Weeks 1-4 Flashcards
Define physical activity
Any bodily movement produced by skeletal muscles that requires energy expenditure
Define exercise
Physical activity that is planned, structured, repetitive and designed to sustain or improve health or fitness
Define physical fitness
Ability to carry out daily tasks with vigour and alertness, without undue fatigue, to enjoy leisure pursuits, to meet unforeseen emergencies, and resist hypokinetic diseases
Define physical inactivity
Doing insufficient moderate-vigorous physical activity to meet guidelines (or to maintain health)
Define sedentary behaviour
Any waking behaviour characterised by an energy expenditure ≤1.5 metabolic equivalents of task (METs), while in a sitting, reclining or lying posture
Describe some key features of adult physical activity guidelines
- At least 150 minutes of moderate intensity activity per week OR at least 75 minutes of vigorous activity (or a combination of both)
- Strength building at least 2 days a week
- Minimise sedentary time
- For older adults: improve balance 2 days a week
What are some differences between the physical activity guidelines of adults to kids and healthy ageing?
- Children aim for 60 minutes of physical activity per day, early years 180 minutes (compared to 150 minutes for adults)
- Children and young people focus on sports and games, not typical exercise
- Early years focus on sports and games/play
- Healthy ageing recommends balance improving exercised 2 days a week
- Under 1 years, 30 minutes across the day of tummy time
What are the levels of physical activity intensity and how can they be described?
Sedentary - sitting or lying with little movement and a low energy requirement
Light - aerobic activity with no noticeable change in RR, can be sustained for atlas 60 minutes
Moderate - aerobic that can be maintained for 30-60 minutes, whilst holding a conversation uninterrupted
Vigorous - aerobic activity lasting up to 30 minutes, where conversation generally cannot be maintained uninterrupted
High - activity that cannot be sustained for longer than 10 minutes
How does fitness impact the relative intensity of day to day activities?
As a person’s fitness level increases, the relative intensity of a certain activity decreases
What is a MET?
MET - Metabolic Equivalents of Task
1 MET = resting energy expenditure
Can describe physical activity or exercise in terms of METS i.e. as multiples of resting energy expenditure
What are some typical MET requirements of day-to-day activities and positions?
Sedentary (<1.6 METs) - sleeping, sitting, riding in a car, watching TV
Light (1.6-3 METs) - sitting studying, standing reading, household walking, playing cards
Moderate (3-6 METs) - vacuuming, walking, water aerobics, mowing lawn
Vigorous (6-9 METs) - stationary rowing @100W, high impact aerobics
High (9+ METs) - stationary rowing @200W, running @17.5km/h
How do MET-minutes relate to the volume and intensity of physical activity?
As a person’s fitness level increases, the relative intensity of a certain activity decreases. Therefore something considered ‘vigorous’ activity to one person, may be considered ‘light’ to another due to their fitness levels.
How do MET-minutes relate to the physical activity guidelines?
Due to activities having different intensities to each individual depending on their fitness level, what is considered ‘high intensity’ may be ‘low-moderate’ to another. therefore, different exercises need to be undertaken per individual to meet their physical activity requirements
What are the key features of a healthy diet?
- Wide variety of foods
- No energy deficits or surpluses
- No nutrient deficits
- High in complex CHOs
- Low in saturated fats
- Low in simple sugars
- Avoid fad diets
What are the differences between food groups and nutrients?
Food groups include vegetables, fruits, meat protein, vegetarian protein, grains, dairy, water and extras
Nutrients are macronutrients (protein, fats, CHOs), micronutrients (vitamins and minerals) and water
Name some animal and plant sources of protein
Animal: beef, pork, fish, lamb, chicken
Plant: eggs, nuts, lentils, beans
What are some examples of grains and the nutritional benefit they provide
Examples: rice, bread, cereals, pasta
Benefits: complex CHO, fibre, energy
What are some examples of dairy and the nutritional benefit they provide
Examples: yoghurt, milk, cheese
Benefits: CHO, protein, fat and vitamins and minerals
What is the recommended TDE intake for ‘extras’ e.g. sweets and soft drinks and why?
<10%, because they are high in energy and low in nutrients
What are the macronutrient proportions for an inactive person?
CHO 45%
Protein 25%
Fat 30%
What are the macronutrient proportions for a healthy (active) person?
CHO 65%
Protein 15%
Fat 20%
What are the macronutrient proportions for an elite endurance person?
CHO 70%
Protein 15%
Fat 15%
What are the type of CHOs and give an example of each?
Monosaccharides: glucose, fructose
Disaccharides: lactose, maltose, sucrose
Polysaccharides: starch, fibre (non-starch), glycogen
What is the role of CHOs in exercise?
- Primary energy source for the CNS (brain) and high intensity physical activity
- Metabolic primer for fat use
- Adequate CHO spares protein use
What is GI?
The index of effect of CHO ingestion and insulin secretion
What do high GI foods do in the body? Give at least three effects
- Increase insulin secretion
- Increase glucose uptake and use
- Increase lactate production
- Inhibit lipolysis
- Increase the rate of glycogen depletion
Name 5 high GI foods
- Glucose
- Carrots
- Honey
- Corn flakes
- Whole meal bread
- White rice
- Brown rice
- Sultanas
- Bananas
Name 5 moderate GI foods
- Corn
- Sucrose
- Potato chips
- All-bran
- White pasta
- Oatmeal
- Sweet potato
- Oranges
Name 5 low GI foods
- Apples
- Fish sticks
- Butter beans
- Kidney beans
- Lentils
- Fructose
- Peanuts
What are the three main roles of amino acids?
- Major structural components of tissues
- Major regulatory chemicals
- Provide creatine for creatine phosphate
What are the guidelines for protein intake post exercise?
- 15-25g protein 0-2 hours post exercise for optimal muscle protein synthesis and increased strength and muscle mass
- 0.3g/kg protein after exercise and 3-5 hours over multiple meals
- Protein (casein) immediately before sleep for overnight recovery
What type of protein is considered the best and why?
