From Powerpoint Flashcards
All-or-none theory
- When a single muscle fiber shortens, it generates its maximum force capability; there is no gradation of force
- When a motor unit is stimulated, all the muscle fibers it innervates contract with maximum force
- The amount of force generated during a muscle group’s contraction depends on the following
a. The size of the individual muscle fibers contracting (the larger the fiber, the greater the force)
b. The number of muscle fibers recruited (more fibers equal more force)
c. The length of the muscle fiber prior to contraction
d. The speed of contraction
The length-tension relationship 1, Force 2. peak force 3. what happens at approximate resting length 4. effects of poor posture?
1) The amount of force that a muscle can exert is related to its length
2) Peak force production is usually seen at resting length or slightly greater (1.2 times resting length)
At approximate resting length, more of the myosin cross-bridge heads can align with active actin receptor sites
4) Therefore, clients with poor posture that have chronically shortened or lengthened muscle groups are not able to produce optimal force at the misaligned joints
Force vs. velocity
- A maximal force contractino is dependent on?
- the higher the speed of contractions, the?
- optimal speed of contraction while lifting weights?
1) A maximal force contraction is dependent on the number of actin and myosin cross-bridges formed
2) The higher the speed of contraction, the fewer the number of connected myosin and actin cross- bridges
3) An optimal speed of contraction while lifting weights appears to be 1 to 2 seconds concentric, followed by 2 to 4 seconds eccentric
Slow-twitch (Type I, Oxidative)
Contract slowly Contract less forcefully Fatigue resistant Primary energy system is aerobic Used in endurance activities
Fast-twitch (Type II, Glycolytic)
Contract rapidly Contract forcefully Fatigue quickly Primary energy system is anaerobic Used in short-term activities requiring strength and power
Contrast type IIa from type IIb
Fast-twitch fibers are further classified into type IIa and type IIb
Type IIa fibers are slightly more oxidative than type IIb
It is possible to increase either the oxidative qualities or the glycolitic qualities of type IIa fibers through training
However, muscle fibers cannot be changed from one type to another
Neural adaptation from Muscular adaptations toregular resistance training
Improved recruitment patterns
b. Improved motor learning c. Neural adaptations are responsible for gains in strength with little or no change in muscle cross- sectional area after as much as 6 weeks of training
Muscular adaptations toregular resistance training? 7
Neural adaptations Hypertrophy of fast-twitch fibers 3) Increased size and number of actin and myosin 4) Increased lean body mass 5) Increased connective-tissue strength 6) Decreased risk for joint injury 7) Increased bone density
Chronic stress has manynegative effects on the body Physiological system Musculoskeletal system Cardiovascular system Immune system CNS Gastrointestinal system
- Tension headache, neck and shoulder discomfort, and back pain
- Premature coronary artery disease (CAD), hypertension, increased platelet adhesiveness, and heart attack
- Suppression of T-cell function, increased vulnerability to infections, and viral illnesses
- Impaired memory and neural degeneration
- Stomach ache, nausea, constipation, and diarrhea
These negative changes primarily occur due to elevated levels of stress hormones (norepinephrine and cortisol)
Exercise may help decrease stress hormone levels and alleviate these symptoms
Isometric (static)
a. No visible movement occurs
b. The resistance matches the muscular tension
c. Examples
1. Wall sit
2. Plank
Concentric (shortening)
a. Muscle shortens and overcomes resistive force
b. Examples
1. Up-phase of biceps brachii curl
2. Up-phase of push-up
Eccentric (lengthening)
a. Muscle produces force as it lengthens, returning toward resting position
b. External force exceeds the contractile force of the muscle
c. Examples
1. Down-phase of biceps brachii curl
2. Down-phase of push-up
Levers
1) A lever is a rigid bar (bone) with a fixed point around which it rotates when an external force is applied to it
2) The fixed point is the fulcrum (joint)
Torque
1) Rotation at a joint
2) Result of a force acting on a lever at some distance from the fulcrum
3) Rotation occurs in the direction of the greater force
Muscular roles
1) Agonist (prime mover)
2) Antagonist (“opposing” muscle)
3) Synergist - name 5 things that the synergist can do?
