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CHAPTER 1
Exercise affects how body develops, levels of hormones in body, blood lipid/fat profile, body composition….
Fitness isn’t important, but amount of energy you use in doing physical activity & what you’re using the energy on is important to health
Fitness experts – work from perspective of how we evolved, genetic make-up & how exercise affects genome
Genotype = genetic constitution of someone
Phenotype = measurable traits/characteristics of someone – some are controlled by genes, others by genes + environmental factors, others shaped entirely by environmental factors
- ie: blue eyes, aggressive behaviour, language (respectively)
Relationship between genotype and phenotype – genotype + environment = phenotype
- nature vs nurture debate = importance of innate qualities vs personal experiences in determining or causing differences in physical & behavioural traits, as well as health
- some researchers argue that genotype is programmed to be active, and living in a sedentary enviro leads to disease (poor phenotype)
- we are designed to be active and being sedentary means that we can’t expect ourselves to remain healthy
Epigenetics – study of changes in phenotype caused by enviro and not genotype -ex: diet [The foods available to your immediate ancestors would have been affected by their geographical location and exposure to these foods would have caused some epigenetic adaptation. So if we feed an Inuit population and a European population a diet based on lots of grains, the incidence of type 2 diabetes will be higher in the Inuit population because this is a “newer” food to them. This is despite the fact that the genome of Intuit and Europeans is essentially the same.]
No epigenetic adaptation to sedentary lifestyle – bc ancestors were more physically active, sedentary lifestyle rn is a drastic change and we have not completely adapted
Diet + stress management impacts your response to exercise program & normal physiological function
To reach genetic potential/allow for correct expression of genetic make-up, must have exercise programs that contain high intensity components and target the entire musculature -bc we evolved and did a lot of endurance things (hunting, tracking, gathering) but also needed short outputs of large energy for fights/sprints (fight/flight response) -must have enviro conductive to genetic make-up (bad enviro ex: sedentary lifestyle & diet based on processed foods)
Physical fitness = the ability to carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure time pursuits and to meet unforeseen emergencies
“Are you fit?” “Fit for what?” – bc swimmers are fit for swimming but not mountain climbing
Components of physical fitness (health-related components): -cardiorespiratory (aerobic) endurance -muscular strength -muscular endurance -flexibility -body composition
Components of fitness (performance-related components): -power -speed & quickness -agility
-balance -motor skill
Performance-related components are imp too (elderly need balance to avoid getting hurt)
Back injuries and motor control
Back injuries often caused by: -poorly conditioned muscles -muscle imbalances in the trunk -inflexibility in muscles crossing the shoulders and hips -poor lifting technique -poor motor control of the spinal musculature
McGill believes: balanced stiffness on all sides of spine = stability; so endurance/strength is 2nd^ to the relationship between muscle groups, bc muscle imbalances = back problems; ex: weaker extensor strength in comparison to flexor strength = lower back problems
But poor motor control (coordination) = also leads to back injury (bc small motor error = causes rotation of a single spinal joint = pressure on ligaments and disks = injury) = is coordination a component of fitness?
Exercises that include coordination component = improves strength, endurance and coordination in the same amount of time as a simple strength/endurance exercise on machine
Fall prevention and balance training
Longer you can do dips as you age = longer you will be able to push yourself out of a chair; more squats/lunges as you age = stronger legs = better ability to handle stairs as you age; more strength training = longer you’ll be independent/able to lift groceries
CONCLUSION: muscular strength & endurance are health related
40% of seniors fall = 40% seniors move to residential homes bc of a fall = but strength & balance training reduces falls by 40% and is v effective for people >80y/o
Strength training while sitting on machines = does not challenge balance and coordination, but stuff like tai-chi works a lot better and helps seniors prevent falls
Fall-prevention strategies ex: vigorous cross-steps; shooting out an arm to grab something (explosive movements); dumbbell snatches w v light dumbbells = helps protect muscles from injury when reacting quickly (bc when you lose balance, you try to right yourself by rapidly driving your centre of gravity back inside your base of support)
Functional movement
