Members Exclusive Article
By John Destacamento, February 24th, 2021

This is an EfitX member exclusive article. Please do not copy information without consent from EfitX or Web Wizzy. The topic is to understand how calories enters and leaves your body. This content will assist you and your coach on how to plan an effective weekly caloric deficit strategy.


  1. Consumption of food and liquids.
  2. Transfusions or surgery
  1. Exhaling (Cardiac Output)
  2. Excreting (restroom)
  3. Sweating
  4. Discharge of skin cells, hair and other…
  5. Amputation
  • Consumption of foods including liquids.
  • Exhaling (Cardiac Output)
  • Excreting
  • Sweating

Photo (c) Jiri Miklo – Fotolia

Image by PublicDomainPictures from Pixabay


Cardiac Output (K. Pai, 2020) is every breath exhaled from your lungs. While we inhale the majority of nitrogen and oxygen, we exhale a significant amount of carbon dioxide and other bi-products. Most weight loss results is achieved by increasing how much oxygen we intake and how much we exhale on a daily basis.
On average, a person without exercising may exhale up to 2.3 pressure pounds of carbon dioxide (B. Palmer, 2015) on a daily basis. Adding proper exercise may increase that amount up to 8 times. Keep in mind this measurement is in pressure pounds and not to be confused with body weight.


I have used many fitness wrist watches. While they are great of monitoring rhythmic changes of your heart beat and also provide some useful health features, they have yet (Feb 2021) to provide enough information to accurately measure caloric output thus measure carbon dioxide. A Stanford University study (J. Dusheck, 2017) shows fitness trackers accurately measure heart rate but not calories burned. Currently the only accurate methods to measure calorimetry is with either body heat release devices, ECG devices or the output of Carbon Dioxide which is commonly measured by a capnography (Om Prakash Singh1, 2018) device. This would also require to breath into this device for many hours to accumulate formulated readings. A person’s heart will beat approximately 100,000 times per day. Exercising will increase the daily total but the actual cardiac output can not be determined without measuring stroke volume.


Cardiac output = stroke volume × heart rate

Here’s an example: If a patient's stroke volume is 75 mL, along with each heart contraction at 60 beats/minute, the cardiac output is 4,500 mL/minute (or 4.5 L/minute).

Resource: Nursing Center (L. Bonsall, 2016)

To make it simple, more cardiac output is produced by people of higher stroke volumes per heart rate volume. This means when comparing two subjects that accummulate 100,000 heart beats per day, the person with a higher stroke volume will produce more carbon dioxide output. Improving oxygen intake produces more cardiac output overall but there are variable amounts of different types of gases.


Now that we know that oxygen intake and cardiac output is the main measurement for expending more calories, we can break it down on how to produce it. There are five different ways.

1. RMR-BMR – This is the amount of calories to survive and to live our regular lifestyle. RMR Resting Metabolic Rate is the measurement of calories for sedentary activity while BMR Basal Metabolic Rate is the amount when lifestyle activities are performed. On a daily basis, RMR is fairly constant and variable factors may exists due to physical factors such as genetics, body mass, and health conditions. RMR changes when body composition changes. This can be done by increasing or decreasing muscle mass. BMR is always a variable amount of expended calories and is determined based on your daily activity level.

2. MAL - This is an EfitX created term so you may not find any other definitions online. MAL stands for Metabolic Activity Level. Since BMR produces variable calorie expenditure regularly, it needs to be adjusted when activity levels are significantly more or significantly less. Also to adjust to a person's metabolic rate. Users of EfitX can find a slide control setting to adjust this amount. Our suggestion is to adjust the MAL amount weekly based on your activity variances throughout the week. Some examples are: maybe you had to run several errands this week or walked up 6 flights of stairs on which you normally don’t do. THIS DOES NOT INCLUDE YOUR VOLUNTARY EXERCISE ACTIVITY.
3. RESISTANCE - Resistance training workouts is the process to develop muscle tissue. This is better known as hypertrophy. When muscles are challenged in a set by set process for a duration of 30 to 120 minutes, heart rate usually fluctuates between 60% to 90% bpm. This is anaerobic training.

4. EPOC / RT AFTERBURN – Excess Post-exercise Oxygen Consumption (EPOC) is the measurement of increased cardiac output produced after you have exercised. EPOC is known to be present for long periods after exercising up to 96 hours. This is part of a recovery process to mainly replenish glucose, ATP and to repair cellular tissue. EPOC is significantly greater after challenging resistance workouts versus cardio aerobic exercise.

5. CARDIO / AEROBIC – Cardiovascular exercise is better defined as any escalated amount of resting heart rate during exercise. Aerobic exercise is movement which sustains heart rate within a targeted heart rate zone. This target is approximately between 65% to 85%. Unlike resistance training, performing aerobic activity regularly produces small amounts of EPOC. This is due to lighter loads and earlier muscle adaptation as rhythmic movements become efficient to perform.


Recently, more studies and fitness programs are emphasizing the benefits of resistance training. In my opinion, both are equally important but each are utilized for different purposes.

