Dr. Andrew's Corner

Breathing Reserve (BR) is usually determined during a pulmonary exercise stress test. It is the difference between the maximal voluntary ventilation (MVV) and the maximum ventilation measured during the exercise test.

Normal males have a breathing reserve of 15 liters per minute or 20 to 40% of the MVV. (Wasserman et al)

Some experts do not believe direct MVV measurement to be reliable because it is very effort dependent and is very difficult to put acceptability criteria together. However, FEV1 is well defined, when and how is it acceptable. Therefore, it is a fairly well-defined measure that can be used to predict the MVV.

The formula for MVV, when derived from FEV1 is 40 * FEV1 or some are using 35 * FEV1.

Calculation: BR (L/min) = MVV - Max VE.

BR% = (MVV - VE / MVV) x 100.

Example: If MVV = 82 L/min and
VE at max exercise is 65 L/min,

Then:

BR = 82 - 65 = 17

BR% = (82 - 65 / 82) x 100 = 21%

Last update: 11/1/08

By: Andrew Huszczuk and John Hoppe

There is no advantage to true BBB measurements, and in fact there are distinct disadvantages!

Early publications about measurement of VO2 and VCO2 date back to the early 1900's, with collection of exhaled gases in bags.

Then in the 1930's Douglas used gas collection bags during his expedition to the Andes; the resulting publicity credited him with the term "Douglas Bag". The collected gases were subsequently analyzed and their volume measured.

Douglas bag and mixing chambers measurements using discrete gas analyzers were the standard until computers made on-line measurements with mixing chambers relatively easy.

In the late 1960's, Beaver and Wasserman of Harbor-UCLA developed the first Breath-by-breath (BBB) measurement system and later with Brian Whipp became the gurus and advocates of BBB measurements. It was hoped that the intra-breath information of BBB measurements would yield information about the dynamics of muscle O2 uptake.

With the strong influence of the Harbor-UCLA team on purchasing decisions of new customers, many instrument manufacturers were eager to follow what was thought to be the future trend in VO2 measurements. However, the promise of measurement of muscle dynamics using BBB measurements failed totally.

Today, there is almost total consensus among experts in the field of VO2 measurements that there is not a single advantage to BBB measurements, and in fact definite disadvantages due to much more noisy data and unavoidable measurement errors at both very low and high ventilation rates*.

Copyright (C) 2008 Vacumetrics Inc

* See also "Breath-by-Breath (BBB) vs. "True Breath by Breath"
on VacuMed.com (Dr. Andrew's Corner)

5 June 2008

VO2 means oxygen consumption and usually refers to
the volume of oxygen consumed in 1 minute.

The following is written in the context of VO2 measurements for fitness or athletic evaluation. Clinical VO2 testing most often involves the monitoring of EKG and other physiologic indices,
and the reason for the test most likely will be to assist in diagnosis of disease or measurement
of disability or progress of rehabilitation.

The air we breathe contains roughly 21% oxygen (O2), 78% Nitrogen (N2) and various trace gases, such as Argon, Carbon Dioxide (CO2) and a few more.
We can ignore N2 in our discussion, since it does not partake in metabolism.

1. Note: Wondering why the "2" as in O2 and CO2? Perhaps you had the measles when this subject was discussed in school. The reason

1. is that some gas molecules get lonesome and always hang around in pairs.

Of course, your chemistry teacher would have a more elegant explanation, but would we Dummies understand it?

So we inhale 21% O2 and exhale, typically, 17%O2 and about 4% CO2. We have consumed, "burnt", metabolized roughly 4% oxygen. Of course, nothing is ever that simple, because the first part of your exhalation is the very last part of your inhalation. So it is still nearly 21% O2, but then as the source of exhaled gas comes from deeper in the lungs, it contains more and more CO2, and less and less O2. This change in gas concentration occurs rapidly, and the precise measurement requires some sophisticated instruments.

