week 4 discussion


Ashworth College

Question Description

notes Note: The online classroom is designed to time students out after 90 minutes of inactivity. Because of this, we strongly suggest that you compose your work in a word processing program and copy and paste it into the discussion post when you are ready to submit it.

Learning Outcomes

This week students will:

  1. Compare normal physiological functions of the cardiovascular, respiratory, and neuromuscular systems at rest and during exercise.
  2. Explain acute and chronic physiological responses that occur with exercise.


Welcome to Week Four! As a fitness professional, it is important to understand physical activity requires the body to continuously produce ATP to sustain activity. If the body is not able to generate enough ATP for energy, an anaerobic energy imbalance occurs resulting in lactate buildup and fatigue. An individual’s exercise tolerance is highly dependent on the body systems’ ability to meet these demands. As a future fitness expert or practitioner, it is imperative to be able to evaluate a person’s exercise ability prior to designing any fitness program. This week, we will be comparing normal physiological functions at rest and during exercise in the pulmonary, cardiovascular, and neuromuscular systems. We will also be explaining acute and chronic physiological responses that occur with regular exercise.

Required Resources

Required Text

  1. Katch, V., McArdle, W., & Katch, F. (2015). Essentials of exercise physiology. (5th ed.). Retrieved from https://www.vitalsource.com/
    1. Chapter 9 The Pulmonary System and Physical Activity
    2. Chapter 10 The Cardiovascular System and Physical Activity
    3. Chapter 11 The Neuromuscular System and Physical Activity


  1. Films Media Group. (2010). The body in motion: The respiratory system (Links to an external site.). Retrieved from the Films On Demand database in the Ashford University Library.
  1. Films Media Group. (2010). The body in motion: The muscular system (Links to an external site.). Retrieved from the Films On Demand database in the Ashford University Library.
  1. Films Media Group. (2010). The body in motion: The circulatory system (Links to an external site.). Retrieved from the Films On Demand database in the Ashford University Library.
  1. How the body responds to exercise (Links to an external site.). (2009). Retrieved from
  1. Physiological responses to exercise (Links to an external site.). (2013). Retrieved from
  1. ThreeTreasuresStudio. (2010). Simple exercise physiology (Links to an external site.). Retrieved from