Coordination of movements required to achieve a functional outcome = ex: training frail seniors who fear falling by getting them to lie down and get back up again (helps physically and lets seniors know that if they fall, they can get up and get to the phone to call for help)
Important to incorporate motor coordination & balance into functional exercises
Performance and health are inseparable
General physical skills
Body composition = result of fitness = must train components of fitness, eat properly, manage stress for good body comp
Natural killer T-cells remain suppressed longer after bouts of severe exercise = excessively high exercise stress = reduces effectiveness of body’s immune system
Critical thinking
Epidemiological studies = comparing the health of populations as they present themselves w/o any manipulation, looking for correlations between variables of interest (***correlation is not causation; a physically active group may not be healthier than a sedentary group bc of just dpa, but bc they maybe have a better diet, smoke less, better genes, etc)
Can only trust these studies if criteria satisfied: -association between exercise & health must be repeatable (reliable) -association between exercise & health must be strong (ex: exercise decreases CVD risk by 1% is not a good result; exercise decreases CVD risk by 50% is a promising result; exercise decreases swamp fever by 50% but chances of getting swamp fever is 0.000001%, then results still are not favourable) -association between exercise & health must be logical -other obvious factors/variables must be shown not to be the cause of the association
Terms: Conjecture = a conclusion deduced by surmise/guesswork or a belief w/o sufficient evidence for proof Hypothesis = a conjecture (proposition)/set of propositions set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation (working hypothesis) or accepted as highly probably in light of established facts Theory = a coherent group of general hypotheses used as principles of explanation for a class of phenomena Law = a theory that has received validation in all possible ramifications, and to known levels of accuracy
Planning to change your activity level
Select one thing as your target behaviour change and work that into your lifestyle before changing additional behaviours
Set SMART goals: -Specific = what, how, where, when, with who and how long will you do this? -Measurable = will you know when it’s done? -Acceptable = will you feel good about doing this? Is this a personal goal for you or is someone else influencing your choices? -Realistic = are you able to do this? Timely = is there a deadline attached? Set short & long-term goals, and create new goals once old ones are achieved
How active are we?
Physical activity = any activity above resting levels (ie: going for a walk, gardening) – will not improve fitness
Exercise = a subset of physical activity that is planned, structured, & repetitive – will improve fitness
CHAPTER 2
Physiological conditioning = planned program of exercise directed towards improving functional capacity of a particular bodily system
Principles of physiologic conditioning: -overload principle -specificity principle -reversibility principle -individual differences principle
Overload - adapting to the amount of training (applies to any skills that can be improved w training)
Exercising a system at a level above that at which it normally operates forces the system to adapt and function more efficiently
This principle = explained by Hans Selye’s general adaptation syndrome (GAS) = stress (like exercise) disrupts organism = initially weakens organism (fatigue) = organism responds by adapting and enhancing their capacity (supercompensation = becoming fitter by adapting to stress)
Supercompensation = only occurs if training is difficult enough to disrupt homeostasis and is followed by adequate rest
Inadequate rest = excessive fatigue/injury is likely to occur
Imp to train again before enhance capacity drops towards baseline again = relates frequency of training and reversibility principle
Overload can be accomplished in 3 ways: -increase intensity of exercise while maintaining duration and frequency -increase duration of exercise while maintaining intensity and frequency -increase frequency of exercise while maintaining intensity and duration
Degree of overload = keep pace with changes in capacity = if you adapted and you don’t change to overload again, will not continue to improve
Do not increase duration, frequency and intensity all at once = too much too soon is most common injury cause
FITTness formula = sets up effective exercise -F = frequency; “how often” -3-5 workouts per week, evenly spaced = optimal -more frequent = greater improvements