Much easier to measure are mixed exhaled gases. Assume you exhale into a plastic bag, close the bag quickly and massage it so that you are sure the gases are mixed. Now a single measurement of this mixture will give you mixed exhaled O2 and CO2, again, ignoring N2. As I said above, the typical mixture will contain from 16% to 17% O2 and 3% to 4% CO2. That in itself tells us only that we are alive, it does not tell us how much O2 we consumed. For that we need to know or measure the volume of the bag. Exhaled volume is mostly expressed as "VE" (Volume, exhaled) or "minute ventilation". You guessed it, it means the volume exhaled in 1 minute.

In practice, we want to measure not just one breath, but the gas concentrations and volumes of many breaths over longer time periods. This early method of gas collection in large bags, known as the "Douglas Bag Method", is still practiced by some purists and for teaching purposes, but modern, computerized instruments greatly simplify those measurements. Computers also take care of necessary corrections for temperature, humidity and barometric pressure.

Now to calculate VO2, a simplified equation might look like this:

VO2 = VE x (O2inspired - O2expired)

In plain language, this means VO2 equals the total volume of gas exhaled in 1 minute (VE) multiplied by the difference between inhaled and exhaled oxygen.
So if you exhaled a total of 10 liters of gas during 1 minute, and your mixed exhaled O2 is measured at 17%, then

VO2 = 10 x (0.21 - 0.17)

(Note that 21% and 17% must be written as a fraction,
which is 0.21 and 0.17)

simplified to: VO2 = 10 x 0.04 = 0.4

so your VO2 in this example would be 0.400 liters (or 400 milliliters) per minute, which is close to typical for a person at rest.

But that is usually not the end of the calculation. Surely, it is obvious that the VO2 of a mouse will be so much less than that of a human. Just the same, the basic VO2 of a small person will be less than that of a much larger person. It is conceivable, therefore, that a maximum oxygen consumption (VO2max) of 2 liters of a 5 foot tall person may actually make him or her more fit that the VO2max of 2.5 liters of a 6 foot tall person.

How do we take care of that?

Well, we report VO2 in relation to body weight in kilogram. For this calculation liters are converted to milliliters by multiplying liters x 1000.

1. Example: The 5-footer has a body weight of 60kg, so her VO2max of 2 liters divided by her body weight equals to 33 milliliters per kg (ml/kg). (2000 divided by 60)

The 6-footer weighs 90kg, so 2500 divided by 90 = 27.7 milliliters per kg.
You see, the 5-footer really has a higher VO2max when expressed in milliliters per kilogram of body weight. It's not only fair, there is just no other way to compare the mouse to the elephant (or the human).

Naturally, all this is still a bit of oversimplification, but good enough for us Dummies.

To continue to chapter 2, click here:
Why measure VO2

Copyright (C) John Hoppe 2008
12-12-08

Why measure VO2 ?

You take a 15-minute walk during your lunch hour, are you fit? Your neighbor plays golf twice a week, is he fit? Your mother tends her garden every day, is she fit? Your cousin runs a marathon several times a year, is she fit? (Oh yah) Who is fit? Who is not?
VO2 measurements are useful in a number of applications. There is the Resting VO2 test, the sub-maximal and the VO2max.

Resting VO2 is always expressed in ml/kg. You see terms like REE (Resting Energy Expenditure), RMR (Resting Metabolic Rate) and BMR (Basal Metabolic Rate). The differences are subtle, depending how you prepared for the test.

Most resting VO2 tests, as a person in a fitness facility might experience, involves refraining from exercise, food and stimulating liquids for a few hours, then getting comfortable in a reclining position and finally breathing into a face mask for several minutes in order to analyze your exhaled breaths.

Your REE or RMR is that O2 required to sustain your basic body function without any voluntary or involuntary (such as shivering) muscle movement. With that information, conclusions may be drawn about your dietary needs; about weight loss management, and adherence to a weight reduction program may be monitored. More on www.vacumed.com, click on "Dr. Andrew's Corner".