Benefits: Strengthens heart, improves blood flow through arteries, increases capacity of the lungs. Improves endurance performance. Expends calories mainly in real-time.

Benefits: Strengthens or maintains strength in muscles and joints, increases metabolism by changing body composition. Improves mobility and physical strength performance. Expends calories in real-time and with the presence of EPOC for up to 96 hours.


Today there are many claims on specific methods to expend fat quicker. While performing cardio is still one of the quickest ways to lose weight, not only fat is coming off your body. Vigorous amounts of cardio exercise produce significant amounts of water excretion. There is also beliefs that most of the expenditure from cardio is fat. For short bouts this is not true. Any type of exercise whether it is resistance training or cardio the first resource of energy will come from abundant forms. So, if you have glucose readily prior to cardio exercise, you may spend several minutes expending that prior to hitting surplus fat or subcutaneous fat.

Cardio for long periods without proper nutrition may lead to detrimental effects such as a negative balance of nitrogen and muscle catabolism. This is one reason why I don't support the “Fasted Cardio” method because the procedure begins when the body is within a “hungry “state where nitrogen balance and glucose are low. A study by J Physiol Anthropol (J. Anthropol. 2014) shows nitrogen balance is more affected by subjects that exercise when the restoration attempt is delayed. Nitrogen supports the maintenance of muscle, so depriving your body from it may lead to muscle loss. While this delay can be replenished quicker by eating something, it may seem controversial on why fasted cardio was performed in the first place. Cardio is great but it needs to be performed properly to achieve weight loss results. At the end of the day, creating a caloric deficit will supersede any fancy technique.


One bodyweight pound = 3500 calories

(220 – age) x 0.75 = THR (Target Heart Rate)

BodyWeight (lbs) x 4 = ETHR-EPR (estimated THR expenditure per hour)


Using the formulas above: a person that weighs 200 pounds at age 30 has a THR of 142 bpm and most likely will expend around 800 calories per hour exercising while sustaining a target heart rate of 75%. If this person performs one hour per day every day of the week it adds up to 5600 calories. But this is only true if heart rate averages 142 bpm throughout every session. Remember with cardio, expenditure is mainly in real-time, meaning there is less afterburn post exercise of the cardio session.


Weight training workouts produce volatile results in caloric expenditure. While real-time expenditure is similar to cardio training, there is also the presence of EPOC.
This afterburn effect is developed from challenging workouts (not easy-peasy workouts). Sometimes you may experience soreness called DOMS (Delayed off-set muscular soreness). The amount of soreness perceived does not necessarily equate to more caloric expenditure and cardiac output however, it does make lifestyle activities more difficult to perform. This may result to an increase of your lifestyle BMR. For example, a simple walk from your car to the office was three times more challenging because of a brutal leg workout from the previous day. Weight training also promotes muscle growth which also may increase RMR/BMR and metabolism. (J. Davis n.d.)

EfitX measures two types of workout volume to assist on measuring EPOC results. There is also a proprietary formula to convert volume into EPOC calories. When comparing Strength Volume versus Endurance Volume, Strength Volume is a significant higher producer of EPOC caloric expenditure.



  • Produce more resistance training volume each week on a weekly basis. For beginners, focus on just total resistance training volume in whole. Novice to advance exercisers, it is important to draw focus on improving strength volume to avoid the body from adapting.
  • Perform cardio requirements two to four times per week, based on your coach’s recommendations.
  • Consume the suggested amounts of calories recommended by a qualified nutrition coach or registered dietician. For beginners, focus on just the amount of calories for a few weeks, there after begin adjusting macronutrients to compensate the changes.
  • Routines and protocols should provide a sequence which optimizes strength hypertrophy and maximizes fat expenditure in real time.


There are so many other variables which may off-set the measurements above. The most significant culprit of inaccuracy is the consumption of calories where even most of the best nutrition trackers fail to provide accurate information. Fitness Apps based on user-input data usually provides incomplete or inaccurate data thus excludes the measurements of some important nutrients such as potassium. As mentioned above true calorie expenditure is difficult to measure unless you are breathing through a capnography device all the time. With all this said, the margin of error is fairly large so it is important to be fairly aggressive on trying to produce big enough numbers to make a difference. However it is important to select feasible and safe amounts. Consult a professional if you need assistance.


Exhaling carbon dioxide is the main method for expending calories. Cardiac output is not accurately measured with heart rate alone. There are five ways to produce cardiac output and that is from RMR/BMR, MAL, resistance training, EPOC , and cardio activity. While cardio activity is a simpler routine to perform, resistance training can produce more significant long-term results for fat loss. Special fat burning techniques are usually over-rated because it really depends whether you've created a caloric deficit at the end of the day. There is a fairly big margin of error to measure both calorie intake and calorie output so it’s better to be aggressive on choosing amounts in order to make a difference.

To help improve research in this area, here is a resource where you can view latest cardiovascular studies and participate by uploading your activity stats. Dr. Euan Ashley's lab:

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