Kin 232 - Hydration

What are the 8 essential functions of water in the body?

1. Maintains internal stability (temperature, pH, etc.) 2. Facilitates enzymatic reactions for energy production 3. Supports cardiovascular function and oxygen delivery 4. Delivers nutrients and removes metabolic waste (urea, CO2) 5. Evaporation of sweat lowers body temperature during exercise 6. Protects joints, lubricates movement, and hydrates cells 7. Aids in food breakdown and nutrient absorption in the gut 8. Essential for muscle contractions and nerve signalling

What percent of the whole body is water?

65%

What percent of the brain, bone, muscle, kidneys and liver are water?

Brain & muscle = 73%, Bone = 22%, kidney = 79%, Liver = 70%

What water inputs do we have?

Water/beverages, food, metabolic processes (small amount)

What water outputs do we have?

Insensible (sweat, radiation, etc ), respiratory (breath), Urine (biggest output), feces/stool/GI

Euhydration?

Water inputs match outputs (hydrated) --> want to be in this state

What are the 6 factors influencing the need for fluid?

1. Body size and composition (smaller = easier to get dehydrated, ↑BF, ↓MM → loses less H2O than ↓BF, ↑MM) 2. PA 3. Environmental: heat & altitude (thinner air → breathe faster → lose more H2O) 4. Health status 5. Medications (diuretics) 6. Some herbal supplements

What is the adequate intake recommendation?

2.7L for females (2L from liquid), 3.7L for males (3L from liquids) - ↑mass - ↑muscles mass - ↑greater need

How does caffeine work - 3 things?

1. Crosses the Blood-Brain Barrier, 2. Adenosine Receptor Antagonist, 3. Increases Neural Activity

Caffeine - Crossing the blood-brain barrier?

Caffeine is fat-soluble, allowing it to pass quickly into the brain and affect the central nervous system

Caffeine - adenosine Receptor Antagonist?

Blocks adenosine receptors: Adenosine promotes sleepiness and relaxation when bound, by blocking these receptors, caffeine keeps you feeling alert and energized

Caffeine - Increases Neural Activity?

Stimulates the release of dopamine and norepinephrine, increasing focus, concentration, and wakefulness, also impacts serotonin, potentially improving mood and motivation

Peak levels of caffeine time?

45 minutes after consumption

Half-life of caffeine?

5 hours (large range 2-11h —caffeine can affect your body for several hours) Genetic variability in the activity of CYP1A2 among individuals. Some people are "fast metabolizers", while others are "slow metabolizers" of caffeine

What is Health Canadas recommendation for Caffeine intake?

Should not exceed 400 mg of caffeine per day on a regular basis - energy drinks are large contributors to this (brewed coffee - 96mg, Red Bull - 80mg)

What are energy drinks?

beverages containing stimulants (usually caffeine) marketed as products that enhance mental and physical performance

What other ingredients do energy drinks often have + implications?

ginseng, taurine, and sometimes herbal extracts (can cause + banned substances tests), often carbonate - not good for gi & athletes

Why can using energy drinks/caffeine every day be a problem?

could be masking an underlying cause thats creating this lack of energy

Is Caffeine a diuretic?

no

Thermoregulation during exercise?

Exercise increases metabolic heat due to muscle contractions, small amounts lost through the skin, but most is transferred to the core, Thermoreceptors (Brain & Skin) detect the rise in body temperature, hypothalamus responds by increasing blood flow to the skin, initiating sweating, Vasodilation increases blood flow to the skin, aiding in heat transfer from core to skin by evaporation - the primary cooling mechanism during exercise (sweating)

How does exercise training improve thermoregulation?

Trained individuals sweat more efficiently and regulate temperature better during exercise, training leads to earlier sweating, increased sweat rate, & improved cardiovascular efficiency

At what & dehydration does the body recognize a need for a response?

2%

What happens at 2% dehydration?

~2% Dehydration = ↑ Plasma osmolality → noted by osmoreceptors & Baroreceptors → hypothalamus = ↑ Thirst, release ADH (Anti-diuretic hormone) + Kidneys release renin = vasoconstriction conserving sodium & H2O → ↓Urine output by ↑ H2O reabsorption = more concentrated urine

What is hypo-hydration?

Dehydrated state

Draw the Hypohydration to impaired endurance performance diagram?

use slide 97

What are the effects of 2% (mild) dehydration on performance?

