Metabolism & Energy Metabolism & Energy RequirementsRequirements

Nutrition & Performance

Metabolism & Energy Metabolism & Energy RequirementsRequirements

• Metabolism – the total sum of all chemical changes or reactions in the body

• TCB = total calories burned; amount of energy that you expend during day-to-day activities (i.e. sports, walking, working, etc.)

• TMR = total metabolic rate; equal to BMR + TCB

• BMR = basal metabolic rate; the amount of energy used by the body to perform vital functions (i.e. respiration, brain activity, etc.); decreases with age (from 2 years of age *peaks at puberty)

Other factors affecting BMROther factors affecting BMR:

• ·        Gender• ·        Body size/composition• ·        Fitness level• ·        Sleep• Pregnancy• BMR = 1 calorie X ___ body weight

(kg) x 24

Identifying the Energy-Balance Identifying the Energy-Balance EquationEquation

• TCB = total calories burned; amount of energy that you expend during day-to-day activities (i.e. sports, walking, working, etc.)

• DCI = Daily Caloric Intake, total amount of calories ingested in a 24 hour period

• Energy-Balance Equation= DCI-TCB• +ve Energy Balance= More Calories taken In

than burned• -ve Energy Balance = More Calories burned

than calories taken in

Nutritional Factors in Nutritional Factors in Performance and HealthPerformance and Health

• What is eaten, how it is eaten and when it is eaten may have marked effects on health and performance.

• Poor nutrition contributes to a host of health concerns as well as limitations to athletic performance

• Sports nutrition is one of the most studied areas of nutrition, and many long-held concepts of good nutrition, particularly those relevant to athletes, are being challenged.

Six Classes of NutrientsSix Classes of Nutrients

• FOOD is the carrier of nutrients • To get the nutrients we need, we require the right food

exposure• There are 6 classes of nutrients, which include:• 1. Water• 2. Vitamins• 3. Minerals• 4. Proteins• 5. Fats

• 6. Carbohydrates

Energy and FoodEnergy and Food• Energy(fuel) is derived from foods that contain three

different compounds in combination or as separate: Proteins, Fats, and Carbohydrates

• Vitamins and Minerals do NOT provide energy although they have many very important functions

• Water is a nutrient that literally ties everything together• It helps circulate nutrients to tissues, allows for

metabolism to take place, regulates body functions etc.• Each nutrient is equally essential, no class of nutrient Each nutrient is equally essential, no class of nutrient

can be eliminated in order tocan be eliminated in order to maintain a general level maintain a general level of healthof health

Energy and FoodEnergy and Food

• 1 gram of PROTEIN yields 4 calories of energy

• 1 gram of CARBOHYDRATE yields 4 calories of energy

• 1 gram of FAT yields 9 calories of energy

Composition of ProteinsComposition of Proteins

• The basic units of protein structure are AMINO ACIDS

• All amino acids contain nitrogen• Nitrogen is necessary for the formation of

peptide bonds• Proteins are essentially long chains of

amino acids linked together by peptide bonds

Composition of ProteinsComposition of Proteins

Synthesis of proteins in humans requires approximately 22 distinct amino acids

9 of these amino acids are ESSENTIAL ESSENTIAL AMINO ACIDSAMINO ACIDS

• Essential Amino Acids: amino acids that CANNOTCANNOT be synthesized by the body and must be obtained from plant or animal proteins ingested in the diet

NONESSENTIAL AMINO ACIDS

• The remaining 13 amino acids are termed

• NONESSENTIAL AMINO ACIDSNONESSENTIAL AMINO ACIDS

• Nonessential Amino Acids can be obtained from diet but can also be synthesized from other substances present in the body as long as there is an adequate source of Nitrogen

INCOMPLETE PROTEINS

• ·       Dietary proteins that contain low amounts of one or more of the essential amino acids are known as INCOMPLETE PROTEINS

• Incomplete proteins are generally of plant origin- nuts, grains, legumes and seeds

COMPLETE PROTEINS

• ·       Dietary proteins that contain all the amino acids essential and nonessential are known as COMPLETE PROTEINS

• Complete proteins are generally found in animal sources and products: meat, dairy products, eggs and fish

Food Sources of ProteinFood Sources of Protein

• Animal products & milk are richest in essential amino acids

• Plant proteins contain only some of the essential amino acids

• Common sources: fish, skinless poultry, fish, lean beef, skim milk, low-fat cheeses, nuts, legumes, and grains

