KNR 280 Exam 1

Exercise

A planned, structured, and repetitive bodily movement done to improve or maintain one or more components of physical fitness Has a goal: improve health, look better, etc. It is *physical activity (PA)*

Physical fitness

A set of outcomes or traits that relate to the ability to perform physical activity. Related to health Ex: VO2 max.- ability to bring in oxygen and bring it to your muscles

Metabolic Pathways, how many DIFFERENT outputs

ATP-PC system: ATP, creatine phosphate Anaerobic glycolysis: ATP, lactate Aerobic glycolysis: ATP, H+, Pyruvate, Acetyl CoA Krebs: CO2, ATP, H+ Beta oxidation: Acetyl CoA, H+ ETC/OP: ATP, H20

Minerals

Essential (not produced in the body) Elements, not from plants or animals Play roles in: bone and bone density, metabolism, enzyme function, muscle contraction, oxygen transport Calcium, phosphorus, magnesium, iron, potassium, sodium, zinc, etc...

ATPase

Hydrolysis --> ATP --> ADP + Pi + energy for work + heat ATPase is the enzyme responsible for the ability to breakdown ATP for energy If you break down then you are fatiguing

Summary of Krebs

Notice oxaloacetate starting and ending the krebs cycle Oxaloacetate combines with Acetyl CoA to begin and end the cycle

Nutrition focus

Nutrition can be considered from a *performance or health perspective* Diets of sedentary, average adults will differ greatly from competitive athletes There is no single dietary plan that works for everyone

Beta Oxidation

"Chops" fatty acids into chunks Each 2-carbon chunk is converted to Acetyl-CoA and moves to the Krebs cycle *A 12-carbon FFA would result in 6 Acetyl-CoA's* *NO ATP produced directly - this is a "preparation" pathway* Responsible for "starting your food" DO NOT FORGET IT MAKES H+!!!!!! MAKES 0 ATP

Aerobic def

"with oxygen" both aerobic and anaerobic relate to energy metabolism or how we transfer and use energy Our body prefers aerobic metabolism Activities that are *low-to-moderate in intensity and longer in duration* - during a marathon your body is trying to be as aerobic as it can at all times

*Factors influencing the energy pie, and energy expenditure during certain activities*

*10-30%- PA 10% TEF 60-80% RMR*

Protein

*10-35%* Growth and maintenance of lean tissue Repair of damaged tissue Fuel source during starvation Hormone production Immune function Recommended levels of protein consumption: -Sedentary = 0.8 g/kg/d -Endurance = 1.2-1.4 g/kg/d -Strength = 1.4-2.0 g/kg/d

Fat

*20-35% or 0.5 to 1.5 g/kg/d Major fuel source for endurance activity Highest macronutrient energy density (gkcal/g) Component of cell membranes and nerves Insulation Shock absorption Hormone production Fat soluble vitamin absorption (A, E, D, K)

EPOC (2)

*Excess post-exercise oxygen consumtion* is the elevation above resting oxygen consumption that occurs after exercise (*deficit and debt*) *High intensity exercise, at maximum results in larger DEFICIT and larger DEBT to repay!*

ATP, a reversible reaction

*Hydrolysis*: ATP --> ADP + Pi + energy for work + heat *Phosphorylation*: ADP + Pi + energy --> ATP What do we convert to make more ATP??? FOOD! Any time you break ATP you generate heat Phosphorylation: adding a bond back -olysis: separation/break down of

Why EPOC occurs, what's being paid back?

*Restoring ATP-PCr stores* Restoring what little O2 was stored in blood and muscle Respiratory and cardiovascular systems don't just drop back to resting levels instantly (about 1-2% of EPOC) Elevated hormone levels Elevated body temp (metabolic by-product) *Lactate clearance and removal* 95% restoring atp-pcr and lactate clearance and removal, 5% everything else

ATPPC or Phosphagen System (how it works)

1) CP + ADP --> Cr + *ATP* 2) That new ATP is used for energy (work) 3) Once ATP stores are stabilized... 4) *ATP* --> ADP + Po 5) Pi + Cr --> *CP* *It's like forgetting your wallet* Lighting fast (almost immediate) Cheap fast way to get you through until you make it back to your apartment

Energy (2)

60-70% of the energy in the human body is degraded to heat The remainder is used for mechanical work and cellular activities

Exercise Physiology

A basic and an applied science that *describes, explains and uses the body's response to exercise and adaptation* to exercise training to maximize human physical potential. Typically broken down by body system: the study of the impact of exercise on the physiology of body systems

Nutrients

A chemical that an organism needs to live- which must be taken in from environment: CHO (carbohydrates), Fat, Protein, Vitamins, Minerals, Water Nutrients are anything we take in, in order to live

