mins the energy will be coming from fat reserves.

ATP (anaerobic) > Creatin Phosphate (anaerobic) > Lactic (anaerobic) > Aerobic (carbs)

Swimming 1km in 20 mins
Swimming 1km in an hour

Depends on what you do for the other 40 minutes.