Exercise Nutrition

What is the Effect of Creatine in a Sprint exercise

increases peak power during repeated 10 seconds efforts.

Why does Creatine improve Performance?

more PCr = more ATP available = able to exercise at higher intensity for longer. it is due to an increase in muscle phosphocreatine stores. it also dilutes cellular proteins causing protein synthesis.

Chronic Creatine intake and training

regular creatine intake and training enhances muscle growth relative to training alone.

Super- Training Effect

can train harder due to the anabolic effect of creatine. the extra cellular water promotes protein synthesis.

Creatine Side Effects

increases muscle size and body mass (1-2 kg over first few days due to an increase in intracellular water). Creatine draws more water into the cell causing u to gain 2-4 pounds. this is an issue is sports like running where being lighter is an advantage. it makes u bigger (good for football, bad for runners)

What stimulates Glucose uptake into the muscle

Skeletal Muscle Contraction and insulin release

Post-activity Carb ingestion

After a CHO depleting activity, you should consume carbs within 30-60 minutes after. this is because your body is looking to replenish its stores. High carb diet enhances performance

When to use fats vs. Carbs during exercise

carbs allow you to work harder and longer. Athletes need carbs. Higher intensity = need carbs. when u consume more fat, you will burn more fat. if you allow your body to adapt to the high fat diet, your performance is not hindered cuz the high fat diet can be used for low to moderate intensities

Carb Loading Process

6 days before competition, do about 90 minutes of PA, then decrease this everyday leading up to the comp, then doing none the day before the competition. you must also increase your carb intake leading up the comp day. 6 days out, have about 50% of your diet be carbs, this increases on day 4 to 70%. This stays until comp day. This allows the muscle to increase its glycogen stores and hold onto more glycogen in prep for race day.

what does CHO during exercise do?

helps maintain blood sugar and enhance performance

sports drinks during exercise

a glucose polymer sports drink is easier to digest than regular carbs and hits the bloodstream faster. the drink provides glucose just like regular carbs. you need it to replenish your glucose stores fast. It also has electrolytes that will help to replenish fluid loss. At low blood sugar, the liver runs out of glucose to supply the muscle and brain so we need to have a sports drink to replenish that to allow us to keep going harder for longer

gender differences in metabolism

women often under eat relative to energy expenditure leading to health issues and performances issues. Women have a better ability to down regulate their metabolism compared to men. Women basically slow their metabolism so they can go longer without food. intense training is seen by the female body as starvation so it down regulates metabolism so u can live.

RED-S

the ability of women to down regulate their metabolism causes RED-S (relative energy deficiency syndrome) it stops ur period

Roles of Nutrients

1. provide energy

   • provide the energy u need to survive

   • breakdown body tissue to survive

   • micronutrients are important b/c they facilitate the processes that allow us to use energy from macros by making ATP regeneration more efficient

2. promote growth and development

   • need amino acids to make protein and therefore build muscle mass

   • stimulating the muscle while taking protein will stimulate muscle building

3. regulate metabolism

What are the components of Screening for Athletes

• medical check up

• MSK screening

• physiological testing

  • exercise testing for strength, power, endurance and VO2

• psychological testing

  • performance levels could be low cuz of lack of confidence

• nutritional screening

  • most informative when compared with:

    • dietary evaluation

    • biochemical testing of blood or urine

    • body comp analysis

    • clinical assessment of appearance or well-being

How is Diet Assessed?

• Retrospective Techniques - not recommended

  • dietary history or recall

    • interviewer asks athlete to describe their normal food intake.

    • last several week is more representative of real intake compared to last 24 hrs

  • food frequency questionnaire

    • checklist of food consumed

    • quick and easy

  • limitations

    • memory isn’t reliable. They also may change their answers to please the interviewers

• prospective techniques - recommended

  • analysis of duplicate meals

    • most accurate but very expensive - have to analyze their portions with exactly

  • food records

    • best practical option

    • 3-7 days of tracking food

    • use computerized food analysis data base

    • over 3 days of tracking u typically get lazy

    • include 2 weekdays and 1 weekend

  • limitations

    • may change their eating habits to please the interviewer

    • inaccuracies can occur due to missing foods in database

    • typically these underestimate intake (by up to 20%)

