Home Exercise Machines

Beady · 29th June 2006, 08:57 AM

I guess this belongs here.

I've got an exercise bicycle that has one of those electronic consoles that gives you various statistics regarding your workout (distance traveled, calories burned, etc). Does anyone know how accurate these things are? I'm most interested in the calories/carbs burned in a session.

Pangea · 29th June 2006, 09:05 AM

Machines that allow you to enter your weight are usually more accurate than ones that don't. The calories burned are based on an average weight (I think I read somewhere that the average weight used is around 150-175 pounds), so unless you fall somewhere in that range, it's not really accurate.
I know there are websites (fitday.com is one) that allow you to enter your weight, general fitness level and activity and it calculates your calories for you.

El Greco · 29th June 2006, 09:24 AM

There are also other machines which not only allow you to enter your weight but also receive your HR from a chest belt transmitter you wear; these are supposed to be sufficiently accurate (there are some studies from the Polar pulse meters that show the calculations are rather accurate for practical purposes). The most common ones that don't allow any kind of user input are of course not accurate, but can still be useful as a relative indication of energy expenditure.

Jekyll · 29th June 2006, 09:37 AM

I've always been somewhat sceptical about these things.

It's easy to see how you could measure the external work done in exercise, but I doesn't see how they can account for all of the internal work, the adjustments your body has to make to itself to get the work done(how hard the heart has to pump, how heavily you breath etc.) and work done in recovery (what your body has to do to stop itself from hurting).

What makes it even harder to make an estimate is that these things don't just vary from person to person, but with practice as well. As you become accustomed to the exercise, these things get easier.

If someone could fill me in on how these estimates work, I'd appreciate it.

Meffy · 29th June 2006, 09:44 AM

In this case I'd say it's safest to count results, not inputs. Weight loss, muscle strength, whatever your goal is -- progress toward that is something you can measure more reliably than the estimates you'll get in a consumer exercise gizzy.

Lisa Simpson · 29th June 2006, 09:57 AM

The most accurate way is probably going to be a heart rate monitor, because it can actually measure how hard your heart is working. Comparing my Polar heart monitor to the treadmill at the gym, the numbers are nearly identical. The numbers on the elliptical machine are 30% more (for calories burned) than my HRM says. And I looked at the fitday site mentioned above. It was 50% less than my HRM says.

Pangea · 29th June 2006, 09:59 AM

Originally Posted by Lisa Simpson

And I looked at the fitday site mentioned above. It was 50% less than my HRM says.

Well, nevermind, then!

Bikewer · 29th June 2006, 10:07 AM

Heartrate and respiratory activity are probably the best measures of output. My wife had a stationary bike with a lot of this stuff on the console; I found the "speedometer" function to be wildy inaccurate.
Most cyclocomputers have some sort of calories-expended-per-workout function; I can't imagine that these things are very accurate. Just too many variables to input

Meffy · 29th June 2006, 10:15 AM

I've seen metabolic measurements being taken in TV shows. As Bikewer mentions, respiration is a big part of it. The subject always seems to be wearing a mouthpiece/nose clip or a mask while tests are under way. [edit] ... connected to a CO₂ measuring device, I'd think.

Lisa Simpson · 29th June 2006, 10:30 AM

Originally Posted by Meffy

I've seen metabolic measurements being taken in TV shows. As Bikewer mentions, respiration is a big part of it. The subject always seems to be wearing a mouthpiece/nose clip or a mask while tests are under way. [edit] ... connected to a CO₂ measuring device, I'd think.

If you are an athlete, that's a good measurement. For the home exerciser, a HRM should be accurate enough.

Overman · 29th June 2006, 11:04 AM

Home exercise machines are also great for hanging dry cleaning on!

Meffy · 29th June 2006, 11:09 AM

@Lisa: Long as there's an accurate way to map individual heart rates to calorie consumption, it ought to work.

Lisa Simpson · 29th June 2006, 11:24 AM

Originally Posted by Meffy

@Lisa: Long as there's an accurate way to map individual heart rates to calorie consumption, it ought to work.

My HRM asked for my age, height, weight and sex. Even if the calorie calculations are not 100% exact for me specifically, I'm sure it's close enough based on other women my age, height, and weight.

Meffy · 29th June 2006, 11:27 AM

My home exercise machine comes with no displays, no keyboards, darn it all. But it can throw up a marvelous rooster-tail of tilled earth! =^_^=

l0rca · 29th June 2006, 02:21 PM

There's probably scales on the internet where you can look at your height, height, and measure your heatbeat to see what you're burning.

29th June 2006, 08:57 AM	#1
Beady Philosopher Join Date: Dec 2003 Location: 44:57:19N, 73:16:18W Posts: 5,490	Home Exercise Machines I guess this belongs here. I've got an exercise bicycle that has one of those electronic consoles that gives you various statistics regarding your workout (distance traveled, calories burned, etc). Does anyone know how accurate these things are? I'm most interested in the calories/carbs burned in a session.
	__________________ I tolerate with utmost latitude the right of others to differ with me in opinion without imputing to them criminality. I know too well all the weaknesses and uncertainty of human reason to wonder at its different results. -- Thomas Jefferson

29th June 2006, 09:24 AM	#3
El Greco Summer worshipper Join Date: Nov 2003 Location: Παρά θιν'αλός Posts: 14,268	There are also other machines which not only allow you to enter your weight but also receive your HR from a chest belt transmitter you wear; these are supposed to be sufficiently accurate (there are some studies from the Polar pulse meters that show the calculations are rather accurate for practical purposes). The most common ones that don't allow any kind of user input are of course not accurate, but can still be useful as a relative indication of energy expenditure.
	__________________ "Robbing a bank is no crime compared to owning one" - Bertolt Brecht "Let it go and come to bed already, El Greco" - MoeFaux

