Aerobic Conditioning

Indication for aerobic conditioning

• Decreased endurance with exercise

• Decrease ability to perform functional activity

  • Stairs

  • Community mobility

  • Household chores

• Decreased aerobic capacity

Benefits of aerobic conditioning

 Improved cardiovascular and peripheral (muscular) endurance

 Decreased anxiety and depression

 Enhanced physical function

 Enhanced sense of well being

There is good evidence that aerobic exercise is beneficial for improving aerobic capacity in people with mild and moderate stroke.

True

Contraindications to aerobic conditioning

 Unstable heart rates

 Uncontrolled hypertension

 Acute infection

 Aortic aneurysm

 Severe aortic stenosis

 Acute or poorly controlled congestive heart failure

 Active or recent myocarditis

 Acute thrombophlebitis

What are the general recommendations for aerobic physical activity?

• Children (6-17): 60 min of moderatevigorous aerobic ex per day

• Adults (18-65): 30 min of moderate intensity ex 5 days/wk or 20 min of vigorous activity 3 days/wk

• 80% of Americans do not get recommended exercise

What is the recommended amount of aerobic activity and strength training (by the Department of Health and Human services)?

• Aerobic activity: At least 150 minutes a week of moderate aerobic activity — such as brisk walking, swimming or mowing the lawn — or 75 minutes a week of vigorous aerobic activity — such as running or aerobic dancing. You can also do a combination of moderate and vigorous activity, preferably spread throughout the course of a week

• Strength training. Do strength training exercises at least twice a week. Consider free weights, weight machines or activities that use your own body weight — such as rock climbing or heavy gardening. The amount of time for each session is up to you

What must be monitored during aerobic conditioning?

 Heart Rate

 Blood Pressure

 Rate of Perceived Exertion

 Respiratory Rate

 Oxygen saturation

 Skin (color, sweating)

VO2 Max

• AKA max O2 consumption or uptake, peak oxygen uptake, or max aerobic capacity

• The maximum rate of oxygen consumption as measured during incremental exercise, most typically on a motorized treadmill while measuring ventilation and O2 and CO2 concetration

Maximal oxygen consumption in no way reflects the aerobic physical fitness of the individual, and is not an important determinant of their endurance capacity during prolonged, sub-maximal exercise.

False

MVO2

A measure of the oxygen consumed by the myocardial oxygen

 At rest, the myocardial muscle extracts 70-75% of the oxygen from the blood flowing through the heart

 During exercise, the demand for oxygen increases. To meet this demand, there is an increase in coronary blood flow to meet oxygen demands

Metabolic Equivalent (MET)

The amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O2 per kg body weight x min

• A method for expressing the energy cost of physical activities as a multiple of the resting metabolic rate

• Energy cost of an activity can be determined by dividing the relative oxygen cost of the activity (ml O2/kg/min) x by 3.5

What is deconditioning?

 Occurs with prolonged bed rest

 Often seen in patient with extended acute illness or long-term chronic conditions

 Can result in: Decreased m, mass, strength, CV function, total blood volume, plasma volume, heart volume, orthostatic tolerance, ex. tolerance and bone mineral density

Overload principle

 Overload is stress on an organism that is greater than the regular stress placed on it

 To improve cardiovascular or muscular endurance, an overload must be applied to the system/ organism

 The overload must be above the training stimulus threshold for conditioning/adaptation to occur

 Training stimulus thresholds are dependent on the individual’s health, level of activity, age and gender

 The higher the level of fitness, the greater the level of exercise needed to elicit a change

 A conditioning response generally occurs at 60 – 90% of maximal heart rate (50-80% of VO2 max)

Why does exercise increase cardiac output?

Inc cardiac output is caused by active muscles and their need of oxygenated blood

What is one circualtory risk with rapid cessation of exercise?

Blood pooling - inadequate amount of blood returning to the heart because muscles are no longer pumping blood against gravity; blood can get stuck, especially in the LEs

How does the body respond to increased exercise?

• Inc gas exchange

• Inc mm metabolism which causes inc bod temp

• Inc epinephrine

• Inc stimulation of jt and mm receptors

• Inc blood flow and O2 extraction from blood

*O2 consumption depends on vascularity of mm, fibers, # of mitochondria, and oxidative mitochondrial enzymes in fibers

Left-sided HF

• The heart's pumping action moves oxygen-rich blood as it travels from the lungs to the left atrium, then on to the left ventricle, which pumps it to the rest of the body

• The left ventricle supplies most of the heart's pumping power, so it's larger than the other chambers and essential for normal function.

• The left side of the heart must work harder to pump the same amount of blood

Right-sided HF

• Usually occurs as a result of left-sided failure

• When the left ventricle fails, increased fluid pressure is, in effect, transferred back through the lungs, ultimately damaging the heart's right side. When the right side loses pumping power, blood backs up in the body's veins.

• This usually causes swelling or congestion in the legs, ankles and swelling within the abdomen such as the GI tract and liver (causing ascites) - PERIPHERAL EDEMA