Difference between damper settings and calories burned

[vsaksena]

I want to understand the following scenario:
I erged 11000 in 60 min with a damper setting of 3 and the monitor shows the calories burned were 575. Then I erged 11000 in 60 min with a damper setting of 6 and the monitor shows the calories burned were 575. I believe I put in lot more efforts when the damper setting was at 6. Is there any explanation to this scenario?

[jamesg]

Yes, as you can see it's far better to row at low drag. When you lengthen your stroke you'll be able to do far more work too.

[TabbRows]

James is correct on damper setting.

The damper setting only adjusts the resisitance to the fly wheel on the erg and doesn't have any real effect of caloric expenditure. The higher the setting the higher the resistance (look up drag factor). Higher drag often means is that you have to engage more upper body muscles (arms and back) early in the stroke cycle inorder to pull the flywheel. Feels harder after a while because these muscles are weaker than your legs. But it doens't mean you expend more calories doing so.

Regardless of your damper setting or stroke rate you were only rowing at a 2:43.64 pace and thus only producing 79.87 watts of power. Under the calorie calculations used by C2 that equates to 575 calories (which is equivalent to running or walking at just over a 10 minute/mile pace.

Your actual calaories burned will be slightly different depending on your weight and basal metabolic rate (how many calories you'd burn on a daily basis just existing plus the level of activity you do). There are a number of BMR calculators around that can help you determine this. (Note, not BMI calculators which only tell fat people they're fat and provide no real basis for judging level of fitness). The basic calorie expended formula is BMR times watts generated times duration of exercise.

So focus more on technique and generating power through your legs and less on ways to manipulate calorie counting. The pounds will come off over time and your erging will improve too. At your present pace, you'll only burn off a pound every 66,000 meters or so, assuming you ate no more than it takes for you to maintain your current weight.

[Citroen]

I erged 11000 in 60 min with a damper setting of 3 and the monitor shows the calories burned were 575. Then I erged 11000 in 60 min with a damper setting of 6 and the monitor shows the calories burned were 575.

Yep, that's how the curve fitting maths in the PM2/PM3/PM4 monitors work. They calculate (k)calories based on you being 80Kg and using 300 (k)cals just to go up and down the rail doing no work.

Use a HRM watch and software (which will use your vital stats) to get a more accurate estimate of the calorific value of your rowing sessions.

[hjs]

I want to understand the following scenario:
I erged 11000 in 60 min with a damper setting of 3 and the monitor shows the calories burned were 575. Then I erged 11000 in 60 min with a damper setting of 6 and the monitor shows the calories burned were 575. I believe I put in lot more efforts when the damper setting was at 6. Is there any explanation to this scenario?

The damper setting has nothing to do with the amount of work you do. The pace or watts are what matter.
The lower the pace xxx/500m or the higher the watts the more energy you use.

[djh]

The lower the pace xxx/500m or the higher the watts the more energy you use.

Just a slightly pedantic clarification: The higher the watts the faster the rate of energy you use. Multiply watts (a measure of power) by time and you get watt-hours (a measure of energy). Converting from watt-hours to ergs or to calories is a simple matter of scaling.

[Bob S.]

Converting from watt-hours to ergs or to calories is a simple matter of scaling.

Normally, that is true, but it doesn't work for the calories values shown on the indoor rower monitors, since C2 has some extra calories added in to account for energy expended that has not gone into spinning the fly wheel (basal metabolism plus acceleration and deceleration of your own mass on the slide). I suppose that this is useful for those who are working on weight problems.

Bob S.

[vsaksena]

So, last time, I put the damper at 1 and was able row upto 12000 in 60 min. At the end of it, I was able to continue for further distance while in case of setting the damper at 6, I was totally out of energy. Should I continue to set the damper at 1 and continue with the rowing or should I bring it back to 3 and try to improve the timing?

[djh]

Well, if you insist on staying on topic, the answer is that the amount of energy you expend is the same, even though I don't deny that your body may work more efficiently with certain damper settings than at others. Similarly, climbing a hill at a set speed theoretically requires the same amount of energy regardless of how big your steps are. Nobody regards shifting a bicycle to a lower gear as "cheating", and you should feel free to set the damper to whatever level gives you the best workout. For me, a damper setting of 1 (or is the lowest 0? the scale is a bit ambiguous) doesn't provide enough resistance at the catch. But a setting of 11 (10?) isn't good for me either. I like it set near 4. But I wouldn't tell you at what gear to ride a bicycle.

If our bodies were perfectly efficient at transforming chemicals into mechanical energy, the damper setting probably wouldn't matter. But that's clearly not the case.

[jamesg]

VS, around damper three is usually ok, Drag Factor 120-130. Lower is fine, but you'd need to be quick to catch the flywheel.

What you have experienced is the effect of adapting the load to our muscular capabilities, similar to the idea of Impedance; to get maximum power transfer, the impedance of a source (an amplifier for example) and of the load (loudspeakers) must be the same.

