Muscular Strength and Endurance Quiz

Muscular Strength

• Muscular strength is the maximum force a muscle can generate in a single effort.
• One Repetition Maximum (1RM) is a common test for muscular strength.

Muscular Endurance

• Muscular endurance is the ability to sustain repeated muscle contractions over time.
• Examples include pushups and situps performed to fatigue.

Motor Unit

• A motor unit consists of a single motor neuron and all the muscle fibers it innervates.

Muscle Fiber

• A muscle fiber is a single cylindrical cell that makes up skeletal muscle.
• It has a striated appearance and the ability to contract.

Hypertrophy

• Hypertrophy is the increase in the size of muscle fibers.
• It typically results from resistance training or strength training.

Muscle Fiber Types

• Slow-twitch muscle fibers:
  • Most resistant to fatigue.
  • Used for endurance activities.
• Fast-twitch muscle fibers:
  • Primarily rely on anaerobic metabolism.
  • Fatigue quickly.

Activities and Muscle Fiber Use

• Activities using slow-twitch muscle fibers:
  • Long distance running
  • Cycling
  • Swimming.
• Activities using fast-twitch muscle fibers:
  • Sprinting
  • Weightlifting
  • High-intensity interval training (HIIT).

Low Back Pain

• Proper posture and strong core muscles help reduce the risk of low back pain.
• 80% of Americans will experience low back pain at some point in their lives.

Metabolic Rate

• Increased physical activity, higher muscle mass, hormonal changes, and environmental factors like temperature can increase metabolic rate.

Muscle Mass and Gender

• Men typically have higher testosterone levels than women.
• This allows men to build more muscle mass.

Muscle Loss

• Muscle mass begins to decline after age 30.

Strength Training Benefits

• Strength training improves:
  • Metabolic health
  • Insulin sensitivity
  • Reduces body fat
• It helps prevent and manage chronic diseases.

Types of Muscle Contractions

• Isometric exercise:
  • Applying force without changing muscle length (no visible joint movement).
• Concentric contraction:
  • Muscle shortens as force is exerted.
• Eccentric contraction:
  • Muscle lengthens as it contracts.

Plyometric Exercise

• A type of exercise that involves a jump from a platform to the ground and back up.

Isokinetic Exercise

• Exercise with constant speed of force application.

Strength Training Recommendations

• Minimum training days per week: 2-3 days.
• Training intensity for weight training: Determined by the amount of weight lifted (1RM).
• Variety: Include different exercises in your program.

Dynamic Flexibility

• The ability to move joints through their full range of motion with speed and control.
• It does not affect static stretching effectiveness.

Flexibility Factors

• Factors that determine flexibility:
  • Muscle length
  • Joint structure
  • Elasticity of connective tissues

Joint Capsules

• Fibrous tissues that surround and enclose joints.
• Provide stability, support and allow for movement.

Elastin Fibers

• Yellow fibers that make connective tissue flexible.

Connective Tissue

• Tendons and ligaments are the two principal types of connective tissue in a muscle.

Flexibility Benefits

• Improved range of motion
• Reduced risk of injury
• Better posture
• Enhanced athletic performance

Flexibility Recommendations

• Stretching frequency: At least 2-3 days per week.
• Repetitions per stretch: 2-4 repetitions.
• Recommended technique: Static stretching.

Stretching Techniques

• Ballistic stretching:
  • Involves bouncing or jerky movements and is considered dangerous.
• Proprioceptive neuromuscular facilitation (PNF) stretching:
  • Contracting a muscle prior to stretching.
  • Often requires a partner.
• Active stretching:
  • Using your own muscles to stretch.
  • May not provide a deep stretch.
• Passive stretching:
  • Stretching with assistance from external forces.
  • Essential to stretch slowly and gently to avoid injury.

Spinal Regions

• The five regions of the spine, from top to bottom:
  • Cervical
  • Thoracic
  • Lumbar
  • Sacral
  • Coccygeal

Back Pain

• The lumbar region of the spine is the most common site of back pain.

Essential Fat

• The minimal amount of body fat necessary for the body to function effectively.
• Women have a higher proportion of essential fat than men due to biological and reproductive functions.

Body Composition Evaluation

• Height and weight tables:
  • Correlate height and weight to assess body composition.
• Body Mass Index (BMI):
  • Based on the concept that weight should be proportional to height.
• Hydrostatic weighing:
  • Predicts body fat percentage based on the principle of water displacement and body density.

Obesity

• Approximately 42.4% of Americans are obese.

Obesity Risk Factors

• Processed food consumption:
  • High in sugars and unhealthy fats.
• Increased daily caloric intake:
  • Has risen by at least 300 calories since 1970.
• Weight gain in the abdominal area (visceral fat):
  • Increased risk of cardiovascular diseases.

Body Fat Deficiencies

• Women: Less than 17–18% body fat can result in amenorrhea (menstrual dysfunction) and loss of body mass.
• Men: Less than 5–6% body fat can result in muscle wasting, fatigue, and hormonal imbalances.

Female Athlete Triad

• A condition characterized by:
  • Low energy availability (with or without eating disorder)
  • Amenorrhea (menstrual dysfunction)
  • Decreased bone mineral density (osteoporosis)

BMI Classifications

• Overweight: BMI of 25–29.9
• Obese: BMI of 30 or above.