PM3 calories

[tohams]

My understanding is that calories burned depends on the rowers weight. Since I didn't enter my weight into the PM3, what weight is it assumed for? And does anyone know the conversion formula?

Thanks!

[whp4]

My understanding is that calories burned depends on the rowers weight. Since I didn't enter my weight into the PM3, what weight is it assumed for? And does anyone know the conversion formula?

Thanks!

The assumed weight is 175 lbs (80 kg) and a base rate of 300 cal/hr to move through the rowing motion at 30 strokes/min. Then cal/hr is gotten by the formula (watts) x 4 x 0.8604 + 300 - you can get watts from the PM3. I've never seen a weight adjustment formula published, and don't think there's any real need for it - it's all just an estimate in any case, even if you weigh exactly the assumed weight. Mostly, I would use it as an aid for comparing the effects of two very different workouts - how long does a slow workout have to be to burn X calories compared to a shorter, faster paced one, for example. In such a comparison, I think the sensitivity to body weight largely drops out.

Bill

[Citroen]

I was talking to one of the instructors at the gym (who understands the rowing machine). He said, as far as he was concerned, the main and only value of the calories display was that you could get the newbie ladies to row at close to one calorie indicated per stroke.

They'd understand that (even though in the real world it was meaningless). It would also give them a chance to compare workouts (as stated above).

The maths / physics behind rowing is described in glorious detail at: http://www-atm.physics.ox.ac.uk/rowing/ ... meter.html

You get a more sensible display using watts or pace. I always have the display set to show average pace.

[Birkyboy]

I am NOT far off the 'example' weight used for Kcals.

However.. the readings on my HRM are always much less as they reflect not only the pace.. but how hard I am working against that pace.. My Average HR.

The difference would be as much as 100/150 kcals on a h/m.

[Citroen]

I am NOT far off the 'example' weight used for Kcals.

However.. the readings on my HRM are always much less as they reflect not only the pace.. but how hard I am working against that pace.. My Average HR.

The difference would be as much as 100/150 kcals on a h/m.

Even your watch will be adrift of the calories you are actually using. Although, assuming it has your age, weight an height then it's maths may be a little more accurate. If the numbers from the PM3 differ wildly from the numbers in your HRM watch, trust the watch to be more likely to be more accurate.

[whp4]

I am NOT far off the 'example' weight used for Kcals.

However.. the readings on my HRM are always much less as they reflect not only the pace.. but how hard I am working against that pace.. My Average HR.

The difference would be as much as 100/150 kcals on a h/m.

In my opinion, trying to estimate caloric expenditure from HR is even more of a fool's errand. At least the PM2/PM3 knows how much work was done on the flywheel - a gadget trying to estimate caloric expenditure from HR doesn't even know that. My HR for a 5k row can vary widely (for the same pace) depending on how tired I am and what sort of fitness I have at the moment; any estimation of how many calories I burn based only on that is going to be pure fantasy. Of course, the saving grace for the manufacturers of such gadgets is that it is almost impossible for a typical purchaser to check the results provided for accuracy!

Bill

[BobD]

I don't care about the work done at the C2 fan, I want to know what effort my heart is putting out.

Whether tired or not, there is a very good track of effort with my Polar HRM. If I run easy and keep my HR down I do less work and the HRM shows it. If I run hard with a high HR the HRM shows this too.

My HRM measurements come in at just about what the various studies show for a calorie burn rate per hour for running for instance. So I trust the HRM calories count.

[Ducatista]

I was talking to one of the instructors at the gym (who understands the rowing machine). He said, as far as he was concerned, the main and only value of the calories display was that you could get the newbie ladies to row at close to one calorie indicated per stroke.

Enthusiasts do tend to look down their noses at the calorie readout, don't they? Whatever.

To any newbie reading this: there is no shame in setting your display on calories. The readout may be of questionable value in determining actual caloric expenditure, but it has the advantage of showing much finer increments than time/500M. I switch to calories every once in a while just to see how long I can maintain the same reading. Harder than it sounds, if you're used to reading meters. And for long, easy, steady-state rows (junk meters, as I fondly think of them), I particularly like to see how long I can maintain 666. Childish but fun, and if it keeps my ass on the seat, it's all good.

[Citroen]

I switch to calories every once in a while just to see how long I can maintain the same reading. Harder than it sounds, if you're used to reading meters. And for long, easy, steady-state rows (junk meters, as I fondly think of them), I particularly like to see how long I can maintain 666. Childish but fun, and if it keeps my ass on the seat, it's all good.