Milk/dairy protein. Due to leucine content and digestion/absorption kinetics of BCAAs
What is the whey to casein ratio in dairy protein?
20% whey + 80% casein
What are the types of fats?
Saturated
Unsaturated (mono, poly, trans)
What are the roles of fats? (6)
- Main energy reserve
- Primary energy source during low-moderate intensity activity
- Component of cell membranes
- Component of hormones and other cell regulators
- Provides satiation
- Major vitamin carriers
If someone is on a low fat diet, what vitamin and mineral deficiencies may they display? (6)
Fe, Mg, Ca, Zn, Folic acid, Vitamin E
How much of body mass of males and females is fat?
Males ~15%
Females ~25%
Where is fat stored?
Mostly in adipose tissue.
Small amounts in muscle and plasma.
Name the fat soluble vitamins
A, D, E, K
Name the water soluble vitamins
8x B vitamins, vitamin C
What are the 7 major minerals?
Ca, Mg, Na, K, P, S, Cl
What do antioxidants do in the body?
Protect cell membranes
What are the recommendations for fluid intake for athletes?
- 2-2.5L/day
- 5-10mL/kg in the 2-4 hours pre-exercise
- 0.4-0.8L/h during exercise
- Sports drinks not required until exercise is longer than 1 hour or there is excessive sweat loss
What are some problems with supplements?
- Product labels often inaccurate
- Lack of quality research
- Many have unpleasant side effects
- May contain banned substances for competition
- Difficult to establish safety due to multitude of ingredients
What are some benefits of protein supplements for athletes?
- Post exercise recovery
- To increase lean muscle mass
- Portable nutrition
What are benefits of amino acid supplements for athletes?
- May be an energy source for endurance athletes
- May enhance lean mass with resistance training
What is the benefit of creatine supplements for athletes?
Positive effects on acute high intensity exercise, which in long term improve lean mass gains and muscular strength and power
What are the two main goals of nutrition before and during exercise?
- Prevent dehydration
- Assist energy provision with CHO intake
At what duration of exercise would you need higher CHO intake?
> 1 hour
What are two disadvantages of high CHO intake during pre-comp nutrition?
- Increased water weight
- May cause diarrhoea
What are some considerations for a pre-competition meal?
- Timing: 3-4 hours pre-exercise
- Digestibility and absorption: low in fats and protein, higher in CHO
- GI: low-moderate
- Person’s food preferences
What are the three competition fuelling strategies and when would you use them?
- Carb loading for >90 minutes of exercise
- Pre-event fuelling for >60 minutes of exercise
- Quick-refuelling for when there is <8 hours recovery between two sessions
What are the two goals of nutrition during exercise?
- Maintain blood glucose
- Delay glycogen depletion
What are some palatability influences on intake during exercise?
- Flavouring
- Concentration of substances
- Presence of electrolytes
- Temperature of drink
What are some upper GIT symptoms someone may experience with exercise?
- Nausea
- Vomiting
- Belching
- Heartburn
- Chest pain
What are some lower GIT symptoms someone may experience with exercise?
- Bloating
- Cramps
- Flatulence
- Urge to poo
- Diarrhoea
What are some factors that may increase upper GIT symptoms during exercise?
- Diet high in fibre, fat and protein
- Hypertonic drinks
- Dehydration
- Exercise intensity
What are the five main influences on gastric emptying rate during exercise? What are their influences?
- Volume - higher volume = higher emptying rate
- Temperature - colder fluids empty faster
- Carbonation - slows rate of emptying and delays water and CHO absorption
- Osmolality - high osmolality (hypertonic) slows emptying
- Intensity of exercise - slows but only effect >75% max
What are the 3 ways which CHOs are absorbed?
- Passive diffusion
- Facilitated/carrier mediated
- Active
How is water absorbed in the body?
By diffusion with osmotic gradients. Mostly in the small intestine.
How is sodium transported into:
a) epithelial cells
b) interstitial fluid
a) diffuses or co-transports
b) active
What are the three main influences on absorption from the GIT during exercise?
- Osmolality - hypotonic to isotonic best
- CHO content - low-moderate concentrations absorbed faster
- Sodium - low-moderate concentrations increase water and glucose absorption
What are the 3 main considerations for solutions consumed during exercise and why?
- Fluid content (hydration) - blood volume/flow and thermoregulation
- CHO content (energy) - slows glycogen depletion
- Electrolyte composition - restore
What are the four goals of nutrition recovery spot exercise?
- Replace fluid losses
- Replace electrolyte
- Replace glycogen stores
- Protein (for resistance training)
When would you want a higher CHO concentration (~8%) and lower CHO concentration (6-8%) in sports drinks?
- Higher for energy provision
(also long duration and cooler temperatures) - Lower if hydration is the main factor
(also during hot, humid, shorter duration)
What is anthropometry and what values does it include?
The study of body structure composition.
It includes height, weight, body lengths, somatotypes, body composition, relationships to health and sport
What does somatotypes refer to?
A person’s physique
What are the three somatotypes to which people can be plotted on a somatochart?
- Ectomorph
- Endomorph
- Mesomorph
What are characteristics of an ectomorph?
- Long and lean
- Longest living
- Postural problems
What are characteristics of an endomorph?
- Rounded, stocky, lots of muscle and fat mass
- Shortest life span
- Prone to CVD and postural problems
What are characteristics of a mesomorph?
- Athletic and muscular
- Best with physical work
- Least postural problems
Describe the differences between the 2-compartment and multi-compartment models of body composition
2-C model only took into account fat mass and fat free mass (FFM)
Multi-C model takes into account other body components such as ICF, ECF, protein and minerals
Name indirect techniques commonly used to assess body composition (6)
- Hydrostatic weighing
- Skin-fold thickness tests
- Girth measurements
- Electrical impedance
- Imagine
- Air densitometry
What are the desirable, overweight and obese waist circumference measurements for females?
