What difference does it make?
Hunterg46
Posts: 133
Does it making any difference (for fitness training) doing 10 miles on rollers in 20 minutes or the same distance but in 1 hour say?
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Is it a trick question? :?
More problems but still living....0 -
One lasts 3 times longer than the other. That's a good sized difference.0
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Yes it does last 3 times longer, but im only doing the same difference...?0
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So...
10miles in 20mins - averaging 30
or
10miles in 60mins - averageing 10?
or does the time you do it in make no difference..?0 -
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Endurance more than anything0
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I'm not sure I understand what you're talking about...
Try walking up the stairs - and then try running up the stairs. See if it feels any different....0 -
Hunterg46 wrote:Yes it does last 3 times longer, but im only doing the same difference...?
OK. In theory, it takes the same amount of energy to travel ten miles in 20 minutes as it does to travel ten miles in one hour. But I don't think that was your question. I don't think it's possible one of us to know if YOU will receive any more training benefit from one or the other. You would probably get different BENEFITS from each but which would be BETTER??? Who knows???0 -
dennisn wrote:Hunterg46 wrote:Yes it does last 3 times longer, but im only doing the same difference...?
OK. In theory, it takes the same amount of energy to travel ten miles in 20 minutes as it does to travel ten miles in one hour. But I don't think that was your question. I don't think it's possible one of us to know if YOU will receive any more training benefit from one or the other. You would probably get different BENEFITS from each but which would be BETTER??? Who knows???
Is that right?0 -
drag increases to the 2nd power of speed.
Double your speed and drag goes up 4 times.0 -
chrisw12 wrote:neil² wrote:drag increases to the 2nd power of speed.
Double your speed and drag goes up 4 times.
Is that right (on rollers like the op asked)?
This is fun isn't it.
I was about to say I didn't figure drag. More of a "It takes X amount of energy to climb a stair whether it takes you one minute or two" :oops: :oops:0 -
It takes more energy to do run than walk the same distance, surely.Smarter than the average bear.0
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Basically, the amount of work you have to do to go twice as fast is always more than twice as much.
For example air resistance: if you go twice as fast, the work rate is 8 times greater - true you finish in half the time, but the total energy used is still 4x greater.
Cycling at different speeds uses the same mechanism, obviously, but walking and running are quite different movements - I don't have any specialist knowledge here, but I would guess that running is less efficient than walking as you're constantly using energy to (effectively) jump up in the air?
Have a look at wikipedia on aerobic & anaerobic exercise too, as it clearly makes a difference once you start to go over the aerobic threshold. I think this answers most of the questions on training benefits too.
Finally, go out and cycle 5 miles at 10mph, then do it again at 25, and you tell me which you think did more for you! Of course subjective feelings of exhaustion do not necessarily reflect the actual training done, but I think there's a bit of a clue there.0 -
Now.... pulling that PhD thesis off the shelf.... there it is... p35 "running displays a near constant metabolic cost, in relation to the distance travelled, for increased running speeds. These observations are supported by Harris et al. (2003) who report no change in mean metabolic task cost...with running speed." I can't see why it would be different for cycling on rollers.
If you are trying to burn calories then I think that you might be right; if you are training to optimise muscle then the normal target zones apply.0 -
neil² wrote:Now.... pulling that PhD thesis off the shelf.... there it is... p35 "running displays a near constant metabolic cost, in relation to the distance travelled, for increased running speeds. These observations are supported by Harris et al. (2003) who report no change in mean metabolic task cost...with running speed." I can't see why it would be different for cycling on rollers.
If you are trying to burn calories then I think that you might be right; if you are training to optimise muscle then the normal target zones apply.
Would you like to put that in plain English, it`s a little confusing?Smarter than the average bear.0 -
Rugby legend Gavin Hastings used to have an advert on the telly that said walking a mile burns off the same energy as running a mile...0
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antfly wrote:neil² wrote:Now.... pulling that PhD thesis off the shelf.... there it is... p35 "running displays a near constant metabolic cost, in relation to the distance travelled, for increased running speeds. These observations are supported by Harris et al. (2003) who report no change in mean metabolic task cost...with running speed." I can't see why it would be different for cycling on rollers.
