HPEX 301 exam 2 review

What is muscular strength?

ability of a muscle to generate max force

What is muscular endurance?

ability to generate force over and over again

What are muscle fibers?

Long, thin cells that make up skeletal muscle

What is a fascia?

Dense layer of connective tissue that surrounds fibers

What are tendons?

Connective tissue that connects muscle to bone. Muscle action causes the tendons to pull on the bones rather than push them

What is muscle action?

Shortening of skeletal muscle (causing movement) or the lengthening of a skeletal muscle (resisting movement)

What is a motor unit?

A motor nerve and all the muscle fibers it controls

What’s the process of a muscle action?

• A message (nerve impulse) reaches the neuromuscular junction

• The impulse triggers the action process by allowing interaction of contractile proteins in muscle

• When the signal is removed, the nerve stopes sending signals, making the muscle action stop

What are the 3 main categories of skeletal muscle exercise?

• Isotonic

• Isometric

• Isokinetic

What is isotonic (dynamic) exercise?

• Movement of a body part at a joint

• Ex. bicep curls or a lot of exercise activities or sports

What is isometric (static) exercise?

• No movement of body parts

• Ex. pressing the palms of the hand together or holding a plank

• Great way to develop strength during early stages of injury rehab

What is isokinetic exercise?

• Speed of muscle shortening or lengthening is regulated at a controlled rate

• Ex. machine that provides accommodating resistance throughout full ROM

What is concentric muscle action (positive work)?

• Movement of body part AGAINST resistance or gravity, usually when the muscle shortens

• Can happen during isotonic or isokinetic exercise

• Ex. upward movement of a bicep curl

What is eccentric muscle action (negative work)?

• Movement of body part WITH resistance or gravity, usually when the muscle lengthens

• Ex. downward movement of a bicep curl

What are slow-twitch muscle fibers?

• Type I

  • Slow contraction, low force, highest resistance to fatgiue

  • Predominately in aerobic exercise since they generate high ATP

  • Red or dark in color

  • Used more for endurance events

What are fast-twitch fibers?

• Type IIA

  • Fast contraction, high foce, high resistance to fatigue

  • Seen in both aerobic and anaerobic exercise

  • White/pink in color

  • Used more for middle distance

• Type IIX

  • Fastest contraction, highest force, low resistance to faituge

  • Seen in anerobic exercise like sprinting, jumping, heavy lifting

  • White in color

  • Used more for short distance events

How does fiber recruitment work?

• There is a steady increase in muscle fibers recruited when the muscular force produced increases.

• The fibers go from slow-twitch to intermediate fibers and finally to fast-twitch fibers as intensity increases

• So, high-intensity exercise like weightlifting recruits large numbers of fast-twitch fibers

What 2 factors determine muscle force?

• Size of the muscle

• Number of fibers recruited during the contraction

What is the one-repetition max (1 RM) test?

• Measures the max amount of weight that can be lifted at one time

• It’s been criticized as an unsuitable for use by older people or highly deconditioned people

What’s one test to assess muscular strength?

1 RM test

What are two tests to assess muscular endurance?

• Push-up test

• Sit-up test or curl-up test

How do you achieve increased muscular strength and increased muscular endurance?

• Increased muscular strength= high resistance + low repetitions

• Increased muscular endurance= low resistance + high repetitions

What’s the difference between hypertrophy and hyperplasia?

• Hypertrophy: Increase in muscle size d/t increase in fiber size (increase in SIZE)

• Hyperplasia: Formation of new muscle fibers (increase in NUMBER)

What are the recommendations to improve muscle strength and endurance?

• Strength: 3 sets of 6 reps each exercise

• Endurance: 4-6 sets of 15-18 reps

What is the resting metabolic rate?

• Amount of energy expending during all sedentary activity

• Usually increased with strength training

What is a neuromuscular junction?

It’s where a motor nerve and individual muscle fiber make contact

What are the 5 structural limitations of movement?

• Shape of bones

• Stiff muscle

• Connective tissue

• Tendons

• Tight skin

What is a stretch reflex?

