Exam 2 Flashcards
What is important about muscular fitness?
- Burn some calories
- increase bone mineralization
- joint protection/lower back
- sports performance
- independent living as we age
Slow twitch characteristics:
- efficient in using oxygen
- delayed in muscle firing
- Do not fatigue easily
- Best suited for endurance sports, including cycling, marathon running, and long-distance triathlons.
Fast Twitch characteristics:
- do not burn oxygen efficiently
- fast to fire; best for explosive body movements
- tire out quickly
- best suited for short bursts of activity, including sprinting races, pole vaulting, and cross -fir style events
What does Muscular health include?
- Strength
- Endurance
- Flexibility
- Also includes: speed, power, agility, and balance
What are the factors that influence muscular strength:
Sex:
From 12 to 14, males are not much stronger than females, but changes occur afterward. Male hormones increase at puberty
Sex effect:
- College-aged women typically have 50 to 60
% of the arm/shoulder strength and 70 % of the leg strength as that of men - Higher % body fat and less lean tissue in women men
What are some factors that influence muscular strength?
Muscle Fiber Type, Genetics, and Training
What is Myostatin?
Growth factor released by the muscle that inhibits protein synthesis.
- The abnormal muscles have low proportions of mitochondria, which may
compromise force generation - Remember….mitochondria is where energy for contraction is generated
1 Rep Max:
Dynamic, Moving, and Isotonic
= maximum force generates during one repetition
Isometric Strength:
Same length of muscle fiber/joint movement, or no movement
Isokinetic Strength:
= Same speed
Maximum Torque
Muscular endurance:
- ability to keep going
- repetition of submaximal contractions or submaximal holding time ( static or isometric endurance).
- Essential for some sports performances
- Work/Activities of Daily Living
- Not to be confused with aerobic endurance
Speed/Power:
- requires rapid acceleration
- involves the contraction of fast-twitch muscle fibers
- speed of movement includes reaction time and movement time
- reaction time ( time from the stimulus until the beginning of the movement –> nervous system function)
- We can’t change the speed of nerve impulses, but we can change the speed of muscle fiber contraction.
Power:
combination of strength ( force) and velocity of the force production
Power equation:
force x ( distance/time)
Agility:
The ability to change position and direction rapidly, with precision, and without loss of balance.
*Composite of strength, speed, balance, and coordination.
* Helps to avoid injury in recreational activities and in potentially
dangerous situations
What are some factors to consider when accessing agility?
- excess weight hinders agility
- extreme strength or aerobic fitness are not prerequisites
- agility deteriorates with fatigue
- aerobic and muscular endurance can help maintain agility for extended periods.
Preload and Elastic Recoil:
A muscle exerts force when it is stretched ( preload) just before contraction
What is happening during reload and Elastic Recoil?
- aligns contractile elements ( cross-bridges) in muscle for maximal force
- stores elastic ( potential) E in the muscle-tendon complex
- contributes to the power and economy of movement
Force- Velocity Relationship:
- Resistance increases and the velocity of shortening decreases.
- strength training has little effect on the velocity of unloaded movements and vice versa.
-
Eccentric contraction:
Muscle lengthens- external force on the muscle is greater than the force that the muscle can generate, thus the muscle is forced to lengthen due to the high external load. (e.g., stretching)
Isometric contraction
No change in muscle length
because the external force on the muscle is the
same as the force being generated by the muscle-results in no movement.
Concentric contraction
- Muscle length is reduced and shortens because the external force on the muscle is
less than the force being generated by the muscle- results in movement.
Power training:
(15 to 25 repetitions at 30 to 60
percent of maximal strength, as fast as possible)
Balance:
Balance depends on the ability to integrate visual input with information from the semicircular canals in the inner ear and
from muscle–joint receptors (e.g., muscle spindles)
Static balance:
keeping still can be measured by a test such as a stork stand
Dynamic balance:
the ability to maintain equilibrium while in motion
Flexibility:
The available range of motion around a joint/joints
Static
Position held still for 5 to 10 seconds.