Desirable <75
Overweight 80-87.9
Obese >88
Asian overweight >80
What are the desirable, overweight and obese waist circumference measurements for males?
Desirable <90
Overweight 94-101.9
Obese >102
Asian overweight >90
What are the WHO BMI classifications for the general population?
Underweight <18.5kg/m2
Ideal 18.5-24.9kg/m2
Overweight 25.0-29.9kg/m2
Obese +30kg/m2
What are limitations to BMI measurements?
BMI is a measurement of excess weight, rather than excess fat. For example, it does not take into account different muscle mass’. A bodybuilder may be considered ‘obese’ due to their height to weight ratio
What are the three components of TDEE
- Resting metabolic rate (sleeping, basal and arousal metabolism)
- Thermic effect of feeding and other influences
- Thermic effect of physical activity
What is the difference between basal metabolic rate (BMR) and resting metabolic rate (RMR)
BMR is the minimal energy needed to maintain vital functions whilst awake
RMR is BMR + digestion
What can influence a person’s RMR? (9)
- Thyroid hormones (higher levels increase RMR)
- Sex (M>F)
- Fat-free (lean) body mass (higher with more skeletal muscle)
- Protein turnover (higher with more protein turnover; growth, pregnancy and lactation)
- Age
- Climate
- Fever
- Nutritional status
- Health status
What is obligatory thermogenesis?
The energy required to maintain body temperature for digesting, absorbing and assimilating food (diet-induced thermogenesis)
What is facilitative thermogenesis?
Thermic effects of activating sympathetic nervous system e.g. when cold
What are the three physical activity components of TDEE?
- Occupational activity
- ADLs
- Exercise
What is the main aim of exercise training?
To cause biological adaptations that influence performance in specific tasks
What are the four principles of exercise training?
SORR
- Specificity
- Overload
- Responsiveness
- Reversibility
What is the specificity principle in relation to exercise training?
SAID principle: Specific Adaptations to Imposed Demands
Responses specific to the training performed
E.g. arm training for shot-put, aerobic training for running
What is the overload principle in relation to exercise training?
You must overload the body relative to normal to get a response, and training must be progressive
This can be done through duration, intensity, frequency
What is the responsiveness principle in relation to exercise training?
Considering an individuals variations:
Initial fitness level, genetics, recovery, nutrition, health status
What is the reversibility principle in relation to exercise training?
Use it or lose it
Detraining (de-conditioning) - the loss of physical capacity with inactivity
What is the FITT principle and what does it stand for?
The FITT principle addresses the factors influencing training responses
Frequency, Intensity, Time, Type
How can frequency be varied in a training program?
- How many training sessions per week
- 2 minmum, 5 maximum
- Too many will compromise recovery
How can intensity be varied in a training program and what effect can it have?
- Too low - no response
- To high - risk of injury, inadequate time for recovery, risk of overtraining
- Higher intensity = faster adaptations
How can time (of session and program) be varied in a training program?
- Longer or shorter duration
- Effects on quantity of training
- Minimum duration influenced by intensity and fitness of individual
- Program 6+ weeks as a minimum
What are some training recommendations to improve performance? (FITT)
- Balance of frequency and duration
- Increase duration then intensity
- Start at least 3x a week, moderate intensity, short duration
What are some training recommendations to maintain performance? (FITT)
- Less training ~2x a week
- Maintain intensity
What are the 4 types of training programs
- Circuit - short intervals of varying activities, for general fitness
- Resistance - repetitious exercises using body weight or external resistance
- Continuous - aerobic/endurance
- Interval - alternating activity and relief, for aerobic anaerobic and resistance
What is periodisation and what is the difference between linear and non-linear training periodisation?
Periodisation is a training method to optimise strength performance, by balancing training volume and intensity.
In non-linear periodisation, changes in training volume and intensity are made more frequently.
What are some values that can be taken to determine if someone is overweight? (8)
- Percent body fat
- Waist circumference
- Hip circumference
- Waist:hip ratio
- Waist:height ratio
- BMI
- BMI + waist
- Fat mass index (FMI)
Name some health risks related to excess body fat
- CVD - CAD, CVA, HTN
- T2DM
- Hyperlipidaemia
- Sleep disorders
- MH
- Fatty liver and gallbladder disease
- CA’s
- Respiratory problems
- Increased risk with surgery and anaesthesia
- Chronic pain
- Infertility, erectile dysfunction
What is the optimal BMI for someone over 65yo?
25-30kg/m2
What are some contributing factors to obesity? (3)
Environmental; diet, lack of physical activity
Genetic
Name regulators of food intake in the body (4)
- Neuronal influences from the GIT (mechanoreceptors - gastric distention)
- Energy stores (insulin, leptin, resistin, adiponectin)
- GIT signals (cholecystokinin, glucagon-like peptide 1, ghrelin)
- Neuropeptides in the brain
What is Leptin, where is it secreted?
Leptin is a hormone secreted from adipose tissue
How does leptin work? What does it do?
Leptin is created in the ob gene, inside the fat cell. Leptin moves from here into the blood stream, signalling the hypothalamus to reduce or stop the drive to eat after reaching the ‘set point’ for the body’s total fat content.
Obese people have excessively high leptin levels.
It suppresses appetite, increases metabolic rate and inhibits neuropeptide Y secretion.
What does Neuropeptide Y (NPY) do?
Increases appetite and decreases SNS effects on metabolic rate.
What are adipocytes and what influences them?
Adipocytes are specialised connective tissue that are lipid storing cells.
The number and size of fat cells varies, influenced by food intake, activity levels and genetics.
What are the two ways adipocytes and increase?
Hypertrophy and hyperplasia.
How does adipocyte hypertrophy and hyperplasia differ during child development?
Hypertrophy has most increase at ages 1-6, with nil change 6-13 and goes to 100% by the age of 13.
Hyperplasia has some rapid growth 0-1, constant growth to 10 and rapid increase until the age of 20
What changes occur to an adipocyte during weight loss?
