Oxygen uptake requires a precise measurement of the volume of expired air and of the concentrations of oxygen in the inspired and expired air. The process requires that all of the air a person breathes out be collected and analyzed while they rest quietly. The KORR™ indirect calorimeters contain a precision air flow sensor that measures the volume of expired air, and an oxygen sensor that measures the concentration of oxygen. Once the factors of humidity, temperature and relative humidity are accounted for, the KORR™ instrument provides the most accurate results available in a compact metabolic analyzer.
- Proof of “normal” metabolism
Most overweight people are convinced they have a slow metabolism. The truth is that statistically, most overweight and obese individuals have average or higher than average metabolic rates. Taking a measurement removes this excuse. Seeing that their bodies can indeed burn calories can be very encouraging and motivating.
- Stabilize weight loss
Regardless of the method used to lose weight, a patient’s RMR will decrease after weight loss. The decrease is actually below the level predicted by fat-free mass (FFM). Although the cause is unclear, it appears that in most cases, if a patient can maintain his new weight for 6 months, his RMR will eventually rise to the expected level. Pinpointing the precise number of calories necessary to maintain is key to surviving this crucial period.
- Pinpoint caloric weight loss zone
When restricting calories, knowing a baseline RMR is invaluable. KORR Metabolic Analyzers calculate a “weight loss zone” for 1 ½ pound a week weight loss, or practitioners can use the RMR to calculate a caloric goal unique for their patients.
- Detection and Diagnosis of hypo-metabolism
In cases where a patient has a clinically low metabolic rate, further diagnosis and treatment by a physician will be required before successful weight loss can be achieved.
- Assess the effect of weight loss treatment on metabolism
Once calories are restricted, medications are introduced, or an exercise plan has been implemented, the human body will respond. This is especially true of significant interventions, such as bariatric surgery. The caloric goals of a dietary plan will rarely sustain a patient throughout an entire weight loss regimen. The result is the dreaded “plateau.” Periodic assessment of RMR will show the effects of the treatments and allow adjustments to the caloric goals.
- Proper nutritional care is VITAL for the hospitalized patient. Studies show that hospital stays are reduced an average of 60% when nutritional status is evaluated and needs are met.
- The formulas that predict caloric needs for nutritional assessment (Harris Benedict, Miffin, etc) are inadequate for certain populations, especially sick or hospitalized patients. RMR is recommended for the following populations:All patients receiving parental or enteral nutrition
- Hypermetabolic patients (burns, trauma, sepsis, head injury)
- Starvation-adapted or malnourished patients
- Extremely obese patients (>=200% of ideal body weight)
- Patients with non-healing wounds
- Patients with abnormal body composition (multiple sclerosis, cerebral palsy, cystic fibrosis, spinal cord injury, amputations).
- Patients who can benefit from education about appropriate calorie intake.
How to add RMR Testing
How to add RMR testing to my practice
Frequently Asked Questions (FAQ)
Below are some frequently asked questions about RMR. If you have a question that is not anwered below, please contact us at 1-800-895-4048 or fill out our contact form on our contact page.
Additional researchers at the University of Pennsylvania noted that the obese have Resting Energy Expenditures that are particularly difficult to predict. Their findings read, “Caloric prescription for weight reduction must be tailored to individuals rather than recommending the same caloric intake to persons with varying metabolic rates.” (Foster GD, et al, Metabolism. 1988 May;37(5):467-72.)
If calorie intake is decreased, most studies indicate that strength training can reduce the loss of fat-free mass (lean muscle) but not prevent the decline in RMR that invariably comes with dieting.(Geliebter)
But studies are difficult to compare and summarize due to the many differences in the resistance training protocols and experimental designs. Researchers at West Virginia University found success maintaining RMR through intensive high volume resistance training designed to affect more muscle groups and by increasing protein intake to 80 g/day. (Bryner)
Economics are an additional concern related to TPN. Its significant cost must be considered when contemplating the value of determining a patient’s precise caloric need through RMR testing. A study by Foster measured REE in 100 TPN patients and compared those results to the published guidelines for determining TPN needs. Following those published guidelines instead of the actual REE resulted in the administration of 6947 excess liters of TPN per year! (Foster, Flancbaum)
VO2 Max is the maximum rate of oxygen consumption that can be attained during the most intense exercise possible. The measurement requires that the subject breathe into an oxygen consumption analyzer during an all-out effort (usually on a treadmill or bicycle) as part of a graded exercise protocol. These protocols involve specific increases in the speed and intensity of the exercise. While exercising, the person wears a mask to collect all the air he breathes in and out for a measurement of the volume of exhaled gas and the concentration of oxygen in that exhaled gas. This determines how much oxygen is used during each minute of the exercise test.
A person’s oxygen consumption rises in a linear relationship with exercise intensity — up to a point. There are specific physiological markers (AeT, AT) that can be detected throughout the test as oxygen consumption is measured. Eventually, oxygen consumption plateaus even if the exercise intensity increases. When the person is no longer able to keep up with the oxygen demands of his muscles and complete fatigue forces him to stop exercising, then his oxygen consumption has reached a maximum, and VO2 Max can be calculated. The test usually takes between 10 and 15 minutes.