-I = intensity; “how hard” -keep intensity down if you aren’t exercising regularly to reduce injury chances, but too low intensity (<50% max HR) is not ideal -most important factor in determining training effect -optimum exercise threshold = 60-70% of individual’s age-predicted maximal heart rate -optimal cardiovascular training = elevate heart rate to 70%-90% of maximal heart rate for at least 15min (>85% for beginners = > chance of musculoskeletal injury) -Methods to assess intensity: -percentage of maximal heart rate = age-predicted maximal heart rate = 220 – age, then determining a percentage range (ex: assumption made -> maximal heart rate = 220 – 22 = 198bpm, 60% of 198 = 119bpm, 90% of 198 = 178bpm, target heart range = 119-178bpm, 10s target heart rate= 20-30beats) (take heart rate for 10s immediate after stopping exercise for efficiency & bc heart rate drops rapidly during recovery from exercise) -heart rate reserve (Karvonen formula) = optimal exercise range is 50-85% of heart rate reserve = more accurately reflects % of used aerobic capacity bc % of aerobic capacity & % of heart rate are not the same thing, & protects you from having too low a threshold target since it takes into account your resting heart rate (maximal heart rate = 198bpm, resting heart rate measured = 60bpm, maximal heart rate-resting heart rate = 138bpm, lower level of target heart range = resting heart rate + 50% of HRR = 60 + 0.5138 = 129bpm, upper level of target heart range = resting heart rate + 85% of HRR = 60 + 0.85138 = 177bpm; target heart range = 129-177bpm, 10s target heart rate = 22-30beats) -rate of perceived exertion (RPE)(Borg scale) = based on typical heart rate divided by 10 (predicted max for 22y/o from above is 16-17 on this scale)
6 Nothing at all 7 Very, very light
Reversibility principle = use it or lose it = regular program of activity must be maintained to prevent de-conditioning and loss of unctional capacity = do not rest too long bc longer than necessary rests means they miss chance to overload their system and force even more adaptation
Generally 48hr rest is enough, except for after v severe exercise
Reversibility = diff for diff components of fitness (cardio endurance/VO 2 max = least persistence & can lose in a few days, muscle mass/hypertrophy = most persistent & can take weeks/months to lose)(aerobic enzymes/cellular structure for aerobic energy production = diminish faster than contractile proteins in muscle bc buildup of contractile proteins is tough and it will be persistent once you have a large muscle mass built up)
Training history = athletes w training history in cardio = can return to those levels quicker than those w/o training history
Individual differences principle – limits on adaptability
Training benefits = best when programs are designed to meet one’s needs and capacities
Fitness plans = adjusted to body’s response to exercise = make adjustments and do additional work to challenge fitness weaknesses
Response to exercise program = varies from each person, also affected by age and gender
Beginners = should start w cardio
Energy production (Intensity)
Energy = capacity/ability to perform work (required for muscle contraction, digestion…)
Power = rate of change of energy/how quickly we can perform work (power output = muscle function during exercise = rate at which muscles can produce energy – ex: 50 push-ups in 4 mins vs 50 push-ups in 2 mins = power output for push- ups has doubled bc work done performing 50 push-ups divided by half the time, but w the same body weight and same distance moved during each push-up, work done is the same)
Power output = another way to assess intensity
FITTness formula = for aerobic exercise = power output ~10-15% of max
Aerobic energy production = producing energy w oxygen
Anaerobic = producing energy in the absence of oxygen
Warm-up – prepares body for exercise to follow (does not train any particular component of fitness) -active (general & specific exercises) or passive (taking how showers, massages…are less effective) -general part = includes activities like jogging, dynamic stretching, and calisthenics -sport-specific = specific dynamic stretches & movements that will be used in the sport (ie: easy rallying in tennis, passing a ball back & forth w a partner)(acceptable as long as it’s not excessive, so performance isn’t affected) -static stretching isn’t as effective as dynamic stretching -intensity = should be able to work a mild sweat w/o fatigue -purpose: -gradual increase in metabolic requirements = improves cardiorespiratory performance (ex: higher cardiac output & aerobic power); increase in body temp facilitates enzyme activity in skeletal muscle & increases blood flow & O2 delivery to skeletal muscle -prevents high muscle acidity early in the exercise session (high acidity levels = increase muscle fatigue) -gradual increase in deep muscle temp = decreases work of contraction = reduces chances of injury
(elastic components of muscle susceptible to injury when muscle is cold, warming muscle alters stiffness of connective tissue = greater force & length needed to tear the musculotendinous unit) -improves neural transmission for motor unit recruitment = improvement in contraction & reflex times of skeletal muscles -lessens danger of inadequate blood flow to heart (myocardial ischemia) in early stages of exercise (abrupt, strenuous exercise may be associated w such problems) -provides a screening mechanism for potential musculoskeletal/metabolic problems that may be problematic at higher intensities -lubricates joints -provides psychological prep for the event (increase focus..)