If you are trying to burn calories then I think that you might be right; if you are training to optimise muscle then the normal target zones apply.
Would you like to put that in plain English, it`s a little confusing?
Yes - sorry...
Metabolic cost of exercise = the amount of energy needed; e.g. calories burned. This is primarily related to running distance and is not related to running speed - just under 1 kcal/kg/km is typical for athletes - if you weigh 70 kg, you will need just under 70 kcal to run 1 km, irresepctive of speed. Sorry - don't know figures for cycling, or even if this is true for cycling on rollers.
The issue of zones is that training is not just about burning calories, but improving strength, power etc.0 -
Power= work done divided by time.
Work done is a measure of energy expended and to move a mass through a fixed distance always requires the same amount amount of work to be done (or energy to be expended. The power you need to apply to the mass to move it depends on how quickly you move it through the distance.
So the quicker you move it the more power you ned to expend on the job in hand. That;s why it's harder to run a mile a mile than it is to walk a mile, you need to expend more power, the total work you do is the same you just do it quicker running.
This, of course, ignores friction and drag.0 -
Irrespective of the total amount of work done to cover the same distance, riding rollers at 30mph or 10mph will use different energy systems within your muscle cells (or at least the same systems but in different proportions).
So the short answer is yes, you'll be training different aspects of your physiology.0 -
owenlars wrote:Power= work done divided by time.
Work done is a measure of energy expended and to move a mass through a fixed distance always requires the same amount amount of work to be done (or energy to be expended. The power you need to apply to the mass to move it depends on how quickly you move it through the distance.
So the quicker you move it the more power you ned to expend on the job in hand. That;s why it's harder to run a mile a mile than it is to walk a mile, you need to expend more power, the total work you do is the same you just do it quicker running.
This, of course, ignores friction and drag.
Thanks for that post. I knew that there was something in the back of my old brain that
said "power=........". So, you're basically saying(ingnoring friction, and drag) that riding a bicycle 10 miles takes the same amount of power no matter how fast, or slow, you go????. Still takes the same total effort??? You've done no more work either way????0 -
It requires the same energy expenditure. To go faster requires a higher power output but since you're then doing it for a shorter time, the work done is the same.0
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neil² wrote:Now.... pulling that PhD thesis off the shelf.... there it is... p35 "running displays a near constant metabolic cost, in relation to the distance travelled, for increased running speeds. These observations are supported by Harris et al. (2003) who report no change in mean metabolic task cost...with running speed." I can't see why it would be different for cycling on rollers.
If you are trying to burn calories then I think that you might be right; if you are training to optimise muscle then the normal target zones apply.
I'm no exercise expert and as you said running may be different from cycling but that statement seems to directly contradict Dr Coogan's Normalised power algortithm and training stress score. :?0 -
neil² wrote:Now.... pulling that PhD thesis off the shelf.... there it is... p35 "running displays a near constant metabolic cost, in relation to the distance travelled, for increased running speeds. These observations are supported by Harris et al. (2003) who report no change in mean metabolic task cost...with running speed." I can't see why it would be different for cycling on rollers.
This is interesting. How is mean metabolic task cost defined? I only ask because I struggle to see how the statement could be true in practice. I see the logic behind it if all other factors were equal, but what about increased energy demands to manage your thermoregulatory system for instance? You burn energy by sweating... does the same amount of energy get used regulating your temperature at a slower speed (as although you generate a smaller quantum of heat at any one time you are also generating for longer)? Or is there some kind of exponential relationship?0 -
On a dead flat good smooth road, no wind, 75kg bike + rider with CdA of 0.3m^2 to cover 10-miles:
@ 5m/s (18km/h / 11.2 mph) ~= 120kJ mechanical energy (at rear wheel)
@ 10m/s (36 km/h / 21.3 mph) ~= 340kJ
this is because power - speed on a bicycle is a cubic relationship.
As roads get hillier, the gap would narrow as hill climbing is more directly proportional to power and mass.0
