Aerobic and Anaerobic Fitness

Energy Systems

• Aerobic and anaerobic fitness rely on energy systems.
• The body uses food to make adenosine triphosphate (ATP), which is stored as a basic form of energy.
• There are three primary energy systems:
  • Phosphagen (ATP-PCr)
  • Anaerobic glycolytic
  • Aerobic oxidative
• The energy system used depends on the duration and intensity of the activity.

Phosphagen (ATP-PCr) System

• Function: Provides immediate energy for short, explosive activities.
  • Examples: Sprinting, jumping, lifting heavy weights
• Mechanism: Uses stored phosphocreatine to quickly replenish ATP.
• Duration: Primarily used for activities lasting up to about 10 seconds.
• Oxygen Dependency: Anaerobic (does not require oxygen).

Anaerobic Glycolytic System

• Function: Supplies energy for activities lasting longer than the phosphagen system but still relatively short.
  • Examples: 400-meter sprint, interval swimming
• Mechanism: Breaks down carbohydrates (glucose) in the absence of oxygen to produce ATP, resulting in lactate as a byproduct.
• Duration: Used for activities lasting from about 30 seconds to 2-3 minutes.
• Oxygen Dependency: Anaerobic.

Aerobic Oxidative System

• Function: Provides energy for sustained, low- to moderate-intensity activities.
  • Examples: Running a marathon, swimming for extended periods
• Mechanism: Uses oxygen to break down carbohydrates, fats, and sometimes proteins to produce ATP.
  • Carbohydrates are used at high intensity.
  • Fats are used at mild to low intensity.
• Duration: Primary energy source for activities lasting longer than a few minutes.
• Oxygen Dependency: Aerobic (requires oxygen).
• Oxygen limits energy production.

Ex Phys Review

• Aerobic:
  • Oxygen is used to break down carbs and fats for energy.
  • Depends on respiratory and cardiovascular systems.
  • Long duration.
  • The rate of energy supply is limited.
• Anaerobic:
  • Absence of oxygen.
  • Stored carbohydrates are broken down.
  • The rate of energy supply is high.
  • The capacity of supply is limited.
• Both systems work simultaneously depending on the activity.

Cardiovascular Fitness and Older Adults

• Aerobic fitness is lost at a rate of 10% per decade in both men and women, regardless of activity levels.
• Anaerobic fitness declines at a faster rate.
• This decline is linked to losses of mobility and independence.

Benefits of Aerobic Exercise

• Physiological benefits:
  • Increase in cardiac output at maximal exercise
  • Increased blood volume
  • Increased blood flow
  • Increased number of capillaries in working muscles
  • Increased extraction of oxygen by muscle tissue
  • Increased maximal oxygen consumption
  • Decreased heart rate
• Functional benefits:
  • Improved endurance during activity
  • Increased maximal exercise capacity
  • Increased tolerance for submaximal activity at any given work rate
  • Decreased stress on the body at a given work rate
• Health benefits:
  • Increased risk of premature death
  • Reduced risk of CVD, cancers, and diabetes
  • Improved body composition

Benefits of Anaerobic Exercise

• Increased capacity for high-intensity work.
• Increased resistance to fatigue in high-intensity exercise.
• Builds muscle mass, strength, and power.
• Helps mitigate the decline with aging and contributes to the loss of function and mobility.

Aerobic Exercise

• Frequency:
  • 3-5 days per week for moderate intensity.
  • 3 days per week for vigorous intensity.
• Intensity:
  • 5 to 6 for moderate intensity.
  • 7 to 8 for vigorous intensity (on a scale of 1-10).
• Time:
  • 30-60 minutes for moderate intensity.
  • 20-60 minutes for vigorous intensity.
• Type:
  • Any modality that does not impose excessive orthopedic stress.
  • Walking is the most common type of activity.
  • Aquatic exercise and stationary cycle exercise may be advantageous for those with limited tolerance for weight-bearing activity.

Walking

• Most common activity.
• Can achieve moderate intensity.
• Measure using walking cadence (120 steps/min for moderate).
• Achievable and practical.