VO2max testing typically involves a graded exercise test, meaning the workload is steadily increased to exhaustion. In a sub-maximal test workload is usually increased to a pre-determined heart rate or workload short of a maximal effort, or to a point that determines the lactate or anaerobic threshold (next chapter). Formulas have been published to predict VO2max from a sub-maximal test, but there are considerable doubts about the accuracy of such predictions.
A poor analogy might be to claim that you could predict the maximum speed of a car by accelerating to 55 miles per hour.

VO2max (Maximal oxygen uptake) was first described by Hill and Lupton in 1923 as "the oxygen intake during an exercise intensity at which actual oxygen intake reaches a maximum beyond which no increase in effort can raise it".(1) In other words, there is a point at maximal exercise where your oxygen consumption no longer increases, even though your workload does increase further. To be sure, you can perform this supra-maximal effort for a very limited time, typically less than a minute.

VO2max can be considered THE universal measure of aerobic fitness. It allows you to compare couch potatoes with runners, rowers with tennis players, swimmers with spinners, and so many more. It does not tell you about their skill, just their relative ability to perform work. Let's look at two runners, equal in weight. Runner #1 has a maximum VO2 (VO2max) of 3 liters, runner #2 a VO2max of 3.3 liters. Yet runner #1 beats runner #2. This may be because runner # 1 has better skills, running efficiency, Nike shoes, or better steroids. But it could also mean that if runner #2 improved his skills, he has the potential to be the better runner.

Modern, computerized VO2 measurement systems will compare your test results with "predicted" or so-called "normal" values. Such normal values have been published in the literature and are based on testing groups of "typical" populations, broken down by gender, age, height, and in some cases, ethnicity. A typical printout of such a VO2max test is shown below.

Figure courtesy of VacuMed

Between resting and maximum VO2 measurements are the "Thresholds": Ventilatory, lactate, anaerobic. We will talk about this in a future chapter.

In medicine, there are additional reasons for measuring VO2, but this may get too complicated for us Dummies.

Click here to see a video of a typical VO2 test

Click here for more
Sample Printouts

To continue to chapter 3, click here:
Anaerobic, Lactate and Ventilatory Thresholds

(1) Hill, A. V. and H. Lupton, Muscular exercise, lactic acid, and the supply and utilization of oxygen. Q. J. Med. 16:135-171, 1923

Copyright (C) John Hoppe 2008
12-27-08

All references to thresholds here are in relation to VO2 testing. A search of the literature, or Google, will find references to other methods of determining some thresholds. But beware, there is much mis-information on the web!

For the Aerobic Threshold I found this explanation in Wikipedia(1):
"The aerobic threshold (AeT) is a term sometimes used by sports coaches and trainers to describe a level of exercise intensity somewhat below the anaerobic threshold. It, however, is not a defined physiological term.
The AeT is sometimes defined as the exercise intensity at which blood lactate reaches a concentration of 2 mmol/liter (at rest it is around 1 mmol/liter). This tends to be at a heart rate of approximately 20-40 bpm less than the anaerobic threshold."

In physiology, AeT refers to an increase in ventilation (breathing volume) that occurs rather early in an exercise session, sometimes also called the first ventilatory threshold (VT1).

The Lactate Threshold (LT): Blood lactic acid increases with increasing exercise workload. Most lactic acid is re-cycled in the muscles and liver, a very complex process. Every individual has a point (work rate) where the rate of lactate production exceeds the rate of re-utilization. At that point the lactic acid then increases disproportionately to workload. This point is called the lactate threshold. To determine this point it is necessary to puncture (lance) your skin (typically earlobe or fingertip) every 1 to 2 minutes and collect a drop of blood for analysis.

The Ventilatory Threshold (VT or VT2). At the LT, or very close to it, your ventilation also increases disproportionately to increases in workload. When plotted on a graph, this is often the most recognizable event demarcating the ventilatory threshold, see figure 1. When workload increases at a steady, linear rate, and ventilation initially follows with a like increase, then a sudden deviation is certainly an event that must have significance.

Figure 1

Figure 1 shows Ventilation and heart rate plotted against a linear
increase in workload. VT1 and VT2 are determined by changes in slope of ventilation.