Types of Protein: Animal sourcesTypes of Protein: Animal sources • Milk or complete milk protein – protein from

cow’s milk that has undergone filtration; casein & whey are still together

• Casein – isolated part of milk protein that prevents muscle breakdown

• Whey – part of milk protein that builds muscle; absorbed more quickly that its sister casein protein

• Egg protein – high protein efficiency ratings and support for building muscle; contains highest quantities of some key amino acids; allergies to egg white are not uncommon

Vegetable sources:Vegetable sources: Protein Protein

• Soy protein isolate – can contain >90% protein and provides high amount of glutamine, arginine, and branched-chain amino acids (BCAA); soy isolates lower cholesterol levels, and can increase body’s production of thyroid-stimulating hormone and thyroxin (bursts body’s ability to burn fat)

Vegetable sources:Vegetable sources: Protein Protein

• Rice protein – high in glutamine and alanine; role in preventing muscle breakdown; assists in carrying nitrogen to the muscle

Protein RequirementsProtein Requirements

• General Protein Requirement • Average adult male = 0.84g protein/kg

body weight/day• Average adult female = 0.75 g protein/kg

body weight/day • CALCULATING YOUR OWN:• Convert your IDEAL body weight into kg (/2.2)• Multiply this value by the # above dependent

on gender

Protein RequirementsProtein Requirements

• Athletes – increased need of daily protein (0.8 value TO 0.94 – 1.5TO 0.94 – 1.5 range and higher)* to be discussed later

Resistance Training and ProteinResistance Training and Protein

• Resistance training – major fuels that provide energy to perform activity are phosphocreatine & carbohydrates

• Synthesis of new muscle tissue requires extra protein, but this is most needed during initial phases of weight training & muscle gain

• Daily intake formula relates to body mass anyway, so there is an increased need as muscle mass increases from training

Excess amino acidsExcess amino acids

The body removes and excretes the “amino” group (called deamination); converts remainder of molecule to glucose, glycogen, or fat (stored as energy)

Energy from Protein during Energy from Protein during Prolonged ExerciseProlonged Exercise

Contribution of protein to energy production:• 2-5% kcal at REST• 4-15% kcal during EXERCISE • Protein metabolism during exercise depends on

variety of factors: intensity, duration, modality (type of training), level of protein, energy intake, age, and gender

Energy from Protein during Energy from Protein during Prolonged ExerciseProlonged Exercise

• Endurance training – 20-50% decrease in the rate of protein synthesis and an increase in rate of protein breakdown in liver & skeletal muscles (within skeletal muscle, protein catabolism is isolated to non-contractile proteins = 35% of total proteins)

CARBOHYDRATESCARBOHYDRATES

• SIMPLE Carbohydrates

• Monosaccharide – glucose, galactose & fructose

• Disaccharide – sucrose (gl+f), maltose (gl+gl), lactose (gl+ga)

• Easily processed and easily consumed

CARBOHYDRATESCARBOHYDRATES• COMPLEX Carbohydrate• Polysaccharide • Starch, glycogen, & the fibres (eg. cellulose)

• Plants store sugar as starch whereas animals (ie. humans) can store a limited amount of sugar as glycogen (liver & skeletal muscle)

• Starch & glycogen used by body for energy production; fibre is not

• Disaccharides & Polysaccharides – are broken down by digestion into monosaccharides before being absorbed

DIGESTIVE PROCESS to DIGESTIVE PROCESS to convert CARBS to ENERGY:convert CARBS to ENERGY:

• Monosaccharides absorbed by small intestine & travel to liver where they are transformed into GLUCOSE.

• Glucose stored in liver (GLYCOGEN) or released into blood.

• Blood glucose taken up & used by cells or stored as intramuscular glycogen.

• 2 forms of carbs serve as major fuels for metabolism (ATP production).

