UNIT 7: Musculoskeletal Fitness

Question 1

What are muscle fibers made up of?

Answer 1

Muscle fibres are made up of myofibrils

Question 2

What are Hypertrophy and Atrophy?

Answer 2

Strength training increases the number of myofibrils and the size of muscle fibres = hypertrophy

Inactivity reverses the process = atrophy

Strength gains do not occur without neurological adaptations

Question 3

What are the 3 Muscle Fiber Types?

Answer 3

Type I fibers (slow twitch, slow oxidative) - Aerobic

Type IIa fibers (fast oxidative glycolytic) - Glycolytic

Type IIb fibers (fast twitch, fast glycolytic ) - Alactic

Question 4

What are Motor Units?

Answer 4

Motor units (nerves connected to muscle fibres) are recruited to exert force

Question 5

What is the size principle?

Answer 5

The size principle dictates that motor units are recruited in a specific order based on the amount of force required for a task. Smaller motor units are activated first, followed by larger ones as more force is needed. This recruitment pattern ensures task-appropriate force output.

Henneman’s size principle states that under load, MUs are recruited from smallest to largest: slow-twitch, low-force, fatigue-resistant muscle fibers are activated before fast-twitch, high-force, less fatigue-resistant muscle fibers

Question 6

Fibre recruitment of different percentage of 1RM

Answer 6

Question 7

What is Strength?

Answer 7

functional/movement, amount of force produced in a single maximal effort

Question 8

What is Hypertrophy?

Answer 8

increase in size of the muscle cells/increase in diameter (SR) and # of cells (contractile unit, myofibrillar)

Question 9

What is Power?

Answer 9

Ability to produce max force in minimum time (speed)

Question 10

Gains in the Beginning of a Program

Answer 10

Question 11

Neural Control of Strength Gains

What are the Acute Adaptations in the first 1-10 weeks of resistance training?

4

Answer 11

First weeks of resistance training (1-10 wks)

1. Recruitment of motor units
   - Increased number and synchronicity
   - Increased frequency of discharge from the a-motor neuron: rate coding
2. Decrease in autogenic inhibition (GTO): reduce inhibitory impulses
3. Reduction in the co-activation of antagonist muscles
4. Increase in co-activation of agonist muscles: accessory muscles

Question 12

What are Physiological Effects of Strength Training?

5

Answer 12

• Increased muscle mass and size of muscle fibres
• Increased utilization and coordination of motor units
• Increased strength of tendons, ligaments, and bones
• Increased storage of fuel in and blood supply to muscles
• Improvements in blood-fat levels and biochemical processes

Question 13

What is Fiber Hyperplasia?

Answer 13

• Muscle fibers can split in half with intense weight training (cat research)
• Each half then increases to the size of the parent fiber
• Conflicting study results may be due to differences in the training load or mode
• Satellite cells may also be involved in the generation of new skeletal muscle fibers
• Hyperplasia has been clearly shown to occur in animal models; only a few studies suggest this occurs in humans

Question 14

What are the Benefits of Muscular Strength and Endurance?

Answer 14

• Improved performance of physical activities
• Injury prevention (lower risk of developing functional limitations)
• Improved body composition
• Enhanced self-image and quality of life
• Improved muscle and bone health with aging (slow progression). Reduce osteoarthritis/pain and disability
• Prevention and management of chronic disease, fewer CVD events
• Improved blood glucose levels

Question 15

How can we Assess Muscular Strength and
Endurance?

Answer 15

• Muscular strength assessed by determining repetition maximum (1 RM): the maximum resistance that can be lifted once
• Muscular endurance assessed by counting the maximum number of repetitions of a muscular contraction, or the maximum amount of time a person can hold a muscular contraction

Question 16

transient hypertrophy

Answer 16

“pump”
acute hypertrophy

Question 17

how to test muscular endurance

Answer 17

push ups (UB)
flexed arm hang

wall sit (LB)

Question 18

example of power test vs max strength test

Answer 18

vertical jump and broad jump (power test)
squat and deadlift (maximal strength test)

Question 19

FITT-VP Principle

Answer 19

Question 20

power vs strength vs endurance vs hypertrophy

Answer 20

Question 21

volume in FITT-VP principle

Answer 21

reps x sets x frequency

Question 22

FITT

Frequency

Answer 22

Health Canada and the Canadian Society for
Exercise Physiology (CSEP) recommend 2-4
days per week.

Allow 1 full day of rest between workouts for whole
body routines. Or on consecutive days alternate
upper vs lower body (split-body routines).

Question 23

FITT

Intensity
RPE
Reps in reserve

Answer 23

Question 24

FITT

Rep max continuum

Answer 24

strngth and power - less than 6 reps
hypertrophy - 8 - 12 reps
endurance - 15+ reps

Question 25

FITT

time

Answer 25

Expressed as repetitions, sets, rest time, and tempo of lift (cadence, speed) and number of exercises (or in type)

Good to match objective measures with subjective measure (such
as RPE). Another subjective measure is the RIR

need to include all 4

Question 26

What is RIR?

Answer 26

Reps in Reserve (RIR): helps identify intensity – subjective measure

The Borg Rating of Perceived Exertion (RPE)

Question 27

why does a more trained individual need to go gym more

Answer 27

level of homeostatsis changes
need a larger stimulus to progressively overload

Question 28

tempo

Answer 28

time in concentric vs eccentric

Question 29

FITT table for different goals
(get a good idea of this)

Answer 29

Question 30

FITT

Rest period

Answer 30

Rest period – the time dedicated to recovery between sets & exercises.

General guideline is:
- 2-5 minutes rest for power and strength.
- 30 s – 1.5 min for hypertrophy and endurance.