Cool down – a warm up in reverse & is not just stretching (ex: runners = min cool down = 5mins of slow jogging & walking, followed by stretching exercises for quads, hamstrings and calves) -keep moving until heart rate has dropped below 100bpm (bc skeletal muscles actually help pump blood back to heart) -purposes: -maintains the venous return to the heart & brain (prevents post-exercise venous pooling and too rapid a drop in bp = reduces likelihood of post-exercise light-headedness & fainting) -maintains a large blood supply to the muscle = help reduce acidity levels -hastens removal of lactate from working muscles = lactate then used for energy in recovery process -reduces immediate post-exercise tendency for muscle spasms/cramps -allows heart rate, O2 uptake & body temp to gradually return to resting levels -reduces []s of exercise hormones (relatively high immediately after exercise & can cause post-exercise disturbances in cardiac rhythm)
Training errors Common mistakes: -not planning effectively = should have training strategy & sched -not individualizing your program = should know strengths/weaknesses, improve weaknesses in training not avoid -not keeping a record of training & performance = helps make necessary adjustments to your plan & monitor if you’re achieving goals -too much too soon = overload too high = increase chance of injury (or insufficient overload = reduces improvements) -not warming up effectively = increases injury potential -having unrealistic expectations = discouraged when rapid improvements don’t occur
Overuse injuries – pain in/around joints (pain that isn’t mild muscle soreness) s a big sign -listen to your body -ex: impact from foot strikes due to running stresses body & causes some damage to muscle/connective tissue -take time to recover between exercise sessions
Overuse syndrome – rare -symptoms: -sudden weight loss -chronic fatigue (consistently tired, little desire to train) -lack of appetite -insomnia -increase in morning pulse rate of more than 5bpm (taken just after waking up before getting out of bed)
CHAPTER 3
Cardio anatomy and physiology = often taught first bc simpler, but requires movement & muscle action
-transverse flexion = moving upper arm towards & across chest w elbows facing sides = PECTORALIS MAJOR, ANT DELTOID, BICEPS BRACHII -medial rotation (internal rotation) = rotary movement around longitudinal axis of bone toward center of body; turning upper arm inward = PECTORALIS MAJOR, LATISSIMUS DORSI, ANT DELTOID, TERES MAJOR -lateral rotation (external rotation) = turning upper arm outward = TERES MINOR, POST DELTOID
Elbow -flexion = bringing forearm toward upper arm; bending joint & decreasing angle = BICEPSBRACHII, BRACHIALIS, BRACHIORADIALIS -extension = straightening joint & increasing angle; bringing forearm away from upper arm = TRICEPS BRACHII Forearm (radioulnar) -pronation = internal rotation of forearm resulting in palm moving down -supination = external rotation of forearm resulting in palm moving up = BICEPS BRACHII Wrist -flexion = moving palm of hand toward front of forearm -extension/hyperextension = moving back of hand toward back of forearm -ulnar deviation = moving little finger side of hand toward medial side of forearm (fist pointing towards you) -radial deviation = moving thumb side of hand toward lateral side of forearm (fist pointing away from you) Spine (Thoracic, Lumbar) -flexion = moving spine forward; thorax moves toward pelvis = RECTUS ABDOMINIS, ABDOMINAL OBLIQUES -extension/hyperextension = moving spine back; thorax moves away from pelvis = ERECTOR SPINAE, LOWER TRAPEZIUS -lateral flexion (abduction) = move spine to the side; thorax moves to side toward pelvis -reduction (adduction) = straightening spine from lateral flexion -rotation = turning spine to side; thorax rotates to one side = OBLIQUES, PSOAS MAJOR Hip -flexion = moving thigh or top of pelvis forward = ILIOPSOAS, RECTUS FEMORIS, THIGH ADDUCTORS + ABDUCTORS -extension = moving thigh or top of pelvis backward = GLUTEUS MAXIMUS, HAMSTRINGS, THIGH ADDUCTORS -adduction = moving thigh inward w hip straight = THIGH ADDUCTORS, GLUTEUS MAXIMUS -abduction = moving thigh outward w hip straight = THIGH ABDUCTORS -transverse adduction = moving thigh inward w hip bent = THIGH ADDUCTORS -transverse abduction = moving thigh outward w hip bent = THIGH ABDUCTORS, GLUTEUS MAXIMUS -medial rotation (internal rotation) = turning thigh/pelvis inward = THIGH ABDUCTORS -lateral rotation (external rotation) = turning thigh/pelvis outward = GLUTEUS MAXIMUS, THIGH ABDUCTORS Knee -flexion = moving lower leg toward back of thigh = HAMSTRINGS, GASTROCNEMIUS, THIGH ADDUCTORS -extension = moving lower leg away from back of thigh = QUADS Ankle -plantar flexion = extension of ankle resulting in forefoot moving away from body = GASTROCNEMIUS, SOLEUS -dorsiflexion = flexion of ankle resulting intop of foot moving toward body = TIBIALIS ANTERIOR Foot (intertarsal) -inversion (supination) = TIBIALIS ANTERIOR -eversion (pronation)