• It’s a reflex caused by rapid stretching of muscle spindles

• Activating this reflex is counterproductive to flexibility since the muscles shorten rather than stretch

What are proprioceptors?

• specialized receptors in muscles and tendons that provide feedback to the brain about the position of the body parts

What are muscle spinders?

• Type of proprioceptors within MUSCLE that provide feedback to the brain about the position of body parts

What are Golgi tendon organs?

• Type of proprioceptors within TENDONS that provide feedback to the brain about the position of body parts

What is hypokinetic disease?

Also known as lower back pain and is associated with a lack of exercise

• Causes

  • Weak abdominal muscles from sedentary individuals

  • Lack of flexibility in hip flexor muscles

• Can also be caused by hamstrings and lower back muscles that aren’t properly stretched

What are two tests that assess flexibility?

• Sit-and-reach test (measures trunk flexion)

• Shoulder flexibility test (measures shoulder’s full ROM)

What are the 3 types of stretches?

• Dynamic

  • Effective for sports and exercise program

  • Fluid, exaggerated movements that mimic movements of exercises

• Ballistic

  • Effective for athletes involved in quick movements

  • Rapid and forceful bouncing movements

• Static

  • Effective to improve flexibility

  • Slow lengthening of a muscle to the point of slight discomfort

• Proprioceptive neuromuscular facilitation (PNF)

  • Stretching with alternately contracting and relaxing muscles

    • CR stretching: first contact the muscle to be stretched then after it’s relaxed, its slowly stretched

    • CRAC stretching: came contract-relax routine but it adds contraction with the antagonist muscle

What is body composition?

Relative amounts of fat and fat-free tissues in the body

What are the major types of fat in the body?

• Essential fat

• Storage fat

What is essential fat?

• Fat necessary for body functions like facilitating nerve impulses

• Found in nerves and cell membranes

• Men have 3% and women have 12% (it’s more since they have breasts, uterus, and other sex-specific sites)

What is storage fat?

• Contained within adipose tissue and provides energy, insulation, and protection

• It can be visceral (around internal organs) or subcutaneous (below the skin)

What are the classifications of fat based on 20-39 yrs?

• Men

  • Body fat <8% and BMI <18.5: underweight and increased health risk

  • Body fat 8-19% and BMI 18.6-24.9: average, normal health risk

  • Body fat 20-24% and BMI 25-29.9: over-weight and increased health risk

  • Body fat >25% and BMI >30%: obese and high health risk

• Women

  • Body fat <21% and BMI <18.5%: underweight and increased health risk

  • Body fat 21-32% and BMI 18.6-24.9: average, normal health risk

  • Body fat 33-38% and BMI 25-29.9: over-weight and increased health risk

  • Body fat >39% and DMI >30%: obese and high health risk

What are the classifications of fat based on 40-59yrs?

• Men

  • Body fat <11% and BMI <18.5: underweight and increased health risk

  • Body fat 11-21% and BMI 18.6-24.9: average, normal health risk

  • Body fat 22-27% and BMI 25-29.9: over-weight and increased health risk

  • Body fat >28% and BMI >30%: obese and high health risk

• Women

  • Body fat <23% and BMI <18.5: underweight and increased health risk

  • Body fat 23-33% and BMI 18.6-24.9: average, normal health risk

  • Body fat 34-39% and BMI 25-29.9: over-weight and increased health risk

  • Body fat >40% and BMI >30%: obese and high health risk

What are the classifications of fat based on 60+ yrs?

• Men

  • Body fat <13% and BMI <18.5: underweight and increased health risk

  • Body fat 13-24% and BMI 18.6-24.9: average, normal health risk

  • Body fat 25-39% and BMI 25-29.9: over-weight and increased health risk

  • Body fat >30% and BMI >30%: obese and high health risk

• Women

  • Body fat <24% and BMI <18.5: underweight and increased health risk

  • Body fat 24-35% and BMI 18.6-24.9: average, normal health risk

  • Body fat 36-41% and BMI 25-29.9: over-weight and increased health risk

  • Body fat >42% and BMI >30%: obese and high health risk

What is the general healthy percentage of body fat for young men and women?