Sport

A form of physical activity which involves competition

Metabolic pathways, fuel and IMPORTANT output

ATP-PC system: Fuel = *PC*, direct output =*ATP* Anaerobic glycolysis: Fuel = *CHO*, Direct output = *ATP* Aerobic glycolysis: Fuel = *CHO*, Direct output = *Pyruvate* Krebs: Fuel = *Acetyl CoA*, Direct output = *H+* Beta oxidation: Fuel - *FFA*, direct output = *Acetyl CoA* ETC/OP: Fuel = *H+*, direct output = *LOTS of ATP*

Sex

Absolute energy expenditure is significantly higher in males compared to females by 741 kcal/d, and non-resting energy expenditure is also higher in men by about 263 kcal/d.

Electron Transport Chain

Aerobic Mitochondria NADH and FADH are *oxidized* ADP is *Phosphorylated* O2 is used directly H20 is formed Lots of ATP! Hydrogen ions go into it Oxygen is used to take some H+ ions and make metabolic water Makes lots of ATP! More than any other pathway, even more than them added together

Krebs

Aerobic (without using O2) Mitochondria *Pyruvate is now Acetyl CoA* More ATP, *plus NADH and FADH for ETC* CO2 formation *Prep for more ATP - via the ETC!* Pyruvate is Acetyl-CoA 1st step is also the last step (cycle) Gives little ATP, main job is to give lots of H+ ions and CO2. This is the reason why we need to breath out. Preparation pathway

VO2max (2)

Aerobic capacities of 80-84 mk.kg.min have been observed amoung elite male long-distance runners and cross-country skiers The highest VO2max value recorded for a male is from an olympic champion cross-country skier who has a VO2max of 94 ml.kg.min Cold weather = have to work harder to get your oxygen The highest recorded for a female is 82 ml.kg.min in a Russian cross-country skier Poorly condition adults (couch potatoes) may have values below 20

Aerobic Metabolism

Aerobic metabolism refers to the process whereby energy is transferred in the presence of oxygen In aerobic metabolism, energy demand does not outpace oxygen delivery. - ATP-PCr requires no oxygen. Anaerobic glycolysis is the result of demand outpacing oxygen delivery Your *heart* and circulatory system are able to deliver oxygen in sufficient quantities to meet the body's needs for energy transfer In this circumstance, you initially use carbs as a fuel source and then shift to fat as the primary source Heart and respiration are the biggest factors If the intensity remains relatively low, this type of activity can go on indefinitely The only limiting factors will be orthopedic stress and low levels of carbs

Without oxygen (glycolysis)

An important part of glycolysis is also to provide Hydrogen for aerobic metabolism later down the line NAD (nicotinamide adenine dinucleotide) is one such transporter for these H's as seen NAD is the carrier When it grabs the 2 H's, NAD is changed to NADH + H But, we need more NAD to continue glycolysis, NADH must get rid of those H's and get back to work 1) With oxygen, NADH can shuttle the hydrogens into the mitochondria 2) Without oxygen, *PYRUVATE* serves as the "holder" for H, creating *LACTATE*

PCr System Summary

Anaerobic Occurs in the Cytosol of the cell Fast acting *Highest production rate of ATP (i.e. more ATP per unit of time)* *Does not DIRECTLY involve CHO, Pro, or Fat for energy production* Does not produce lactic acid Predominantly active for 3-10 seconds, perhaps up to 15 seconds (1-2 seconds is ATP) About 50% of PC stores are restored within 30 sec. of recovery, with 100% in about 2 min. Recovers faster than any other pathway Relevant for resistance training

Summary of glycolysis

Anaerobic Occurs in cytoplasm Net result *glucose*: 2 ATP, 2 pyruvate Net result *glycogen*: 3 ATP, 2 Pyruvate This pathway makes more ATP per step than CP Longer, takes more time, but makes more ATP Rate-limiting enzyme: Phosphofructolkinase

Anaerobic Metabolism - Part I

Anaerobic metabolism refers to the transfer of energy when there is a limited amount of oxygen available This occurs when we are first starting to move and also when we are active at high intensity At these times, the need for energy is greater than the speed at which the blood can deliver oxygen Metabolic pathways are little assembly lines. Ex: Anaerobic: CP -> CP -> ATP. CHO -> Glycolysis -> ATP. Aerobic: CHO -> glycolysis -> krebs -> ETC -> ATP. Fats -> beta oxidation -> krebs -> ETC -> ATP. Proteins -> glycolysis -> krebs -> etc

Physical Activity (PA)

Any bodily movement that is produced by the contraction of skeletal muscle that increases energy expenditure. Ex: running, cycling What does it mean when we say a person is physically active Broad definition includes sport, exercise, recreational activities that require movement, ADLs, human powered transport, physical labor, vocational movements, etc. So: kinesiology is the study of *physical activity* (including exercise and sport)