If I'm interested in the calories I can get that data from my logcard. My main focus is on pace. Occasionally I'll look at the watts (again on my logcard).

[Ducatista]

If I'm interested in the calories I can get that data from my logcard. My main focus is on pace. Occasionally I'll look at the watts (again on my logcard).

OK, but on my PM2, your pace (let's say 2:00/500M) can be broken down into 120 increments. If I've chosen calories, my pace (let's say 900 cal/hour; not sure if that's 2:00-ish, but it doesn't really matter) can be broken down into 900 increments on the monitor. A much finer scale, enabling me to see finer variations in my pace. Both measurements are constructs—after a 10K-meter workout you're not 10K meters from your starting point, obviously. Your preferred readout correlates to on-the-water measurements and is the standard for competition. My occasional preference, calories, gives me finer feedback.

It's not a good-vs.-bad choice, it's representation vs. resolution. But the gym instructor will condescend to only one of us, go figure. (My quibble is with him, not with you, in case you couldn't tell.)

[whp4]

If I'm interested in the calories I can get that data from my logcard. My main focus is on pace. Occasionally I'll look at the watts (again on my logcard).

OK, but on my PM2, your pace (let's say 2:00/500M) can be broken down into 120 increments. If I've chosen calories, my pace (let's say 900 cal/hour; not sure if that's 2:00-ish, but it doesn't really matter) can be broken down into 900 increments on the monitor. A much finer scale, enabling me to see finer variations in my pace. Both measurements are constructs—after a 10K-meter workout you're not 10K meters from your starting point, obviously. Your preferred readout correlates to on-the-water measurements and is the standard for competition. My occasional preference, calories, gives me finer feedback.

It's not a good-vs.-bad choice, it's representation vs. resolution. But the gym instructor will condescend to only one of us, go figure. (My quibble is with him, not with you, in case you couldn't tell.)

Yep, if you want to get the finest resolution on the PM2 or PM3, the calories display will give it to you. I use it for that purpose myself sometimes (trying to row as steady a pace as possible). Of course, if you're really a number/measurement fiend, Ergmonitor from http://www.ps-sport.net goes far beyond what the stock monitors provide.

I dislike the "calories burned" numbers (or at least labeling them as such) on exercise equipment because in my experience, the people who cling to such things are the ones likely to be mislead and give up when they see they've burned 7000 calories and the scale tells them they haven't lost the corresponding 2 pounds. Never mind that they are feeling and maybe looking better...

Bill

[Ben Rea]

i think the calories part should be taken off for the PM4. If it assumes your weight then why even use it. usless tool.

[Ducatista]

Maybe C2 should rename the readout "Tiny Increments Per Hour," or "Fine Tuning," or "Relax, Some People Find The Sensitivity Of This Pace Scale Useful And You Don't Have To Use It If You Don't Want To."

[Sasha]

i think the calories part should be taken off for the PM4. If it assumes your weight then why even use it. usless tool.

Useless for you. Not for everybody. And I think Ducatista nailed the name with "Relax, Some People Find The Sensitivity Of This Pace Scale Useful And You Don't Have To Use It If You Don't Want To."

[lowwall]

The Watts setting is the only "real" measure of output on the rower (or, properly speaking, ergometer). Anyone who disdains calories but accepts meters or 500 splits as gospel is just proving their ignorance.

FWIW, assuming your erg is nearly horizontal, the low friction rollers essentially remove weight from the dynamic picture, so any adjustment for weight would be minor and probably lost in the noise of the other estimates used in the calorie equation.

This may seem counterintuitive, but think of the difference between climbing stairs and doing leg presses on a machine (where your body is fixed in position and the legs push on a plate attached to weights). In the former case, every step requires you to lift your body weight, so the work expended is directly proportional to your weight (well almost, you have to count in the base metabolic rate which will normally be greater for the larger person). In the latter, only the weight moves, so the caloric expenditure is equal no matter what the size of the person pushing it.

How do we get from the leg press to erging? Imagine an erg where the chain was connected via a couple of pulleys to a pile of weights instead of a flywheel. Now, lay all the way back, keep your arms locked and straighten you legs. You've just done a leg press, and the amount of weight at the end of the chain will determine how many calories you've just expended.

The only difference between hooking a flywheel and a pile of weights to the end of the chain is the former allows you to vary resistance merely by changing how fast you pull. That's a lot more convenient than getting up to add or subtract weights all the time.