• Men: 8%-19%

• Women: 21%-32%

What is the android pattern?

• Pattern of fat distribution characterized by fat stored in the abd region. Commonly seen in men

• Greater risk at developing heart disease and diabetes d/t fat being close to vital organs

What is the gynecoid pattern?

• Pattern of fat distribution characterized by fat stored in the waist, hips, and thighs. Commonly seen in women

What are some diseases associated with obesity and being overweight?

• Cardiovascular disease

  • Coronary heart disease leading to heart attacks

• HTN and high cholesterol

• Diabetes

• Inflammatory cytokine release linked to Alzheimer’s

• Menstrual abnormalities, fertility issues, and complications during pregnancy

• Sleep apnea

What are some diseases associated with being underweight?

• Malnutrition

• loss of muscle mass and strength

• Increased risk for osteoporosis

• Menstrual abnormalities leading to infertility

• Eating disorders linked to heart issues, digestive disorders, kidney damage, anemia, lethargy dry skin, decreased immunity

What are the field methods for assessing body composition?

• Height/Weight tables

• Body Mass Index

• Skin Fold Assessment

• Waist Measurements and Waist-Hip Ratio

What are height/weight tables?

• determine whether a person is over weight

• Pros

  • determine if a person is too fat

• Cons

  • does not reveal how much of the body weight is fat

  • do not recommend their use to determine an ideal weight

What’s a BMI?

Determine whether someone is overweight or obese. Best used to obtain an initial estimate of whether one’s percentage is at a healthy level

• Pros

  • BMI indicates that you are underweight, normal, or overweight.

  • simple and inexpensive method for deter mining your weight status

• Cons

  • can over- or underestimate body fatness

  • NOT a perfect predictor of body fat percentage

What is a skinfold assessment?

used to estimate a person’s overall body fatness by using a skinfold caliper. The 3 sites used in men are the abd, chest, and thigh. In women, it’s the suprailium, triceps, and thigh

• Pros

  • easy and inexpensive measure to obtain and can provide GOOD estimates of body fat

• Cons

  • 3%-4% margin of error

  • needs a trained technician

  • not a good measure to assess body composition for obese individuals

What is the Waist Measurements and Waist-Hip Ratio

used to estimate risk of disease associated with high body fat

• Pros

  • good indicators of whether body fat distribution is unhealthy

• Cons

  • DOES NOT provide an estimate of body fat percentage

What are the lab measures for assessing body composition?

• Dual energy X-ray absorptiometry (DXA)

• Hydrostatic weighing (underwater weighing)

• Air displacement

• Bioelectrical Impedance Analysis (BIA)

What is Dual energy X-ray absorptiometry (DXA)?

low-radiation X-ray scan of the body to obtain estimates of body fat percentage

• Pros

  • provides a measure of total body fat as well as of regional fat distribution

  • used to assess bone density as it relates to osteoporosis and osteoporosis risk

• Cons

  • equipment is expensive, and because it uses an X-ray, only trained professionals can perform the scan

What is Hydrostatic weighing (underwater weighing)?

Weighing the person both on land and in a tank of water to determine body volume and density

• Pros

  • CAN estimate body fat %

• Cons

  • very time consuming and requires special equipment

  • does not appeal to most individuals because it involves being completely submerged under water

What is Air displacement?

Person ins seated in a chamber (Bod Pod) and sensors are used to estimate the amount of air that is displaced when the participant is in the chamber.

• Pros

  • body volume and then body fat can be calculated

  • less time consuming than under water weighing

• Cons

  • equipment is expensive

What is Bioelectrical Impedance Analysis (BIA)?

person either stands on the sensors of a scale-like piece of equipment or holds sensors between both hands. a very low-level electrical current (too low to be felt) is passed through the body between the electrodes or sensors. Body fat is estimated according to the resistance to the flow of the current

• Pros

  • Fairly accurate, fast, portabel, reasonable cost

• Cons

  • Reuslts vary with age, gender, body temp, diet, and hydration level

What’s a better conductor of the current in BIA?

Lean tissue since it contains more water