Chapter 6 EXAM REVIEW

1. What is a definition of fatigue?

An inability to sustain muscle contraction, reversible by rest

2. What are 3 causes of fatigue

1. Inadequate energy delivery/metabolism (BG/Glycogen depleted)

2.Accumulation of metabolic by-products (like hydrogen ions)

3. Failure of muscle contractile mechanism

4.Altered neural control of muscle contraction

(REVIEW)

3. What is meant by “hitting the wall”

This term is usually used when glycogen depletion occurs during exercise, is when fatigue sets in and one loses ability to go into a high intensity

4. The pattern of glycogen depletion (muscle fiber type) depends on ______

Intensity (determines what fibers you use)

5a. What is the possible cause of fatigue in an event lasting 15-30 seconds

Depletion of creation phosphate or depletion of ATP (phophagen system hitting it’s limit)

5b. What is the possible causing of fatigue in an event lasting 2-4 hours

Glycogen depletion

6. What are the two scenarios where glycogen depletion can occur? What can an individual do to avoid this?

• Moderate intensity, longer duration (>90 minutes)

• High intensity intermittent (> 60 minutes)

• To avoid this, an athlete should consume carbohydrates during exercise

6A. What can an individual do to avoid glycogen depletion during exercise

a.     To avoid this, an athlete should consume carbohydrate during exercise. This is because that will increase BG and delay fatigue and the need to rely on liver glycogen

7. Why does glycogen depletion occur more rapidly during the first few minutes of exercise

Because of o2 deficit, and because we have to rely on glycosis until aerobic pathways (o2 consumption) ramps up

8. The type of muscle fibers recruited (Type I vs Type II) depends on ____

intensity

9. What is a cause of acute muscle soreness

a.     accumulation of metabolic byproducts (lactate and H+)

b.     Tissue edema (plasma fluid into interstitial space)

c.      edema -> acute muscle soreness

Why does high lactate production coincide with decreased performance/fatigue? (Hint: Hydrogen, pH, enzyme activity, calcium and actin/myosin interaction)  Review from last test for metabolic byproducts

As exercise intensity goes up intensity goes up, two things happen

1. 1) increase in H+ production from breakdown of ATP. This decreases ph inside the muscle, which inhibits enzymes, and affects or inhibits calcium release. As a result of decreased PH and limited calcium release into the sarcoplasm, fatigue occurs since this results in an inability for the muscles to contract (actin/myosin can’t bind). 

2. 2)  increase lactate production

10. What is DOMS

Delayed Onset Muscle soreness

11. What is the cause of DOMS

Eccentric Muscle Contractions

12. Be able to explain one strategy that can be used to avoid DOMS

a.     Start with low intensity and increase gradually.

b.     Start with high-intensity, exhaustive training (soreness intense at first, much less later).

13. Heat cramps are associated with what?

14. What is the recommended treatment for heat cramps

Stretching