Metabolic rate

BMR is typically in the range of 1,200 to 2,400 kcal x day When daily activity is added in, the typical daily caloric expenditure is 1800-3000 kcal x day Energy expenditure for very large athletes in intense daily training can exceed 10,000 kcal/day

Running economy

Besides VO2 and Lactate threshold, another important factor for performance is *efficiency* Just as miles/gallon varies between cars, work per calorie varies between individuals Some people get MORE at a given oxygen consumption *or SPEED* Efficiency = work output/energy expended *Economy = oxygen cost of walking/running* *VO2mas, Lactate Threshold, Efficiency!!!!* Biggest 3 predictors for how well you perform

Fatigue - Metabolic Cause 2

Besides fatigue at the enzymes due to lactate, fatigue may result from outright depletion of CP or glycogen Either of these situations impairs ATP production CP supplementation Getting enough CHO via diet Run out of fuels - you're done

Aerobic Fat Metabolism

Beta oxidation: obviously these FFA are BIG, and result in lots of energy... but this pathway has one big drawback... Fat burns in a CHO flame... Oxaloacetate is REQUIRED for Acetyl-CoA to enter Krebs cycle. *Oxaloacetate will be converted to glucose* when no other glucose is available. *No available glucose, No fat metabolism* When we run out of glucose you'll use oxaloacetate. Fat burns: when you don't have glucose you won't do very well without it

Energy (3.)

CHO provides about 4 kcal of energy/gram, compared to about 9 kcal/gram for fat. CHO energy is most accessible. However, not the most available (quantity) Used in both aerobic and anaerobic metabolism We use CHO in the form of glucose Glycogen: stored CHO!!

Quiz review

CP- fastest, one step, no byproduct, no macronutrients Krebs- produces CO2, why we breath out, makes most H+, Acetyl coA (fuel) ETC- fuel H+ ions, make a lot of ATP, H2o (biggest producer) Beta oxidation- fats (fuel), produces acetyl coa and a few H+ ions Glycolysis- can be aerobic/anaerobic, happens in cytosol of cell, 2nd fastest pathway

Energy Balance

Caloric need is determined by a number of factors (age, sex, size, etc...) Consume to much --> weight gain Consume too little --> weight loss Your consumption of macronutrients determines energy gain Burn calories by burning more than you take in by *physical activity, BMR-RMR (basil metabolic rate - resting metabolic rate), TEF (thermic effect of food) - when you eat your body burns calories in order to bring in new food*. For kids, growth also burns calories

Different fuels for dif folks

Chp 3, 4, 5 slide 70 1) Why muscle glycogen and liver/blood not identical? Muscle glycogen is right there in the muscle because liver/blood is too far. All about convenience 2) Why FFA "low" during high intensity? You're still waiting on oxygen. FFAs are best energy source down the line. 3) It says "low", but where would amino acid be highest? All the way under low-intensity (<50% max) when you depleted your CHO and need amino acids to get it done

Beta oxidation

Complete fat (FFA) breakdown requires enough CHO to keep oxaloacetate available- otherwise FFA's are converted to Ketones (not a preferred fuel). *Decrease pH, especially problematic at rest* Relevant during fasting, starvation, diabetes, and long-duration events (where CHO is depleted) If im out of CHO and fat i'll use protein.

Factors influencing metabolism

Daily energy expenditure Genetics Health Organ function Endocrine function Age Drugs Sex (male/female) Body composition

Key points (nutrition)

Dietary plans are a *balance* of kcals and nutrients High-energy intake can result in: unwanted weight gain (fat), obesity, chronic diease (cardiovascular and metabolic diseases, etc...) Low-energy intake can result in: loss of muscle mass, menstrual dysfunction, loss of, or failure to gain, bone density, increased risk of fatigue, injury, and acute illness Goldilocks zone

Energy measurement

Direct calorimetry involves using a calorimeter to directly measure heat produced by the body The higher the heat, the greater the rate of metabolism and we can KNOW how many calories burned Remember: one kcal equals the amount of heat energy needed to raise 1 kg of water 1 degree C from 14.5 to 15.5 degrees C

Atwater General factors

Each macronutrient contains a different caloric density - representing how much each is "worth" Carbohydrates = *4* kcals/gram Fats = *9* kcals/gram Proteins = *4* kcals/gram Alcohol = *7* kcals/gram

Economy

Economy influences race-pace World-class distance runners might use 75-80% of their VO2max when running vs lesser runners at 85-90% b/c they are just as economic at the same speed - and require a lower intensity Partially related to lactate threshold, but also to economy Being able to use less oxygen to go a given speed means a lower RELATIVE intensity, further away from lactate threshold

Economy for movement

Economy of walking and running gets better as you get older (more economical) because you learn better coordination

Nutrition and Physical Activity

Energy for movement comes from the food we eat - each works through different metabolic pathways The three (or four) sources of energy are: CHO, Fats (lipids), Proteins, Alcohol Referred to as *macronutrients (or substrates)* Alcohol is not a CHO, fat or protein!!!