↑ fatigue and rate of perceived exertion, impair attention and psychomotor skills, impair immediate memory skills, impair neuromuscular control, ↓ accuracy, power, and strength, ↓ muscular endurance, ↓ motivation, ↓ sprint performance

What are the effects of >3-4% (severe) dehydration?

↓ sweat rate and evaporative heat loss, ↓ blood volume, ↓ blood pressure, ↑ in core body temperature, cardiovascular strain, altered metabolic and central nervous system functioning

What are the 5 steps to minimizing dehydration?

1. Assess hydration status and start exercise hydrated. 2. Hydrate to maintain body mass losses within 2-3% 3. What to drink? 4. Calculate sweat rate 5. Rehydrate after exercise

What is the gold standard for assessing hydration?

Plasma osmolality - measures the conc of solutes in plasma (blood test)

What colour of urine is hydrated vs un-hydrated?

Highly hydrated - lighter in colour (pale yellow), dehydrated - darker in colour (dark yellow)

What's an Osmometer?

measures urine specific gravity - ratio of the density of urine compared to water, and is influenced by both the number and molecular weight of solutes

Euhydrated, minimally dehydrated, dehydrated levels on the osmometer?

Euhydrated: <1.020, Minimally dehydrated: 1.020 - 1.024, Dehydrated: >1.024

Minimizing dehydration: what % body mass loss should not be exceeded?

keep body mass losses to no more than 2-3%

How to calculate body weight loss during exercise?

BW before - BW after = BW loss, BW loss/ BW before X 100 = % BW loss

Minimizing dehydration: Fluid choice for short exercise (<45 mins)?

Carbohydrate target: non needed (eat 2-3 h before exercising), drink water

Minimizing dehydration: Fluid choice for longer exercise (45-75 mins)?

Carbohydrate target: May be required, small amounts, water and a banana

Minimizing dehydration: Fluid choice for start & stop exercise (1-2.5h)?

Carbohydrate target: 30-60g/h, sports drink

Minimizing dehydration: Fluid choice for ultra exercise (>2.5-3h)?

Carbohydrate target: up to 90g/h, Sports drink, granola bar

3 types of tonicity?

Hypotonic, Isotonic, Hypertonic

Hypotonic, Tonicity, % carb, use?

Tonicity: lower conc of solutes compared to blood plasma, Carbs: < 6%, Use: Rapid hydration, with lower carb conc

Isotonic, Tonicity, % carb, use?

Tonicity: similar conc of solutes compared to blood plasma, Carbs: 6-8%, Use: Most sporting situations

Hypertonic, Tonicity, % carb, use?

Tonicity: higher conc of solutes compared to blood plasma, Carbs: >8%, Use: high caloric intake is the goal, dehydration isn't the top concern (recovery drink)

How to calculate % carbs in a sports drink?

Carbs (G)/Volume X 100 = % carbs

During exercise, hydration - what drink to choose?

Drink that contains approx 500mg of sodium/L

What is the function of sodium?

Necessary for nerve function and muscle contraction, Regulates the amount of fluid in blood & extracellular fluid balance, Helps transport molecules across cell membranes (sodium-potassium pump), regulates BP

Association b/w cramp & sodim intake?

Sodium intake is one piece to the puzzle (other things: Food position, grass to turf, fitness, dehydration, low calorie intake, magnesium intake, alcohol intake)

5 recommendations for during exercise hydration?

1. Chose a drink that contains ~ 500mgs of sodium/L 2. Drink 100 - 200mls every 15 mins (unless individual sweat rate overrides this) 3. Cool drinks are recommended 4. Flavoured (3&4 increases desires to drink)5. Choose a drink of appropriate tonicity

How to calculate sweat rate during exercise?

Pre-exercise wt(kg) - Post-exercise wt(kg) + Total fluid intake (L) = sweat loss, sweat loss/Exercise duration = Sweat Rate (L/hr) (* would do several trials)

Is dehydration during exercise bad?

Not necessarily - some loss may be useful

Rehydration after exercise?

Many athletes have a fluid deficit after exercising, Aim for 150% of the fluid deficit - 1.5L of fluid for each 1kg of bodyweight lost, (Fluid loss/weight loss X 1.5 = amount to drink)

Can we drink too much?

Yes

What is overhydration?

excess of total body water resulting from excessive intake of low- or no-sodium fluids such as water, Side-effects vary widely: confusion, blurred vision, poor coordination, rapid breath, vomiting can result in cellular edema & hyponatremia

What is hyponatremia?