Atrophy - decrease in cell size.
Don’t lose numbers.
What are some influences on early fat gain and risk factors for obesity in children? (5)
- Maternal weight gain
- Gestational diabetes
- Breast feeding and slow exposure to solid food
- High fat mass as a child
- Obese parents
Is diet or exercise alone more effective for creating a negative energy balance, and hence weight loss?
Diet
What FITT principles are applied to exercising to create an energy deficit?
Frequency - 5+ days a week
Intensity - moderate continuous, or high intervals. Or a combination of both
Time - 30+ minutes a day or 60 minutes walking. Can change depending on intensity
Type - mainly aerobic with some resistance
What are some health risks of a negative energy balance? (6)
- Amenorrhoea and OP risk
- Malnutrition
- Electrolyte imbalances
- Oedema
- Cardiac arrhythmias
- Death
What are some conditions that can cause a negative energy balance?
- Drug induced aversions (appetite suppressants; amphetamines, chemotherapy)
- Diseases associated with cachexia (renal failure, cancer, TB)
- MH (anorexia)
How can exercise be beneficial for people with eating disorders?
Resistance training can maintain muscle and bone mass
What does RED-S stand for? What is it about?
Relative Energy Deficiency in Sport
High energy expenditure, inadequate energy intake = net energy deficit
What is the female athlete triad?
A part of the RED-S affecting females. It includes energy drainage (psychological and physical fatigue), amenorrhoea (loss of menstrual cycle for >3 months) and osteoporosis
What are some short term consequences for females in the female athlete triad?
- Stress fractures
- Low body and muscle mass
- Depression
What are some long term consequences for females in the female athlete triad?
- Increased risk of OP
- Reduced risk of oestrogen dependent cancers
- Potential fertility problems
What are some ways to treat athletic amenorrhoea? (4)
- Reduce training volume by 10-20%
- Increase energy intake by 5-10%
- Calcium intake ~1500mg a day
- Maybe, contraceptive pill for oestrogen source
What are some consequences for males with RED-S? (3)
- Lower testosterone levels
- Reduced fertility potential (lower sperm count, reduced sperm motility, morphological abnormalities)
- Potential effects on bone
What characteristics of male athletes put them at risk of RED-S? (2)
- Those with high training volumes
- Those with energy restriction as a goal
What are some factors to consider regarding PA, sedentary behaviour, body composition and male reproductive function? (3)
- MET levels - higher METS = increased sperm motility
- Sedentary time - no changes to semen quality
- Obesity - decreased fertility and erectile dysfunction
What are some effects cycling may have on male reproductive function? (2)
- Perineal compression associated with erectile dysfunction
- Increased intrascrotal temperature alters sperm viability
What are some considerations for exercise during pregnancy? (8)
- Weight gain
- Lordosis and back pain
- Balance problems - uncommon
- Respiratory changes
- CV changes
- Thermoregulation
- Risk to foetus
- Urinary incontinence
What are some CV changes during pregnancy? (3)
- Increased blood volume, HR x SV = CO
- Decreased MAP
- Supine or prolonged standing may decrease venous return
What are some absolute contraindications to aerobic exercise during pregnancy? (10)
- Haemodynamically significant heart disease
- Restrictive lung disease
- Incompetent cervix or cerclage
- Multiple gestation at risk of premi labour
- Persistent second or third trimester bleeding
- Placenta prevue after 26 weeks gestation
- Premature labour during current pregnancy
- Ruptured membranes
- Pre-eclampsia or pregnancy induced HTN
- Severe anaemia
What are some relative contraindications to aerobic exercise during pregnancy? (13)
- Anaemia
- Unevaluated maternal cardiac arrhythmia
- Chronic bronchitis
- Poorly controlled T1DM
- Extreme morbid obesity
- Extreme underweight (BMI <12)
- Hx of extremely sedentary lifestyle
- Intrauterine growth restriction in current pregnancy
- Poorly controlled HTN
- Orthopaedic limitations
- Poorly controlled seizure disorder
- Poorly controlled hyperthyroidism
- Heavy smoker
What are warning signs to discontinue exercise whilst pregnant? (9)
- PV bleeding
- Regular painful contractions
- Amniotic fluid leakage
- Dyspnoea before exertion
- Dizziness
- Headache
- Chest pain
- Muscle weakness affecting balance
- Calf pain or swelling
What are recommendations for a pregnant woman if she has had no regular exercise prior to pregnancy? (6)
- Consult with doctor prior to commencing program
- Low-moderate intensity aerobic exercise
- 30 minutes a day at 3-5 METs
- Don’t try to obtain substantial fitness gains
- Don’t use exercise for large weight loss (unless medically recommended and supervised)
- Use exercise to stability weight and maintain fitness
What are recommendations for a pregnant woman if she exercised prior to pregnancy? (2)
- Generally ok to continue training
- Usual aim is to maintain fitness, not improve
What are some activities not recommended during pregnancy? (4)
- Activities with an increased risk of trauma (e.g. horse riding)
- Activities with physiological risk factors (e.g. scuba diving)
- Activities involving lying in supine positions after the first trimester
- Activities pregnant women who are not already active should avoid (running, strenuous strength training)
What are the physical activity recommendations for pregnant women? (4)
- Aim for at least 150 minutes of moderate intensity activity every week
- Muscle strengthening activities twice a week
- Activities in bouts of at least 10 minutes
- Don’t bump the bump
What are aerobic exercise recommendations for pregnant women? (4)
- Large muscle group dynamic activity
- 30 minutes a day of low-moderate intensity
- RPE of 11-13 (HR not reliable for monitoring)
- Program not progressive; maintain intensity
What are flexibility exercise recommendations for pregnant women? (2)
- Limit activities to normal ROM
- Usually exclude activities associated with lying supine
What are some maternal benefits of exercise? (10)
- Controls maternal weight gain
- Improved mental wellbeing and body image
- Reduced risk of gestational diabetes
- Reduced risk of pre-eclampsia
- Reduced risk of gestational hypertension
- Reduced pelvic and lower back pain
- Reduced risk of acute c-section
- Reduced risk of prolonged labour and instrumental delivery
- Reduced risk of macrosomia
- Reduced risk of pre-term delivery
What are some foetal benefits of maternal exercise? (4)
Assuming adequate maternal nutrition
- Decreased risk of excess birth weight
- Decrease in fat cell growth
- Increased stress tolerance
- Increased neurological development
What are some special pregnancy populations (pregnancy related health conditions) that exercise may benefit? (4)
- Diabetes (type 1 and 2)
- Obesity (BMI >33kg/m2)
- Chronic HTN
- Pre-eclampsia - little evidence
What are four considerations for post-pregnancy exercise?