• 1 gram carbohydrate yields 4 calories of energy

Food Sources of CarbohydratesFood Sources of Carbohydrates

• Primary source = bread• Others = legumes, grain (wheat, rice,

oats, barley, corn) products such as pasta, & waffles, dried & fresh fruits, honey, sugar, and potatoes

• 60% recommendation of total caloric intake (45% complex vs. 10-15% mono- & disaccharides)

FATS & OILSFATS & OILS • LIPIDS – term used when discussing fats in the

body• Fatty acid

  The common lipid in the body; contains C, H, & O just as carbohydrates

• 3 most common: stearic acid, oleic acid, palmitic acid

• 2 essential fatty acids: linoleic acid & alpha-linolenic acid

Fatty acids

• Saturated Fatty Acid – C atoms are saturated with H atoms; e.g. palmitic acid

• Monounsaturated Fatty Acid – double bond exists between C atoms 2 less H atoms; e.g. oleic acid

• Polyunsaturated Fatty Acid – 2 or more bonds between C atoms are double bonds; e.g. alpha-linolenic acid

• * Location of double bonds btw C atoms influences the physiological effect of the fatty acid:

• Omega-3 fatty acid – first double bond btw 3rd & 4th C atoms

• Omega-6 fatty acid – first double bond btw 6th & 7th C atoms

Main Lipids in Body:

1. Triglycerides – 1 molecule of glycerol bound to 3 fatty acids; stored in adipose cells

2. Phospholipids

3. Cholesterol – sterol; forms parts of some hormones, forms bile acids used in digestion, and is incorporated into cell membranes; attributes to arteriosclerosis

ENERGY FROM LIPIDSENERGY FROM LIPIDS • Fatty acids represent the predominant fuel source to

aerobically manufactured ATP while AT REST and during LIGHT – MODERATE ACTIVITY

• Cholesterol – not used as energy source for the body cannot lower these levels with exercise alone

• LIPOLYSIS – process by which fatty acids are split from triglyceride molecule so they can be utilized; hormone responsible for this (lipase) is greatly influenced by epinephrine & norepinephrine

• During EXERCISE – free fatty acid concentration in blood may 8 fold; once in the skeletal muscle, FAs are activated at expense of 1 ATP molecule

• 1 gram fat yields 9 calories of energy

Food Sources of Fatty Acids:

• Saturated fats – animal fats (pork, beef, whole milk products), fats that are solid at room temp. (butter, lard), and certain plant oils (coconut, palm kernel); contributes to high blood cholesterol levels & cardiovascular disease

• Monounsaturated fats – no effect on blood cholesterol levels; olive & canola oil

• Polyunsaturated fats – soybean, sunflower, and corn oils

VITAMINS & MINERALSVITAMINS & MINERALS

• Important role in the metabolism of lipids, carbs,& proteins, and in muscle function

• Individuals at-risk for low vitamin/mineral intake are those who consume a low-calorie diet

• USA - 80% residents buy vit/mineral supplements & 85% competitive/elite athletes use them on a regular basis

• Supplementing one’s diet with vitamins and minerals to levels above the RDA does not increase physical performance

• RDA can be met easily with a varied & well-balanced diet

Vitamins • Nutrients that do not yield useful energy but

serve as parts of enzymes that are essential for life.

• Water-soluble (not stored in body; excess are passed in urine) & fat-soluble (stored in body in liver & fatty tissue; accumulations can cause toxic effects)

• Richest sources – green leafy vegetables, whole & enriched grains, skim or low-fat milk products, nuts & seeds, lean meats, poultry, and citrus fruits

MineralsMinerals • Inorganic compounds found in body that are vital to

proper bodily function

• Major minerals – body needs 100mg or more per day; examples – calcium, chloride, magnesium, phosphorus, potassium, sodium, and sulfur

• Trace minerals – required in the diet in amounts less than 100mg per day; examples – copper, fluoride, iodide, iron, manganese, selenium, zinc

• Sources – both plant & animal; more concentrated in animal products b/c animals eat plants

Meal TimingMeal Timing• In order to maintain optimal energy supply food

intake must be maintained throughout the course of a day.

• Regular food consumption over the course of the day will ensure adequate supply of carbohydrates to be available for energy consumption

• More importantly prevent protein from becoming the primary source of energy where lean muscle mass wasting could occur

• This can impact lean body mass ratio where lean muscle mass decreases and the proportion of bodyfat is higher

Meal TimingMeal Timing• Studies on caloric intake over the course of the

day revealed the following results:• Diets of equivalent caloric total intake those that

ate one big meal/day showed lower lean muscle mass ratio an higher bodyfat %

Vs.• Subjects that consumed balanced meals over the

course of a day (same # of calories) had higher lean muscle mass and lower bodyfat %

Weight Gain And Weight Loss

• Energy In Food

• Energy is commonly measured in KILOCALORIES (kcal)