1) Agonist (prime mover)
a. Causes a desired motion
b. Opposite of antagonist
2) Antagonist (“opposing” muscle)
a. Acts in opposition to the action of the agonist
b. The antagonist stretches as the agonist contracts
3) a. Can act as an assister, stabilizer, or co-contractor
b. Assister
1. A muscle that assists an agonist muscle in its function
2. Example: the teres major is involved in all the same actions as the latissimus dorsi but due to its smaller size and position it can only contribute a fraction of the amount of force
c. Stabilizer
1. Example: when all portions of the trapezius contract to stabilize the scapulae during a side lateral arm raise
2. This allows the scapula to become a stable base for efficient arm movement
d. Co-contractor
1. Example: when the gluteus maximus contracts to counteract the hip flexion that occurs while rising from a low squat
2. This allows the rectus femoris to extend the knee as a person is rising without inclining the trunk forward
e. Both stabilizing and co-contracting play important roles in posture and efficient joint mechanics
Compare/contrast performance interval training and fitness interval training?
Performance interval training is designed to enhance competitive performance, while fitness interval training is designed to improve overall general fitness.
Muscle fatigue of 0-30 sec?
depletion of ATP
Muscle fatigue of 30 mintues of heavy exercise?
buildup of lactic acid
Muscle fatigue during a marathon?
depletino of glycogen stores.
The rhythmic squeezing action of large muscles against the veins within tese muscles is called the ?
muscle pump
Anaerobic threshold is reached somewhere between what percentage?
50 and 85
Optimum exercise intensity for fitness improvements is in te range of approximately? percent of maximum heart rate?
60 and 90
4 factors that limit flexibility?
- the elastic limits of the ligaments and tendons crossing the joints
- the elasticity of the muscle tissue itself
- the bone and joint structure
4 the skin
List the steps necessary for muscle to contract according to the sliding filament theory?
- there must be sufficient ATP near actin and myosin as well as a nervous impulse
- Actin and myosin must link to form a cross bridge.
- Energy from ATP causes myosin to swivel
- Actin is moved toward the center of the sarcomere causing the muscle fiber to shorten.
Why would a client make large initial gains after the first 3 weeks of strength training.
They have recruited previously inactive motor units and has increased the coordination of her motor units during her strength-training exercises. It is probably not due to muscle hypertrophy.
What type of bone is the scapulae?
Flat
What type of bone is the thoracic vertebrae?
Irregular
What type of bone are the tarsals?
short bones
What type of bones are the metatarsals?
Long bones
What type of bones are the carpals?
Short bones
What type of bones are the ribs?
flat bones
What type of bones are is the tibia?
long bones, also the radius
Hand joint?
Condyloid
Briefly describe how first and second-class levers differ from a third-class lever?
In the first two classes of levers, the motive force is further away from the axis of rotation than the resistive force. The motive force of the third class lever is closer to the axis of rotation than the resistive force.
sway-back posture
a long outwarrd curve of the thoracic spine with an accentuated lumbar curve and a backward shift of the upper trunk
Muscles that primary cause lateral flexion of the trunk
Erector spinae, rectus abdominus, external obliques, internal obliques
Muscles that primary cause hip abdcution
Gluteus medius and minimus
Muscles that primary cause knee flexion
gastrocnemeus, biceps femoris, semitendinousus, semimembranosus, gracilis, sartourius
Muscles that primary cause shoulder abduction
deltoid (middle), supraspinatus
Muscles that primary cause shoulder external rotation
infraspinatus, teres minor, and deltoid (posterior)
Muscles that primary cause plantarflexion and eversion
peroneus longus and brevis
Muscles that primary cause hip extension
gluteus maximus, biceps femoris, semitendinousus and semimembransus
Muscles that primary cause scapular elevation
Rhomboids, levator scapulae, and trapezius (upper)
Minerals function in the body?