- Return to exercise slowly after delivery
- Influenced by delivery complications
- Usually ok 6-8 weeks postpartum
- Consider abdominal separation
What are some considerations for lactation and exercise? (3)
- Exercise does not compromise breast milk quality/quantity or infant growth if nutrition is appropriate
- Exercise may slow bone loss during lactation, resulting in higher BMD levels 1 year postpartum
- Breast feeding recommended prior to exercising (less breast discomfort during exercise and less lactic acid in milk)
What are some benefits of post-pregnancy exercise? (7)
- Maintain or regain fitness
- Maintain or lose body weight
- Decrease risk of postpartum depression
- Stress relief
- Slow bone loss during lactation
- Improve insulin sensitivity in those with GDM and T2DM
- Social support
On average, how much of female and male body mass is water?
60% males
55% females
How is water distributed throughout the body?
a) Intracellular volume
c) Extracellular volume
a) 2/3 ICF
b) 1/3 ECF
What are some functions of body water? (7)
- Transport medium for most body nutrients and gases
- Moistens surfaces for nutrient transfer
- Medium for most waste elimination
- Lubricates joints (water and proteins)
- Gives structure and form to most body structures (water is non-compressible)
- Provides cushioning for many body structures
- Body thermoregulation
How much of our water do we get from:
a) Fluids
b) Food
c) Metabolism
a) Fluids 50-60%
b) Food 30-40%
c) Metabolism 10-15%
How much of our water do we lose from:
a) Urine
b) Faeces
c) Sweat
d) Skin
e) Lungs
a) Urine 50-60%
b) Faeces 5%
c) Sweat 5%
d) Skin 20-30%
e) Lungs 10-15%
What does fluid in the body effect? (4)
- Osmolarity
- Blood volume
- Arterial blood pressure
- Cardiac output
What are some roles of the renal system? (7)
- Formation and excretion of urine
- Regular blood volume and pressure
- Regulate mineral concentrations (sodium, potassium, calcium, plasma ion)
- Stabilise blood pH
- Conserve nutrients - glucose and amino acids
- Excrete waste - urea, ammonium
- Detoxify poisons - drugs
What part of the brain regulates body fluid and electrolytes?
Hypothalamus
What are inputs to the hypothalamus regulating body fluids and electrolytes? (4)
- Osmoreceptors
- Atrial baroreceptors
- Arterial baroreceptors
- Thirst
What are hormonal and modulator outputs regulating body fluids and electrolytes? (4)
- Antidiuretic hormone (ADH) or vasopressin
- Aldosterone
- Angiotensin Converting Enzyme (ACE)
- Atrial Natiuretic Peptide (ANP)
Antidiuretic hormone (ADH)
a) Where is it secreted from?
b) What three inputs does it respond to?
c) What effects on the body does its release have?
a) Cells in the pituitary
b) Osmoreceptors, baroreceptors, angiotensin II
c) Increased water reabsorption in kidneys = decreased urine output and increased extracellular volume, and increased arterial BP
Aldosterone
a) Where is it secreted from?
b) What is its release stimulated by?
c) What effects on the body does its release have?
a) Adrenal cortex
b) Low arterial BP and low renal flow
c) Increased sodium (and therefore water) reabsorption in the kidneys, decreased sodium loss in sweat, increased plasma volume
What effects does angiotensin II have on the body? (4)
- Increased aldosterone release
- Increase ADH release
- Arteriolar vasoconstriction - increases BP
- Increase thirst
How does angiotensin converting enzyme (ACE) work?
- Secreted by lungs, converts angiotensin I to angiotensin II
Atrial Natiuretic Peptide (ANP)
a) Where is it secreted from?
b) What is its release stimulated by?
c) What effects does it have on the body?
a) Atrial cells (mostly right atrium)
b) Release primarily stimulated by atrial stretch (increased central blood volume)
c) Increase of diuresis, decreases arterial BP
What effects does exercise have on fluid and electrolyte balance? (3)
- Increased sweating
- Increased osmotic pressure in cells due to metabolites
- Increased hydrostatic pressure due to increased BP
What are some acute physiological responses to exercise? (7)
- Increase ADH release
- Increase renin, angiotensin II and aldosterone release
- Decrease ANP release
- Increased sodium reabsorption
- Increased water reabsorption
- Decreased urine output
- Increased plasma volume
What are some effects of repeated days of physical activity? (4)
- Increased release of fluid balance hormones
- Increased plasma volume
- Possible haemodilution
- Possible pseudoanaemia
How could someone prevent dehydration with exercise? (6)
- Ensure adequate hydration pre-exercise
- Weigh before and after exercise
- Ensure pale yellow urine
- Hydrate during exercise if long duration, high ambient temperature or humidity
- Have an appropriate sports drink if required
- Be conscious of salt intake
What is hyponatraemia and what are some symptoms?
Hyponatraemia is low sodium levels, due to excess water intake relative to sodium.
Symptoms include headache, confusion, nausea, cramps, seizure, APO, death
Who is most at risk of hyponatraemia? (7)
- Less accustomed to prolonged exercise
- Poorer physical condition
- Unacclimatised to heat and humidity
- Consume a low salt diet
- Take diuretic medications
- Sweat profusely
- Consume large quantities of plain water
What can someone do to prevent hyponatraemia? (3)
- No more than 1L of plain water per hour during or after exercise
- Adding some sodium and glucose to drinks
- Sprinkle salt on food in days prior to and following exposure
What are the two major causes of renal disease?