The Anaerobic Threshold (AT). "Anaerobic" means "without air" and now we are stepping on thin ice. The term "AT" was originally suggested by Dr. Karlman Wasserman of UCLA, but the term and the scientific reasoning behind it have been seriously questioned in recent years. It's safe to say that the AT is going out of favor.

Ok, there is agreement that there is a threshold "T", a change in physiologic response to increasing workload, an unbalance. Scientists are still debating the cause. The issue is what to call it. Some have called it the Fitness Threshold, Thermal Threshold etc. The most important point here is that, for most people and under most conditions, the LT, VT and AT occur at the same point, although nit-picking scientists will quibble and split hairs that us Dummies either can't understand or don't care about.

There is also agreement that you can perform work for prolonged periods below the "T", but working above the T will quickly lead to exhaustion.

There is further growing consensus that the T measurement may be more useful than VO2max for most people. After all, unless you are a super athlete that wants to brag, or may otherwise benefit from knowing your VO2max, what's the point? The fact is, VO2max test results depend very much on motivation. Is a person that is trying to collect disability payments motivated to perform well?

The "T" clearly defines the limit of your day-to-day operational capability. For untrained individuals, the T may be approximately 50% of their VO2max, for trained athletes it will be more like 80 to 90% of their VO2max, therefore, the T is either expressed as a percentage of VO2max, or in liters of VO2 per minute, or as the heart rate at the T for training purposes. Nevertheless, this suggests valuable implications for athletic training, where the goal is to move the athlete's T as close to VO2max as possible.

Since the T is less dependent on motivation, and does not require exercising to exhaustion, it can be measured more often for a person engaged in a fitness program. Increasing your T is what you should aim for and even us Dummies know that frequent exercise of most any kind will get you there.

(1) Wikipedia is a registered trademark of the non-profit Wikimedia Foundation

Copyright (C) John Hoppe 2008
12-12-08

Most University testing for athletic purposes only. Prior appointments are necessary!

1.
Dr. Desmond Ebanks
Alternity Healthcare LLC
639 Park Road
West Hartford CT 06107
Tel: 806-748-4064
Click here for Alternity Healthcare web site

2.
Dr. Marc Silberman
NJ Sports Medicine & Performance Center
689 Valley Road
Gillette NJ 07933
Tel: 908-647-06464
New Jersey Sports Med web site

3.Mike Craven
Mechanicsville Fitness Center
aka: Mike's Olympic Gym
7495 Old Hickory Drive
Mechanicsville VA 23111
Tel: 804-543-9293

3.A
Chris Eschbach, PhD
Meredith College
Raleigh, No Carolina
Lab phone: 919-760-8769
Meredith College VO2 testing web site

4.
Out of business, but link still active:
Click here for G2 Health web site

5.

Ohio University
Work Physiology Laboratory
001 Irvine Hall
Athens OH 45701
Tel: (740) 593-2291
FAX: (740) 797 2778
e-mail: hagermaf@ohio.edu

6.
Nathan "Nate" Thomas
Mobile Utah Testing Lab
Salt Lake City UT
Tel: 801-302-9549
FAX: 801-397-2118
Nate@hakenya.com
Hakenya web site

7.

University of Las Vegas
Exercise Physiology Lab
Box 53034 Kinesiology Dept
4505 Mryland Pkwy
Las Vegas NV 89154-3034
Tel: (702) 895-3766
FAX: (702) 895-4191
e-mail: lagolding@aol.com

8.
Ken Nicodemus
Exercise Physiologist / Director
The Fit Stop Human Performance Lab
Tel: (760) 634-5169 Fax: (866) 409-5888
Fit Stop web site

9.
Holden MacRae
Pepperdine University
Dept of Sports Medicine
Malibu CA
Tel: (310) 456-4278
FAX: (310) 317-7270
e-mail: holden.macrae@pepperdine.edu

10.
Susan Ceriale
Wellness & Fitness Institute
University of Santa Barbara
Santa Barbara CA 93106
Tel: (805) 893-4000
FAX: (805) 893-7054
e-mail: sceriale@gte.net