Dangerously low blood sodium levels defined by plasma sodium <135 mmol/L

UBC Alcohol & sport short-term impact (4)?

Dehydration - alcohol has a diuretic effect, Sleep - Alcohol impairs sleep reducing quality & quantity, Injury - Alcohol consumption prolongs injury recovery & muscle damage, Decision making - decreases cognitive performance resulting in poor decision making

UBC Alcohol & sport long-term impact (3)?

Body composition - alcohol is high in caloreis and excess can lead to increased BF, Muscle fuel - Alcohol impairs the body's ability to use & store muscle glycogen, Hormone impairment - Alcohol can cause long-term elevations in the stress hormone cortisol

If you choose to drink (UBC recommendations)?

Drink < 2drinks/day (female), < 3drinks/day (male) - now changed, Eat food with or before you drink, hydrate with water, alternate option - be the designated driver

What is alcohol related to health-wise?

Cancer, heart disease, liver cirrhosis

New guidelines for alcohol?

None is the healthy amount, >6 drinks/week of >3 drinks/week (women) → healtb risks become increasing high

What happens in the mouth during protein digestion?

Mechanical digestion occurs through chewing, no significant chemical digestion

What happens in the stomach during protein digestion?

Hydrochloric acid denatures proteins, unfolding them into long polypeptide chains, Pepsin, begins breaking down these proteins into smaller polypeptides

What happens in the small intestine during protein digestion?

Enzymes from the pancreas (such as trypsin and chymotrypsin) and enzymes from the brush border of the small intestine further break down the polypeptide chains into free amino acids and smaller peptides

How is protein absorbed?

Amino acids & small peptides are absorbed by enterocytes (intestinal cells) that line the small intestine through various transport mechanisms

How is protein transported once absorbed?

Once absorbed, amino acids enter the bloodstream and are transported to the liver and other tissues for use in protein synthesis and other metabolic processes

Draw the overview of the digestion of carbs, proteins & fats?

Use slide 46

What are proteins composed of?

Amino acids

How many amino acids do humans have?

20 Amino Acids - make structural and functional proteins (bone, peptides, etc)

Structure of amino acids?

Contain Nitrogen, R-Side Chain -AA's differ in size, shape, composition, electrical charge and pH

How many nonessential and essential amino acids are there?

11- nonessential, 9 - essential

what are nonessential amino acids?

Can be synthesized by the body from other amino acids

What are essential amino acids?

Cannot be made by the body and must be obtained through diet

What are branched-chain amino acids (BCAA)?

A subset of essential amino acids critical for muscle health and metabolism

What are the 3 types of BCAA and their functions?

Leucine: Key for protein synthesis and muscle recovery via mTOR pathway, Isoleucine: Supports energy regulation and immune function, Valine: Important for muscle metabolism and tissue repair by supporting nitrogen balance

What can amino acids do (4)?

1. Undergo deamination: removal of the nitrogen (amine) group, resulting in the formation of urea, which is excreted from the body in urine 2. Their carbon skeletons enter the Krebs cycle at various points, contributing to the body's glucose, ketone, and lipid pools. 3. Be incorporated into body proteins or used to synthesize other nitrogen-containing compounds, such as nonessential amino acids 4. Be oxidized for energy

What does the Nucleus contain for protein synthesis?

DNA - contains genetic information necessary for protein synthesis

3 steps in protein synthesis?

1. Recognition of Need: Body recognizes its need for specific proteins, and relevant gene(s) are "switched on" (activated) 2. Transcription: DNA is unwound and transcribed to produce messenger RNA (mRNA), which carries the "recipe" for a protein 3. Translation: The mRNA instructions are read by ribosomes to assemble amino acids into a polypeptide chain, ultimately forming a protein

What are the 4 protein structures?

Primary structure (sequence of amino acids forming 1+ polypeptide chains, Secondary structure - Alpha helix, Pleated sheet (Coiling or folding of polypeptide chains as a result of hydrogen bonds b/w amino acid chains), Tertiary structure (3-dimensional shape caused by weak interaction among side groups), Quaternary structure ( final 3-dimensional strucutre formed by all of the polypeptide chain making up the protein)

What are the 5 protein functions?

1. Structure and motion (collagen, Keratin, contractile fibres of muscle) 2. Transport (Hemoglobin) 3. Chemical messaging (Hormones) 4. Catalysis - speed up reactions (Enzymes - type of proteins) 4. Immune function (Antibodies - type of protein that helps build antibodies)

What amino acids are needed for protein synthesis?