Muscle Action
Sternocleidomastoid = both sides working together produces neck flexion (cervical flexion); right one produces rotation to the left & lateral flexion to the right; left one produces rotation to the right & lateral flexion to the left
Deltoid (anterior, medial/lateral, posterior heads) =all help w abduction of the arm; anterior = flex & horizontally adduct arm; posterior =extend & horizontally abduct arm
Latissimus dorsi =extension & adduction at shoulder joint
Pectoralis major =flexion, horizontal adduction & adduction at shoulder joint; when shoulder is flexed = extensor
Biceps brachii = flexion at elbow joint; weak flexor of shoulder
Brachialis = flexion of elbow
Brachioradialis = flexion of elbow
Triceps = extension at elbow joint
Trapezius = shoulder girdle movments; some impact on cervical/thoracic spine
Rhomboid = adduction & downward rotation of scapula (if it targets latissimus dorsi, you’re working this muscle too)
Abdominals (rectus abdominus) = trunk flexion
Abdominals (internal and external obliques) = both produce trunk flexion; left external oblique + right internal oblique causes rotation to right; right external + internal oblique contracting gives lateral flexion to the right
Erector spinae = extension of the spine (series of deep-lying muscles attached along the back of the spine)
Iliopsoas = flexion of hip & trunk The iliopsoas is actually two muscles ( iliacus and psoas ) that start out separately and then join together to a common insertion. It is a deep-lying muscle with fibres running from the lumbar vertebrae and iliac bone to the front of the thigh (femur). As the psoas attaches to the spine it is a very important muscle in relation to back pain and I will discuss this later in the text.
Gluteus maximus = extension at hip
Quadriceps = extension at knee; only rectus femoris (of the quads) crosses hip joint and has action flexion at hip joint
Hamstrings = flexion at knee & extension at hip
Thigh adductors = adduction of thigh
Thigh abductors = abduction of thigh
Tibialis anterior = dorsiflexion of ankle (toe rotating towards knee)
Gastrocnemius = plantar flexion at ankle (toe pointing away from knee) & flexion at knee (it’s a bi-articulate muscle = two-joint muscle)
Soleus = plantar flexion (toe pointing away from knee) at ankle (does not cross knee joint)(single-joint muscle = uni- articulate)
Muscle and joint movement classification
Agonist—A muscle that causes the motion of the exercise. So the biceps is an agonist in the biceps curl. Antagonist—A muscle that can move the joint opposite to the movement produced by the agonist. The triceps is the antagonist for the biceps curl. Target—The primary muscle intended for exercise. Synergist—A muscle that assists another muscle to accomplish a movement. Stabilizer—A muscle that contracts with no significant movement to maintain a posture or fixate a joint. When doing the back squat, the muscles of the trunk (all of them) contract to stabilize the spine. Dynamic stabilizer—A bi-articulate muscle that simultaneously shortens at the target joint and lengthens at the adjacent joint with no appreciable difference in length. Dynamic stabilization occurs during many compound movements. For example, the hamstrings dynamically stabilize the knee and hip during a back squat. The dynamic stabilizer assists in joint stabilization by countering the rotator force of an agonist.
extends to push a lever upwards. I grant you, the external force is being applied to the shins, but you cannot claim that the end of the segment is supporting the weight. The leg curl is also an open-chain movement Functional— “an exercise which allows one to gain motor development or strength in a manner in which it is used in the execution of a particular task (e.g., specific sport skill, occupational task, or daily activity).” Balancing on wobble boards or sitting on oversized beach balls doesn’t fit this definition. Doing a deadlift would.
Exercises
Free Weights
- Back squat
- Overhead Squat
- (^) Deadlift
- Bench press
- Press (shoulder press or military press)
- Biceps curl Machine
- Leg press (can be done lying or seated)
- Leg curl (can be done lying or seated).
- Knee (leg) extension
- Lat pull-down
- Seated row
- Triceps extension Calisthenics (Body Weight)
- Push-up
- Sit-up
- Curl-up (crunch)
- Air-squat
- Pull-up
- Back extension
- Dips
Resistance training safety
- Use common sense!
- Perform one or more warm-up sets with relatively light weights, especially for exercises that involve the shoulder or knee. If you have been doing aerobic exercise first for 15 minutes or more and are fully warmed up, you may not need to do these warm-up sets for all muscle groups.
- Make sure you lift from a stable base.
