8 measurement of energy expenditure in athletes

6-Measurement of energy expenditure in athletes

Advanced; Nutrition and Fitness

Dr. Siham Mohamed Osman Gritly


Terms to be learned

• Basal metabolism is the minimum amount of energy needed by the body at rest in the fasting state

• -basal energy expenditure (BEE) is the amount of energy used in 24 hours by person who is lying quietly, 12 hours after the last meal in comfortable temperature and environment or -resting energy expenditure (REE)-the amount of energy used by a person in 24 hours when at rest 3-4 hours after a meal


• metabolic rate-MR an expression of the rate at which the body utilizes oxygen, -the basal metabolic rate (BMR) is the basal energy expenditure expressed as kcal/kg body weight

• -total energy expenditure-the sum of the resting energy expenditure, energy expended in physical activity and the thermic effect of food

• -obligatory thermo-genesis is a portion of the thermal effect of food, the energy required to digest, absorb and metabolize nutrients

• .


• Maximal oxygen consumption (VO2); is An important measure of sports fitness; aerobic capacity, where the amount of oxygen body can consume and turn into energy

• -respiratory quotient (RQ) -is the ratio of carbon dioxide expired/moles of oxygen consumed or the ratio of oxygen used in metabolism (and therefore heat generated), to carbon dioxide eliminated

It is known as respiratory exchange ratio

respiratory quotient of;

Carbohydrate=1.0

Fat=0.7

Protein=0.82


Human energy

• Energy is the ability to do work

• Work is one form of energy, it is known as mechanical or kinetic energy.

• Energy are found in different forms in human

body Energy are of four types;-


Types of energy in human body

• 1-Chemical energy;– Storage form of energy

• 2- electrical energy for nerve impulses

• 3- Heat energy;– Product of metabolism energy to

keep body temperature at 37degree C

• 4- Mechanical energy;– Capacity to do metabolic work (muscle to be able to move)


Measurement of Work, PhysicalActivity, and Energy Expenditure

Work and power=

Work is the product of = force x distance

power; is how fast work is done it divided by time

Power = work/time

Measurement systems

– English

– Metric

– International Unit System (SI)

Energy measurement systemsTerms in the English, Metric and International Systems (IS)

sources; Melvin- Nutrition for Health, fitness & Sport


Unit English system Metric system International system

distance Foot (ft) Meter (m) Meter (t)

Time Second (s) Second (s) Second )s)

Force Pound (Ib) Newton (N) Newton (N)

Work Foot-pound (ft-Ib)

Kilogram-meter (kgm)

Joule (J)

power Hourse-power (hp)

Watt(W) Watt(W)

Interrelationships between work measurement systems sources; Melvin- Nutrition for Health, fitness & Sport (1)

Weight Distance Work Power

1 kilogram=2.2 pounds

1 meter=3.28 feet

1kgm=7.23 foot-pounds

1 Watt=1 joule/second

1kilogram=1,000 grams

1 meter=1.09 yards

1 kgm=9.8 loules 1 watt=6.12 kgm/minute

454 grams=1 pound 1 foot=o.30 meter

1 foot-pound=0.138 kgm

1 hourepower=550 foot-pounds/second

1 pound= 16 ounces 1,000 meters= 1 kilometer

1 foot-pound=1.35 joules

1hoursepower=33,000 foot-pounds/minute

1 ounce= 28.4 grams 1 kilometer=0.621

5 mile

1 newton=0.102 kg 1 hoursepower=745.8

watts


Interrelationships between work measurement systems sources; Melvin- Nutrition for Health, fitness & Sport (2)

Weight Distance Work Power

3.5 ounces=100 grams

1 mile= 1.61 kilometers1 inch=2.54 centimeters1 centimeter= 0.39 inch

1 loule= 1 newton meter1 kilojoule= 1,000 joulew1 megajoule= 1,000,000 joules1 joule= 0.102 kgm1 joule= 0.736 foot-pound1 kilojoule= 102 kgm


Measurement of work output and physical activity

• Nutrition scientists are used two conditions and systems to measure work output and energy expenditure;-

• 1-specific techniques in controlled laboratory research

• 2-measurement of energy expenditure within normal daily activities including sport performance


1-specific techniques in controlled laboratory research

• 1-to measure work output under laboratory conditions, scientists used devices known as ergometers

• An ergometer, such as cycle or arm ergometer is designed to provide accurate measurement of work, power and total work output over specific period of time



Ergometers;- an ergometer a device which measures the amount of work performed. The indoor rower is calibrated to measure the amount of energy generating. different types can be used


2-to measure work output during normal physical activity,

• 2-to measure work output during normal physical activity, devices such as pedometers and accelerometers have been used

• Pedometers and accelerometers devise for measuring daily physical activity. They are attached to the body to detect motion throughout the day, providing an estimate of total daily activities

• not for measuring energy expenditure


• Those devices are not measure or predict the energy expenditure, but use to measure the pattern of physical activity and in weight control


pedometers (sports and physical fitness)

• Often worn on the belt and kept on all day, it can record how many steps the wearer has walked that day, and thus the kilometres or miles (distance = number of steps × step length).

