Lifespan Muscle Changes and Dysfunction

Question 1

What happens to our muscle mass / strength / functional capacity in the different stages of life?

Answer 1

• early life it grows rapidly
• adolescence and adult life it grows more slowly in the beginning and then slowly goes down
• older age is starts to deplete a bit faster

Question 2

what happens in your older age if you make the right choices with your functional capacity at a young age?

Answer 2

you will have much better functional capacity than those who weren’t.
- unfit people go back down to the same muscle strength as almost a toddler (this is bad)
- fit people go to the muscle strength at the very end of early life as an elder (this is good) and they do not lose much muscle

Question 3

what happens if you lose enough strength?

Answer 3

you wont be able to do things on your own (ex. showering)
- loss of independence

Question 4

what can we do to have a higher muscle mass trajectory?

Answer 4

• increase PA
• technology
• occupational therapy

Question 5

Peak height velocity happens later in males or females?

Answer 5

males. females start puberty and adolescence earlier

Question 6

do males or females have higher skeletal muscle mass at all ages?

Answer 6

males

Question 7

what happens to females fat free mass at around age 14

Answer 7

they experience plateau in the accumulation

Question 8

what is the condition for us losing muscle mass as we get older

Answer 8

Sarcopenia

Question 9

why is preservation of muscle mass important?

Answer 9

• higher levels of fundamental motor skills
• increased physical activity participation
• reduces rate of injuries
• enhancing changes in body composition
• improves skills and performance in sport
• essentially:
• life-long PA participation
• health (physical and mental)
• overall quality of life

Question 10

what is sarcopenia caused by?

Answer 10

• disuse
• nutrition
• metabolic
• hormonal
• reduction in lean tissue

Question 11

what does sarcopenia lead to?

Answer 11

• loss of strength and function
• increase risk of disability
• reduces quality of life and increases risk of death
• loss of independence

Question 12

what is dynapenia?

Answer 12

• age related strength loss

Question 13

what happens to our muscle fibers in sarcopenia?

Answer 13

• we lose sarcoplasmic volume
• we lose myofibril density
• reduction in cross-sectional area by fiber size
• we see losses in fiber numbers
• change in fiber type (preferential loss of type II fibers- most likely to experience disuse bc we are not power training)

Question 14

muscle mass and _______ are not the same thing

Answer 14

strength

Question 15

why do we lose strength as we get older?

Answer 15

we lose neuromuscular connections (big portion) as well as muscle mass (small portion)

Question 15

older adults who participate in ______ _________ and _____ ________ __ have higher levels of muscle strength

Answer 15

more frequent and more intense PA

Question 16

what is muscle strength highly associated with?

Answer 16

functional activities

Question 17

what is acute muscle soreness?

Answer 17

• pain felt during and immediately after exercise
• lasts a few minutes to a couple hours

Question 18

what is DOMS?

Answer 18

• delayed onset muscle soreness
• onset is 24-48hrs post exercise (strength training)
• can persist up to 3 days

Question 19

symptoms of DOMS?

Answer 19

• tenderness to the touch
• ROM limitations due to pain/stiffness
• fatigue
• short term losses in strength

Question 20

what is DOMS caused by?

Answer 20

• high intensity resistance exercise – weighted eccentric contractions
• inflammatory response to ‘micro-tears’ induced by training
• NOT lactate buildup

Question 21

who is DOMS most common among?

Answer 21

• new exercisers
• new stimuli/type of training

Question 22

do you need to feel soreness to have benefits from exercise?

Answer 22

no

Question 23

DOMS alleviating symptoms?

Answer 23

• stretching
• massage
• none steroid anti-inflammatory drugs
• foam rolling
• heat/cold

Question 24

Prevention of DOMS?

Answer 24

- hydration - warm-up / cool-down - slow progressions / appropriate intensity

Question 25

What is rhabdomyolysis?

Answer 25

- breakdown of muscle caused by heavy heavy exercise - translates to : striated muscle breakdown

Question 26

What causes rhabdomyolysis?

Answer 26

- injury/trauma (even car accident) - high intensity exercise with inadequate rest - hot environments can exacerbate the onset

Question 27

what is symptoms of rhabdomyolysis?

Answer 27

- weakness / soreness - urine colour - dark brown / tea coloured (this is because byproducts of muscle breakdown is entering blood stream) - muscle swelling - can lead to kidney failure and death - tested through creatine kinase in a urine test

Question 28

treatment of rhabdomyolysis?

Answer 28

- physical therapy - IV fluid / electrolytes - dialysis