MODULE 3: NUTRITIONAL CONSIDERATIONS FOR EXERCISING INDIVIDUALS / ATHLETES

COMPONENTS OF ENERGY EXPENDITURE

What is metabolism?

Total amount of energy required for each of our physiological actions.

Difference between RMR and BMR?

BMR requires extreme fasting conditions, extended periods of rest, tight environmental control.

70% of energy we expend each day goes toward non movement related physiological activity.

Thermic effect of food

TEF is used for digestion, absorption and assimilation of ingested food/nutrients.

Act of eating increases metabolism BUT IT DEPENDS ON WHICH MACRONUTRIENTS we ingest.

Protein has highest TEF , Fat has lowest.

PHYSICAL ACTIVITY

High variable

sedentary - 10 to 15%

Highly active - 30 %

ESTIMATION OF ENERGY NEEDS

Measuring oxygen consumption can help measure energy cost

Direct mathematical relationship between amount of oxygen we breathe in and amount of energy required by the body

Burning of fuel mixture (CHO + Fat) provides 4.82 calories per litre of Oxygen.

Putting it into perspective....At rest, we burn 3.5 ml of oxygen / kg body weight /

minute

Person = 70 kg

Oxygen consumption per hour --- 3.5 x 70 x 60 = 14.7

Oxygen consumption per hour --- 14.7 x 24 = 352Therefore, Calories burnt = 3.52 x 4.82 = 1700 kcal

When exercise is added : breathing harder and faster ---- more oxygen --- therefore more calories burnt.

Oxygen consumption and energy expenditure are closely related!

ESTIMATION OF ENERGY EXPENDITURE

Indirect calorimetry

Estimation of EE via measurement of oxygen consumption and carbon dioxide production.

Direct calorimetry

Direct mesurement of heat output by the body, used as index of energy expenditure.

Double labeled waterThe Doubly Labelled Water (DLW) method uses the natural

occurring stable isotopes of water (D2O and H218O) to assess energy expenditure

The DLW method is entirely safe and non-restrictive, requires only periodic sampling of body fluids and is well suited for measurement of energy expenditure in free-living or hospitalized patients.

The basis of the DLW method is to follow the decline in enrichment of the stable isotopes of oxygen (oxygen-18, 18O) and hydrogen (deuterium, 2H) in body water after initial labeling of the body water pool.

As oxygen-18 is lost from the body in the form of water and carbon dioxide (CO2), whereas deuterium is lost only as water, the difference in loss from the body reflects the CO2 production during the period. Because CO2 production is the result of fat, carbohydrate and protein oxidation, it is an index of energy expenditure.

Bioelectrical impedance analysis

• This procedure involves sending a very small current through the body—800 mA at 50 kHz, which is unable to be felt—and measuring its resistance.

• The underlying theory to this procedure is :Lean tissue offers less resistance to a current as it contains more water and electrolytes than adipose tissue

• This is an affordable and non-invasive method. Another advantage of this procedure is that no special training or skill is required

Several factors may influence its results such as It quickly estimates the REE based on its estimation

hydration state of the subject, prandial/fasting state, exercises, diuretics use, menstrual period,

PREDICTIVE EQUATIONS

Mifflin-St Jeor (1990) in kcal/day

Male: (10 x W) + (6,25 x H) – (5 x A) + 5Female: (10 x W) + (6,25 x H) – (5 x A) – 161

W = Weight in KgH = Height in cmA = Age in years

Owen Equation

MenRMR (kcal/day) = 879 +10.2 (weight in kg)

Women:RMR (kcal/day) = 795 + 7.2 (weight in kg)

Harris and Benedict (1919) in kcal/day

Male 66.4730 + 13.7516(W) + 5.0033(H) – 6.7550(A)

Female 655.0955 + 9.5634(W) + 1.8496(H) – 4.6756(A)

Physical activities records:Low cost method that estimates EE from an extremely detailed registry off all physical activity studies is limited due to various existing codesperform daily

Dietary questionnaires

ENERGY AVAILABILTY

A new concept that is being promoted is that of energy availability—that is, the energy that is left for body functions once the energy cost of training is taken into account

There is evidence that the body can tolerate a certain level of reduction in energy intake, but energy availability lower than 30 kcal (126 kJ) per of lean body mass is associated with impairments of metabolic, hormonal, and reproductive function.

Definition of energy availability Total energy intake—energy cost of training

Example of low energy availabilityAthlete = 50 kg, distance runner, 10% body fatTraining programme = 1000 kcal/dayEnergy intake = 2250 kcal

Calculations: Body fat = 10% or 5 kgLean body mass (LBM) = 45 kgEnergy availability = 2250 -1000 = 1250 kcal= 1250/45 kg

= 28 kcal/kg LBM

Example of adequate energy availabilityAthlete = 60 kg distance runner, 10% body fatTraining program = 1000 kcal/dayEnergy intake = 3250 kcal

Calculations: Body fat = 10% or 6 kgLean body mass (LBM) = 54 kgEnergy availability = 3250 -1000 = 2250 kcal= 2250/54 kg

= 42 kcal/kg LBM

• POWER EVENTS OF HIGHER WEIGHT CATEGORY (80 KG AND ABOVE)

• ENDURANCE EVENTS

• TEAM EVENTS, ATHLETICS AND POWER EVENTS OF MIDDLE WEIGHT CATEGORY (65KG)

• EVENTS OF LIGHT WEIGHT CATEGORY

• SKILL GAMES

ACTIVITY - Categorize different sports according to the groupshttp://www.ilsi-india.org/PDF/Conf.%20recommendations/Nutrition/Nutrition%20&%20Hyd.%20Guidelines%20for

%20Athletes%20Final%20report.pdf

MARATHON, LONG DISTANCE RUNNING,

WALKING, HOCKEY, WEIGHT LIFTING,

WRESTLING, JUDO, ROAD CYCLING,

ROWING , SWIMMING, FOOT BALL, THROWING EVENTS

BASKETBALL, GYMNASTICS, TABLE TENNIS,

YATCHING, BOXING, VOLLEY BALL, SKILL

GAMES SHOOTING, ARCHERY , EQUESTRAIN,

Functions of macronutrients- in brief

MICRONUTRIENTS

• Micronutrients include vitamins and minerals.

• They do not provide energy.

• They are needed in small quantities.

• Deficiencies and excesses of the micronutrients can affect health

Functions of micronutrients- (brief)

VITAMIN METABOLIC ROLE

A Antioxidant function

Thiamin Carbohydrate metabolism

Riboflavin Mitochondrial electron transport

Niacin Multiple metabolic pathways

Pyridoxine Amino Acid synthesis

Folate Red blood cell synthesis

Cyanocobalamin Red blood cell synthesis

Ascorbic Acid Antioxidant, Tissue repair

D Calcium homeostasis, Immunity

MINERALS PROPOSED BENEFITSUMMARY OF RESEARCH FINDINGS

Calcium Important for forming bone and teeth, clotting blood, and transmitting nerve impulses.

Zinc Associated with immunity

Selenium Antioxidant.

Iron Helps to transport oxygen around the body