RNI

recommended nutrient intake: amount of nutrient necessary to meet the needs of essentially all of the population (CANADA)

RDA

Recommended Dietary Allowance: amount of nutrients necessary to meet the needs of essentially all of the population. 2 standard deviations on either side

AI

Adequate Intake: estimates based on observation of healthy individuals

• used when there isn’t enough data to give RDA

• more of an estimate

UL

upper limit: intake above this will cause health issues

EAR

Estimated Average Requirement: amount of a nutrient that would meet the needs of 50% of the population

• problematic b/c it only uses the mean and there may be ppl who need higher requirements that if they follow this will not be meeting their dietary needs

Ergogenic Aid

A procedure or treatment that enhances performance. includes shoes, training, drugs, and imagery

functional food

a food that has health benefits

Neutraceutical

a food component that has or may have pharmaceutical benefits (e.g., antioxidants)

Explain the Balance Technique

it is the classic method used to determine dietary recommendations. it measures the amount of nutrients that is ingested vs the amount that is excreted from all routes. positive balance (anabolic) = ingestion>excretion, used to grow. negative balance (catabolic) = excretion>ingestion, used to lose weight. if you are an athlete, u wanna be in positive balance. most anabolic phase in childhood, second is in puberty. but you can still be in anabolic as an adult when building muscle or gaining weight.

Essential Nutrient

Indispensable nutrients. cannot be made in the body and therefore need tone ingested or deficiency will occur.

Conditionally Essential

Nutrient that is sometimes essential depending on needs at current time. Histamine is an example that is only needed sometimes in periods of growth

Non essential Nutrients

Dispensable. Can be made in the body from other compounds.

What is exercise (sports) nutrition

relatively new area of study. it is exercise (non-competitive PA) vs Sport (competitive)

what are the two areas of interest for exercise nutrition

1. nutrient requirements

   • how does regular exercise affect food requirements?

     • Regular exercise usually increase food requirements

2. performance Effects

   • can supplementation with food or food components enhance performance

     • more creatine than u eat normally will enhance performance, as well as carbs and amino acids

important questions to ask when evaluating a claim?

is there any underlying rationale for how the supplement works?

good data?

is the person selling it using it gain money?

is it too good to be true?

Epidemiological Research

determines whether a relationship exists between two variables but DOES NOT determine causation - only shows correlation

2 types of epidemiological research

1. retrospective

   • study past behaviour to see if it affects someone’s current life

2. Prospective

   • study things that happen now and see if it affects their future

   • look at what they are eating now and follow them for a year and see if they get heart disease now or in the next decade

Experimental Research

involves an intervention. necessary for developing a cause-effect relationship. potential cause is manipulated (individual variable). smaller sample sizes and more labour intensive. often times you can’t compare age groups tho

considerations when evaluating experimental research

1. is there a good rationale for the proposed effect?

2. were the methods appropriate?

   • bias?

   • control of other factors affecting results

   • number and type of subjects

   • sufficient dosage

   • harmful side effects

   • validity of tests used

   • data analysis

3. have the results been replicated by others?

   • contradictory results?

   • confirm or deny your own findings

New revisions in Canada’s New food guide

• no more rainbow (sad)

• serving sizes gone because they don’t apply to everyone

• increase fibre

• lower meat intake and lower sat fat

• made simple statements as advice to ppl

  • plenty of fruits and vegs

  • eat plant protein foods

  • healthy fat, not sat fat

  • limit processed foods

  • make water ur drink of choice

  • choose whole grain foods

• it decreased the CHO recommendations b/c Canadians have too many carbs

• dairy is no longer its own food group, it is now within protein

What is the food exchange system

• originally for diabetes

• 6 food groups - similar in group energy and macro content

  • diff in macro and energy content of different exchanges (i.e., veg = 25 cal, milk = 120 cal)

  • also, different fat content (varies in milk and meat fat %)

• fat has over double as many cals as carbs and protein

• low fat diet is the way to lose body fat - less carbs (less cals)

• ppl tend to eat on a time-restricted energy diet - intermittent fasting

  • body adapts to new diet over first few days

• example of food exchange system

  • 125 ml of OJ, 17 small grapes, and 1 medium apple are all 60 cals,15 CHO and trace amounts of protein and fat

what are the 8 key nutrients

protein, vitamin A, thiamin, riboflavin, niacin, vitamin C, iron, calcium

What is nutrient density?