Variability of EE

Energy requirement are extremely variable, there are lots of factors to consider Most important ones: muscle mass, size and age!

Metabolism

Energy transfer and transformation 1st Law of Thermodynamics: energy can neither be created or destroyed... *only changed* in form Both: anabolism (anabolic- taking small things and building them into bigger things) and Catabolism (catabolic- take big things and break them down into smaller things) Macronutrients --> Metabolism --> Energy

ATP-PC or Phosphagen System

Entirely anaerobic energy production Cells store only a limited amount of ATP, so we must have a "little bit" ready for quick use Main function is to *maintain* ATP levels, providing rapid ATP Lasts only 3-15 seconds Burns through its fuel very fast, then you can't rely on it to make ATP This works by involving another high energy compound besides ATP, and that's phosphocreatine or creatine phosphate Goal is to resynthesize ATP from ADP almost instantly- CP is stored in the muscle in greater quantity than raw ATP, by about 4-6 times depending on the fiber type

Vitamins

Essential (not produced within the body) in small quantities Originate from plants or animals Used for growth, cell maintenance, metabolism and healthy reproduction Fat soluble - absorbed with the help of fat - A, D, E, K Water soluble- absorbed with water - B Complex, C Have the potential for toxicity when taken at extremely high doses over a long time - generally fat-soluble vitamins (but some water-soluble too). These are restricted to mega-doses. A "normal" consumer will not ever be at risk

Water

Extremely important for life and before, during, and after exercise Should take in about 2.2 to 3.5 liters per day. Again, depends on things like size and PA Dehydration is one of the major limiting factors during exercise performance Thirst mechanism is adequate for most non-athletes - but probably not for athletes It is possible to drink "too much" water May lead to potentially fatal condition known as *hyponatremia* - or water intoxification Hyponatremia occurs when too much water is ingested, usually after large sweat loss in 2005, a study demoed that 13% of runners in the Boston Marathon developed hyponatremia This happens if you don't have enough other "stuff" (electrolytes, sodium)

Energy measurement (2)

For CHO (per mole): RQ = 6CO2/6O2 = 1.0 For palmitic acid (a FFA, per mole): RQ = 16CO2/23O2 = 0.7 If we know the fuel - we know the pathway If we know the pathway and the quantity of oxygen and carbon dioxide - we know the *intensity!* .7-1.0 is a mixture of Carbs and Fats (both use the Krebs cycle to make CO2) All of these fatios have already been worked out- RQ = .7 is 0% CHO and 100% fat RQ = .79 is 28.6% CHO and 71.4% FAT (*rest on average*) RQ = 1.0 is 100% CHO and 0% fat RQ range is basically .7-1.0, allows us to know fuel source and kcal's burned/unit of oxygen Protein utilization is so low (we ignore it, limitation of RQ)

CHO

General recommendations: CHO *45-65%* or 4.5 to 10 g/kg/d CNS Primary fuel source Only anaerobic fuel source Required for fat metabolism Regulates protein metabolism CHO are the single fuel source of the CNS! Your brain likes it and nothing else If you don't take in enough CHO for your CNS, then you'll use protein which isn't ideal

Anaerobic Pathway #2

Glycolysis: generating anaerobic energy from glucose

Excess Post-Exercise Oxygen Consumption

I'm not working hard anymore, why am I still breathing hard? *Paying back* your friend and taking care of the credit card bill Women's 400 m final: race 50-60 seconds. Anaerobic

Cori Cycle

If the PC system is about forgetting your wallet, this is about using your credit card

Resting Metabolic Rate

In the average adult human, resting metabolic rate is highly variable between individuals (+- 25%), but is consistent within individuals (+-5%) Because RMR energy expenditure occurs predominantly in muscle and the major organs, the main source of individual variability in RMR is organ and muscle mass Influenced by sex; males have a higher value than females by approx 50 kcal/d

Averages

In young "healthy" individuals, the 40-60th percentiles for maximal oxygen consumption are about: 45 ml.kg.min for men and 38 ml.kg.min for women Women have a smaller VO2 avg b/c men have a high muscle avg, men carry more hemoglobin (use oxygen better)

Energy measurement (1)

Indirect calorimetry involves: measuring O2 consumption, measuring CO2 release, calculating the RER (respiratoryr exchange ratio) (or RQ- respiratory quotient) value, calculating the energy expended per liter of O2 consumption Instead of measuring heat produced- we measure O2 used and CO2 made while creating ATP Oxygen assumption and CO2 productions!