- Diabetes 45%
- Hypertension 27%
What are the three patient groups under severe renal disease?
- Haemodialysis
- Peritoneal dialysis
- Renal transplant
What medication are people with CKD commonly on and how does this impact their exercise?
Prednisone - a corticosteroid, which impairs maintenance or growth of muscle mass
What is the main physical fitness issue in people with CKD?
- Very low aerobic capacities (VO2 max)
What are some fitness tests that can be used for people with CKD? (3)
- ADLs
- Stair climbing
- 6 minute walk test
What are aerobic testing considerations for people at:
a) Stages 1-4 of CKD
b) Renal transplant
c) Stage 5
d) Haemodialysis
e) Peritoneal dialysis
a) Stages 1-4 of CKD - usual considerations
b) Renal transplant - usual considerations
c) Stage 5 - medical supervision
d) Haemodialysis - test on non-dialysis days
e) Peritoneal dialysis - test when no fluid in abdomen
What are the strength test considerations for people with CKD? (3)
- 3RM or more (not 1RM)
- Isokinetic - slower velocities
- Sit to stands
What are CV/aeorbic activity training recommendations for people with CKD? (6)
- Low-moderate intensity activities (40-60% max, then progress if able)
- As many days as possible
- RPE 11-13 (HR is a poor indicator), non-dialysis days RPE 11-16
- Begin with intermittent (interval) activity
- Progress to continual activity
- Aim for 30-45 minutes continuous, longer if overweight
What are strength activity training recommendations for people with CKD? (5)
- Aim to increase or maintain muscle mass
- 1 set of 10-15 reps to fatigue
- 8-12 exercises targeting major muscle groups
- 2x week, non-consecutive days
- Motivation often difficult
What are exercise timing considerations for dialysis patients
a) pre-dialysis
b) post-dialysis
c) during dialysis
d) non-dialysis days
a) pre-dialysis - fluid load problems e.g. breathlessness
b) post-dialysis - fatigue, hypotension. Don’t train immediately post
c) during dialysis - possible during the first 2 hours of dialysis e.g. cycling, resistance training trial
d) non-dialysis days - exercise usually better tolerated
What is the main cause of sudden cardiac death and exercise, in people over 35 years old?
Coronary artery disease
What are the main causes of sudden cardiac death and exercise, in people under 35 years old?
- 67% Structural abnormality
- 33% Electrical abnormality
- Frequently genetic or congenital conditions
If an athlete has a sudden cardiac death during or shortly after exercise, are they usually symptomatic or asymptomatic?
Asymptomatic
What is the main cause of sudden death in young athletes?
Hypertrophic cardiomyopathy
Followed by commotion cords, coronary artery anomalies and LVH indeterminant
How can exercise improve and worsen CV disease?
Improve: reduces some risk factors of heart disease
Risk: may cause problems and death in those with existing CVD
Risk: lack of regular exercise may increase risk of CVD
What part of the heart is affected from exercise-induced cardiomyopathy?
The right ventricle
What needs to be determined prior to fitness testing or prescribing exercise? (3)
- Health status
- Risk status
- Safety/intensity of exercise
What is the purpose of pre-exercise screening? (4)
- Identify those with risk factors and symptoms needing medical assessment prior to exercise
- Identify those with conditions needing medically supervised exercise testing and programs
- Identify those with contraindications to exercise
- Identify those with additional needs for safe testing and exercising (e.g. pregnancy)
What are the three types of pre-exercise screening?
- Pre-exercise questionnaire
- Medical evaluations
- Musculoskeletal assessments
What is assessed in a pre-exercise questionnaire? (6)
- History of diseases and illnesses
- Past family medical history
- Surgical history
- Past and present health behaviours e.g. smoking, PA
- Current use of drugs/medications
- History or signs of cardiopulmonary disease
What is the ESSA Adult pre-exercise screening tool and what does it involve?
- Developed by ESSA (Exercise and Sports Science Australia) and SMA (Sports Medicine Australia)
- Used to classify people into three risk categories
- Stage 1 is compulsory - any “yes” answers requires medical clearance before new exercise program or aerobic fitness testing
- Stage 2 is recommended
What are some signs and symptoms of cardiopulmonary disease? (9)
- CP
- SOB
- Dizziness or syncope
- Palpitations or tachycardia
- Dyspnoea, especially at night
- Ankle oedema
- Claudication with exercise
- Heart murmur
- Undue fatigue
In the ESSA APSS, it asks about ‘any other condition’ that you think requires a medical opinion. What would this include? (10)
- Serious musculoskeletal conditions (OA, OP, back pain) or bone fractures
- History of blood clots
- Recent substantial weight loss without trying
- Epilepsy
- Rheumatic fever
- Latter stages of pregnancy or Hx of problems in pregnancy
- Psychiatric conditions
- Undiagnosed symptoms of indigestion
- Regular use of medications (prescribed or over the counter)
- Any other chronic medical condition affecting ability to exercise
What is the HR window for sedentary activity?
<40% HR max
What is the HR window for light activity?
40 - <55% HR max
What is the HR window for moderate activity?
55 - <70% HR max
What is the HR window for vigorous activity?
70 - <90% HR max
What is the HR window for high intensity activity?
90 and above % HR max
In stage 2 of the APSS, what risk factors are assessed? (11)
- Age and sex (higher risk if male 45+yo, female 55+yo/lower w menopause complications)
- Family Hx of CVD (MI, CABG or sudden cardiac death in close male relative <55yo, or close female relative <65yo)
- Smoking status (higher risk if current or past smoker)
- Body composition (higher risk if BMI 30+kg/m2, or waist circumference >94cm males, >80cm females)
- BP (higher risk if diagnosed or medicated for HTN)
- Cholesterol (higher risk if diagnosed or medicated for hyperlipidaemia)
- Blood sugar (higher risk if diagnosed w hyperglycaemia)
- Medications
- Hospitalisations
- Pregnant
- Musculoskeletal injuries
What assessments are part of the ‘medical evaluations’ screening? (4)
- Resting BP, RHR and ECG
- Exercise stress test
- Bloods
- Musculoskeletal assessment
What is included in the functional movement screening as part of the ‘musculoskeletal assessments’ screening tool? (7)
When is it mainly used?