Dynamic
Involves movement patterns for a range
Ballistic
Bouncing ( not recommended0 - using momentum
How much should be lifted to improve strength?
you usually need to lift 2/3 or 75% of one’s maximal force
Overload principle:
As adaptation to loading takes place, more load must be added.
- the adaptation to strength training includes:
- increased size because of increases in contractile proteins ( actin and myosin)
Early gains in strength appear to be more influenced by neural factors- i.e better coordination among motor units. True/False
True
Normal inhibitory mechanisms:
Golgi tendon organs
– Inhibit muscle contraction
if tendon tension too high
– Prevent damage to bones/tendons
Antagonists:
oppose against force
Fiber Type Transformation:
- occurs during endurance training and NOT during resistance training
-resistance training - no transformation of fibers- just improvements in existing capabilities
Transient hypertrophy:
the pumping up of muscle during a
single exercise bout due to fluid accumulation from the blood plasma into the intercellular spaces of the muscle.
Chronic hypertrophy:
the increase of muscle size after long-
term resistance training due to the individual size of muscle fibers (fiber hypertrophy).
Fiber Hyperplasia:
- muscle fibers split in half with intense weight training.
- each half then increases to the size of the parent fiber
- it has been clearly shown to occur in animal models; only a few studies show this occurs in humans too.
DOMS ( Delayed-Onset Muscle Soreness)
- This is the pain you feel a day or 2 after lifting weights when you have not lifted for a while
- results primarily from eccentric action
- associated with damage or injury w/in muscle
- soreness may be aggravated by inflammatory reaction inside damaged muscles
- is felt 12 to 48 hours after a strenuous bout of energy
What is the “ fitness of our musculoskeletal system is related to:
- Function: ability to perform tasks requiring muscle strength and power
Health: risk of chronic diseases and/or injury
Isometric Strength test:
Muscle action when tension is produced but there is no change in the length of the muscle.
Isometric testing advantages :
- simple
- cheap
- saves time
Isometric testing disadvantages:
- specific to the joint angle ( doesn’t reflect the full ROM)
- doesn’t correlate with sports performance
- more likely to perform the Valslava Maneuver
Isotonic Strength test:
- dynamic
- muscle action in which muscle shortens or lengthens with varying tension and velocity while overcoming a constant resistance throughout a ROM
Isotonic testing advantages:
- correlates better with a sport
- relatively inexpensive
- accessible
- psychologically seeing work done
Isotonic Testing Disadvantage:
- measuring the weak point in the ROM
- doesn’t measure strength at different speeds
Isokinetic strength test:
Maximal tension developed at all joint angles throughout the ROM with the speed being constant ( have accommodating resistance at a controlled speed of movement)
Isokinetic testing advantages:
- measure the strongest point in ROM
- measure strength at different speeds
Isokinetic Dynamomentry:
- Assesses strength development at a constant speed
- Can access sit- specific strength as allowable by testing device.
Flexion:
The joint angle is decreased
Extension:
The joint angle is increased
What determines flexibility?
- joint structure
- muscle elasticity and length
joint structure:
- joints vary in direction and range of movement
- joint capsules = semi-elastic structures that give joints strength and stability but limit movement
Muscle elasticity and length:
- collagen = white fibers that provide structure and support
- elastin = yellow fibers that are elastic and flexible
- titin = muscle filaments with elastic properties
Nervous system activity:
- stretch receptors control muscle length
- is a muscle is stretch, receptors send a message to the spinal cord, which then sends a signal back to the muscle telling it to contract
- a strong muscle contraction produces an opposite reflex that causes the muscle to relax
- Proprioceptive neuromuscular facilitation (PNF)
PNF:
A technique for stretching muscles that relies on neuromuscular reflexes to stimulate training effects
Range of Motion ( ROM):
flexibility assessment
Devices:
- Goniometer
- Inclinometer
- Electrogonimeter
- Flecometer
- Tape measures
- Joint specific
NO single test for overall flexibility
What is the issue with the sit and reach box test?