• A total of 10,000 steps per day, equivalent to 5 miles (8.0 km), is recommended by some to be the standard for an active lifestyle,


A pedometer is a device, usually portable and electronic or electromechanical, that counts each step a person takes by detecting the motion of the person's hips. Because the distance of each person's step varies, an informal calibration, performed by the user, is required if presentation of the distance covered in a unit of length (such as in kilometres or miles or miles) is desired


Components of Energy Expenditure

• There are three major ways individual can burn calories during the day which account for the total energy expenditure :

• 1-Resting metabolic rate (RMR),

• 2-The thermic effect of food (TEF),

• 3-Physical activity energy expenditure (PAEE).

1-Resting metabolic rate RMR or Basal Metabolic rate

• is the number of calories we burn to maintain our vital body processes in a resting state.

• It is usually determined by measuring the body’s oxygen utilization while the person lay or sit quietly in the early morning before breakfast after a restful night’s sleep.

• RMR typically accounts for about 65-75 percent of the total daily calorie expenditure.



• Basal energy expenditure BEE or basal metabolic rate BMR is determined largely by body size, body composition, Gender and age.

• Lower in females compared to males• BMR is typically measured by indirect

calorimetry under fasted conditions while subjects lie quietly at rest in the early morning for 30–40 min.


• The Harris-Benedict equation is a mathematical formula used to calculate BEE:

• Adult males: • BEE (kcal/day) = 66 + (13.7 x wt in kg) + (5 x

ht in cm) - (6.8 x age). • Adult females: • BEE (kcal/kcal) = 655 + (9.6 x wt in kg) + (1.7

x ht in cm) - (4.7 x age).


2-The thermic effect of food (TEF)

• results or estimation from eating food, and is the increase in energy expended above your RMR or BMR that results from digestion, absorption, and storage of the food.

• also called the specific dynamic effect (SDE) of food

• or the specific dynamic activity (SDA) of food.


• The sum of the TEF and any increase in the metabolic rate due to overeating is known as

diet-induced thermogenesis

• It accounts for about 5-10 percent of the total calories human body burn in a day.


• effect of foods:• Carbohydrate: 5–10%• Fat: 0–5% is very easy to process and has very

little thermic effect• Protein: 20–30% is hard to process and has a much

larger thermic effect• Alcohol: 15–20%• The percentages are calculated by dividing the

energy expended during digestion and absorption (above basal) by the energy content of the Food.

• basic formula for determining TEF is to multiply the total calories you eat by 10%. So, if you eat 2000 calories a day, you'll burn about 200 calories digesting that food

• Factors that affect the thermic effect of food; The thermic effect of food is increased by both aerobic training and anaerobic

• duration • intensity



3-Physical activity energy expenditure PAEE,

• accounts for the remainder of the daily energy expenditure,

• PAEE is the energy expended in exercise, the activities of daily living,

• PAEE can vary considerably depending on how much you move throughout the day. For example, your PAEE would be high on a day that you participate in several hours of vigorous sports competition or exercise,


Total Energy expenditure

• Energy expenditure is the total of resting or basal metabolic rate, thermal effect of food and physical activity

Total Energy expenditure or Calories expended =

RMR + TEF + PA


laboratory techniques for Measurement of energy expenditure

• Measurement of work is not the same as measurement of energy expenditure

• Most common devices to measure energy expenditure in human are calorimetries

• measures energy expenditure by;• 1- Direct calorimetry• 2- Indirect calorimetry• 3- Doubly labeled water technique• 4-Computerized Instrumentation


1-Direct calorimeter

• Direct calorimetry is a devise used to measure energy expenditure in human

• A person lives or works in the chamber for an extended period of time.

• Changes in water temperature relate directly to an individual’s energy metabolism.


2-Indirect calorimeter

• Indirect calorimeter used to measure

metabolism by determining the amount of oxygen consumed and the carbon dioxide produced under laboratory conditions (The Respiratory Quotient (RQ)

• It is also used to measure VO2max, and cardiovascular and respiratory function

• Indirect calorimetry measures energy expenditure (EE) by calculating the metabolic rate through measurements of oxygen consumption (VO2) and carbon dioxide production (VCO2).

• Indirect calorimetry is used much more often than direct calorimetry in terms of determining energy expenditure for individuals because it is much cheaper and easier to administer

• There are different types of indirect calorimetry,



Indirect calorimeter measures oxygen intake and carbon dioxide output to determine energy expended during daily activities


The Respiratory Quotient (RQ)

• The Respiratory Exchange Ratio• The ratio of carbon dioxide produced to oxygen

consumed

• The RQ provides information about the nutrient mixture catabolized for energy.

• The RQ equals 1.00 for carbohydrate, 0.70 for fat, and 0.82 for protein.


• The ratio of the volume of carbon dioxide released to the volume of oxygen consumed by a body tissue or an organism in a given period.