- Deep squat
- Hurdle step
- In line lunge
- Shoulder mobility
- Active straight leg raise
- Trunk stability push-up
- Rotary stability
- Mainly used for sport
What is graded exercise stress testing (GXT) and what is it used for?
Stress testing, often for evaluating CV function
What should you be aware of when doing a GXT? (3)
- Reason for the test
- Patient Hx
- Consent
What should the patient avoid leading up to a GXT? (6)
- Food consumption at least 2 hours before GXT
- Alcohol
- Cigarettes
- Caffeine
- Many over the counter herbal medications
- Continuation or acute cessation of prescribed medications to be consulted with doctor
What measurements are taken in a GXT (4) and when are they taken?
- HR
- BP
- RPE
- 12 lead ECG
- They are taken at rest before exercise, during a progressive test and after the test
What equipment may be used to perform a GXT? (4)
- Treadmill
- Cycle ergometer
- Arm ergometer
- Lifting or workplace tasks
What is the bruce protocol that is used in GXT?
When is it OK, what are its limitations?
A table of ‘stages’ with relative speeds and gradients, where someone does 3 minutes at each stage on a treadmill and progresses. This is the most widely used protocol and is programmed into most testing equipment.
It is good for pt’s who are not frail, who do not have extremely low functional capacity and can handle the gradients orthopaedically.
Limitations include being relatively large increments in workload with each stage, the long stages (3 minutes) at some workloads may be problematic
Steepness may lead to premature leg fatigue, vs CR fatigue
What are some alternate treadmill protocols, the Bruce protocol?
- Blake-Ware or Naughton (1-2min stages with increments of 1MET or less)
- Ramp protocols (small increments every 10-15 seconds, perception of effort requires usually less)
When would a cycle stress test be more suitable for a patient? What is the difference between using an electrically or mechanically braking cycle?
If a pt has weight bearing or gait problems, or treadmill not working.
Electrically braked cycles (preferred) - cadence not critical
Mechanically baked cycles - cadence critical
When is an arm ergometer recommended? (6) What load increases should be used?
- Severe lower-limb orthopaedic problems
- Lower extremity amputation
- Peripheral vascular disease
- Neurological disorders
- Myocardial symptoms present with upper body activity only
- Return to work post MI that involves extensive upper body activity
- Increases should be small, at <25W
Name two effort/symptom rating scales
- Borg’s Rating of Perceived Effort (RPE) scale
- OMNI Rating of Perceived Effort
What is a normal GXT response? (4)
- Nil ischaemia
- Nil cardiac dysrhythmias
- HD stable (HR and BP responses)
- Reach acceptable workload (MET level)
What are three main types of ECG abnormalities?
- Supraventricular dysrhythmias
- Ventricular dysrhythmias
- High-grade conduction abnormalities (blocks)
What are three reasons for stopping a GXT?
- Sign or symptom limited (absolute or relative indications)
- Reached predetermined submaximal level
- Maximal level of exertion reached
What are considerations for medical supervision with a GXT? (5)
- Cardiologist is not always present during the test
- Cardiologist always reviews and interprets ECG and other measurement data
- Medical supervision to be present or nearby during the exercise test
- Preferable for cardiologist to be present for high risk patients
- Staff should be trained in CPR
What are the benefits of GXT? (3)
What groups is the GXT less diagnostic for? (2)
Benefits:
- non-invasive
- relative cost effects
- good value if pt has CV risk factors and/or symptoms
Less diagnostic:
- <40yo
- Apparently healthy
What are the reasons for doing GXT? (5)
- Evaluate possible cardiac disease
- Evaluate existing cardiac disease
- Evaluate effectiveness of surgical procedures
- Evaluate effect of pharmacological therapy
- Evaluate functional capacity
Why is pre-operative exercise testing beneficial?
- Due to the significant risk associated with surgery, it can test multiple body systems under stress and identify and specific risks for surgery complications or mortality, can guide pre-operative pre-habilitation programs
What is the resting energy expenditure per day of skeletal muscle?
54.5kj/kg (13cal/kg)
What is the resting energy expenditure per day of adipose tissue?
18.8kj/kg (4.5cal/kg)
What is the resting energy expenditure per day of bone?
9.6kj/kg (2.3cal/kg)
What is the density of skeletal muscle? In kg/L
1.06kg/L
Approximately 15% denser than fat
What is the density of adipose issue? in kg/L
0.9kg/L
What is the water:protein:salts/minerals% of skeletal muscle?
- water 75%
- protein 20%
- salts/minerals 5%
What percentage of body weight is skeletal muscle, in healthy males and females?
Males ~42%
Females ~36%
What is the general organisation of skeletal muscle?
Muscle fibres (cells), organised by connective tissues. At the ends of muscles are collagen matrixes, forming tendons or aponeurosis
What are the levels or organisation in skeletal muscle? (5)
- Muscle
- Fascicle
- Muscle fibre
- Myofibrils
- Sacromeres
What are the roles of skeletal muscle? (4)
- Force
- Movement and posture
- Metabolism and thermoregulation
- ?Endocrine organ
What nervous system innervates skeletal muscle? How does it recruit muscle fibres?
Somatic motor nervous system.
It recruits muscle fibres by recruiting motor units, all muscle fibres in a motor unit are the same.
What are the three categories of motor units and what are fibres to the predominantly contain?