Anaerobic metabolism (2)

Individuals with higher lactate thresholds expressed as a percent of their VO2max are capable of the best endurance (aerobic) performance Why? --> they can run harder before they cross their threshold and fatigue starts setting in

Fatigue - metabolic causes #1

Lactate - Accumulation: as previously discussed, lactate accumulation (more specifically decreased pH of tissues) is detrimental to performance *Inhibits ATPase (and other key enzymes)* Besides disrupting ATPase, a decreased pH or increased acidity may also result in interference with other enzymes in all metabolic pathways. *Rate-limiting enzymes- very sensitive to changes in temp., pH, fuel concentration --> slow down our metabolic pathways* PFK slows --> everything slows Overall, lactate/H+ accumulation interferes with enzyme activity and results in a decreased ability to generate energy - resulting in less force generation and slower force generation

Lactate

Lactate is always being produced (even at rest) Lactate is always being removed/cleared - balance between production and clearance When lactate accumulates, it signals inhibition of performance - too many H's, not enough pyruvate and NAD = decrease pH and lack of fuel for aerobic pathways So, when I get too much, how do I CLEAR it? Hydrogens are bad guys

Elite athletes vs Regular Folks

Large male football/basketball players in training may require 9000-11000 kcals/day Competitors in other sports may be eating 4000-6000 kcals/day A small, sedentary, elderly woman may only need 1000 kcals/day

Fad diets

Many americans believe that, in terms of weight gain/loss, diet composition matters This gives the impression that you can eat what you like, in quantities that you want, without having to exercise, and still lose weight Ex- atkins diet

Forms of energy

Many forms of CHO, fats, and proteins, but they must be reduced to specific types for metabolism For example, CHO can be consumed as fructose, galactose, sucrose, maltose, lactose, etc... These CHO are eventually converted to glucose or glycogen in the body

Aerobic Performance Predictors

Maximal Oxygen consumption Lactate threshold Running economy The elite performers of the world have high values for all of these

INDIRECT Calorimetery

Metabolic analyzers: lab-based, portable units

DIRECT calorimetry

Metabolic chamber: pennington biomedical research unit

VO2max

Metabolism increases with increased exercise intensity, but oxygen consumption is limited to a degree Impossible to continuously increase intensity and maintain Most common aerobic type performance test done Avg. resting VO2max = 3.5 ml/kg/min (oxygen your body mass uses/min) VO2max is the max amount of oxygen you can bring in and use in the ETC Maximal oxygen consumption relates directly to athletic performance and health To attain VO2max, an exercise test can be used while monitoring oxygen use and carbon dioxide production Maximal intensity/oxygen you are capable of using *either relative or absolute value*

Lingo

Mode: type of exercise/what you're doing Intensity: light/moderate/vigorous, Supramaximal (any activity where you are below your max intensity) vs maximal vs submaximal, relative workload (relative to you; ex- bench pressing your own weight, usually a % or ratio) vs absolute workload (hard for some and easy for others) Duration- how long Frequency: how often you will do it Acute vs chronic: go with response and adaptation Response (your body's response to doing a certain acute thing) vs adaptation (how your body changes over time (chronically))

Myth and truth

Myth: the accumulation of lactic acid is responsible for the muscle soreness we feel 24-48 hours after exercise Truth: lactic acid is removed from your body as oxygen is delivered to your muscles. During recovery, lactic acid levels drop immediately and do not contribute to muscle soreness- lactate has a half-life of 15-25 min, with "full" clearance in about an hour Further, remember that exercises not necessarily stressing the anaerobic glycolysis pathway can still cause soreness (DOMS!!) DOMS is caused by an inflammation response triggered by microscopic damage to muscles caused by stressing them beyond their capabilities. the inflammation response causes swelling, tenderness, heat production and pain. As the overlap of actin and myosin decreases, ability to maintain tension decreases

Myth vs truth

Myths: only low intensity exercise causes you to burn fat and lose weight. Avoid high intensity exercise if the goal is to lose fat. Truth: While fat is the predominant energy source during low-to-moderate intensity exercise, it is also the predominant energy source when recovering from all forms of exercise. Energy out > energy in (remember that energy pie and balance scale) Use more total energy to lose more total weight. Also keep in mind that at higher exercise intensities you are also burning more total calories. At higher exercise intensities you also burn more *total* calories

Basic Reaction

NADH + H --> NAD Pyruvate --> Lactate Lactate Dehydrogenase So, we get to continue glycolysis with NAD, but Pyruvate can no longer be taken to the mitochondria for the Krebs cycle, those 2 H's are not available for use in ETC NOT nearly as efficient as aerobic metabolism, plus we have the lactate, or lactic acid, to deal with!!

