Chapter 4 Flashcards
Muscular strength =
the amount of force a muscle can produce with a single maximum effort
Muscular endurance =
the ability of a muscle or group of muscles to remain contracted (sustain a level of muscular force) or to contract repeatedly
Muscles consist of many ______ connected in bundles
muscle fibers (cells)
Muscle fibers/cells are made up of?
myofibrils
Myofibrils contain ____ and ____ filaments
which slide together and contract the fiber
actin and myosin
Strength training increases the?
of myofibrils and the size of muscle fibers
hypertrophy
size of muscle fibers
atrophy
Inactivity reverses the process (No appreciable increase in # of muscle fibres)
characteristics of Slow-twitch fibers (red)?
Fatigue resistant
Don’t contract as rapidly or forcefully as fast-twitch fibers
Rely primarily on oxidative energy system
characteristics of Fast-twitch fibers (white)?
Fatigue more quickly than slow-twitch fibers
Contract rapidly and forcefully
Rely more on non-oxidative energy system
Intermediate fibers
fuel system between slow + fast-twitch
The type of fibre activated depends on?
the nature of the physical demand
Endurance activities (walking, jogging) use more
_____ fibres, while strength/power activities
use more ____ fibres
slow-twitch, fast-twitch
A “motor unit”?
1 nerve connected to 2 or many muscle fibers
what are some Physiological Effects of Strength Training?
Increased muscle mass and size of muscle fibers
Increased utilization and coordination of motor units
Increased strength of tendons, ligaments, and bones
Increased storage of fuel in and blood supply to muscles
Increased size of fast-twitch fibres
Increased size of slow-twitch fibres
Improvements in blood fat levels
Improved blood vessel health
Improvements in biochemical processes
Benefits of Muscular Strength and Endurance?
Improved performance of physical activities
Injury prevention (maintaining posture, mechanics)
Improved body composition
Enhanced self-image and quality of life
Improved muscle and bone health with aging
Prevention and management of chronic disease
Muscular strength assessed by determining?
the maximum resistance that can be lifted one time
Muscular endurance assessed by?
counting the maximum number of repetitions (or length) of a muscular contraction
Static (isometric) exercise =
muscle contraction without a change in the length of the muscle