Principles of Exercise Adaptation

• Threshold and overload
• Progression
• Maintenance
• Regression/reversibility
• Specificity
• Individualization

Progression for Older Adults

• Start at a lower intensity and progress slowly.
• Progress in frequency and time first.
• Do this for 4-6 weeks.
• Progress for 2-6 months, then start maintenance.
• Little aerobic gains after 6-8 months.

Anaerobic Fitness Training

• Should be done after a good aerobic pase is developed.
• Most often trained based on need; injuries possible.
• Anaerobic interval training:
  • Work-to-rest ratios of 1:3 to 1:4 (longer rest, harder work period).
• Guidelines:
  • Perform once a week or every 2 weeks.
  • Harder than steady-state exercise, near muscular exhaustion.
  • Recovery must be incomplete.

Research Benefits of Aerobic Exercise and Training

• Multimodal training programs (endurance exercise combined with strengthening exercise) are more effective than either alone.
• Multimodal components:
  • 15-30 minutes to start, progression to 30-45 min with RPE of 12-14.
  • Consider including balance training (Hurst et al. 2019, Cadore et al. 2013).
• Training for frail adults: multimodal programs are best, 3x/week for at least 3 months (more than 6-8 months is best).

Intensity, Frequency, and Duration

• 70 female participants.
• Consistent intensity has a larger effect than progressively increasing intensity.
• More minutes/week, more sessions/week, and longer duration were more beneficial.
• Example:
  • 2 sessions/week, 8 weeks cycle ergometer.
  • 50% of max effort, 1-minute work, 1-minute rest, repeat 8-10 times.
  • Reduction in BP, increase in VO_2 max, and improvement in TUG times.
  • Potential for very little time commitment; showing benefits similar effects seen in longer training programs.

Bone Density

• Postmenopausal women, pool-based jumping program of 24 weeks with 3 times/week for 30 min:
  • 5 min warm-up, 20 min HIIT of 30s jump/30s rest, 5 min cool down
  • Increased bone density and functional fitness.

Improved Anaerobic Fitness

• Anaerobic training improves muscle mass, muscle strength, and muscle power.
• All decreased with age.

Nordic Walking

• Aerobic and anaerobic walking with special walking poles; training for cross country skiing.
• More effective than conventional exercise, has a very low injury risk.
• Upper body and lower body targeted benefits aerobic and anaerobic systems less load on knees perception of sport-related equipment use low injury risk (9.26 per 1000 hours).
• Improved balance, improved metrics: VO_2 max, peak HR, RER, reduced lactate, increased caloric expenditure.

Muscular Fitness and Adherence

Exercise Phys Review

• Muscle strength changes with age: peak muscle strength between 20-30 years old.
• Training increases strength at all ages; chronic benefits include increased muscular strength, power, endurance, muscle size, balance, coordination, flexibility, bone mineral density, tendon and ligament strength, insulin sensitivity and glucose tolerance, well-being and self-esteem, decreased body fat.
• Maximum voluntary contraction decreases significantly starting at age 60 concentric contraction (muscle shortens), eccentric contraction (muscle lengthens) little to no change isometric contraction (no change in muscle length) some loss of strength loss mostly attributed to less excitable muscu mass.

Resistance Training and Older Adults

• Research studies support positive adaptations following training: increases hypertrophy, increased production of myosin, actin, and other muscle constituents.
• 10-12 week programs show 5-10% increase in muscle CSA all ages even frail older adults.

FITT Guidelines

• Frequency: 2 days per week.
• Intensity: 50% of 1RM for beginners, progress to 60-80%.
• Time:8-10 exercises.
• Type: 2-3 sets of 8-12 reps of each; dynamic and static.

Program Variables

• Choice of exercise: body weight, weight machine, free weights, elastic bands.
• Sequence of exercise: multijoint exercises done first, alternate upper/lower body.
• Sets and reps: high weight/low reps (strength), low weight/high reps (endurance).
• Rest: longer rest periods when training for strength.

Exercise Selection

• Concurrent training: cardiovascular fitness and muscular fitness training happens simultaneously.
• Benefit shown in research: single-mode benefits about the same.