we want more nutrient dense foods. ex. 250 ml of pop has 25g of CHO and 100 cals. 250 ml of skim milk has 90 cals and 8 g of protein, 0g of fat, 12 g of CHO, and calcium, iron, vitamin A and Thiamin, riboflavin, niacin and vitamin c. Skim milk is much more nutrient dense

Different types of Vegetarianism

• vegan (most restrictive)

  • no animal products

• Ovovegetarian

  • eat eggs, no other animal products

• lactovegetarian

  • eat milk products

• ovolactovegetarian

  • eat milk and egg products

• Pescovegetarian

  • eat fish

• semivegetarian

  • eat chicken/fish but no red meat

Concerns with Plant-Based Diet: Vitamin B12, D

vitamin B12 is only found naturally in animal products, unless the food is fortified. Need to supplement Vitamin D all the time, especially in the winter!

Concerns with plant-based diet: Minerals

minerals are not absorbed as well from plant based foods because the plants create compounds that bind the minerals together (iron, zinc, calcium). could supplement iron

Concerns with Plant-based diet: proteins

unlikely to be deficient unless u get under 60g/day. complete protein = animal products. incomplete protein = plant-based.

What are complete vs. incomplete proteins

a complete protein is found in animal products and contain all the essential amino acids. An incomplete protein is found in plants. In an incomplete protein, one or more of the essential amino acids is not present.

what are complementary proteins

complementary proteins are those that you consume within the same day and NOT the same meal that together will allow you to get all the essential amino acids for that day. ex. beans and grains eaten in the same day, or veggies, milk, meat, fish, chicken, and eggs.

how many essential amino acids are there and what are they

9 of them. Methionine, Lysine, Phenylalanine, tryptophan, threonine, leucine, valine, histidine

What are the benefits of a plant-based diet

• low total fat

• low total saturated fat

• high in fibre

• low in calories (energy)

• high antioxidant vitamins (C & E)

• high in phytochemicals which may have positive health benefits

which foods do NOT require a food label

• fresh fruits

• fresh veggies

• raw meat and poultry

• raw seafood

• those prepared/processed in store (bakery items, salads)

• those with very few nutrients (tea, coffee)

• alcoholic beverages

what does a Canadian food label contain

• serving size

• core list (CHO, fat, protein, and breakdown of each)

• vitamin, minerals (% of daily intake)

• ingredient list (descending order by mass)

• health claims

What does Health Canada forbid the use of in foods as of 2018

Partially Hydrogenated Oils (PHO)

what does it mean if a food item is “Free” of something

“free” claims indicate the amount of a nutrient of energy is nutritionally insignificant

What does the nutrient content claim “light” mean

it is for substances that are low in fat, and low In calories, but NOT light in colour

what can u confidently make health claims about on food labels?

you can only make health claims that relate to a scientifically established relationship between diet and risk reduction. for example, sodium, potassium and high BP. OR, veggies and fruit reducing the risk of some types of cancer

food intolerance

an adverse rxn but not life threatening. ex. lactose intolerance

food allergy

allergic rxn to a food component that can result in swelling, rash, itching skin, tearing, and even breathing difficulties. anaphylactic shock and death (in minutes). allergies are usually to proteins in milk, eggs, fish, nuts, and wheat.

Food poisoning

nausea, vomiting, diarrhea caused by bacteria in food (salmonella, e.coli, etc. much of this is due to poor food handling.

food additives

things that are added to food. they are generally safe but make sure they are approved

food processing

can reduce nutrient density or introduce bacteria

what are food supplements

they are poorly regulated. they are man-made, isolated from a food or are chemically made. they are used significantly to enhance performance. not all of them are safe tho. some of them that claim to do stuff don’t actually do that stuff. some supplements are banned by certain organizations.

explain the PCr fuel available to muscles

PCr is for immediate use. it has a small supply of about 3-5 seconds of intense exercise. PCr is formed oxidatively (using O2) from foods that have been eaten previously. It can provide energy anaerobically as well. if you take creatine in large amounts, you can phosphorylate it, then u can increase your power

Anaerobic Glycolysis

provides ATP quickly but also produces lactic acid which will lower the pH of the muscle cell causing discomfort and ultimately process shutdown. it uses only CHO in the form of glucose. without NAD+, anaerobic glycolysis will shut down.