Recommended Resources


  1. Films Media Group.(2012). Lifelong Physical Activity (Links to an external site.). Retrieved from the Films On Demand database in the Ashford University Library.
  • Accessibility StatementHWE 340 Exercise and Physiology
    Week Four Guidance
    Welcome to Week 4! Last week we analyzed exercise recovery, oxygen uptake, exercise plans, and factors affecting physiologic responses during exercise. While you read the course materials this week, try to answer the following questions:
    What reactions occur in the cardiovascular system when it moves from a state of rest to a state of exercise?
    What reactions occur in the respiratory system when it moves from a state of rest to a state of exercise?
    What reactions occur in the neuromuscular system when it moves from a state of rest to a state of exercise?
    What are some acute and chronic physiological responses that occur in the body with exercise?
    This week, there are two assignments to complete. In the first assignment, you will need to complete a discussion comparing the resting state and exercise state in one of the following systems: cardiovascular, respiratory, and neuromuscular systems. In addition to the discussion, you will be assessing how your body reacts to physical activity. You will have the opportunity to participate in an exercise activity and document how your own body systems react to the stress of exercise in a journal. Please read the Course Guide on how to complete this activity. Your first discussion response is due by Day 3 and the journal is to be submitted to your instructor by Day 7.
    The respiratory system
    What is the respiratory system responsible for doing? We all know it delivers oxygen to other parts of the body. Most importantly, we often think of our heart and lungs. If we cannot breathe in enough oxygen to meet the demands of our body, we begin to feel short of breath. If this continues for a prolonged amount of time, we may begin to hyperventilate and panic and eventually pass out. However, the functions of the pulmonary system are more detailed than just delivering oxygen to the body. It has three primary functions: 1) “supply oxygen required for metabolism, 2) eliminate carbon dioxide produced in metabolism, 3) regulate hydrogen ion concentration [H+] to maintain acid-base balance.” (Katch, McArdle, & Katch, 2011, p. 266). For the purposes of this course, we will primarily be looking at the first two functions.
    First and most importantly, it is essential to know, “the body regulates the rate and depth of breathing exquisitely in response to metabolic needs,” (Katch, McArdle, & Katch, 2011, p. 287). In simplified terms, if the muscles, heart, liver, kidney, etc. need more oxygen, the lungs along with the heart will increase their output to meet the metabolic needs of the organs and systems. Normally, we do not think about breathing. It is an inherent response. Neurons in the brain activate the diaphragm and intercostal muscles to stimulate breathing. During rest, we inhale and exhale at less-than maximal tidal volumes. Normal tidal volume in an adult male is 600 mL and for adult females is 500 mL. Maximul total lung capacity in males is 6,000 mL and 4,200 mL in the adult female (Katch, McArdle, & Katch, 2011). Comparing the maximum total lung capacity in the male and female, you can see why genetically men are faster and often quicker than women in sports and other activities. Exercise training cannot increase static lung volumes. While we can improve lung efficiency and expiratory volumes, static lung volumes remain consistent.
    Acute and chronic responses of the respiratory system
    At rest, respiratory rate is about 12 breaths per minute for an adult with a tidal volume of about 0.5 L of air with each breath. Each minute, an adult breaths in and out about 6 L. of air. During exercise, respirations increase to about 35-45 breaths per minute. Tidal volume increases significantly to 2.0 Liters with each breath and a minute ventilation of 100 L. In well-trained athletes, the minute ventilation can reach numbers as high as 160 L/min. As you can see, the more trained a person becomes, the more efficient his or her respiratory system will also become. Other chronic adaptations of the respiratory system include increased oxygen-carrying capacity of the blood and improved gas exchange (Katch, McArdle, & Katch, 2011). Next, we will discuss the cardiovascular system.
    The cardiovascular system
    The cardiovascular system is a closed circuit containing a main pump and tubes going to and from the systems of the body back to the heart. The cardiovascular system has two main functions: to receive deoxygenated blood from the body and to pump oxygenated blood to the body. While this seems simple enough, the cardiovascular system is crucial to our survival. The average adult heart pumps 36.8 million times a year. What is even more amazing is that most of the time, we are not aware of our heart beating. It has its own intrinsic will to beat. We do not have to consciously remind it to work.