- S - slow twitch, low tension, fatigue resistant (~ type I fibres)
- FFR - fast fatigue resistant, fast twitch, moderate force (~type IIA fibres)
- FF - fast fatiguable, fast twitch, high force (~type IIX/IIB fibres)
What factors affect which motor units are best suited and recruited for a task? (4)
- Force required
- Duration of activity
- Availability of energy
- Fatigue of fibres
What is the size principle, in regards to progressive increase in force and motor unit recruitment?
What motor units are recruited first for light-moderate intensity activities?
The type and number of motor units recruited varies as increase in force requirements (exercise intensity)
S motor units have lower thresholds for activation, so are recruited first for light-moderate intensity activities.
What are characteristics of slow motor units with type I fibres? (4)
- Usually small motor units
- Low-moderate force
- Long duration
- Many every day activities
What are characteristics of fast motor units with type IIA fibres? (4)
- medium sized motor units
- higher force
- higher speed
- moderate - long duration
What are characteristics of fast motor units with type IIX/IIB fibres? (4)
- large to very large motor units
- high force
- high speed
- short duration
What are three ways muscle fibres can be classified?
- Morphology (red/white, large/small, capillary density)
- Contractility (speed (twitch), force (tension), fatigabilty)
- Metabolism (oxidative/glycolytic, myosin ATPase)
What are the two main muscle fibre categories?
Which is dominant for aerobic and anaerobic activities?
What else differs these two groups?
- Type I - dominant in aerobic (endurance) activities
- Type II - dominant in anaerobic (power) activities
- Also differ by type of neuron innervation
For each major muscle fibre types (4), what are their speed usage and metabolic characteristics?
- Type I: slow, oxidative
- Type IIA: moderately fast, oxidative, glycolytic
- Type IIX: fast, moderately oxidative, glycolytic
- Type IIB: fast, glycolytic
What muscle fibre type do most people have in major arm and leg muscles?
45-55% of people, type I
What muscle fibre type would an endurance athlete predominantly have?
More and larger type I
What muscle fibre type would a power athlete predominantly have?
More and larger type II
What are the neurological determinants of muscle force? (3)
- Number of motor units recruited (more MUs = more force, small motor units for fine motor control, large motor units for gross movements)
- Size (type) of motor units recruited (larger MUs = more force)
- Synchronicity of activation (synchronous MU recruitment = maximal forces in the highly trained e.g. weight lifters, asynchronous MU recruitment of S/FFR allows cycling of motor units for good fatigue resistance e.g. continuous running)
What are the anatomical-physiological determinants of muscle force? (8)
- Size of fibres; more myofibrils = ‘thicker fibres’ = more force
- Cross sectional area; larger muscle = larger cross-section = larger force
- Muscle architecture/fibre alignment; parallel, pennated, other
- Muscle length; ratio of fibre to muscle length 0.2-0.6 (20-60% muscle length. shorter fibres usually stronger, longer fibres can shorten faster being more powerful but not as strong
- Sacromere length; extent of actin-myosin cross-bridge overlap and attachments influence muscle force
- Joint ROM; max muscle force varied through ROM, depending on its capacity of fibre length and sarcomere overlap
- Velocity; as velocity increases, force decreases
- Fibre type; type II fibres produce more force and power than type I at the same velocity (except 0). type II fibres can produce much more force and power at higher velocities
How are arrangement of muscle fibres described?
Relative to the axis of force
What is parallel muscle architecture?
- Fibres parallel to force-generating axis
- Strap, fusiform, fan-shaped
- Example - biceps brachii
What is pennated muscle architecture?
- Fibres at an angle relative to force-generating axis, usually varying between 0 and 30 degrees
- Unipennate - single angle
- Bipennate/miltipennate - 2 or more angles
- Example - deltoid
What is an example fo an ‘other’ muscle architecture type? (Does not fall under parallel or pinnated)
Tongue
What are some characteristics of complex fusiform muscles? (4)
- Muscle fibres do not run the full length of the muscle
- Fibre length usually longer in fusiform vs pennated
- Fibre length to muscle length ratio larger than in pennated muscles
- Advantage for quick muscle shortening AKA increases velocity of shortening
What effect does pennated muscles have on force?
- Pennation decreases each fibre’s maximum force on the tendon. The greater the angle of pennation, the more loss of force (up to 13%)
- Pennation increases fibre packing and sarcomere number per physiological cross-sectional areas (PCSA) of muscles
- Increased PCSA = greater force
When comparing the physiological cross-sectional area (PCSA) and fibre length in quadriceps and hamstring muscles, which has:
a) greater pennation
b) greater PCSA
c) longer fibre length
Based on these factors, which is specialised for force and which for speed?
a) greater pennation - quads at 4.6 degrees, hamstrings 0
b) greater PCSA - quads at 21.7cm2, hamstrings 11.7cm2
c) longer fibre length - hamstrings at 111mm, quads 68mm
Quads - force
Hamstrings - speed
What are characteristics of muscle with shorter fibres and larger PCSA, in relation to ROM and velocity, and force at muscle length and speeds? (3)
- smaller ROM and velocity
- more force at shorter muscle length
- more force at slow speeds
What are characteristics of muscle with longer fibres and smaller PCSA, in relation to velocity, and force at muscle length? (2)
- more force at longer muscle lengths
- higher velocities
How is muscle force (tension) generated at the sacromere level?
Through actin-myosin cross-bridge cycling
Whilst under tension, what can a muscle fibre do? (3)
Shorten, lengthen or stay the same
What does contraction describe?
Term to generically describe all conditions of tensions, OR shortening
What are ‘other’ determinants of muscle force (2)?
Not neurological or anatomical-physiological
- Adrenaline; beta 2 receptors
- Limbic inputs; face slapping, smelling salts
What are muscle levers? How many classes are there?
A lever is a rigid rod (usually a length of bone) that turns about a pivot (usually a joint)
There are three classes.
- Class 1 e.g. head and neck during extension
- Class 2 e.g. standing on tip-toes, pivot at toe joints and foot is ‘lever arm’
- Class 3 e.g. elbow joint