- Avoid holding your breath while doing resistance training exercises. You should breathe out during exertion. Breath- holding can cause a significant rise in arterial blood pressure and in the workload of the heart. This is particularly dangerous for people with high blood pressure and heart disease. Holding your breath causes an increase in thoracic pressure, which can cause decreased venous return to the heart. As blood flow to the heart and brain is significantly reduced, this may lead to dizziness and fainting. Holding your breath can cause a valsalva maneuver, which is a forced exhalation against a closed glottis. This increases intra-thoracic pressure, which can lead to the dizziness and fainting described above.
- Do not overly arch your back during exercises like the bench and overhead press.
- Do not round your back (especially when lifting heavy weights in exercises like squats and deadlifts). The spine should maintain its normal alignment (neutral spine), which has a slight lordotic curve in the lumbar region. Allowing the lumbar spine to round is a dangerous maneuver. Keep the core tight.
- Use a spotter or safety racks for free-weight exercises like the bench press or other lifts where you could drop the bar on yourself.
- Perform all exercises through a full range of motion, unless they are specialized supplementary or rehabilitative exercises.
- Use relatively light weights when starting a new exercise, or when resuming training after a lay-off of two or more weeks.
- If you feel pain around or in a joint, reduce the amount of resistance and increase the number of repetitions, or use different exercises, or do a combination of both. If the pain is severe and consistent, it may be necessary to stop all lifting that affects the painful joint(s) and to have the injury examined and treated medically. It is usually not necessary to stop all resistance exercise completely.
- Only attempt near maximal lifts (2-3 RM range) after a minimum of several weeks of training in the exercise movement and proper technique instruction. One-RM lifts should only be performed by advanced weight-trainers with several months of lifting experience.
- Apply ice to joints under heavy stress immediately after your workout to help the joint recuperate and prevent injury.
- Include supplementary exercises to improve joint stability and muscle balance within muscles of a group and between those of opposing groups (acting on opposite sides of a joint). Lack of balance between muscles has been found to be a cause of athletic injury.
- Avoid bouncing too vigorously at the bottom of a squat exercise. At the end of the range of joint motion, always perform the movement slowly and in a controlled fashion.
- When squatting, avoid moving the knee outside of a vertical plane. Any sideways deviation will place potentially dangerous forces about the knee. The knee should track over the toes.
- (^) Use knee and elbow wraps only on the heaviest lifts, if at all. Heavy and tight wraps can cause injury. If used, put them on immediately before and remove them immediately after each lift.
- For complete muscle development and joint stability, perform several variations of an exercise (such as flat bench press, incline press, and decline press for the chest and shoulder muscles).
- Do not perform explosive exercises such as cleans, jerks, and snatches without qualified instruction, as poor technique can result in very high and potentially dangerous forces on muscles, tendons, and ligaments.
- Re-rack weights and keep the area clear.
- Check the immediate area before lifting—make sure it is safe to proceed.
- Full squats (done properly) are safe.
CHAPTER 4 Benefits of resistance training : (some more effective w certain types of exercise than others)
Increases Decreases Helps Muscular strength Body fat Prevent injuries Muscular endurance Stress & tension Rehabilitate injuries Strength of bones Resting heart rate (w endurance/ circuit training)
Improve cardio-respiratory function (w endurance/circuit training) Tensile strength of ligaments & tendons
Alter metabolism to improve caloric utilization Thickness of cartilage Facilitate quicker recovery from workouts and competitions Muscle mass (hypertrophy) Increase self-image & confidence Stamina (duration of effort before exhaustion)
Improve appearance
Flexibility (assuming full range of movement during training)
Increase feeling of well-being
Speed & power Induce fatigue & relaxation (help sleep patterns) Blood volume and hemoglobin (w endurance/circuit training) Muscle enzyme levels Skill (free weight programs) Maximal work capacity Equalization of muscle development
throughout ROM bc of changing leverage & inherent mechanical properties of muscles + easier to move a constant weight once it’s been accelerated due to less resistance)(ex: last part of a push-up is easier once you have your body weight moving up and have more leverage)
-isokinetic contraction = contraction where muscle shortens or lengthens @ constant velocity (does not occur in nature & only when you are working on machine that controls movement velocity)