Ox Phos

provides more ATP than the other systems but it does so at a much slower rate because it is limited by the ability to deliver and use O2. It is heavily affected but training, if you are trained, you can deliver more O2 to the muscle and therefore provide more ATP than you could before. you DO NOT form lactic acid

explain glycolysis briefly

Explain the Krebs cycle briefly. What are some key things associated with the Krebs cycle.

you do not form lactate because O2 is not limited. Key thing: Krebs cycle is a CYCLE! it recreates itself. at several places there is the formation of NADH (3 places for each time around), a very similar compound of FADH2, both of which produce a lot of ATP.

Explain the ETC

occurs in the matrix of the mito. it is a series of protein complexes. at complex 1, NADH gives up an H+ and electrons to become NAD+. H+ moves thru complexes until it reaches the ultimate acceptor of electron at O2. The product of the ETC is water! CO2 is produced (we exhale it). the proton gradient allows ATP synthase to spin and create ATP and water. the ETC can become more efficient with training but it 80% determined by genetics.

Digestion

complex compounds (food) becomes simple compounds (nutrients). Anabolic Process

Absorption

nutrients → stored as complex compounds for later use (ex. simple sugars stored as glycogen). anabolic process

Catabolic processes in the body include:

Mobilizing stored energy (breaking down complex compounds to simple) to fuel muscle contraction. includes ATP, PCR stores, anaerobic glycolysis, and Ox Phos

metabolism

all physical and chemical transformations in the body. it includes anabolism and catabolism

anabolic

synthesis during growth or training (overload leads to increased skeletal muscle mass and strength with strength training)

catabolic

the formation of ATP from phosphogens, or breakdown of glycogen to glucose to lactic acid and ATP, or glycogen, fat, and/or protein to CO2, H2O and ATP

what is growth

anabolism > catabolism

metabolic rate

it is the measure of how rapidly the body is using its stored energy. when it is expressed for one day it is called the Total Daily Energy Expenditure (TDEE).

what is metabolism determined by

• resting energy expenditure

• food intake

• physical activity

what is RMR or REE

RMR is resting metabolic rate. REE is resting energy expenditure. They are both the basal functioning and a small increment due to previous PA. Typically RMR is measure. RMR exceeds BMR by about 10%. RMR = 1kcal/kg/hr.

what is RMR effected by:

• muscle mass

• age

• gender

• fitness

• weight loss

• low energy diet

• hormones

• caffeine

• smoking

• environmental temperature

RMR for men vs. women

men have more muscle mass. women need more excess fat and energy to support pregnancy. men are also typically more fit. therefore mens RMR is typically slightly higher.

explain the thermic effect of exercise (TEE)

it varies significantly between ppl (can be 15-30% of TDEE but near 0 in sedentary and as high as 50% in ultra-endurance athletes). it is measured as litres of O2 (1L = 5kcals), METs (10-20x RMR with aerobic exercise), or estimated from HR, Ve, onset of blood lactate accumulation, and perceived exertion. TEE increases due to PA

fuel use and fatigue is determined by:

Exercise intensity and exercise duration

Low intensity exercise

can sustain for many hours. Fat is the primary fuel source due to lots of stores, fatigue comes from hypoglycemias (low blood sugar) and dehydration

moderate to heavy exercise

30-90 min continuous or 5-15 min intermittent. CHO is used for fuel. fatigue is due to glycogen depletion, hypoglycemia, and dehydration.

high intensity

sustain for a few min. exclusively carbs for fuel. fatigue occurs long before carb depletion due to low pH in the muscle

Max intensity exercise

can only last a few seconds. fatigue due to PCr depletion. you are only using ATP and PCr, no carbs.

what is a carb (CHO)

it is an organic compound that is made of carbons, hydrogen, and oxygen. there are simple sugars, and complex carbs, and glycogen

what are simple sugars

disaccharides and monosaccharides. disaccharides include maltose (glucose+glucose), Lactose (glucose + galactose), Sucrose (glucose + fructose). monosaccharides include Glucose, Fructose and Galactose.

what are complex carbs

these are starches and are 3 or more glucose molecules combined.