If you have long legs you are automatically at a disadvantage no matter how flexible you are.
Sit and Reach box:
- measure the flexibility of the lower back and posterior thighs
Sit and reach box validity:
This test only measures the flexibility of the lower back and hamstrings and is a valid measure of this.
Sit and reach box advantages:
The sit and reach test is a common test of
flexibility and is an easy and quick test to perform. If using the standard testing procedure, there is a lot of published
data to use for comparison.
FIIT Principle:
- Frequency - how often to stretch
- Intensity - how far to stretch
- Time- how long to stretch
- Type - which stretching exercises to perform
Low Back health:
- Americans spend at least $50 billion each year on lower back pain, the most common cause of job-relates disability and a leading contributor to missed work.
- Back pain is the second most common neurological ailment in the United States- only headache is more common
Causes of Back Pain:
- Any movement that causes excessive stress
Risk factors : - Age greater than 34 years
– Degenerative diseases
– Family or personal history of back trauma
– Sedentary lifestyle, overweight
– Low job satisfaction, certain occupations
– Low socioeconomic status
– Smoking
– Psychological stress or depression
Underlying Causes of Back Pain:
- poor muscle endurance and strength
- poor posture
- poor body mechanics
Preventing lower back pain:
- lose weight, stop smoking, and reduce emotional stress
- avoid sitting, standing, or working in the same position for too long
- use a supportive seat and a medium-firm mattress
- Warm-up and progress properly during exercise
Static stretching
slowly stretching a muscle and
holding the stretched position
Ballistic stretching
suddenly stretching a muscle through a bouncing or swinging movement
Proprioceptive neuromuscular facilitation
obtaining a greater training effect by using
neuromuscular reflexes; for example, contracting a muscle before it is stretched
Passive stretching
muscles are stretched by
the force applied by an outside source
Active stretching
muscles are stretched by a
contraction of the opposing muscles
What can optimal fuel for the body do?
- Delay/prevent fatigue- enhance energy levels
- lead to better and faster recovery-
- reduce soreness and inflammation: enhance immunity- minimize injury
Normal people ( nutrition):
obtain the required energy and nutrients from a balanced diet
athletes ( nutrition):
need to follow a specialized diet
- based on the volume and intensity of training
- require high energy diet because of high energy expenditure during training and competition
- replenishing unavoidable breakdown of muscle is critical to athletes
What % of Carbohydrates make up the kcal burned?
60-70%
What % of fats make up the kcal burned?
15-25%
What % of protein make up the kcal burned?
15%
What is the primary fuel for exersize
Glycogen is the main source of energy during short bursts or higher intensity activity
Glycogen:
- stored in limited quantities in the body
- stores are depleted as exercise continues
- stores must be replenished daily
- glycogen depletion leads to muscle fatigue
Carbs before exercise:
- Pre-exercise meal should be low in fat an fiber, high in carbs, mod. in proteins
- recommended to consume carbs at least 3-5 hrs before exercise
- always recommended if no access to CHO during exercise
- 1 gram/kg as multiple hours prior to exercise
Pre-exercise snacks:
- Snacks ( 1-2 hrs prior):
- jelly on whole wheat bread
- milk and cereal
- yogurt with fruit
pre-exercise meals:
- pasta with marinara sauce, green beans, and low-fat milk
- a muffin and fruit smoothie
- turkey sandwich with whole wheat bread and orange juice
Carbo loading
- not beneficial in events less than 75-90 minutes long
- can postpone fatigue by 20% - the goal is to maximize glycogen stores
- e.g long-distance training
- tapering of exercise while increasing carbohydrate intake 10 to 14 days before race day
Carbs during exercise:
- good for endurance lasting more than 60 minutes
-delays fatigue and time to exhaustion by sparing and maintaining adequate glycogen stores
- recommended 45-60g CHO per hour after the first hour of exercise
- food or sports drinks
Carbs after exercise:
The ideal environment for restoring glycogen
- greatest amount of resynthesis occurs in the FIRST HOUR after exercise
Recommendations:
- consume 50-60- g of CHO as soon as possible after exercise
- small, frequent CHO containing meals
Post- Exercise snacks:
- cottage cheese with fruit
- bagel with peanut butter
- chocolate milk
- crakers and cheese
- 1/2 sandwich with turkey or peanut butter
Protein:
- tissue growth, enzyme, and immune system response
Where is protein found:
Both in plant and animal foods
- animal = complete protein
-plant= incomplete proteins ( except quinoa) - needs are easily;y met by a normal diet, protein supplements are not typically necessary, excessive protein is not beneficial
Post-Exercise Intake:
-“ anabolic window”
Post Exercise carbs:
1-1.5 grams/kg body weight
ex.