Enable enzymes to function; a component of hormones; a part of bone and nerve
Vitamin function in the body?
Aid reactions in the body; release energy in food.
Difference btw LDL and HDL?
low-density lipoproteins contain a greater amount of cholesterol and may be responsible for depositing cholesterol onto the artery walls. High-density lipoproteins are lower in cholesterol and aid in its removal from the cells.
Ideal choloesterol levels in adults
Desirable is 240
LDL levels?
Optimal 190
HDL levels?
below 40 mg/dL are considered a significant risk factor for coronary heart disease.
Saturated fatty acid
one that carries the maximum number of hydrogen atoms, leaving no points unsaturated.
Unsaturated fatty acid
has one or more double bonds, and therefore less hydrogen.
List the primary nutrients found in milk
Calcium, protein, and riboflavin
List the primary nutrients found in meat and bean?
protein, niacin, iron, and thiamine
List the primary nutrients found in vegetables
vitamin a and c
The necessary components of a health history
- demographic information (age, sex, occupation)
- past and present exercise history
- health risk factors
- medications
- recent or current illness and injuries
- surgery and injury history
7 family medical history
sprain vs strain?
sprain is a ligament and strain is a muscle or its tendon
List the 4 componenets measured in a comprehensive exercise assessment.
- cardiorespiratory function
- muscle strength and endurance
- muscle and joint flexibility
- body composition
Cardiorespiratory Fitness Testing?
directly assessed by measurement of oxygen uptake during a maximal graded exercise test, or indeirectly by estimating maximal oxygen uptake (VO2 max) .
Average resting heart rate for me?
70 bmp
Average resting heart rate for women?
75 bpm
During a submaximal exercise test, do not allow the exercising heart rate to exceed what percent of heart rate reserve or macimal oxygen uptake?
85%
To convert a 10 repetition max weight load to a 1 rep max estimation, divide the weight load by?
.75
What age do men and women with two or more cardiovascualr disease risk factors should have a physician supervise maximal exercise test before engaging in any vigorous activites?
men over 45 and women over 55
Bioelectrical impedance def
a body composition testing method based on the principle that the condu tivity of an electrical impulse is greater through lean tissue than through fatty tissue.
Compare contrast Absolute maximal oxygen uptake and relative maximal oxygen uptake.
Absolute does not factor in the weight of teh individual, while relative does factor in the weight of the individual.
Which is worse, upper-body obesity and lower-body obesity?
upper-body obesity
3 guidelines that ensure the client’s hear rate does not exceed 150-155 bpm during the Ross Submaximal Treadmill Test?
1do not go to stage 2 if the heart rate exceeds 140 at stage 1, the person is unfit
- stages 4 and 5 should only be used for individuals under age 50
- never go to the next stage if the heart rate exceeds 145 bpm.
Hydrostatci weighing
underwater weighing, the gold standard of body composition assessment. body density is calculated from the relationship of normal body weight to underwater weight. Body-fat percentage is calculated from body density.
Anthropometric assessments of body composition
the easiest and least expensive methods for assessing body composition. This includes cirucmference and sinfold measures, which are readily used in the field.
