How much is it? It helped some marathon runners who were actually not eating enough and overtraining.
However, it's only as good as the ability of the person administrating it.
I have had it done many times....I actually administer the test, so I do it to myself! Erinzz- it's more than a guess. The test is measuring O2 intake verses CO2 output. This ratio (called a respiratory quotient) can determine exactly how many calories a person is burning (along with total volume of air) as well as what type of calories being burned. it makes sense if you think about it. when carbs are being burned they use less O2 than fat (thus an RQ of 1). If you want the chemical equation let me know. What teh test is trying to determine is where a person is last efficient at burning fat (defined as being able to burn at least 50% calories as fat calories). The theory is that a person should then train at that intensity in order to improve fat burning capabilities.
I am actually doing my thesis on thsi topic. New Leaf's idea makes sense...sort of... but research also shows that a more fit person will burn more fat calories than an unfit person. So it seems like you should train to become as fit as possible as quickly as possible. The trick of course is avoiding overtraining, burning out, etc. If you are new to exercise working at a lower intensity (like new leaf would suggest) makes sense. But it doesn't work for everyone. I actaully love the test though. measuring improvements in cardiovascualr functioning is just as important as measuing improvement in body composition.
Hope that helps
test runs from $100-150. depending on where you go to get it done.
go to www.newleaffitness.com and enter zip code to find closest provider.
in terms of measuring RMR, it's right on the money. standard deviation can be as low as 25-50 calories
And could you post the equations used to obtain the result? I'm interested!
i checked out the website. i don't know if it's more glitz & glam than science, but it's definitely intriguing. i'd love to know how many calories i burn and how much i should eat and if i'm training right.
i took down the phone numbers for two locations that i'm close to on a regular basis. i'll think about it, but i may just give a call and see about getting a test done. if i could find out an accurate number for average number of calories burned in a typical day, it'd be worth millions for me. i exercise a lot and just have no clue about how much i'm burning. also, though, since i spend so much time at the gym, if i could find out how to optimize my time (burning as many calories as possible, but as little muscle as possible) that would be fantastic.
i'd never heard of newleaf before. thanks for the background, 9chrissie.
Accuracy is measured against a closed circuit spirometer. So if a person was to be breathing into a bag, you could actually analyze the data (run it through a CO2 and O2 analyzer). New leaf works off of an open circuit spirometer, which is analyzing air as it is being exhaled/inhaled without collecting it in a bag.
C6H12O2 (carb) + 6 O2= 6 CO2 + H20. So the ratio of oxygen needed to burn carbohydrate and the resulting CO2 output is 1 (6:6). That's how I can tell if you are working out and your RQ is 1, you are burning zero fat. That doesn't help any of us in the real world however, so we find corresponding heart rates.
Same for Fat:
C16H32O2 +23 O2 = 16 CO2 + 16 H2O
This would be a ration of about .7. So if you were exercising I would find the heart rate that corresponds with this intensity and have you train there for fat burning. NOT ALWAYS HOWEVER!!! Each training zone has a specific purpose, you need to do some of all, but in the right ratios. Only way to know is to get tested.
This is not glitz and glam!!! This is science. I will say that there is nothing special about new leaf per se, any metabolic cart will do, so long as a RQ is being measured....
Whew! College exercise physiology class in a couple paragraphs...I hope this makes sense!
ps- this test would also determine calories being burned in each zone (in addition to ratio of fat vs. carbs.) This is WAY BETTER than a machine reading!!! The machine assumes you are male and 180 pounds. They can be way off.
C6H12O2 + 6O2 = 6 CO2 + H2O
right hand side has:
6 C's (ok)
13 O's (??)
2 H's (??)
Similarly with the second equation...?
another question: during the past few weeks, I was not able to go to the gym everyday as I used to and I gained a lot of fat, my fitness level is not good at all these days. is that a good time to get the new leaf test done? do you think I should wait untill my fitness level gets better?
The second equation does actually look balanced. However, an online search reveals about a gazillion different chemical makeups for different kinds of lipids. I don't know if this is just for the fats we consume, and our body stores them all under the same chemical makeup?
Similarly, it seems different carbs have different chemical makeups (e.g. complex carbs). Does the body always digest these, converting them to C6H12O6's, and then burn them?
And if so, doesn't the digestion process have any biproducts that would also be measured?
I guess I'm trying to get an idea for the accuracy of this type of test. I understand that this test yields very similar results to those of a closed-chamber test, but how do we know how accurate the results of the closed-chamber test are?