11.
Steve DaMassa
Clark Community College
Fitness Testing Lab
1933 Fort Vancouver Way
Vancouver WA 98663
Tel: 360-992-2185
e-mail: sdamassa@clark.edu

12.
Cheryl Pitkin
Central Oregon Community College
Exercise Physiology Lab
2600 NW College Way
Bend OR 97701
Tel: (541) 383-7768
Click here for COCC web site

13.
L. Brilla
Western Washington University
MS-9067
Bellingham WA 98225
Tel: (360) 2861
e-mail: physlab@cc.wwu.edu

14.
Brendan Roach
BodyLab Ltd.
43 Hania St
Wellington, New Zealand
Tel: +644-801-17395
Click here for BodyLab web site
Click on U-tube icon for video

15.
Dr. Marcus Strozberg
Meduna do Esporte
2. Osvaldo, S912
Brasil
Tel: +55-85-266-4132
e-mail: strozberg@secrel.com.br

Resting Energy Expenditure "REE"
©1998 VacuMed
By Denise Schwartz, MS, RD, FADA, CNSD

What does REE mean?

Resting energy expenditure represents the amount of calories required
for a 24-hour period by the body during a non-active period. Energy
expenditure can be estimated by numerous published formulas. There are
nearly 200 published energy expenditure formulas dealing with various
conditions, disease states, age, presence of obesity and other
additional factors. (5) One of the most frequently used formulas for
predicted energy expenditure are the Harris-Benedict equations. These
were established in 1919 and took into account gender, age, height and
weight. However, these formulas are skewed towards young and non-obese
persons. (2)

Harris-Benedict Equations (calories/day):
Male: (66.5 + 13.8 X weight) + (5.0 X height) - (6.8 X age)
Female: (665.1 + 9.6 X weight) + (1.8 X height) - (4.7 X age)

weight in kilograms, height in centimeters, age in years

The Harris-Benedict equations have been found to overestimate by 6% to
15% the actual energy expenditure measurements done by indirect
calorimetry. (3) There is a large variation between individuals, when
comparing their measured energy expenditure to the calculated amount.
These equations have limited clinical value when tailoring nutrition
programs for specific individuals for weight loss purposes or acute as
well as chronic illness feeding regimens.

Energy expenditure can be measured directly by putting a person in a
calorimeter and measuring the amount of heat produced by the body mass.
This is expensive and very impractical in the clinical setting. Energy
expenditure can be measured indirectly with a metabolic cart by
analysis of respired gases (usually expired) to derive volume of air
passing through the lungs, the amount of oxygen extracted from it
(i.e., oxygen uptake VO2) and the amount of carbon dioxide,
as a by-product of metabolism, expelled to atmosphere (CO2 output – VCO2)
– all computed to represent values corresponding to 1 minute time intervals.

With these measurements the resting energy expenditure (REE) and respiratory quotient (RQ) can be calculated.

The RQ represents the ratio of carbon dioxide exhaled to
the amount of oxygen consumed by the individual. RQ is useful in
interpreting the results of the REE. The abbreviated Weir equation is
used to calculate the 24-hour energy expenditure. These measurements
are printed out by the metabolic cart after completion of the indirect
calorimetry test. (1,4,5)

Abbreviated Weir Equation:

REE = [3.9 (VO2) + 1.1 (VCO2)] 1.44

VO2 = oxygen uptake (ml/min)
VCO2 = carbon dioxide output (ml/min)

Respiratory quotient (RQ) = VCO2/VO2

Benefits of using REE in the clinical setting

The REE is useful to prevent under and overfeeding of individuals,
especially in the acute care hospital setting. Excessive calories or inadequate feeding regimens can have detrimental effects on clinical outcomes of patients' care. Malnutrition can result from feeding a patient less than his/her metabolic requirements leading to reduced respiratory muscle strength, increased risk of infection, poor wound healing and impaired normal body function. Overfeeding means providing too many calories that can not be used by the body and are therefore converted to fat storage.
This can cause more CO2 to be produced and result in increased work of breathing. The REE measurement is especially beneficial in the ventilator dependent patient population during the process of weaning
the individual from mechanical ventilation to resume (reestablish) spontaneous breathing. (7)

How do you do the test?