A complete VO2 Fitness test can give trainers and clients the tools to set realistic goals and assess improvement. Studies show that previously sedentary people training at 75% of aerobic power for 30 minutes, 3 times a week over 6 months increase VO2 Max an average of 15-20%. Many people are inefficient exercisers, with no understanding of what specific heart rate, intensity or duration would best help them reach their specific goals such as fat burning, endurance training, or cardio conditioning. An initial VO2 Max test can clarify the specific target heart rates that will enable each individual to reach their fitness goals more effectively, with less fatigue and fewer injuries. Periodic retesting provides motivating feedback as the fitness program progresses.
The test also determines the number of calories burned during every level of exercise, providing valuable information when designing a weight loss program. And if CO2 is measured during the test, a Respiratory Exchange Ratio (RER) can determine the proportion of energy coming from carbohydrates and fats at various levels of exercise intensity. Since physical conditioning and exercise intensity affect these proportions, this information can be very helpful when designing a workout intended to burn fat.
VO2 Max testing is a valuable tool for serious athletes to assess performance and evaluate training regimens. Even though extensive training can sometimes cause an athlete to reach a plateau in VO2 Max, he can still use his VO2 Max test results to make further improvements in performance. This is accomplished as he pushes to increase anaerobic threshold (AT) and maintain that threshold for longer periods of time. This enhances both endurance and cardiovascular performance.
Aerobic threshold (AeT) is the first rise or breakpoint in the ventilatory response to increasing rate or grade of exercise. (Sharkey 2002) CardioCoach detects the rise in the ventilatory response and correlates it to your heart rate. The aerobic threshold defines the minimal level of effort that can produce improvement in cardiovascular fitness.
The anaerobic threshold (AT) is defined as the level of exercise intensity at which lactic acid builds up in the body faster than it can be cleared away. Lactic acid build up generally leads to muscle fatigue and soreness. Vigorous effort can be sustained for an extended duration at exercise intensity levels below the anaerobic threshold. AT can be detected by 2 different means: Ventilatory Threshold, or Respiratory Exchange Ratio threshold.
Respiratory Exchange Ratio (RER) is the ratio of expired carbon dioxide to oxygen uptake at the level of the lung. When Carbon dioxide production exceeds oxygen uptake, the RER crosses 1.00. This is anaerobic threshold.
Ventilatory Threshold (VT) is the point during progressive exercise in which ventilation increases disproportionately to oxygen uptake. Ventilation increases to rid the body of the excess Carbon dioxide from lactic acid build up. AT is detected by pinpointing the take off (rising) point in the Ve/VO2 ratio. (Meyers, 1996)
Lactate Threshold is a reference to the accumulation of Lactate in the blood. There are some inconsistencies in the terminology, though. Some use the term to denote the initial rise in lactic acid production. More often, Lactate Threshold is used to describe the maximum steady state effort that can be maintained without lactate continually increasing. This abrupt increase in blood lactate levels is also referred to as the lactate turn point (LT), lactate inflection point (LIP), or onset of blood lactate accumulation (OBLA). (Roberts & Robergs 1997)
The Anaerobic Threshold is defined as the level of exercise intensity at which lactic acid builds up in the body faster than it can be cleared away. Because this is measured by Ventilatory responses (Ve/VO2 or VO2/VCO2), it is often more accurately termed Ventilatory Threshold (VT). (Meyers, 1996)
Respiratory Exchange Ratio (RER) is the ratio of expired carbon dioxide to oxygen uptake at the level of the lung.
Respiratory Quotient (RQ) is the ratio of expired carbon dioxide to oxygen uptake at the level of tissue or cells. Sometimes this term is used interchangeably with RER, but that is incorrect. A VO2 Max test measures RER. (Meyers, 1996)
Frequently Asked Questions (FAQ)
Below are some frequently asked questions about V02 Max. If you have a question that is not anwered below, please contact us at 1-800-895-4048 or fill out our contact form on our contact page.
The key to determining Anaerobic Threshold (AT) during a VO2 Max test is to detect the point when the body is forced to expel the surplus CO2 produced as a result of excess lactate. This can be determined one of 2 ways:
- Measuring VCO2/VO2 (volume CO2/volume O2) and detecting the point when that ratio (RER) equals 1.00. This is the Respiratory Exchange Ratio method.
- Measuring Ve/VO2 (Minute Ventilation/volume O2) and detecting the respiratory compensation point. This is the ventilatory equivalent method.
Multiple studies (1,2) have shown that both methods are valid and reliable for determining AT among healthy subjects. KORR offers products that utilize both methods of AT detect to best meet customer needs. A comparison of methodologies in detection of the anaerobic threshold. Dickson K, Barvik S., Aarsland T, Snapinn S, KarlssonJ. Circulation 1990 Jan;81(1 Suppl):II38-46. A new method for detecting anaerobic threshold by gas exchange. William L. Beaver, Karlman Wasserman, and Brian J. Whipp Journal of Applied Physiology 60:2020-2027, 1986
Women typically tend to have a lower VO2 Max than men.
For men and women, VO2 Max will decrease by 10% per decade regardless of age and exercise activity.
VO2 Max is unique to each person and directly proportional to their height, weight, and body surface area. VO2 Max correlates 0.63 with body mass, 0.85 with fat-free body mass, and 0.91 with active muscle tissue.
VO2 Max is reduced for residents of temperate or tropical areas (compared to those living in circumpolar regions). Also, VO2 Max is reduced by approximately 26% at an altitude of 4,000 meters. This reduction increases as altitude increases.
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