TEST 2: Skeletal Muscular Adaptations

Question 1

Adaptations to Endurance Training

Answer 1

1. increase in # capillaries per muscle fiber
2. increase in capillary density (# capillaries per x-sectional area of fiber)
3. increase in # and size of mitochondria and concentration of Kreb’s cycle enzymes and ETC cytochromes w/in mitochondria
4. increase in myoglobin concentration
5. decrease in size of slow twitch fibers
   - reduced distance from capillaries to mitochondria speeds rate of diffusion of gasses across fiber
6. change in subtypes of fibers
   - FTx to FTa
7. increase % fat used for any exercise intensity
   - greater intramuscular triglyceride storage
   - increase mitochondrial lypolytic enzyme capacity

Question 2

Adaptations to Resistance Training

Answer 2

• Hypertrophy

- Hyperplasia

Question 3

Hypertrophy

Answer 3

increase in size

• addition of myofibrils
• -new sarcomeres added in parallel (not added in series. thicker not longer)
• FT fibers hypertrophy more
• FT hypertrophy by increase rate of protein synthesis
• ST hypertrophy by decrease rate of protein degradation (protein breaking down)

Question 4

Hyperplasia

Answer 4

increase in cell number

• supported by animal research
• similar to hypertrophy
• hyperplasia probably only accounts for 5-10% of increase in muscle size
• -power lifting
• -anabolic steriod use

Question 5

Mechanism of Hyperplasia

Answer 5

Microtears, especially during eccentric component stimulate satellite cells, several of which may fuse to form new fibers

Question 6

Theory of Doms

Answer 6

1. Structural Damage
   - Sarcolemma Damage
   - Z- Disk Streaming (Due to high Ca++)
2. Inflammatory Reaction
   - Neutrophils infiltrate within few hours
   - Release of histamines, kinins, K+, and edema stimulate free nerve endings
3. Regeneration/ Repair
   - increased protein synthesis triggered

Not totally understood. Exercise causes micro damage, then post exercise, in the regenerative phase, protein synthesis is increased, resulting in hypertrophy

Question 7

DOMS and Performance

Answer 7

Reduction in force-generating capacity of muscle
-1-RM reduced at peak at DOMS, but gradually returns to normal as DOMS resolves

Glyocogen resynthesis impaired

• Normal 6-12 hours post exercise, but greatly slows as muscle undergoes repair
• If you must compete again soon, important to refuel son after exercise

Question 8

Minimizing DOMS

Answer 8

1. NSAIDS
2. Analgesic Creams
3. Massage
4. Low Impact Cardio
5. Exhaustive Exercise Bout

Question 9

NSAIDS

Answer 9

decrease pain, but may also slow resolution of DOMS and limit strength gains from workouts (anti-inflammatory)

Question 10

Analgesic Creams

Answer 10

Icy Hot, Biofreeze, etc.

• Feels good, may decrease pain by increasing blood flow and O2 to tissue and speeding removal of waste products from muscle
• probably does not affect healing times

Question 11

Massage

Answer 11

similar effects to analgesic creams

Question 12

Low Impact Cardio

Answer 12

-May resolve DOMS a little faster by increasing blood flow and O2 to muscle and speeding removal of waste products

Question 13

Exhaustive Exercise Bout

Answer 13

high amount of eccentrics

• Produces very large DOMS, but subsequent workouts have less DOMS
• mechanism not really understood
• not smart due to greater injury potential

Question 14

Best Practices for Minimizing DOMS

Answer 14

• Warm Up
• Slow, Steady Progression (10% rule)
• Regular Workouts
• Cool Down
• Stretch

Although you don’t really want the pain of DOMS, you probably don’t want to totally eliminate DOMS because it is likely crucial to hypertrophy and strength gains