For best results, when having a REE done, there are certain conditions
that need to be controlled and others that just require documenting
at the time of the test. During the test the individual is interfaced with a
metabolic measurement system by means of a facemask or a canopy.
A mouthpiece with a nose clip is also sometimes used, but it may create
overly stressful conditions to a subject (patient).

Important considerations or conditions to improve the REE measurement:
(1,4,5)

Individual should rest for at least 30 minutes in bed or a
recliner before the test, however, the person should not be asleep.
No food for at least 2 hours before the test.
Maintain quiet surroundings when the test is in progress and normal temperature. The individual should not move arms or legs during the test.
Normal room temperature should be maintained, avoid drafts or any condition that might result in shivering.
Medications taken should be noted, such as stimulants or
depressants.
Steady state should be achieved, which would be identified
clinically by the following:
5 minute period when average minute VO2 and VCO2
changes by less than 10% and the average RQ changes
by less than 5%.

Stable interpretable measurements should be obtained in a 15 to 20
minute test.

Additional considerations for hospitalized individuals:

If the individual is on specialized nutrition support (enteral or
parenteral nutrition) continuous 24-hour infusion does not need
to be stopped. The nutrients infused should be constant for at
least 12 hours. If feedings are intermittent or cyclic, the feeding
should be held for at least 2 hours. Document the product and
the rate the individual is receiving.
Discontinue any supplemental sources of oxygen if the individual is on room air, which includes nasal cannulas, masks or tracheostomy collars.
If the individual is on a ventilator, the settings should remain
constant for at least 1-1/2 hours before the test.
No recent chest therapy or physical procedures.
Renal failure patients requiring hemodialysis should
not be tested during dialysis therapy.

Interpreting the REE

Interpreting the measured REE includes comparing the results to the
predicted level of energy needs for that individual. Determining the 24
hour calorie intake of that individual from either an oral diet or
specialized nutrition therapies (through feeding tubes into the
gastrointestinal tract or intravenous administration) is required.

It is important to assess the RQ to make certain it is within
physiological range and consistent with the person's calorie intake
and medical history. The physiological range of RQ is 0.67 to 1.3. This value
represents the combination of carbohydrate, fat and protein being used
for energy. If the RQ is greater than 1.0, decrease the total calorie
intake and adjust the carbohydrate to fat ratio. If the RQ is less
than .81 increase the total calorie intake, dependent on the goal for
the nutrition therapy. Food sources and conditions have specific RQ
values that are useful when interpreting the REE and making
recommendations for changing dietary goals and feeding regimens. (1,4,5)

Energy source/condition RQ
prolonged ketosis <0.70
fat 0.70
underfeeding <0.71 protein 0.80 mixed energy 0.85 carbohydrate 1.00 fat storage >1.00

Use of REE in conjunction with weight management programs

In weight management programs, when an individual has trouble losing
weight a frequent comment is that ones metabolism is slow. This can
result in failure of the individual to adhere to a weight management
program incorporating a reduction in total daily calorie intake.
However, once the actual REE is done, there is no longer need
to speculate about the normalcy of metabolism for that person.

Successful maintainers of weight loss report continued consumption of a
low-energy and low-fat diet. (8) Efforts to improve weight loss and
maintenance need to focus on strategies to increase calorie expenditure
through exercise and an appropriate diet based on measured energy needs.
The goal is a lifelong commitment to healthful lifestyle behaviors. (6)

An example of how to successfully use the REE measurement in a weight
management program requires interpretation and counseling by a
registered dietitian. After measuring the REE and calculating the 24
hour intake, the individual would be instructed on reducing their food
consumption by approximately 200-300 calories a day below the
measured REE. This should result in about 1 pound weight loss per week
with additional weight loss due to exercise. If the REE is extremely
low then the focus would be on maintaining the calorie intake at the REE
level and gradually increasing to at least 30 minutes of enjoyable
activity each day.