Maximal oxygen uptake
Also known as maximal oxygen consumption, VO2max, and aerobic capacity
2) The maximum amount of oxygen a person can consume during exercise
3) Expressed in liters or milliliters
Absolute vs. relative VO2max
Absolute
a. O2 uptake determined without body weight as a factor
b. Usually used for non-weightbearing exercise tests such as cycling
c. Expressed in L/min
Relative
a. Absolute O2 uptake divided by body weight
b. Used for weightbearing exercise tests such as walking, jogging and stepping
c. Expressed in mL/kg/min
d. This method allows for comparison to others of different body weights
e. A heavy person may have a high VO2max (L/min) when compared to a lighter person, but when expressed in relative terms (mL/kg/min), the lighter person may show a higher level of cardiorespiratory fitness
Formular for relative O2 uptake
Formula:
Relative O2 uptake = O2 uptake (L/min) x 1,000
BW (kg)
Heart-rate Reserve (HRR)
The result of subtracting resting heart rate (RHR) from maximal heart rate (MHR)
2) Represents the working range between resting and maximal heart rate within which all activity occurs
Formula: HRR = (220 – age) – RHR
Karvonen formula
The mathematical formula that uses HRR to determine target heart rate (THR)
2) A common mistake is forgetting to add back in the RHR
Formula: HRR x desired intensity % + RHR
Metabolic equivalent (MET)
A simplified system for classifying physical activities where 1 MET = resting O2 consumption
2) Resting O2 consumption equals approximately 3.5 mL/kg/min
Formula: 1 MET = 3.5 mL/kg/min
Rating of perceived exertion (RPE)
1) Developed by Gunnar Borg, this scale provides a standard means for subjective self-evaluation of exercise intensity level
2) Original scale: 6–20
3) Revised (modified) scale: 0–10
Submaximal aerobic exercise test
) A cardiorespiratory fitness test designed so that the intensity does not exceed 85% HRR
2) Provides an estimation of the VO2max without the risks associated with maximal exercise testing
3) Examples
a. YMCA Submaximal Step Test
b. McArdle Step Test
c. Rockport Fitness Walking Test (1-mile walk)
d. BYU Jog Test
Graded exercise test (GXT)
1) A treadmill or cycle-ergometer test that measures (clinical setting) or estimates (field setting) maximum aerobic capacity by gradually increasing the intensity until a person has reached a maximal level or voluntary exhaustion
2) Examples
a. YMCA Submaximal Bicycle Test
b. Ross Submaximal Treadmill Protocol
Body Mass Index (BMI)
1) A relative measure of body height to body weight for determining degree of obesity
2) Should not be used solely in determining body composition for the athletic client, because BMI does not distinguish between fat mass and fat-free mass
Formula: Weight (kg)
Height2 (m)
Skinfold measurements
1) Used to determine the ratio of fat mass to fat-free mass in the body
2) Fat mass: adipose tissue
3) Fat-free mass: bone, muscle, and organs
4) Measurements are performed with a skinfold caliper
5) The Jackson and Pollock (1985) three-site method has a relatively small margin of error for the general population
a. Sites for men: chest, abdomen, and thigh
b. Sites for women: triceps, suprailium, and thigh
6) Should be repeated by the same technician during reassessment to decrease error
7) Should be performed prior to physical activity because fluid transfer to the skin could result in overestimations
Bioelectrical impedance analysis
1) Involves passing a small current through the body and measuring the opposition to the current’s flow
a. Fat-free tissue is a good conductor of electricity
b. Fat tissue is a poor conductor of electricity
2) Estimations can have the same margin of error as skinfold measurements as long as the client follows the correct pre-test protocol
a. Abstain from eating or drinking within 4 hours of the assessment
b. Avoid moderate or vigorous physical activity within 12 hours of the assessment
c. Void completely before the assessment
d. Abstain from alcohol consumption for 48 hours before the assessment
e. Avoid diuretic agents, including caffeine, prior to the assessment unless prescribed by a physician
Circumference (girth) measurements
1) Can be used to assess body composition as well as body-fat distribution
2) Measurements are taken with a cloth measuring tape and must be taken at specific anatomical sites for accuracy
3) More practical for obese clients
Calculating desired body weight
1) Once body composition is known, the personal trainer can assist the client in goal-setting using the desired body-weight equation
2) This equation assumes there is no loss in lean BW
Formula:
Desired body weight = lean body weight
1 – desired body fat %
Common flexibility tests
Measures range of motion (ROM) at specific joints
1) Trunk flexion (sit-and-reach)
2) Trunk extension
3) Hip flexion
4) Shoulder flexibility
As with any test or exercise, the client’s health and injury history should be considered