• A KCAL is the work or energy required to raise the temperature of one kilogram of water one degree celsius

• A person’s rate of energy expenditure is related to body mass, intensity of exercise, and work efficiency

Weight Gain And Weight Loss

• Energy Cost

• Energy Cost is the total amount of energy used• Different activities have different Energy Cost• The Energy Cost of exercise and training can be

important from the standpoints of health and performance

• In order to gain the benefits for health a minimum energy cost volume and intensity threshold must be met

Weight Gain And Weight Loss

• Training Intensity and Energy Cost • The intensity threshold is approximately 7.5

kcal/min at approximately 500 kcal/week above resting levels

• In other words regular exercise will increase energy cost above normal by a minimum of 500 kcal/week that results from reaching the minimum intensity of exercise

• Benefits can increase up to 2000 kcal/week

Exercise and Energy Cost

• Several different types of activity can reach these thresholds

• It has been suggested that there may be a graded relationship between energy expenditure and health benefits, especially decreased risk of cardiovascular disease

Weight Gain

• In attempting to achieve higher body masses, considerable thought should be placed into proper nutrition and physical training programs that can:

• enhance lean body mass, • reduce gains in body fat • allow for achievement of optimal performance

Weight Gain

• The following should be considered:1. the goals of weight gain should be to maximize gains in

lean body mass and minimize gains in body fat. A substantial gain in body weight is almost always accompanied by a gain in percent body fat. The increase in body fat can be minimized by appropriate training and dietary practices 

2.An increase in body mass is best accomplished through specific training programs, particularly weight training 

3. Even when ISOCALORIC DIETS are eaten, more fat is gained on the diets higher in fat content.   The diet should keep the fat content under 30%. Individual differences should be considered

Weight Gain

4.Commercial weight gain products are usually unwarranted.  

• Some of these products have high fat content.

• The extra energy can usually be gained through ingesting more food.

• If schedules cause problems for regular eating a supplement may be useful

5. Body mass gains should be relatively slow, about .5 to 1.0 kg/week this rate tends to reduce fat gains 

Weight Gain

6. Monitor body composition closely and often.

• If % body fat begins to rise markedly consider a change in the diet or a change in the training protocol.

• As a general rule athletes in training trying to gain body weight usually gain 1% to 3% body fat for each 10 kg of body mass gained.

Weight Loss

• Athletes attempting to lose body mass should consider the following guidelines:

• 1.The ideal weight is NOT THE LOWEST BODY MASS.

• Starved or dehydrated athletes do not perform at maximum or optimal levels.

• Caloric reduction can potentiate overtraining and thus reduce performance.

• Some studies suggest that caloric restrictions in adolescents can result in shorter adult structure.

Weight Loss• 2. Previously untrained individuals can lose body

fat and gain lean body mass as a result of caloric restriction and training.

• It is unlikely that athletes already possessing relatively low body fat content can achieve body mass reduction without losing some lean body mass.

• Substantial amounts of body mass cannot be lost without losing some amount of lean body mass, especially in the case of caloric restriction.

• The loss of lean body mass can be minimized through training, namely resistance training and by a high protein diet during training. The use of fad diets is not advised.

Weight Loss• 3. The MAXIMUM RATE of acceptable body

mass loss appears to be 1% of body mass per week.

• Faster rates can potentiate the loss of lean body mass and glycogen stores, increase the possibility of dehydration and decrease vitamin and mineral levels.

• Loss of body mass carried out for longer than 4 weeks or a total body mass of more than 5% may potentiate a change in vitamin and mineral status.

• The amount of loss acceptable would be between .5 to 1.0 kg/week and would represent a caloric deficit of 500 to 1000 kcals/day

Weight Loss

• 4. In males low body fat is associated with a low testosterone concentration and increased incidence of injury.

 • Body composition should be checked to make sure

that the male athlete does not decrease below 5% to 6% of total body weight.

• In females body fat should not drop to less than 10%

Weight Loss

• 5. Rapids reductions of body mass can be accomplished through fluid restriction.

•  

• This is NOT RECOMMENDED as it is DANGEROUS and will have a DETRIMENTAL effect on performance

Vitamins and Minerals

• Go to: www.topdocumentaryfilms.com

• Watch “The Truth About Vitamins”

• Read Article “Joint Position Paper: Nutrition and Athletic Performance”

• Sportnutrition-2009