29th June 2006, 09:37 AM	#4
Jekyll Graduate Poster Join Date: Apr 2005 Location: The other other place Posts: 1,589	I've always been somewhat sceptical about these things. It's easy to see how you could measure the external work done in exercise, but I doesn't see how they can account for all of the internal work, the adjustments your body has to make to itself to get the work done(how hard the heart has to pump, how heavily you breath etc.) and work done in recovery (what your body has to do to stop itself from hurting). What makes it even harder to make an estimate is that these things don't just vary from person to person, but with practice as well. As you become accustomed to the exercise, these things get easier. If someone could fill me in on how these estimates work, I'd appreciate it.
	__________________ And I looked. And behold a green horse, and his name that sat on him was death. ~Tyndale New Testament

29th June 2006, 09:57 AM	#6
Lisa Simpson THE Lisa Simpson Administrator Join Date: Mar 2004 Location: 123 Fake Street Posts: 20,054	The most accurate way is probably going to be a heart rate monitor, because it can actually measure how hard your heart is working. Comparing my Polar heart monitor to the treadmill at the gym, the numbers are nearly identical. The numbers on the elliptical machine are 30% more (for calories burned) than my HRM says. And I looked at the fitday site mentioned above. It was 50% less than my HRM says.
	__________________ That's what the Internet does -- you get a free bonus prize of Stupid Lies with every box of Delicious Facts. - cracked.com Facts are satanic litter on the heavenly highway to blind faith! - Betty Bowers

29th June 2006, 10:30 AM	#10
Lisa Simpson THE Lisa Simpson Administrator Join Date: Mar 2004 Location: 123 Fake Street Posts: 20,054	Originally Posted by Meffy I've seen metabolic measurements being taken in TV shows. As Bikewer mentions, respiration is a big part of it. The subject always seems to be wearing a mouthpiece/nose clip or a mask while tests are under way. [edit] ... connected to a CO₂ measuring device, I'd think. If you are an athlete, that's a good measurement. For the home exerciser, a HRM should be accurate enough.
	__________________ That's what the Internet does -- you get a free bonus prize of Stupid Lies with every box of Delicious Facts. - cracked.com Facts are satanic litter on the heavenly highway to blind faith! - Betty Bowers

29th June 2006, 09:05 AM	#2
Pangea New Blood Join Date: Apr 2006 Location: Wyoming Posts: 20	Machines that allow you to enter your weight are usually more accurate than ones that don't. The calories burned are based on an average weight (I think I read somewhere that the average weight used is around 150-175 pounds), so unless you fall somewhere in that range, it's not really accurate. I know there are websites (fitday.com is one) that allow you to enter your weight, general fitness level and activity and it calculates your calories for you.

29th June 2006, 09:44 AM	#5
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	In this case I'd say it's safest to count results, not inputs. Weight loss, muscle strength, whatever your goal is -- progress toward that is something you can measure more reliably than the estimates you'll get in a consumer exercise gizzy.

29th June 2006, 09:59 AM	#7
Pangea New Blood Join Date: Apr 2006 Location: Wyoming Posts: 20	Originally Posted by Lisa Simpson And I looked at the fitday site mentioned above. It was 50% less than my HRM says. Well, nevermind, then!

29th June 2006, 10:07 AM	#8
Bikewer Philosopher Join Date: Sep 2003 Location: St. Louis, Mo. Posts: 9,522	Heartrate and respiratory activity are probably the best measures of output. My wife had a stationary bike with a lot of this stuff on the console; I found the "speedometer" function to be wildy inaccurate. Most cyclocomputers have some sort of calories-expended-per-workout function; I can't imagine that these things are very accurate. Just too many variables to input

29th June 2006, 10:15 AM	#9
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	I've seen metabolic measurements being taken in TV shows. As Bikewer mentions, respiration is a big part of it. The subject always seems to be wearing a mouthpiece/nose clip or a mask while tests are under way. [edit] ... connected to a CO₂ measuring device, I'd think.

29th June 2006, 11:04 AM	#11
Overman Master Poster Join Date: Feb 2006 Location: Chicagoland Posts: 2,630	Home exercise machines are also great for hanging dry cleaning on!
	__________________ Our new album 'The Future is Gonna be Great' on iTunes!!! Our old 'The Evolution EP' still on iTunes

29th June 2006, 11:09 AM	#12
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	@Lisa: Long as there's an accurate way to map individual heart rates to calorie consumption, it ought to work.

29th June 2006, 11:24 AM	#13
Lisa Simpson THE Lisa Simpson Administrator Join Date: Mar 2004 Location: 123 Fake Street Posts: 20,054	Originally Posted by Meffy @Lisa: Long as there's an accurate way to map individual heart rates to calorie consumption, it ought to work. My HRM asked for my age, height, weight and sex. Even if the calorie calculations are not 100% exact for me specifically, I'm sure it's close enough based on other women my age, height, and weight.
	__________________ That's what the Internet does -- you get a free bonus prize of Stupid Lies with every box of Delicious Facts. - cracked.com Facts are satanic litter on the heavenly highway to blind faith! - Betty Bowers

29th June 2006, 11:27 AM	#14
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	My home exercise machine comes with no displays, no keyboards, darn it all. But it can throw up a marvelous rooster-tail of tilled earth! =^_^=

29th June 2006, 02:21 PM	#15
l0rca I know so much karate Join Date: Aug 2005 Posts: 1,100	There's probably scales on the internet where you can look at your height, height, and measure your heatbeat to see what you're burning.