Questão | Responda |
Calorimetery | *The study of energy needs of the body & energy content of foods. *Allows us to determine caloric balance.. |
A calorie is the amount of heat energy to raise the temperature of 1L of water from 14.5C to 15.5C | True |
A bomb calorimeter is used to measure caloric content of foods. | True |
Caloric requirements of humans are large. | True |
Calories are typically measures in kilocalories. | True |
1 Calorie = 1000 calories Capital C = kilocalories | True |
Caloric Content of foods: | Carbohydrates: 4 Calories/gram Protein: 4 Calories/gram Fat: 9 Calories/gram |
Caloric needs of an individual is determined by: | 1) Direct Calorimetry 2) Indirect Calorimetry |
Direct Calorimetry | *Individuals live in a chamber. *Temperature change in chamber indicates the amount of energy spent. |
Indirect Calorimetry | *Uses of oxygen consumption to estimate the amount of calories used. *For every liter of oxygen consumed, the body uses 5 Calories. |
Can determine caloric need by: | 1) Resting Energy Expenditure + Activity Energy Expenditure 2) Harris-Benedict Equation = BMR Males: 66 + (13.7 x weight kg) + (5 x height cm) - (6.8 x age) Females: 665 + (9.6 x wight kg) + (1.8 x height cm) - (4.7 x age) Activity level factor: Sedentary: 1.0 x BMR Low Activity: 1.11 x BMR Active: 1.25 x BMR Very Active: 1.48 x BMR |
Gaining Weight | *Adding 1lb of lean muscle requires 2300-3600 extra calories. *Muscle anabolism occurs at limited levels & limited rates following resistance training. *200-300 Calories/day increase. Greater increases promote fat deposition. |
Losing Weight | *Losing 1lb of fat requires 3500Calories deficit. *Extreme calorie deficit reduces metabolic rate & makes it more difficult to lose weight. *Reduces energy stores for training. *Caloric requirements = nutrient reduction. *Reduction in carbohydrates reduces water weight. *Glycogen requires water for storage. *Reduction of 200-300Calories/day is good. |
Good weight loss strategy for athletes: | *Weight should be managed throughout the year. *Don't weight until in-season or periods of hard training to implement serious weight loss. *Reduce daily caloric intake by small amounts. *Maintain reasonable carbohydrate consumption to maintain energy levels (endurance athletes). *Some evidence suggests extra protein consumption may help prevent muscle catabolism (muscle loss). |
Nutrients are divided into 2 categories: | 1) Macronutrients 2) Micronutrients |
Macronutrients | *Carbohydrates *Protein *Fat *Water |
Micronutrients | *Vitamins *Minerals *Trace Elements |
2 Carbohydrate Categories: | 1) Simple Carbohydrates 2) Complex Carbohydrates |
Simple Carbohydrates: | *Monosaccharides (glucose & fructose) *Disaccharides (sucrose) |
Complex Carbohydrates: | Polysaccharides (starch & fiber) |
Polysaccharide Digestion: | *We can only absorb monosaccharides from the gut into the blood. *All disaccharides & polysaccharides must be broken down into monosaccharides for absorption. *Differences in starch & fiber affect absorption of these carbohydrates. (humans can't absorb fiber) |
Carbohydrates | *All dietary carbohydrates are made of glucose, fructose, & galactose. *Glucose is the only carb we can metabolize. *We convert fructose & galactose in the liver. *Primary is as an energy substrate. 4Cal/gram *Stored in 3 areas. Liver (as glycogen) Skeletal muscle (as glycogen) Bood (as glucose) *Carbs are the only fuel that the brain uses. *Carbs are necessary for hight intensity exercise. *We store 2000-2500Cal of carbs. *Stores must constantly be replenished. *Maintaining blood glucose levels are essential to health & endurance exercise performance. *When blood glucose drops, liver glycogen is broken down into glucose & enters the blood. *Glucose in the blood then causes insulin to be released by the pancreas & glucose to enter the muscle. |
Carbs & Diabetes: 2 Types of Diabetes | 1) Type 1 -Person lacks the ability to produce insulin. -Exact cause is unknown. -Must take insulin injections. 2) Type 2 -Insulin resistant diabetes. -Some genetic predisposition. -Too much sugar intake. -0besity. |
Fats | *Majority of dietary fats exit as triglycerides. -Plant -Animal *Consist of glycerol molecules & 3 attached fatty acyls. |
Fat Digestion/Absorption | *Fats are absorbed from the intestine & transported to the liver. *In the liver they are combined with proteins & cholesterol to form lipoproteins. *Lipoproteins transport fats to peripheral tissue. |
Overconsumption & Atherosclerosis | *Excess dietary fat/calories leads to high blood lipoproteins. *Can adhere to vessel walls & contribute to plaque. Accumulation --> Atherosclerosis *Condition can be exacerbated by diabetes. |
Destinations/Uses for fats | *Energy *Pad & protect organs *Insulation *Cell membranes *Myelin *Blood clotting *Nutrient Absorption |
Fats as an Energy Source | *9Cal from 1gram of fat. *Requires more oxygen to release from fat that from carbs. *Fats are used during low to moderate intensity exercise. |