Average EE

National recommendation is 1800 calories a day for average sedentary woman and 2200 for men (these differ as discussed, but approximate the median) For 19-25 year old women and men who are moderately active, the medians increase to about 2200 to 2800 kcal per day, respectively While total kcals is a critical aspect of nutrition, proper diets also require balanced nutrients...

Energy (3)

One kcal equals the amount of heat energy needed to raise 1 kg water 1 degree C from 14.5 to 15.5 degrees C. Kcals are just a unit of energy. The energy in 1,000 kcals is equivalent to: 3,968 BTU's, 1.163 kilowatt/hours, .001 tons of TNT

Aerobic metabolism (2)

Oxidation of CHO involves *glycolysis*, the *Kreb's cycle* and the *ETC* The end result is water, *CO2*, and 36 or 38 ATP/molecule of glucose depending on the type of muscle Fat oxidation begins free fatty acids, then follows the same path as CHO oxidation: the Kreb's cycle and ETC. The energy yield for fat oxidation is much higher than for CHO oxidation, and it varies with the free fatty acid being oxidized. How much higher depends on what type of FFA- a molecule of glucose oxidized is about *38 ATP*. A molecule of fatty acid oxidized is about *138 ATP*

Protein metabolism

Protein can supply up to *5-10%* of the energy needed to sustain prolonged exercise Only the most basic units of protein - amino acids can be used to energy If at all possible, we want to avoid large amounts of protein metabolism

Aerobic Metabolism (2)

Protein oxidation is more complex because protein (amino acids) contains nitrogen, which cannot be oxidized Protein contributes relatively little to energy production, so its metabolism is often overlooked The complexity of protein metabolism stems from the many types of amino acids Deamination (get rid of nitrogen) or Transamination (transfer amin to someone else)

Nutrition and Exercise

Protein recommendations are a source of controversy among the general public Do we need to consume large amounts of protein if we exercise and wish to increase muscle mass? ex- a 20-25 year old football player in training (220 lbs = 100 kg). recommended intake for "strength" = 1.8-2.0. daily need = 180-200 grams. Assume his typical daily kcal consumption is 5000 kcals, assume this player intakes protein that is 20% of total kcals: divided by 4 kcals/g = 250 grams. that nets 250 grams more than needed. Just by eating a diet made up of 10-35% protein, he will get the amount required - even though he is a "strength" athlete

Key points (protein)

Protein: generally met through diet without the need for any supplementation - save your money and just strive to eat a normal diet American's are notorious for consuming more than adequate amounts of protein - less than 8% of Americans eat less than 10% of their diet in protein (meaning less than 8% would benefit from supplementation)

Proteins

Proteins and CHO can be converted to fatty acids in the process called *lipogenesis*- easy to do..can happen in each cell Protein and fats can also be converted to glucose in via *gluconeogenesis*- slow...only in the liver *it's easy to make fat - difficult to unmake fat*

RER and RQ

RER = Respiratory Exchange Ratio: the ratio of the volume of CO2 produced divided by the volume of O2 consumed on the whole body level Also known as Respiratory Quotient: RQ = VCO2/VO2 Everytime a molecule of fat or CHO or protein is oxidized - we know how much oxygen is used and carbon dioxide is made The ratio tells us the & mixture of the fuel

Anaerobic metabolism

Resting lactate is usually around 1.0 mmol *Lactate threshold* is the point at which blood lactate begins to rapidly accumulate above resting levels during exercise (*relative* point). The *onset of blood lactate accumulation* (OBLA) is a standard value set at either 2.0 or 4.0 mmol lactate used as a reference point to signal lactate build-up (*absolute* point) Relative point depends on your fitness level OBLA: absolute point! 2x or 4x the resting lactate level

Lactate Terms and Importance

Sometimes, lactate builds up past resting levels OBLA, or the *onset of blood lactic acid*, (oxygen delivery not good enough, buffers, etc...). Lactate moves into the muscle, tissue and blood

Fatigue

Specifically muscular fatigue, is demonstrated by reduced force of muscular contraction and reduced velocity of contraction. Defined - failure of the muscle's (cell) contractile mechanism There are many theories to fatigue, and it is a complex issue Here, we will consider fatigue from 2 metabolic standpoints Fatigue- failure to contract at the way you want yourself to keep contracting

