topic 4: muscular fitness - EXER 2101

cardiac muscle

muscle that produces pumping action of heart which moves blood through the body

• involuntary

smooth muscle

muscle that maintains blood pressure that increases or decreases in diameter when relaxes or contracts

• primarily around vessels and hollow tubes and organs throughout the body

• involuntary

• ex: blood vessel

skeletal muscle

muscle attached to the skeleton for locomotion, movement of body parts, and maintaining posture

• voluntary!!

• is the only tissue in the body that can generate force

1) isotonic (dynamic)

2) isometric (static)

3) isokinetic

isotonic

action where there is movement of a body part at a joint, against resistance, while muscle shortens/lengthens

• type of dynamic movement

• concentric: shortening during contraction against resistance

• eccentric: lengthens during contraction against resistance (negative reps)

• ex: bicep curls, squat, push up

isometric

action where tension develops, no joint movement, and no change in length

• type of static movement

• engaging muscles with no activity

• postural maintenance and stability

• ex: plank, raising arm and leaving it, wall sit

isokinetic

action where there is movement at a joint at a constant/fixed velocity

• using equipment allowing that body part to move

• injury recovery, force production

• ex: leg press or leg extension set to a fixed speed

slow twitch fibers (type 1)

produce slow amounts of force, fatigue resistance, postural muscles

• work for long periods without tiring

• effective for endurance (ex: marathon runners, cycling)

• spinal muscles for standing and sitting upright

fast twitch fibers (type 2a)

generate greater amount of force, fatigue relatively quickly, and lower aerobic capacity

• sustain contractions for long periods

• rely on anaerobic systems: quick bursts of energy!!!!

• effective for sprinting, jumping, weightlifting — quick, powerful movement

• most easily “damaged” and feel sore b/c of mechanical intensity and stress

intermediate fibers (type 2b/x)

fibers with characteristics of both slow and fast fibers, balancing between speed/power and endurance

• dont exceed the specialized capacity of pure slow and fast fibers

• ex: 400-800 m sprint, soccer, basketball

functional fitness

the ability to sit, stand, and move correctly and efficiently in everyday life, recreational activities, and sports

• coordinates multiple muscles and include elements of balance

• traditional muscular endurance and strength training programs — restrict the body’s natural movement patterns

  • often isolates single muscles

• whole body movement and practical strength to make daily activities easier and safer

• ex: use MOVEMENT in free weight weight rooms since it requires balance

1) muscular endurance

2) muscular strength

muscular endurance

ability of muscle group submaximally contracts repeatedly over a given period of time

• sustained effort over max force

• repetition and stamina

• ex: multiple push ups/sit ups, holding a plank

muscular strength

ability to exert force — the amount of maximal force generated during one contraction of a muscle or group of muscles

• 1 repetition maximum

• ex: bench press ur PR

strength training program

1) progressive overload

2) reversibility and maintenance

progressive overload

increasing resistance being applied to the muscle as progression or gain in strength occurs

• increasing weight and reps increases demand on muscles

• muscles need to keep adapting

• resistance must increase to ensure it is achieved and progression continues

• atrophy: fail to maintain or increase strength and decrease muscle size

• ex: increasing squat weight every week, 10 reps

reversibility

use it or lose it — maintaining requires less exercise than to get gains

• unless resistance training is continued, there will be a loss of strength

evaluate strength

evaluate maximum weight you can lift once with good form

• can be used toward a goal after several weeks of training

• unsuitable: older adults, deconditioned individuals, sedentary individuals

• mainly type fast twitch type 2a and hybrid fibers at work

• alternate options: sub max tests, body weight tests (wall sits)

evaluate endurance

evaluate how many submaximal intensity repetitions a muscle group can perform

• push up test

• create unofficial tests for specific exercises/populations

• keep it consistent to track improvements

• mainly slow twitch type 1 fibers at work

• ex: modified chair stand test, push ups, step ups from low platform

benefits

• prevent back pain

• reverse/prevent bone mineral density loss

• reduced risk of CV disease

• reduced stress

• higher self efficacy and confidence

• increased NM control

• increased functional fitness

• weight control (impact on RMR)

osteoporosis

loss of bone mineral density, diseases result in weakened and brittle bones

• can be reversed/prevented with regular strength-training exercise programs

resting metabolic rate (RMR)

number of calories your body burns at rest

• increased strength training = increases this

• increased muscle mass = increases energy expenditure

• helps manage body weight and prevent fat gain

• maintain healthy body comp and metabolism!

• excess post-exercise oxygen consumption: after a but of strength training and burn additional calories

hypertrophy

can increase in overall muscle size — increased size of individual muscle fibers, not number of fibers

• from resistance training that stresses muscle

• larger muscles = more force, easier tasks

• more muscles = raises RMR

• better joint stability, posture, and movement

adaptation to hypertrophy

growth to muscle size depends on diet, fiber type, blood levels of testosterone, nutrition, and type of training program

• substantial nutrients

• males have higher testosterone and can muscle bulk more

• endurance training: less hypertrophy, fatigue resistant

• strength training: more hypertrophy, maximal muscle growth

• type 2a hypertrophy fast

clinical benefits

functional status/health play major role in ability to recover from minor injuries

• fall mortality increases with age, 78% lose functional independence

• reduced risk of frailty (slow loss of muscle mass)

• overall improvement in strength: protect from falls

• lowers risk of injury: more comfortable in mobility and agility and protect from fractures from falls

• injuries from preexisting health, not know how use equipment and technique

delayed onset muscle soreness (DOMS)

muscle stiffness and pain developing after unfamiliar or intense exercise

• appears 1-2 days post exercise, worst on day 2 and can last up to 5

• from microtears in muscle fibers, inflammatory response to repair

• eccentric contractions = more soreness (lengthening)

• acute: immediate, lower intensity during/right after exercise

• progressive overload: reduce severity over time for adaptation

exertional rhabdomyolysis (rhabdo)

clinically significant muscle damage caused by excessive PA, beyond typical muscle tears

• too much too soon too fast!

• sudden increases in intensity or volume, high workload without adaptation

• muscle pain, muscle weakness

• cellular components: myoglobin enter bloodstream and can clog kidneys — discolored urine, decreased urination

gender differences

boys and girls differences in muscular strength and growth

• before puberty: little difference in strength between boys and girls

• after puberty: men’s higher testosterone levels than girls develop more muscle mass and quantity before/after training

• both men and women gain strength from resistance training

  • women have higher percent change in strength: b/c starting with lower strength before training

• women typically do not bulk naturally since low testosterone

• differences minimal when muscle considered in relative ay

• hormonal differences influence muscle mass development!!!!