Aerobic Training

How can bouts of exercise be completed to meet ACSM guidelines?

>10 minutes per day or entirely in 1 session

Physical Activity

any bodily movement produced by contraction skeletal muscle that results in energy expenditure over resting needs

Exercise

any planned and structured physical activity designed to improve or maintain physical fitness

Physical Fitness

the ability to perform physical work (requires stg, endurance, cardio, balance, motor control, body composition)

Poor to superior based on energy expenditure (VO2)

VO2 max

measure of body’s capacity to use oxygen; measured when exercise requires multiple muscle groups

Max amount of oxygen per minute when individual has reached max effort (ml/kg/min)

What does VO2 max depend on?

Transport of oxygen

O2 binding capacity

Cardiac function

Oxygen extraction capability

Muscle oxidative potential

Endurance

ability to work for prolonged periods of time and ability to resist fatigue (muscular and cardiovascular)

Myocardial oxygen consumption

measure of oxygen consumed by myocardial muscle

Depends on: arterial o2 content, hg o2 content, cardiac BF, diastolic BP, length of diastole, distention

Afterload

relationship between pressure in LV and aorta (force required at beginning of systole to push blood in)

Aerobic exercise training

augmentation of energy utilization of muscle by means of an exercise program; direct result of levels of fuel and metabolic processes

Adaptation

CV and MSK ability to adapt to training stim over time (10-12 wks to induce training adaptations in aerobics)

Neurological, physical, metabolic

Deconditioning

Prolonged inactivity

Decreases in VO2 max, stroke volume, muscular stg, blood volume, orthostatic tolerance, exercise tolerance, BMD (occurs quicker than adaptations)

Severity depends on inactivity

What are the byproducts of the energy systems?

CO2, water, ATP

What factors influence the dominance of each energy system?

Intensity and duration of physical activity; all active all the time though

What are the 3 energy systems?

Phosphagen, Oxidative system, and glycolysis

Phosphagen system

ATP for short-term, high intensity exercise

Uses CP

Active at start of exercise regardless of intensity (0-30s)

Low ATP yield but quick replenish

Glycolysis

Uses glycogen

Provides energy for moderate intensity, short-duration exercise (30-90s)

Yields more ATP than phosphagen system

Produces lactate as byproduct

Oxidative system

Requires O2

Uses Carbs and Fats

Provides exergy after >90s of exercise

Yields highest ATP

What factors affect the response to acute exercise?

Temperature, humidity, and altitude

How does the NS respond to aerobic exercise?

Stimulates SNS (vasoconstriction of unused muscles, increases myocardial contractility, proportionate to intensity)

How does the Cardiac respond to aerobic exercise?

SA node depolarization freq and HR increase

Increased force of caridac muscle contraction

How does the Vascular respond to aerobic exercise?

Reduces peripheral resistance of working muscles

Increased CO and systolic BP

How does the respiratory respond to aerobic exercise?

Increased gas exchange, muscle metabolism, RR and tidal volume

How does the skeletal muscle respond to aerobic exercise?

Increased BF, O2 delivery extraction and release

Increased production of CO2

Factors related to performance

VO2 max, Lactate threshold, Exercise economy, Fuel source, High percentage of Type 1 fibers

What changes occur in the cardiovascular system with regular aerobic training?

Lower HR and BP, increased BV at rest

Increased SV, CO, and O2 extraction during exercise

What changes occur in the respiratory system with regular aerobic training?

at rest: larger lung volume and diffusion capacity

exercise: larger diffusion, increased ventilation efficiency, less air ventilated at same o2 consumption

What changes occur in the metabolic system with regular aerobic training?

at rest: hypertrophy, capillary density, increased mitochondria and myoglobin

exercise: glycogen sparing, lower blood lactate

What must be done before having a pt do aerobic exercise?

Taking vital signs

When is it contraindicated?

Resting systolic >200

or

Resting diastolic >115

What is a precaution for cardiopulmonary exercise?

Skin of cheeks, nose, earlobes become pink, moist, and warm

BP increases 8-12 per MET

When should exercise be terminated?

Onset of angina

>10 mmHg drop in SBP

Excessive rise in BP

Limbs feel cold, leg cramps, cognitive shift

No increase in HR with increase in intensity

Change in heart rhythm

Severe fatigue

What does frequency depend on?

Health condition (tissue healing phase, precaution, contraindication)

Comorbidities

Age

Fitness lvl

Abilities, participation, individual factors

What is intensity based on?

Overload and SAID principle

Higher lvl of fitness, the greater intensity required to cause adaptation

How is intensity quantified?

Target HR (60-90% max HR)

Max HR = 220-age

or RPE

What does time depend on?

Total work performed

Intensity

Frequency

Fitness lvl

What are the types of aerobic exercise?

Continuous, interval, and circuit training

Continuous training

Prolonged mode of exercise

Submaximal oxidative systems using slow twitch muscle fibers

Most effective way to increase endurance

Interval training

Exercise followed by rest (good for stg and power compared to endurance)

Relationship of work to rest determines demand

Circuit training

series of exercises completed in a given order for a specified number of rounds

Variety of muscle groups and energy systems stressed

How is volume determined?

Frequency x Intensity x Time

How is aerobic exercise progressed?

Depends on overall health and long-term goals

How quickly does deconditioning occur?

2 weeks