Components of fitness

Sport-specific physical fitness: anaerobic power and capacity, cardiovascular respiratory endurance; aerobic power and capacity, muscular strength, power, muscle endurance, balance, flexibility, agility, body composition values that will optimize performance Health-related physical fitness: cardiovascular respiratory endurance; aerobic power, muscular strength, muscular endurance, flexibility, body comp "

Anaerobic Glycolysis Summary

Still anaerobic energy Still occurs in the cytosol Fuel = *glucose (slower) or glycogen (faster)* Without oxygen, NADH + H must drop off hydrogens with pyruvate, forming lactic acid Less ATP per unit of time than PCr, but still more than any aerobic pathway Shines in 15-90 second, high-intensity bursts Lactate isn't a problem in the long-termr (clearance methods), but accumulation indicates short-term limitations To use glucose, you need to get it inside the cell. Insulin (hormone that brings it inside the cell). Glycogen is the fastest way besides CP If you want to go longer than 90 sec, lower your intensity or quit

Vitamins and minerals

Supplemental vitamins or minerals are rarely necessary Just like protein, if you are eating a "normal" diet - you will get enough already However, in some instances supplementation may be necessary Ex- supplementation: vitamin/mineral supplementation may be beneficial during very specific times (weight loss, pregnancy, sickness, etc) Calcium RDA's for... -youth (9-13 years old) = 1300 mg -most adults = 1000 mg -those women over 50 = 1200 mg

Example RER and energy expenditure

Take a 1-hour workout, 180 lb male: Walking at 2. mph: RQ = .85 (49% CHO, 51% fat), total kcal = 244, fat kcal = 113, CHO kcal = 108 Walking at 3.5 mph: RQ = .90 (66% CHO, 34% fat), total kcal = 343, fat kcal = 106, CHO kcal = 207 Want to lose weight - do highest intensity workout you can for you

Anaerobic activities

The ATP-CP and glycolytic systems are major contributors of energy during the early minutes of movement and high-intensity exercise High-intensity, short duration activities. Ex- sprint, weight lifting

Energy transfer - 3 "systems"

The ATP-CP system relies on the "*Phosphogens*"- anaerobic, short-term, intense, explosive The *glycolytic (lactic acid) system* relying on anaerobic breakdown of CHO- still anaerobic, yet slightly longer durations than above The *oxidative system* relying on the aerobic breakdown of CHO, fat and protein. Takes time, duration increased, lower intensity

Maximal testing

The Wingate lab was an example of an exercise test that examined the maximal capacity of the anaerobic systems - peak power, mean power, fatigue index Such tests also exist for determining AEROBIC capacity

Hyponatremia

The blood is diluted with water, but no sodium Sodium is required to maintain the water balance within cells and in the function of both nerve impulses and muscles Sodium is critical for RE-hydration Studies have shown that after prolonged exercise, leading to dehydration, chicken noodle soup (tons of sodium) outperforms water, Gatorade, and other sports drinks as a rehydrater.

Energy

The energy we derive from food (substrates) is eventually converted to a form usable by cells Adenosine Triphosphate, *ATP* ATP is adenine + ribose + 3 phosphate groups linked by 3 chemical bonds (triphosphate) - ADP (adenosine diphosphate), AMP (adenosine monophosphate) ATP is a high energy molecule- breaking phosphate bonds releases energy ATP is the *only* thing our muscles use for energy!! Myosin needs ATP (if you don't have any you don't get muscle contraction)

Difference - aerobic and anaerobic

The factor that differentiates the two is how *quickly you are able to circulate oxygen* to your muscles An activity may be "low" in intensity - but do you have enough oxygen at the muscle? Aerobic fitness! *If energy demand exceeds oxygen delivery*, you are performing predominantly *If oxygen delivery meets/exceeds energy demand*, you are performing

Aerobic Activities

The oxidative system involves breakdown of *all fuel types* with the aid of oxygen This system yields much more energy that the ATP-CP (phosphogen/PCr) or glycolytic systems Can use CHO, Fats, and Proteins Oxygen is the very last piece. Krebs is aerobic but doesn't use oxygen b/c they depend on the ETC to have oxygen

Total Calories

The total kcals (or total EE) required by each person varies greatly Some need 1,000 kcals per day, others need 10,000 *Things that affect how many calories we consume/burn*: Genes, Physical Activity (PA), Gender (males tend to have more muscle mass and muscle burns calories, size, hormones), Age

Creatine Monohydrate

Theoretically, if more Cr is available to react with ADP, more ATP can be generated in this pathway Creatine supplementation has become quite popular An upper limit to Cr storage, however, with excess Cr being excreted in the urine Supplementation is strenuous on the hydration level of the body About 2/3 of studies do show an increase in short-duration, high intensity exercise

Lactate Clearance - *Working backwards*

There are 4 major ways to CLEAR lactate: 1) Oxidized in the heart, cardiac tissue turns it back to Pyruvate and NADH + H (minor method) 2) Oxidized in the mitochondria, turned back to pyruvate and NADH + H. Not effective way to clear lactate b/c you don't have enough *oxygen*. Rest and recovery only method. 3) Sweat, a minimal amount is rid of this way (very small amount) 4) Turned back into glucose, via *Gluconeogensis* in the Liver. -*Protein and fat can also be converted to glucose in the Liver by this process* -Backwards glycolysis -aka The Cori Cycle -Big price - creating 2 lactate nets 2 ATP from glucose, converting 2 lactates back into glucose costs 6 ATP None of the 4 methods will help while running the 400!