120- lbs… 55-82 grams
220 lbs…..100-150 grams
Post-exercise protein:
(10-25g ) is especially important
- if the workout was resistance training
- if an athlete is restricting calories
- if there are multiple workouts in one day
Protein co-ingesting with carbs increases the mixed muscle protein synthesis rate after exercise. True/False
True
Why could whey be better than other protein sources?
- relatively high proportion of branched chain amino acids (BCAA)
- rapidly absorbed
BCAA:
- initiator of protein synthesis
Why is thirst not the best guide for hydration?
- Thirst and dry mouth occur at 1-5% loss of body water.
- losses can be significant…. 2 quarts per hour
- 1 pound lost = 16-24 fluid
- drink before, during and after events
Hypotonic sports drinks:
- Hypotonic sports drinks contain small amounts of carbohydrates (1
-3%) and minerals and are less concentrated than body fluids. - The fluid from the drinks can therefore be absorbed by the body
quickly. - The carbohydrate in these drinks can also help to reduce the risk
of blood glucose falling too low.
hypertonic sports drinks.
- greater amounts of carbohydrates than hypotonic
- more concentrated than body fluids
- main purpose is to provide carbs to refill muscles with glycogen after exercise.
- they do not help prevent/alleviate dehydration rapidly
- glycogen in muscle is replaced most quickly immediately after exercise but athletes often find it difficult to eat at this time
Isotonic Sports Drink:
- same concentration as bodily fluids
- they may be used for fluid replacement by athletes.
- solution similar to commercial ‘sports drinks’ can be made easily at home using sugar or fruit juice and water
Exercise disrupts fluid balance:
- increase body temp
- increase fluid loss via sweat
- becomes difficult to match fluid intake with fluid loss
- performance suffers when fluid losses equal 2% body weight
Assessing Hydration:
- Weight loss during exercise
- weight before and after - thirst
- urine color
Symptoms of dehydration:
- early fatigue
- increased heart rate
- slow recovery
- decreased appetite
- weight fluctuations
- lack of focus and concentration
- headaches
- constant thirst
- dry skin, mouth, hair
Hyponatremia:
- extremely low plasm sodium concentrations
- symptoms similar to dehydration
- confusion, seizures, coma, death
- prevention
- avoid over-consuming water during exercise
- replace sodium that is lost in sweat
Ergogenic aids:
- Physical
- cheering, music, altitude training, sauna and massage, and psychology etc.
-Chemical and pharmacological
- anabolic steroids, stimulants, growth hormones, narcotics, analgesics, beta-blockers, diuretics, amino acids, vitamins, etc.
Desire to win by elite athletes:
fear of disgrace and loss of personal income is greater than fear of harm
Anabolic steroids:
- male hormones have anabolic effects
- accelerated growth of muscle, bone, and red blood cells
- synthetic relative to testosterone
- high volume training needed for beneficial effects
- inhibit protein breakdown
Anabolic steroid: negative effects
Undersired Androgenic effects
- males: testicular atrophy, breast development, lower sperm count, acne
- females: masculinization, facial & chest hair growth, deepening of voice, acne
Additional effect
- aggressiveness, mood swings, altered glucose metabolism, thyroid, lipid profiles
