Measuring 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

Dr. Siham Mohamed Osman Gritly

• 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, Physical
Activity, 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 systems
Terms 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- Kilogram-meter Joule (J)
Ib) (kgm)
power Hourse-power Watt(W) Watt(W)
(hp)


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

1 kilogram=2.2 1 meter=3.28 1kgm=7.23 foot- 1 Watt=1
pounds feet pounds joule/second
1kilogram=1,000 1 meter=1.09 1 kgm=9.8 loules 1 watt=6.12
grams yards kgm/minute

454 grams=1 pound 1 foot=o.30 1 foot-pound=0.138 1 hourepower=550
meter kgm foot-pounds/second
1 pound= 16 ounces 1,000 meters= 1 1 foot-pound=1.35 1hoursepower=33,0
kilometer joules 00 foot-
pounds/minute

1 ounce= 28.4 grams 1 1 newton=0.102 kg 1
kilometer=0.621 hoursepower=745.8
5 mile watts


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

Weight Distance Work Power

3.5 ounces=100 1 mile= 1.61 1 loule= 1 newton meter
grams kilometers 1 kilojoule= 1,000 joulew
1 inch=2.54 1 megajoule= 1,000,000
centimeters joules
1 centimeter= 0.39 1 joule= 0.102 kgm
inch 1 joule= 0.736 foot-
pound
1 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 9C
• 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 & Sport
Activity Activity Preferred Fuel Source Oxygen Activity
Intensity Duration Needed? Example

Extreme 8 to 10 sec ATP-CP No (anaerobic) 100-yard dash,
(immediate shot put
availability)
Very high 20 sec to 3 min ATP from No (anaerobic) ¼-mile run at
carbohydrate maximal speed
(lactate)
High 3 min to 20 ATP from Yes (aerobic) Cycling,
min carbohydrate swimming, or
running
Moderate More than 20 ATP from fat Yes (aerobic) Hiking
min


• 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. 9th
• edition

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


Measuring energy expenditure in athletes

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Measuring energy expenditure in athletes

Similar to Measuring energy expenditure in athletes (20)

More from Siham Gritly

More from Siham Gritly (20)

Recently uploaded

Recently uploaded (20)

Measuring energy expenditure in athletes