Clinicians monitoring weight management programs would be able
to determine if their clients are actually following a reduced calorie
diet based on REE, RQ and the amount of weight loss. These
measurements would be very useful in detecting failure to adhere
to the diet and facilitate better understanding by the client in
achieving his/her weight goal.

It is important that an individual have a framework for making healthful
food choices to obtain realistic weight reduction and maintenance
goals. The challenge is to balance adequate nutrient intake with the
individual's desire to lose weight rapidly and to address the numerous
myths concerning diet modification. The REE takes the guesswork out of
determining the goal for the calorie intake to achieve the desired
outcome.

References

1. Feurer I and Mullen JL. Beside measurement of resting energy
expenditure and respiratory quotient via indirect calorimetry. Nutr
Clin Prac. February 1986;1:43-49.
2. Frankenfield DC, et al. The Harris-Benedict studies of human basal
metabolism: history and limitations. J Am Diet Assoc. 1998;98:439-445.
3. Garrel DR, et al. Should we still use the Harris and Benedict
equations? Nutr Clin Prac. June 1996;11:99-103.
4. Matarese L. Indirect calorimetry: technical aspect. J Am Diet
Assoc. 1997;97(suppl 2):S154-S160.
5. McClave SA and Snider HL. Use of indirect calorimetry in clinical
nutrition. Nutr Clin Prac. October 1992;7:207-221.
6. Position of The American Dietetic Association: weight management. J
Am Diet Assoc. 1997:97:71-74.
7. Schwartz DB: Pulmonary failure. IN Matarese LE and Gottschlich MM:
Contemporary Nutrition Support Practice. Philadelphia, W. B. Saunders,
Co. (In press)
8. Shick SM, et al. Persons successful at long-term weight loss and
maintenance continue to consume a low-energy, low-fat diet. J Am Diet
Assoc. 1998;98:408-413.
The Metabolic (Lung) Simulator
Calibration of Metabolic Systems
Stress Testing
Resting Energy Expenditure "REE"
Why Calibrate Ergometers
How to select a Cycle Erometer
Deception of the Douglas Bag

a "met" was derived from the resting oxygen consumption (VO2) for a 70kg, 40-year-old male and its value is 3.5 ml/min per kilogram of body weight. Therefore, a person working at 5 mets would have a VO2 of 17.5 ml/min/kg.

Some laboratories estimate maximum METS from the maximum work rate achieved using the "Bruce" protocol without actually measuring VO2, which may lead to inaccurate results.

The History of (true) Breath-by-Breath Measurements

5 June 2008

By: Andrew Huszczuk and John Hoppe

There is no advantage to true BBB measurements, and in fact there are distinct disadvantages!

Early publications about measurement of VO2 and VCO2 date back to the early 1900's, with collection of exhaled gases in bags.

Then in the 1930's Douglas used gas collection bags during his expedition to the Andes; the resulting publicity credited him with the term "Douglas Bag". The collected gases were subsequently analyzed and their volume measured.

Douglas bag and mixing chambers measurements using discrete gas analyzers were the standard until computers made on-line measurements with mixing chambers relatively easy.

In the late 1960's, Beaver and Wasserman of Harbor-UCLA developed the first Breath-by-breath (BBB) measurement system and later with Brian Whipp became the gurus and advocates of BBB measurements. It was hoped that the intra-breath information of BBB measurements would yield information about the dynamics of muscle O2 uptake.

With the strong influence of the Harbor-UCLA team on purchasing decisions of new customers, many instrument manufacturers were eager to follow what was thought to be the future trend in VO2 measurements. However, the promise of measurement of muscle dynamics using BBB measurements failed totally.

Today, there is almost total consensus among experts in the field of VO2 measurements that there is not a single advantage to BBB measurements, and in fact definite disadvantages due to much more noisy data and unavoidable measurement errors at both very low and high ventilation rates*.