All of them required to build a specific protein must be present

What happens if there are insufficient amounts of amino acids to build a protein?

An inadequate amount of any one amino acid may stop or slow the formation of a protein

What happens if there are missing nonessential amino acids to build a protein?

If a nonessential amino acid is missing, the body can either synthesize it or obtain it from the amino acid pool in the liver (small but rich) via the bloodstream

What happens if there are missing essential amino acids to build a protein?

essential amino acid missing → synthesis of the protein will halt, and the incomplete protein will be tagged for degradation (break down back into amino acids), amino acids from this process will be recycled back into the amino acid pool

Protein related complications - 3?

Kwashiorkor - protein malnutrition, swelling of the belly (not full malnutrition), Phenylketonuria - genetic disorder, can't break down phenylalanine → builds up and becomes toxic, Protein malnutrition (before Kwashiorkor) - common in the elderly → protein is hard to cook, eat, and costly

Protein recommendations RDA?

0.8g/kg/day (minimum) - though to meet the needs of 98% of the population (problematic research - mostly done on white men)

Protein recommendations % RDA?

10-35% of energy intake, 1g/kg, is easiest to calculate

Protein needs IOM?

10-35% of energy intake, 1g/kg for most, 1.6g/kg for athletes

Protein considerations IOM?

total amount in a day (most important), protein source (need all essential amino acids), distribution (distributed throughout meals)

Why does protein quality/type matter?

Bioavailability: how much of the protein consumed is absorbed/utilized by the body, Amino Acid Profile: need sources of essential and nonessential amino acids, Complete protein source - protein foods that contain all 9 essential amino acids (Animal-based proteins - meat, fish, eggs, dairy, plant sources - quinoa, soy)

What Digestible Indispensable Amino acid score (DIAAS) is considered excellent, good, & no claim?

Excellent - >100%, Good - 75% - 99%, No claim -

plant-based vs animal-based protein AA content?

plant-based AA content falls behind animal-based, often need to mix plant-based sources to make sure you get all essential amino acids (ex: Lysine, leucine, methionine)

Complimentary plant protein recommendations?

Protein combinations at every meal is an outdated recommendation, Recommendation is to have lots of plant-based variety throughout the day, Athletes/people with very limited diets may still benefit from planning their meals with combinations in mind

Consideration for plant protein use?

Many are not complete EAA sources (exceptions are soy and quinoa - still contain lower amounts versus animal sources), especially of leucine, slower absorption and less efficient digestion, EAAs have less bioavailability as they contain competing nutrients e.g. phytates that affect absorption kinetics of AA, not impossible to meet requirements, but very likely need more total protein

Does the timing of protein matter?

Yes - more distributed is better, Minimum threshold for protein synthesis - 20-25g for most adults, max threshold - 0.3g/kg of protein (able to be absorbed)

Older adults' protein recommendation ( over 65 years)?

1-1.2g/kg/day

Is there such a thing as too much protein?

Research shows no significant evidence linking high protein intakes (up to about 2 g/kg/d) with adverse health effects in healthy individuals (exception - ppl with kidney/renal issues), little research supporting the safety and efficacy of protein intake exceeding 2g/kg/d

What are some concerns with high protein intake?

Substitution or removal of carbohydrates and possibly fruits & vegetables (lose fibre/micronutrients), Risk not meeting fibre RDA, High red and processed meat consumption (>50g per day) is a concern for colorectal cancer risk

What are the 4 roles of protein in weight management?

1. Caloric Density: 4 kcal per gram → has energy but is less calorie-dense than fats (9 kcal/g) & comparable to carbs (4 kcal/g) 2. Satiating Nutrient: protein foods enhance feelings of satiety → reduce overall calorie intake & curb hunger (promotes fullness) 3. Muscle Maintenance: supports Lean Muscle Mass → crucial during caloric deficits, as it helps preserve muscle while promoting fat loss 4. Metabolic Benefits: thermic Effect of Food: has a higher thermic effect compared to fats and carbohydrates, meaning more calories are burned during digestion and metabolism

Protein and obesity chain?

Look at slide 69

Role of protein in physical activity?

1. Maximizing gains in muscle mass and strength 2. Preserving lean mass during weight loss by caloric restriction 3. Structural benefits to other protein-containing non-muscle tissues, such as tendons and bone

3 types of protein powders?

Whey, Casin, soy

which type of protein powder is best for muscle building for all?

whey, rapid influx of AA into circulation, the highest gram amount of leucine