In mechanical terms, if the impedance is very high, as in trying to push a wall, no work is done because the wall doesn't move, even tho we may get very tired. If on the other hand we try to lift a feather say a 100 times in 3 minutes, from floor to ceiling, we'll also get very tired, but have done almost no work on the feather. The strategy for delivering most work, as on the erg, is to act on a weight that loads us but also allows quick and repeated movement to full extension.

On the erg there's something more specific, apart from the fact that it only sees the mechanical work we input: to develop max work, we need to use our legs simply because the muscles there are large and can do it. Only a long stroke does this, and lowish drag makes it possible by allowing a speedy pull.

This is typical of the rowing action and leads to all sorts of results: when we use all our muscle together, as in rowing, we can easily overload our CV system. So we have to rate low if we want to carry on for more than 20 seconds while still using a decent stroke.

[icomefrombirmingham]

Sorry, but I'm still confused.

I realise that I have a mental block on this topic of damper settings/drag factor so thanks vsaksena for asking this question again.

So...I think we would all agree that if we erged two 10ks at a pace of 2:00/500m and a rate of 24SPM; one of them (row 1) on a damper setting of 0 and the other (row 2) on a damper setting of 10 we'd all feel more tired after row 2?

If that is the case, then the only reason for the feeling of "extra" tiredness
is that on row 2 we have used more (smaller/weaker) upper body (and perhaps core) muscles than bigger/more powerful leg muscles and that makes us FEEL more tired, even though we haven't used any more energy. That is, the higher damper setting/drag factor has "forced" us to use more upper body musculature....and our body has compensated (if we are rowing perfectly, at the given pace and rate in both rows) by using the legs less?

Is this correct?
Brent

[jcm]

I must say that the drag factor is confusing me too. If we take the term drag strictly, I don't see how higher drag settings require the same amount of energy as lower ones. Drag is defined as :
"the phenomenon of resistance to motion through a fluid"
The higher the resistance, the higher the energy required to move for the same distance. As an example, on the water, the higher the resistance to motion (air density, aerodynamic of the shell), the higher the number of watts required to move the boat at a given speed. This has nothing to do with which muscles are used :
drag force = 1/2 * air_density * coefficient of drag * frontal area * speed^2
Watts = drag force * speed

This seems to align with how C2 describes the drag setting (heavier boat).

I don't claim to understand physics, but this is confusing.

JC

[Citroen]

So...I think we would all agree that if we erged two 10ks at a pace of 2:00/500m and a rate of 24SPM; one of them (row 1) on a damper setting of 0 and the other (row 2) on a damper setting of 10 we'd all feel more tired after row 2?

But, on damper 2 more air is going through the fan so the damping is higher and the flywheel slows more quickly. The PM2/3/4 all measure that deceleration and will compensate for the higher rate of deceleration by giving you a different pace.

It uses the same energy input to pull a 2:00 split on damper 10 that it does on damper 0 but your technique will differ.

The energy input to row 2:00 splits doesn't change due to damping, length of stroke or stroke rate.

http://home.hccnet.nl/m.holst/ErgoDisp.html
http://www.atm.ox.ac.uk/rowing/physics/ergometer.html

[icomefrombirmingham]

Sorry Citroen,

As I said, I have a mental block on this stuff, and I am fully prepared to accept (which is different to understand ) the physics if it tells me that no more energy input is required to pull a 2:00 pace nomatter my stroke length, stroke rate or damper setting.

In your first paragraph, are you saying that one can't row those two 10ks at "0" and "10" damper settings at the same stroke rate and pace? Or that one can, but each will FEEL very different?

I KNOW that I FEEL a lot more knackered after rowing my 10k in 40 minutes (2.00/500) on a damper setting of 10 than on a setting of 0...( I think nomatter what the SPM is?).

So, is this FEELING due only to the difference in technique that I will have had to employ?
Is it the physics of the erg that "forces me" to change my technique?
And is the difference in technique primarily the re-allocation of some of the "load" from the legs (which are more efficient for this kind of work) to the upper body (which is less efficient)?

p.s. I'm not trying to be obtuse, I really just don't get it

[Citroen]

In your first paragraph, are you saying that one can't row those two 10ks at "0" and "10" damper settings at the same stroke rate and pace? Or that one can, but each will FEEL very different?

I can't do that. I row everything on drag 120-125 as that suits me and my technique doesn't improve if I push the drag higher. But I'm not a typical rower at 5'7" and 165lbs.

But, theoretically it is possible to do that. The main difference is the way you'll supply energy into the system. With low damper (drag factor 90) the fan keeps spinning between strokes, so it takes less to accelerate it back to full speed (but the monitor compensates for the higher angular velocity when the next stroke starts). With high drag (drag factor over 200) it slows considerably quicker and you have to supply the energy to spin it back up in a different way.

So the physics says same energy goes into the system. The reality says it will feel easier/more comfortable to do it with a lower drag.