-concentric contraction = when muscle is contracting and shortening
-eccentric contraction = when muscle is contracting and also lengthening (muscle is trying to shorten but external force – ie: gravity – causes muscle to be lengthened)(ex: lowering a weight slowly)
Muscle fibre types
CHAPTER 5
Cardiovascular system
Pulmonary circulation = deoxygenated blood pumped from heart through lungs & oxygenated blood is returned back to heart
Systemic circulation = oxygenated blood is pumped from heart to rest of body & deoxygenated blood is returned back to the heart
-Superior vena cava & inferior vena cava = blood from head + upper extremities & from trunk + lower extremities return to heart
-flows through right atrium – tricuspid valve – right ventricle – pulmonary valve – pulmonary arteries – lungs
-in lungs, blood gives up excess CO 2 and replenishes O 2
-flows through pulmonary veins – left atrium – bicuspid valve – left ventricle – aortic valve – aorta
-blood goes into systemic circulation and delivers O 2 & removes CO 2 in tissues
Skeletal muscle pump = when muscles contract & squeeze veins to push blood back to heart
Veins = have one-way valves to prevent backflow or blood
Aerobic exercise & other exercises that require alternating contraction-relaxation phases are preferred to isometric straining-type exercises (where muscles are held in contraction for long periods) bc isometric &maximal-effort exercises close down blood vessels = harder for heart to pump blood through = high blood pressure (ok for short period for healthy person, but not great if you have issues)
Working muscles = produce energy while using O 2 bc it’s more efficient = exercise -> overload system’s ability to deliver O 2 to working muscles -> adaptation
Cardiac output = heart rate x stroke volume
Cardiac output (Q) = amount of blood pumped in one min by either right or left ventricle of heart
Stroke volume (SV) = amount of blood pumped by left or right ventricle of heart per beat
Heart Rate (HR) = number of heart beats per minute
Typical Values for untrained Individuals at Rest and During Heavy Exercise Q = HR x SV Rest 5.6 Liters/min = 70 beats/min x 80 millilitres/beat Heavy exercise 23 litres/min = 200 beats/min x 115 millilitres/beat
Respiratory (pulmonary system)
Respiration = exchange of O 2 and CO 2 between cells and enviro
External respiration = exchange of O 2 and CO 2 in alveoli (lungs)
Internal respiration = exchange of O 2 and CO 2 at the cellular level
Alveoli = little, thin-walled, hollow sacs in lungs where gas exchange takes place (has large SA for diffusion of gases)
-air enters through nose/mouth- pharynx – larynx – trachea – 2 bronchi – bronchioles - alveoli
Mechanism of breathing – air molecules move from area of high pressure to area of low pressure
Inspiration = diaphragm + external intercostal muscles contract to increase volume in thoracic cavity = increases volume in lungs = decreased pressure = airway is open & air moves into alveoli (pressure in alveoli < pressure in atmosphere)
Expiration = diaphragm + external intercostal muscles relax to decrease volume of thoracic cavity = air forced out of alveoli
Low ventilation volumes = passive expiration = muscles relax & ribs recoil = ventilatory muscles only consume 1-2% of total oxygen
Heavier exercise = abdominal muscles (rectus abdominals & internal intercostals) aid in expiration = air ventilated per breath increases = respiratory muscles use 8-10% of total oxygen
Minute ventilation = tidal volume x respiratory frequency
Minute ventilation (V (^) E) = volume air inspired/expired in 1min
Tidal volume (V (^) T) = volume air ventilated per breath
Respiratory frequency (FR ) = number of breaths per min
Typical Minute Ventilation Values for an Average Size College Age Male V (^) E = V (^) T x F (^) R Rest 6-8 Liters/min = 0.5 litre x 2-16 breaths/min Heavy exercise 125-180 litres/min = 2.5-3.0 litres x 50-60 breaths/min
Light - moderate exercise = minute ventilation increases linearly as workload increases
Hyperventilation = minute ventilation begins to increase out of proportion = ~75-80% of VO 2 max
@ rest 15-20% of systemic blood flow goes to skeletal muscles
During maximal exercise – 85% goes to skeletal muscles, caused by -increased bp -dilation of arterioles in working muscles due to relaxation of smooth muscle in walls of arterioles -decrease in blood flow to other tissues & non-working muscles bc of constriction of arterioles in these regions (can be decreased up to 80%)(critical areas like brain are spared and blood flow increases, heart blood flow increases bc extra work needed, skin blood flow increases to dissipate heat)
Oxygen uptake & VO 2 max
Fick equation: Oxygen uptake (VO 2 max L/min) = cardiac output (Q) x (arterial-mixed venous oxygen difference ml/L)
Or though of as: cardiorespiratory fitness = oxygen transport x oxygen utilization (extraction)
Arterial-mixed venous oxygen difference = how much oxygen is in arteries & how much is in blood returned to heart
Oxygen content of venous blood from a working muscle < oxygen content of venous blood from non-working muscle (bc as you work you use oxygen) -> term: mixed venous oxygen, bc oxygen content of blood as it flows back into right atrium = better indication of how much oxygen body has used
