Improving Muscular Strength and Endurance - Chapter 4 (Key Concepts)

Flashcards cover key concepts from the Muscular Strength and Endurance chapter: muscle structure and function, fiber types, muscle actions, evaluation methods, training principles, safety, program design phases, and common supplements and safety considerations.

What is muscular strength and how is it defined?

The maximum force a muscle can generate in a single effort; commonly assessed by a one-repetition maximum (1RM) test.

What is muscular endurance?

The ability to generate force repeatedly or sustain a contraction over time; commonly assessed with tests like push-ups or curl-ups.

Name the primary functions of skeletal muscles.

Provide force for movement, maintain posture, and regulate body temperature.

What are the main structural components of a skeletal muscle?

Muscle fibers, fascia, and tendons.

What is a motor unit?

A motor nerve and the muscle fibers it innervates; a single impulse can activate multiple fibers for movement.

What happens at the neuromuscular junction when a nerve impulse arrives?

It triggers the contractile process; removal of the nerve signal stops contraction.

Differentiate isotonic, isometric, and isokinetic exercises.

Isotonic: movement with a joint through ROM; Isometric: muscle tension with no movement; Isokinetic: movement at a constant speed using specialized machines.

Define concentric muscle action.

Muscle shortens during movement against resistance (positive work).

Define eccentric muscle action.

Muscle lengthens while producing force against resistance (negative work).

What are the three skeletal muscle fiber types and their key properties?

Slow-twitch Type I (slow, fatigue-resistant); Fast-twitch Type IIa (fast, moderate fatigue resistance); Fast-twitch Type IIx (fastest, fatigue quickly).

Which fiber type is best suited for endurance events?

Slow-twitch Type I fibers.

Which fiber type is best suited for short, fast events?

Fast-twitch Type IIx fibers (with Type IIa for somewhat faster, but IIx is strongest for short, explosive efforts).

What is fiber recruitment?

The process of engaging more muscle fibers to increase force output.

What primarily determines muscular strength?

Muscle size and the number of fibers recruited, with nervous system control; testosterone promotes muscle size.

What is hypertrophy?

Increase in muscle size due to enlargement of existing muscle fibers.

Is hyperplasia common in strength training?

No—the formation of new muscle fibers (hyperplasia) is not commonly induced by typical strength training.

What are anabolic steroids and what risks do they pose?

Synthetic forms of testosterone; risks include liver cancer, high blood pressure, increased bad cholesterol, depression, and prostate cancer.

What is creatine and what does supplementation do?

Creatine phosphate helps replenish ATP; supplementation can increase stored PCr and may enhance performance in short, maximal efforts, with potential GI side effects.

How is muscular strength evaluated?

Primarily with a 1RM test; beginners may use estimated 1RM to reduce injury risk.

How is muscular endurance evaluated?

Push-up tests and sit-up/curl-up tests to assess core/upper body endurance.

What is progressive overload?

Gradually increasing workload (weight, sets, or repetitions) to stimulate continual adaptation.

What is specificity of training?

Adaptations are specific to the muscle group trained and the training intensity; high intensity boosts size/strength, low intensity builds endurance.

What is the recommended frequency for strength gains?

Typically 2–3 days per week for strength improvements.

What does Figure 4.7 illustrate about strength vs endurance training?

Strength gains come from low reps/high weight; endurance gains come from high reps/low weight.

What are common strength training adaptations?

Neural adaptations (increased motor unit recruitment) followed by hypertrophy (muscle size increase).

Are there gender differences in early strength-training responses?

Little difference initially; over time men may gain more due to higher testosterone.

What safety considerations should be observed before starting a strength-training program?

Use spotters, collars, warm up, breathe properly, perform controlled movements, stabilize the core, and start with light weights before progressing.

What is the 5-Point Contact Principle and which areas does it involve?

Five contact points with bench or floor: back of the head, upper back, lower back/buttocks, bottom of right foot, bottom of left foot.

What strategies help staying motivated to weight train?

Plan time to train, make it enjoyable, choose a preferred training space, set a realistic routine, train with a partner, and remember the benefits.

What are starter, slow progression, and maintenance phases in a weight-training program?

Starter: 1–3 weeks with lighter weights and 1 set; Slow progression: 4–20 weeks with heavier weights and 2–3 sets; Maintenance: around week 20 onward, possibly one workout per week to maintain gains.

What is the typical training frequency for endurance training?

3–5 days per week.

What is the difference between isotonic and isometric exercises regarding safety and execution?

Isotonic involves movement with resistance (common in training); isometric involves muscle tension without movement (can be associated with Valsalva risk).