Copyright (C) 2008 Vacumetrics Inc

* See also "Breath-by-Breath (BBB) vs. "True Breath by Breath"
on VacuMed.com (Dr. Andrew's Corner)

5 June 2008

Here is what you need to measure VO2 via the "Douglas Bag Method"

Wasserman, Hansen, Sue & Whipp state: We believe the AT to be the best determinant available to demarcate the upper limit of work rate which can be endured for a prolonged period. Thus, a task performed below the AT can be sustained. A task performed above the AT cannot be sustained as long; the higher the work rate above AT, the less is its tolerable duration.

Also: The VO2 at which blood lactate level begins to be elevated has been used to define the AT in normal subjects.

In other words, the "AT" occurs at the same time as the Lactate Threshold "LT"

Click here for above reference

Biolectric Impedence Analysis (BIA)
BODYSTAT Body Composition Measurement Locations

1.
M-Dietician
Los Angeles,CA
Dr. Amy Lee, M.D.
(213) 977-1030 amylee@mdietician.com

2.
Next Level Fitness
Palm Desert, CA
Casey Washack
(760) 341-8200 nlf@nextlevelfitness.org>

3.
Palm Desert Athletic Club/Desert Fitness Group
Palm Desert, CA
Leslie Shuffleton, DFG
(760) 641-1550 leslie@desertfitnessgroup.com

4.
re:Form FITNESS Studio
San Marcos, CA
TK Smith
(760) 593-7512 tk@hereswhatido.com

5.
Brandon Weight Loss
Brandon, FL
Abida Saleh
(813) 684-5880 abida@shifa-llc.com

6.
Valdosta State University,
College of Nursing
Valdosta, GA
Dr. Melissa Benton or Dr. Maura Schlairet
(229) 245-3775-Benton or (229) 333-7192-Schlairet mjbenton@valdosta.edu or mcschlai@valdosta.edu

7.
Vital Life Health
Clarendon Hills, IL
Dr. Stephen Spates
(630) 734-3454 info@drspates.com

8.
Northshore Sleep Medicine
Skokie/Evanston, Il
Dr. Lisa Shives, M.D.
(847) 674-3600 lshives@nssleep.com

9.
University of Kentucky
Body Composition Core Laboratory
Lexington, KY
Jody L. Clasey, PhD, FACSM
(859) 257-8055 jlclas0@uky.edu

10.
Carrington Health Center
Wellness & Disease Management Department
Carrington, ND
Ryan Zink
(701) 652-7250 or (701) 652-3141 ryanzink@catholichealth.net

11.
Integrative Medical Center
for Wellness and Weight Management
New York, NY
Dr. Samoon Ahmad, M.D.
(212) 585-1111 samoon.ahmad@nyumc.org

12.
Dr. Howard Goodman D.C.
New York, NY
(212) 346-2030 goodmanhoward@yahoo.com

13.
Michelle Ross Nutrition
Michelle Ross, RD
Lodi, CA
(916) 253-3406 info@michellerossnutrition.com
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Hydrostatic Weighing (Under Water Weighing)Locations

Prior appointments may be necessary!

1.
Frederick C. Hagerman, Ph.D.
Ohio University
Work Physiology Laboratory
Athens OH 45701
Tel: (740) 593-2291
FAX: (740) 797 2778
e-mail: hagermaf@ohio.edu
Hydrostatic Weighing, DEXA, BodPod available

2.
Lawrence A. Golding Ph.D.
University of Las Vegas
Exercise Physiology Lab, Kinesiology Dept
Las Vegas NV 89154-3034
Tel: (702) 895-3766
FAX: (702) 895-4191
e-mail: lagolding@aol.com
BIA, Hydrostatic Weighing, DEXA, Calipers and BodPod available

3.
Wellness & Fitness Institute
University of Santa Barbara
Santa Barbara CA 93106
Tel: (805) 893-4000
FAX: (805) 893-7054
BIA and Calipers(5-points)available

5.
Johanna Olson
Central Oregon Community College
Exercise Physiology Lab
Bend OR 97701
Tel: (541) 383-7768
Click here for COCC web site
email: jolson1@cocc.edu
Hydrostatic Weighing available