Fat consumption & weight management | -Fat consumption can be useful. *saliety eat less at each meal -Reduces motility. *reduces insulin spikes *consistent, extended delivery of nutrients -Must be conscious of caloric content. |
Fat Consumption & Exercise Performance | -Fats provide more Calories than carbs, however endurance athletes need to consume carbs. -Fats are used sparingly during extended, high-intensity exercise. -Body stores more fat than carbs. Carbs: *2500Cal *125Cal per mile *20miles from carbs Fat: *60Cal runner *2.4Cal of fat *9Cal per gram *21600Cal=170miles |
Proteins | -Proteins are composed of amino acids. -Amino group on one end, carboxyl group on the other. - There are 20 different amino acids in human metabolism. -Amino acids can be linked together w/ peptide bonds. These bonds help to form the larger molecules known as polypeptides. -Numerous polypeptides bind together to form proteins. -Characteristics of proteins is determined by types of amino acids, sequence of amino acids, & types of bonds. -Determine the shape, consistency, activity, & function of the protein. |
Amino Acids --> Proteins | -Amino acids are absorbed into blood, transported to target tissue. *Energy (4Cal/gram) *Synthesis of proteins -DNA provides blueprint for proteins. -Transcription & translation *which amino acids are used *sequence of amino acids |
Proteins are utilized for a wide variety of functions: | 1) Structural *muscle 2) Carrier/Transport *Blood (hemoglobin) *Membranes 3) Enzymes 4) Hormones *Insulin 5) Maintenance of blood volume |
Protein Abnormalities | -Amino acid sequence can affect shape & function of proteins. -Globin proteins of hemoglobins are composed of 31 amino acids. Substitution of AA #6, a glutamine, w/ a valine results in a malformed polypeptide. |
Essential Amino Acids | *20 amino acids *8 are essential *Body can't synthesize *Must be consumed in diet -Phenylalanine -Valine -Threonine -Tryptophan -Isoleucine -Methionine -Histidine, Arginine (infant & children) -Leucine -Lysine |
Protein Needs & Athletes | -We need 0.8grams/kg body mass of proteins. Bodybuilder would need 1-1.2grams/kg body mass Bicycler would need 1.4-1.6grams/kg body mass |
Too much protein: | -Consumption of more than 4g/kg body mass is dangerous. -Ammonia toxcity |
Water: | *The Most Essential Nutrient(most urgent) *60% of Body Mass is Water *Solvent for all Reactions *Fluid Portion of Blood *Used to Cool Body in Hot Environment -Sweat |
Water, Dehydration, and Exercise Performance | -Dehydration measured in % loss of body mass -A 100 kg man who loses 2 kg is said to be 2% dehydrated -Sweat comes from Plasma Plasma loss → reduced endurance exercise performance |
How much water do we need? | 8 glasses a day? Get outta here, it depends. Dehydration Results in Thirst Most will be fine drinking to thirst |
Micronutrients | -Vitamins *Organic Substances *Essential Nutrients A B complex C D E -Minerals *Inorganic *Essential Nutrients *Elements Iron Calcium Magnesium Chromium Sodium |
Recommended Amounts | Recommended DIETARY Allowance: Average daily requirement to prevent deficiency symptoms Typically need long term deficiencies to develop symptoms Fat Soluble vs Water Soluble Nutrients |
Am I deficient? | Do you have ostensive deficiency symptoms? 3 – 5 day dietary recall is required (write down everything you eat) Consistent deficiencies require changes in dietary habits or supplementation |
Supplementation | -Do athletes need more than the RDA? -Increased caloric intake -Eating a varied diet -Supplements are not a bad insurance policy -Usually best to consume with meals -Generally absorption is enhanced with foods |
Vitamin A | Essential for Light Absorbing Molecules in the Eyes Antioxidant – protects cell membranes Found in: Liver Fish Fish Oils Carrots |
B-Vitamins | 8 closely related vitamins Often used in metabolic reactions that lead to ATP production Typically found in Eggs, Grains, Meat |
Vitamin C | Anti-oxidant Protects Cell Membranes from Damage Can Improve Iron Absorption No Evidence that Mega Doses Bolster the Immune System Found in: Citrus Fruits Green Peppers Tomatoes |
Vitamin D | Necessary for Proper Calcium Metabolism Absorption Deposition and Mobilization Found in: Eggs Salmon Sunshine |
Vitamin E | Antioxidant Protects Cell Membranes Especially Red Blood Cells Found in: Corn Soy Meat Poultry |
Minerals: Iron | Necessary for Oxygen Transport Hemoglobin (blood) Myoglobin (muscle) Neuroglobin (nerve tissue) Cytoglobin (other tissues) Found in: Meat Eggs |
Minerals: Calcium | Maintain Bone Density Numerous Biological Processes are Regulated by Calcium Found in Dairy Green Leafy Veggies can inhibit absorption |
Minerals: Magnesium | Necessary for breakdown of ATP – Free Energy Release Found in: Grains Nuts Seafood |
Minerals: Chromium | Necessary for proper insulin function, insulin activates transports… Found in: Eggs Broccoli Grains |
Minerals: Sodium | Used for Fluid Regulation Action Potential (nerve signals) Found in: Hard not to find it |
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