CHO for ATP

Total: 625 grams, 2,124 kcal We have about 1.4 pounds of CHO ready to go to make ATP You can use all your CHO in a day, so carb load!

Fat for ATP

Total: 7,961 grams, 72,445 kcal. *A far larger quantity in reserve compared to CHO!* Our biggest volume of energy We use fat mainly in the form of triglyceride- 3 fatty acids + 1 glycerol. the 3 fatty acids are the major fuel, but the glycerol head can be used as CHO after conversion in the liver

Anaerobic metabolism (epoc)

Traditionally, EPOC was thought to reflect the anaerobic effort of exercise - if these symptoms work hard, more ATP to regenerate Too simplistic Several factors contribute to cause this increased post-exercise need for oxygen...

Metabolic primer conclusions

We have discussed metabolism through each of the major pathways, and from a substrate standpoint Also, several concepts such as anaerobic capacity (power, fatigue index), VO2, Lactate threshold, fatigue, etc..have been introduced This basis will allow us to continue into chronic adaptation and acute changes with exercise or training

Protein

We use protein in the form of amino acids 1 gram of protein = 4 kcal The *quantity* of protein available in the body is larger than that of CHO, however we do NOT want to rely on protein as a main energy source

VO2max + lactate threshold

We've previously discussed how lactate accumulation can impair performance, or signals impaired performance When this info is combined with Vo2max, much can be known about the athlete High VO2s and High lactate thresholds mean race-pace's at a higher intensity (greater speed)

Metabolism (2)

When bonds are broken: Heat, Physiological function, work Substrates -> Fuel: Food- carbs, fat, proetin -> Energy: ATP, ADP + Pi -> Work: heat and physiological functions The energy isn't lost, just "moved", 1st Law Release heat when we use an ATP

Aerobic Pathways: *Krebs Cycle*

When oxygen is present, NADH is shuttling H's to the mitochondria and pyruvate is being formed without having to turn to lactate The pyruvate is converted to Acetyl-CoA and kicks off the Krebs cycle

EPOC

When we start exercise, we don't have an "extra" amount of oxygen in our muscle cells Therefore, when we begin, we are performing anaerobic, exercise *every time* in those local muscles - ATP-Cr, Anaerobic Glycolysis Eventually, if the intensity is not too high, we are able to get the necessary amount of oxygen to the muscles This is why the initial moments of exercise feel uncomfortable and why within a few moments we get our "second wind" Our fitness level (ability of your body to 'move" oxygen) determines how quickly this occurs Really fit people have smaller EPOC The energy used anaerobically at the start eventually needs to be replaced - why we breathe hard after exercise!

Anaerobic Glycolysis

When: Demands of ATP exceed what is available from stored ATP and PCr system Niche: High intensity, short duration activities (10-90 seconds) The main goal of AEROBIC glycolysis is to create *pyruvate* from glucose to glycogen for use as acetyl-CoA in the Krebs cycle (which will be discussed later) However, when oxygen is not readily available, that pyruvate is converted to *lactate (lactate acid)* instead! 400 meter dash or 800 meter

Aerobic Fat metabolism

beta oxidation (*lipolysis - fat break down*) Breakdown of fatty acids to form Acetyl CoA for Krebs, and more *NADH + H and FADH* for ETC The bigger the FFA, the more ATP

Resting metabolic rate

collectively, fat-free mass, fat mass, age, sex, and PA explain 80-90% of the variance in RMR

Anaerobic def

literally means "without oxygen" On a local level (cellular level) this might be true Better to think in terms of "hypoxic" which means "too little oxygen" Anaerobic activities: *high in intensity, short in duration, or performed before enough oxygen is present*. This makes the *INITIATION* of movement anaerobic - the energy used to stand up and walk out of class is anaerobic activity. When you start walking home it becomes primarily aerobic

RQ summary

ratio of CO2/VO2 Range = 0.7-1.0 Fuel at low end = fat Fuel at high end = CHO Resting RQ = .78 or .79 Intensity at high end = 1.0 (running) Intensity at low end = .7 (laying in bed)