Identify Ways to Increase Adherence

• Barriers and solutions to exercise adherence; levels of prevention.

Levels of Prevention

• Primary prevention: aims to prevent disease or injury before it ever occurs.
• Secondary prevention: aims to reduce the impact of a disease or injury that has already occurred.
• Tertiary prevention: aims to soften the impact of an ongoing illness or injury that has lasting effects.
• Bronfenbrenner (1994): There are multiple levels of influence on physical activity behavior (environmental factors, policy factors).

Physical Activity Adherence Factors

• Demographic factors: correlated, not determinants.
  • Age: declines with age.
  • Sex: women less active than men.
  • Facilitators: improved appearance, social opportunities, weight loss.
  • Adherence is improved with women-only classes, supervised exercise, age-specific programs, and regular meeting times.
• Marital status: partner activity matters.
• Socioeconomic status: higher-income countries have lower activity levels; CAN programs.
• Race/ethnicity: Non-Hispanic whites are more active; Asia/Africa more active than Europeo America.

Adherence Factors: Intrapersonal Factors

• Health status: poor health becomes a barrier; health is a motivator.
• Self-efficacy: improves with activity, well-documented determinant of activity levels.
• Enjoyment: facilitates activity; most older adults don't experience enjoyment.
• Expectations: better health and less physical restrictions higher expectations age may affect loss of function is linked with aging no matter what.

Adherence Factors: Interpersonal Factors

• Family and peer support: can't be overstated in importance.
• Healthcare providers: lack of guidance negatively impacts activity levels.
• Household pets: pet owners have higher activity, lower BMI, fewer ADL limitations, less doctor visits.

Adherence Factors: Environmental

• Walkability: higher activity in more walkable environments.
  • Accessible sidewalks, good street connectivity, residential density
• Environmental conditions can create barriers to activity.
• Snow/ice/rain common reason leads to more activity.
• Rurality built environmental features limited mall waking programs facilitate activity.

Adherence Factors: Policy Factors

• Policy alone does not have a major impact on physical activity rates.
• Access to affordable and convenient exercise options is a key facilitator.
• Silver Sneakers provides free access to facilities and classes for older adults through partnering with Medicare plans.
• Creative polities promote access to physical activity opportunities: reduced cost senior passes 1 20 801 that provide access to us national parks for people ast.

Transtheoretical Model

• Behavior change is an extended process that involves progressing through several stages:
  • Precontemplation.
  • Contemplation.
  • Preparation.
  • Action.
  • Maintenance.

Enhancing Self-Efficacy

• 4 primary sources:
  • Mastery experiences (performance accomplishment, i.e., I did it!).
  • Modeling should have similar age/sex socioeconomic status.
  • Social persuasion: realistic positive feedback, especially from significant others or exercise specialists, is an important factor.
  • Interpretation of physiological and emotional responses.

Other Measures of Exercise Readiness

• Exercise benefit and barrier scale.
• Physical activity self-regulation scale.
• Assessment of self-monitoring, goal setting, eliciting social support, reinforcement, time management, relapse prevention.

Measures of Social Support Interventions

• Health education addresses misperceptions and increases awareness of benefits.
• Skill-building (self-regulation skills used to overcome barriers), goal setting (SMART).
• Process vs. performance goals, time management, self-monitoring.

Increasing Maintenance of Behavior

• Through reward or positive stimulus.
• Negative reinforcement: removal or avoidance of negative stimulus in response to behavior; avoid weight gain with exercise.
• Group exercise adherence is higher in groups.

General Recommendations for Interventions

• Multilevel that address access cost support social contexts and personal barriers.
• Tailor interventions to identify and address individual barriers and customize the intervention based on the findings of a comprehensive evaluation.
• Use self-regulatory skills to assist people in initiating and maintaining physical activity.
• Use a lifestyle approach where physical activity enhances and becomes a regular part of lifestyle.
• Include components of cognitive behavioral strategies like goal setting, self-monitoring, feedback, support, stimulus control, and relapse prevention training.