NSCA Chapter 6Aerobic Training AdaptationsAbby Stevens

Aerobic Exercise

The effects of aerobic exercise are regulated by the intensity, frequency, and duration of the activity

If one exercises at a greater heart rate during aerobic exercise, the training adaptation will be greater than if one exercises at a lower heart rate

The overall adaptation to recurring aerobic exercise is one that represents a more efficient body, resulting in less effort by all organs at every possible level of exercise

Cardiovascular Changes

The cardiovascular system consists of two components: the heart and the vasculature

An understanding of how each component is affected by aerobic training is important for the personal trainer

In the presence of certain chemicals, such as epinephrine, norepinephrine, and acetylcholine, the heart increases and decreases the rate at which it works

Acute Responses

During exercise, an increased stimulation or excitation of the heart occurs in order to supply blood to parts of the body where it is needed, such as a skeletal musculature

Excitation of the heart, or lack thereof, as the sympathetic nervous system or parasympathetic nervous system, respectively, releases neurotransmitters

Because of the effect of the nervous system, the heart rate(HR) and stroke volume(SV) increase during exercise

The increase in HR and SV ultimately increases the cardiac output

Cont.

Chronic Adaptations

Another adaptation to aerobic exercise is an increased blood volume

A larger blood volume leads to a greater stroke volume during rest

Heart rate increases linearly with increasing levels of aerobic exercise is a decreased heart rate at every intensity level including rest, with the exception of maximal heart rate, which is not affected by training

GLUT4 is a protein that is encoded in human genes. It is an insulin regulated glucose disposal transporter

Acute and Chronic Coronary Vascular Adaptations and Responses

Coronary vasculature, composed of the right and left coronary arteries, vasodilates during exercise as a result of the increased oxygen demand placed on the heart muscle

In general adaptations to aerobic endurance training allow the body to perform in extended periods of time at a given intensity

The adaptation of the vasculature, both coronary and peripheral, to aerobic exercise is, for the most part, one of increased density

Aerobic endurance overtraining

Common markers of aerobic endurance overtraining Pg. 115

Decreased performance

Decreased percentage of body fat

Decreased maximal oxygen uptake

Altered blood pressure

Increased muscle soreness

Decreased muscle soreness

Altered resting heart rate

Increased submaximal exercise heart rate

Altered cortisol concentration

Increased sympathetic stress response

Energy Systems

The production of energy is the most critical part of the ability to exercise

Energy production for brain function is the body’s first priority, but the amount of energy needed to perform muscle contractions is very large in comparison

The body meets these demands not only by increasing the fuel stores, also by increasing the efficiency with which it burns fuel

Acute responses and Chronic adaptations

Aerobic exercise is an untrained person who is beginning an exercise program is inefficient

Limitations in the cardiovascular and respiratory systems impose a limit on the metabolic processes that take place in order to allow aerobic exercise to occur

The body changes and adapts by storing more fuel and increasing its ability to utilize that fuel through enzymatic processes and physiological adaptation at the cellular level

Cont.

The body responds to the demands of repeated aerobic exercise by increasing the available fuel sources as well as the enzymes responsible for utilizing those fuel sources through respective energy pathways

Aerobic exercise has a positive effect on fat mass because fat is the predominant fuel source during aerobic exercise

Endocrine System

A very broad system that incorporates the communication between 11 different organs

The glands of primary concern with regard to the metabolism are the pancreas, adrenal cortex, and adrenal medulla

A single bout of high-intensity aerobic exercise has been shown to increase the sensitivity of insulin and actually stimulates insulin-mediated glucose uptake in non-insulin-dependent diabetes mellitus

Skeletal Changes

There aren’t many skeletal changes associated with aerobic-type exercise

Among the most often referred to as positive are the increase in bone mineral density and the alterations that occur in articular cartilage

One troubling fact about aerobic exercise and bone mineral density is that there appears to be little to no increase in bone density in the normal healthy active population as a result of aerobic exercise

Respiratory Changes

The respiratory system has an extremely close relationship to the cardiovascular changes with aerobic training

While blood flow increases during exercise, allowing for more oxygen to be transported to the working muscles the ability of oxygen to diffuse across the alveolar membrane also increases with aerobic training

Aerobics such as mountain biking increases respiratory adaptations

Overall information

Aerobic exercise affects the body in many ways, structurally, metabolically and physiologically

The acute and chronic effects of aerobic exercise are dependent on the frequency, intensity, and duration of the exercise and the unique characteristics of each client

The key to any training program is a continual yet gradual progression over time

Question 1

A 35-year-old female began an exercise program four months ago in which she has been running on the treadmill four days per week. Which of the following describes the adaptations that are most likely to occur with this program?

Increased Decreased

A. Maximal exercise HR Capillary density

B. Systolic BP a-vO2 difference

C. Mitochondrial density submax exercise HR

D. Blood volume Insulin sensitivity

Explanation

The answer is C because the body chronically adapts to aerobic exercise by increasing mitochondrial density to make producing proteins more effectively. Also you see a decrease in submax HR because of the hypertrophy of the heart.

Question 2

Which of the following changes in the body’s substrate use and enzyme levels is due to an adaptation to chronic aerobic exercise?

A. Increased reliance on carbohydrates

B. Decreased reliance on free fatty acids

C. Increased concentration of GLUT4

D. Decreased concentration of hexokinase

Explanation

There is an increased concentration of GLUT4 so the activity of GLUT4 increases so it bringing more glucose to the cell so it can produce more energy. GLUT4 is a protein that is encoded in human genes. It is an insulin regulated glucose disposal transporter.

Question 3

Clients possessing predominantly Type II muscle fibers in their lower body probably would perform well in which of the following activities or events?

I. Olympic weightlifting A. II and IV only

II. 10-kilometer road race B. I and III only

III. 100-meter sprint C. I, II, and III only

IV. Triathlon D. II, III, and IV only

Explanation

The answer is B, because type 2 muscles are fast twitch muscles so they are for powerful and quick movements, therefore a Olympic weight lifter who is lifting a lot of weight at one time and using his a lot of his muscle for a very short amount of time and also the sprinter because they are only running 100 meters and they would only need the muscles for a short period of time.

Question 4

Which of the following is most likely to occur as a result of aerobic endurance overtraining?

A. Decreased VO2 max

B. Increased muscle glycogen

C. Increased body fat percentage

D. Decreased sympathetic stress response

Explanation

Common markers of aerobic endurance overtraining Pg. 115

Decreased performance

Decreased percentage of body fat

Decreased maximal oxygen uptake

Altered blood pressure

Increased muscle soreness

Decreased muscle soreness

Altered resting heart rate

Increased submaximal exercise heart rate

Altered cortisol concentration

Increased sympathetic stress response

Applied Knowledge

SYSTEM TWO ADAPATIONS

Nervous

Energy

Skeletal

Cardiovascular

Endocrine

Cardiovascular

Blood vessels

Heart