• Oligosaccharide = 3-9 glucose molecules.

• Polysaccharides are 10+ glucose molecules.

• glucose polymers or maltodextrin are short (10-20 glucose).

• but starches or fibre or glycogen are thousands of glucose molecules.

  • Starch is amylopectin and is digested and absorbed rapidly.

  • Amylose is another example, but it is digested and absorbed slowly.

  • last kind of complex carbs are dietary fibre. it is a polysaccharide that are resistant to digestive enzymes, they increase satiety and reduce CAD and colon cancer.

• glycogen

  • complex chain of glucose

  • found in animals

  • 12 layers of glycogen - each one has a protein in the center.

Glycemic Index (GI)

numerical system ranking foods based on the rise in circulating blood sugar (rate of entry into the blood) (do not use when trying to lose weight.)

• it is better than simple vs. complex carbs.

• ranking system

  • 70 or more = high index

  • 56-69 = mid

  • <55 = low index

• it assess the rate at which glucose enters the blood after you eat a CHO

• assumes 50g of CHO per serving

• it does NOT consider how much CHO is in a serving of food

Glycemic Load (best classification)

assesses the actual impact of CHO consumption. it assesses glucose entry speed into blood and amount of CHO in a serving (GI x grams of CHO per serving)

20 or more = high

11-19 = mid

10 or less = low

popcorn and watermelon have low GL but high GI

limitation: both GI and GL are altered when consumed with other food

what is a normal blood glucose

80-100mg/ml of blood or 4.4-5.5 mM

what happens when insulin is secreted

when insulin is secreted from beta cells of pancreas which promotes glucose uptake by cells (including fat cells)

what happens when blood glucose drops

the liver will release more glucose to maintain blood glucose as long as it has enough stores to support that

where is CHO stored In the body

blood, liver, muscle, gluconeogenesis (formation of new glucose from glycogen stores)

functions of CHO

• major energy source (Brain and CNS, exercising muscle especially at high intensities

• combined with fat or protein to form cell membranes

• form smaller CHO compounds which are critical for muscle growth

Carb Loading (Super-composition)

important because body CHO stores can be limited and depleted in one exercise bout

it is beneficial for continuous exercise at moderate to high intensity.

Carb loading procedure

6 days before competition, do about 90 minutes of exercise and gradually decrease this over the time period leading up to the comp. DO NO EXERCISE the day before.

6 days before competition, make sure ur diet consists of 50% carbs. on days 4, increase this to 70%.

this procedure allows your body to store excess glycogen for the race day

how much CHO is enough?

DO NOT EXPRESS IN % of total intake

CHO loading = at least 5g/kg closer to 8-10 g/kg if possible

mass will increase with CHO loading by about 1kg

females may be less able to carb load due to less reliance on CHO during exercise. immediate post exercise ingestion is more critical in women

more training = more sensitive to glucose

timing of CHO intake before exercise

1-4 hours prior to exercise

• 4-5g/kg

• in many forms (fluid containing simple sugars or glucose polymers (maltodextrin) solutions or solid CHO

under 1 hour before

• 1-2g/kg

• glucose polymers or low GI CHO - absorbed slower (must be low GI or there may be tummy issues

under 10 min to exercise

• 0.8-0.85g/kg of glucose polymer solution (40-50% solution)

timing of CHO during exercise

30-60g/hr (1g/min) of 6-8% solution. mixture of a drink that is glucose and fructose is better because they use different transporters and there is no backlog.

what is the CHO oxidation rate during exercise

initially, as u consume more carbs, there is a linear effect, but with complex carbs, it doesn’t go up as much (levels off at 1g/min)

max rate u can consume more carbs and oxidize CHO is 1g/min

can consume more CHO is consumed as glucose and fructose since they have different transporters. but always consume more glucose than fructose cuz too much fructose causes tummy issues.

timing of CHO intake after exercise

over 5-6g/kg within a critical window. the critical window is 30-120 min after exercise, especially for woman. liquid CHO before leaving. 1.2 g/kg/hr

more CHO is synthesized when u eat CHO within the first 30 min after exercise. you store more glycogen the closer after exercise you eat