• The respiratory quotient (RQ) obtained from indirect calorimetry, defined by the ratio carbon dioxide production (VCO2)/oxygen consumption (VO2), is affected by extremes of substrate use by the body


3-Doubly Labeled Water Technique

• Provides a useful way to estimate total daily energy expenditure in human

• Expensive and should be used in an laboratory

• Doubly labeled water is water in which both the hydrogen and the oxygen have been partly or completely replaced for tracing purposes (i.e., labeled) with an uncommon isotope of these elements.


• In this method isotopes of hydrogen and oxygen in water are ingested

• Analysis of urine and blood samples provide data on hydrogen and oxygen excretion

• The labeled oxygen is eliminated from the body as water and carbon dioxide

• The hydrogen is eliminated only as water• Subtracting the hydrogen losses from the oxygen

losses provide a measure of carbon dioxide, which can converted to energy expenditure


Isotopes

Atoms with the same number of protons, but

different numbers of neutrons.

Atoms of the same element (same atomic

number) with different mass numbers

C-12 vs. C-14


• The method is safe, requires periodic sampling of body fluids (plasma, urine, saliva),

• is ideally suited for measurement of energy expenditure in free-living or hospitalized patients


4-Computerized Instrumentation

• A computer interfaces with at least three instruments:

• A system that continuously samples the subject’s expired air

• A flow-measuring device that records air volume breathed

• Oxygen and carbon dioxide analyzers that measure the composition of the expired gas mixture


Bomb calorimeters

• Bomb calorimeters measure calorie content by igniting and burning a dried portion of food. The burning food raises the temperature of the water surrounding the chamber holding the food. The increase in water temperature indicates the number of kilocalories in the food because 1 kilocalorie equals the amount of heat needed to raise the temperature of 1kg of water by 1°c


Bomb calorimeters; use to measure the energy content of a given substance


Measurement Unites for energy expenditure

• energy expenditure of exercise metabolism expressed either joules or calories.

• A joule (J) can be defined as the energy used when 1 kilogram (kg) is moved 1 metre (m) by the force of 1 Newton (N).

• A calorie (cal) can be defined as the energy needed to raise the temperature of 1 gram of water from 14.5 to 15.50C. Or is measure of heat


• One calorie is equivalent to 4.184 joules.• People use large amounts of energy so nutritionists use

larger units, called• kilojoules• 1 kilojoule (kJ) = 1,000 joules• 1 megajoule (MJ) = 1,000,000 joules• 1 kilocalorie (kcal) = 1,000 calories or 1 Calorie (Cal)• To convert from one unit to another:• 1 kcal = 4.184 kJ• 1 MJ = 239 kcal


• Calories in food represent a form of potential energy to be used by the body to produce heat and work

• CHO and fats are primary energy nutrients. A caloric value of each food stuff have been identified;

• 1 gram of CHO 4 C• 1gram of fat 9 C• 1 gram of protein 4 C


Energy Sources used During Exercise

1-ATP-PCr energy system• – Adenosine-triphosphate• – Phospho-Creatine

2- Lactic acid energy system• –anaerobic glycolysis


3- Oxygen energy system• – Muscle glycogen and blood glucose

(carbohydrate)

– Muscle triglycerides and blood FFA (fat)

– Protein (amino acids); minor source of energy• Training increases ability to use both fat and

carbohydrate

Fuels Used for Activities of Different Intensities and Durations

sources; Melvin- Nutrition for Health, fitness & SportActivity Intensity

Activity Duration

Preferred Fuel Source Oxygen Needed?

ActivityExample

Extreme 8 to 10 sec ATP-CP (immediate availability)

No (anaerobic) 100-yard dash, shot put

Very high 20 sec to 3 min ATP from carbohydrate(lactate)

No (anaerobic) ¼-mile run at maximal speed

High 3 min to 20 min ATP from carbohydrate

Yes (aerobic) Cycling, swimming, or running

Moderate More than 20 min

ATP from fat Yes (aerobic) Hiking



• Extreme activities All levels of activity intensity use the ATP-CP system initially; extremely intense short-term activities rely only on the ATP-CP system.

References

• Ellie Whitney and Sharon Rady Rolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008 Wadsworth, Cengage Learning

• WHO. 1985. Energy and protein requirements: Report of a joint FAO/WHO/UNU expert consultation. WHO Technical Report Series No. 724. Geneva.

• WHO. 1995. Physical status: The use and interpretation of anthropometry. Report of a WHO expert committee. WHO Technical Report Series No. 854. Geneva.

• Sareen Gropper, Jack Smith and James Groff, Advanced Nutrition and Human Metabolism, fifth ed. WADSWORTH

• Melvin H Williams 2010; Nutrition for Health, Fitness and Sport. 9 th ed, McGraw Hill

• Heymsfield, SB.; Baumgartner N.; Richard and Sheau-Fang P. 1999. Modern Nutrition in Health and Disease; Shils E Maurice, Olson A. James, Shike Moshe and Ross A. Catharine eds. 9 th

• edition

• Guyton, C. Arthur. 1985. Textbook of Medical Physiology. 6th edition, W.B. Company


8 measurement of energy expenditure in athletes

Technology

human energy energy

work work

siham mohamed osman

types of energy

electrical energy

amountof energy

energy expenditurework

humanbody energy