Higher VO2max = able to do more work
Endurance athletes specifically = higher stroke volume than other athletes = v high cardiac output = can transport large quantities of O2 to working muscles
Athletes = lower resting heart rates than non-athletes bc resting stroke volume of athletes is higher, so they can attain same resting cardiac output (HR x SV) as non-athletes w a lower heart rate
Exercise heart rate
Athletes can work at higher workloads & finds lower workloads easier to endure (lower heart rates for more work in comparison to non-athletes)
Stroke volume during exercise
SV increases to highest values during sub-maximal exercise @ 40% VO2max & doesn’t increase further during steady- state aerobic work (highly trained athletes continue to increase after 40%)
For most, any further increase in O2consumption comes from increase in heart rate + small increase due to better extraction rate @ tissue level (greater difference)
High Intensity Interval Training (HIIT) = advanced technique, used only after min of 6 weeks of general conditioning, not for every day -ex: several maximal 400m sprints, each spring followed by 1-3min recovery period -SV higher during recovery period from intense exercise
Paradox of aerobic training
Best way to improve aerobically is to work so hard that you surpass your VO2max and work anaerobically
Anaerobic exercise= when you work at an intensity that exceeds body’s ability to deliver enough oxygen for the muscles to sustain that exercise intensity by burning oxygen
Can still use weight training to improve aerobic conditioning (bc no matter what you do, heart still has to work) -high-weight, low-rep = no improvement aerobically -low-weight, high-rep + variety = improves ability to work those many muscle groups aerobically
Capillary dilution = when you perform high-weight low-rep work with lots of rest between sets, all work is anaerobic so no need for body to build more capillaries
-muscles get bigger but no new capillaries = # capillaries per amount of muscle is going down -run out of energy quickly when doing sustained endurance work
Aerobic training routines
Maximal aerobic power -Maximum oxygen uptake (VO2max) = max amount of O2 one can use during physical work @ sea level (mL/kg*min) -expressing in L/min does not take body weight into account – smaller people = lower values =/= lower fitness -determined by -ability of heart to pump blood (Q) -oxygen-carrying capacity of blood (hemoglobin content) -ability of working muscles to accept alarge blood supply (amount of capillarization within a muscle) -ability of muscle cells (fibres) to extract O2 from capillary blood & use it to produce energy (determined by # of mitochondira & aerobic enzymes in the muscle) -measured by determining difference of amount of O2 in air inspired and expired by person
Age and gender differences in maximal aerobic power -VO2max increases with age, declines after 25y/o partly due to decrease in max hear rate + less physical activity -no significant difference in VO2max between boys & girls before 12y/o -males has VO2max higher than females bc of difference in body comp (males have more muscle and less fat = higher hemoglobin concentration so greater O2-carrying capacity per unit of blood) -cross country skiers show highest VO2max values bc they use more muscle groups than other athletes (more muscle working/contracting O2)
Maximal aerobic power & endurance performance -factors other than VO2max that affect endurance -anaerobic/lactate threshold = percentage of VO2max that can be used in significant amounts before the muscle enviro becomes acidic and causes local muscle fatigue & discomfort -individual variation in mechanical efficiency = O2 req for a given workload/running speed varies, so an efficient individual may run faster w a lower VO2max -motivation = must be prepared to experience considerable discomfort to perform at high levels -available fuel = can affect performance
Heredity & maximal aerobic power -heredity = 93% of observed differences in VO2max
Which VO2max?
You have >1 VO2max, each VO2max is specific to a certain exercise
Can train for VO2max in many diff ways
Systemic cardiorespiratory changes resulting from aerobic conditioning – systemic = changes in delivery of O2 to muscles rather than changes at cellular level (system change ex: increase in SV)
Changes at rest Changes during sub-maximal exercise
Changes during maximal exercise
Heart weight & volume generally increase w long-term aerobic training
Heart rate decreases & stroke volume increases for given sub-maximal workload
Maximal heart rate does not change or decreases slightly
Heart rate decreases & stroke volume increases w no change in cardiac output
Cardiac output decreases slightly for a given sub-maximal workload (with the reduction in sub-maximal cardiac output, the exercise O2 req is met by a corresponding increase in difference due to more capillaries in the working muscles & to biochemical changes that
Max stroke volume increases