    To understand what happens to the heart at rest and during exercise, you must first understand a few terms. Heart rate is simply how many times the heart beats in one minute. Stroke volume is how much blood is pumped out of the heart with each beat. Cardiac output is the amount of blood the heart can pump out during one minute of time. Cardiac output can be determined by multiplying heart rate by stroke volume. Normal cardiac output is about 5 L of blood per minute. Most adults have a resting heart rate about 70 beats per minute (Katch, McArdle, & Katch, 2011). To compare a well-trained heart to an untrained heart, the difference between cardiac output is impressive. A well-trained heart can put out 5 L of blood each minute with a heart rate of about 50 beats per minute. The untrained heart also pumps out 5 L of blood each minute but at a heart rate of about 70 beats per minute. So what does this mean? The well-trained heart is much stronger. It can pump out more blood with each beat (stroke volume) compared to the untrained heart. The untrained heart has to work much harder to pump out the same amount of blood. The untrained heart will eventually wear out before the trained heart will. Take into account how many more times a day the untrained heart will have to beat compared to the trained heart. To understand cardiac output, watch this short video (Links to an external site.)The heart reaps a lot of benefits from regular, sustained exercise. Too many to discuss here. So let’s move on to the neuromuscular system.
    The neuromuscular system
    Two systems in the human body make up the nervous system. These two systems are the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is comprised of the brain and the spinal cord while the PNS includes all of the cranial and spinal nerves radiating out through the body (Katch, McArdle, & Katch, 2011).
    The nervous system and the muscular system work together to create movement. The body has about 250 million muscle fibers. Each muscle fiber is innervated by at least one neuron. One nerve may be responsible for controlling several muscle fibers in one area. A group of muscle fibers and neurons make up a motor unit. Motor units work together to create a muscular contraction. Muscular contraction follows an “all or nothing” rule. Either all of the muscle fibers contract at one time or none of them do (Katch, McArdle, & Katch, 2011). To view how muscle contraction occurs, please view the short YouTube video (Links to an external site.)
    At rest, muscles receive only about 20% of the oxygen available in the body. However, when a person begins to exercise, the muscles will receive up to 80% of the oxygen to meet the demands of activity. Some of the benefits of exercise on the nervous system include releasing neurotransmitters such as endorphins, serotonin, and epinephrine. Endorphins help decrease pain and help a person feel better; serotonin helps improve sleep and mood patterns and epinephrine helps regulate heart rate (Active Lifestyle, 2014).
    The muscular system receives many great benefits from regular exercise. Muscles often experience hypertrophy or muscle enlargement or growth. The actin and myosin within the muscle increase which also results in a stronger muscle contraction. Muscle tendon strength increases and articular cartilage becomes thicker. Within the muscle, mitochondria increase in number allowing the muscles to utilize oxygen more efficiently as well as excrete lactic acid and other waste products more effectively (WCC Physiology Unit, n.d.).
    While exercise places immediate stress on the body, it creates wonderful long term benefits that assist in decreasing morbidity and mortality. In particular, the respiratory, cardiovascular, and neuromuscular systems gain specific benefits from regular exercise including stronger and more efficient systems. In week 5, we will look at some of the chronic adaptations that occur in the body as well as age-related changes in the cardiovascular, respiratory, and neuromuscular systems.
    Katch, V., McArdle, W., & Katch, F. (2011). Essentials of exercise physiology. (4th ed.).
    Baltimore, MD:Lippincott Williams & Williams.
    Korthuis, R.J. (2012) Skeletal muscle circulation. (Links to an external site.)United States: Morgan Claypool Publishers WCC Physiology Unit. (n.d.). Muscular system. Retrieved from http://wccphysiologyunit.weebly.com/long-term-effe...
    WCC Physiology Unit. (n.d.). Muscular system. (Links to an external site.) Retrieved from
    Thinkstock. (2016). Retrieved from http://www.thinkstockphotos.com/search/#177545642/...
    Thinkstock. (2016). Retrieved from http://www.thinkstockphotos.com/search/#459951679/...
    Thinkstock. (2016). Retrieved from http://www.thinkstockphotos.com/search/#510444251/...
    Thinkstock. (2016). Retrieved from http://www.thinkstockphotos.com/search/#186936989%...
    Biology. (n.d.). Muscle contraction process. (Links to an external site.) Retrieved from
    The physiology of cardiac output. (Links to an external site.) (n.d.). retrieved from

    Week 4 - Discussion

    33 unread replies.33 replies.
    Your initial discussion thread is due on Day 3 (Thursday) and you have until Day 7 (Monday) to respond to your classmates. Your grade will reflect both the quality of your initial post and the depth of your responses. Refer to the Discussion Forum Grading Rubric under the Settings icon above for guidance on how your discussion will be evaluated.

    Resting and Exercise State of the Respiratory, Cardiovascular, and Neuromuscular Systems [CLOs: 1, 2, 5]
    Prior to starting this discussion, review the required resources. Since you are the fitness expert, imagine your friend Megan, a 27-year-old adult female, has come to you for advice and information. She has never exercised regularly before, but as she gets older, she wants to take charge of her health and begin a regular exercise program. She has decided to start jogging three days a week and wants to prepare to participate in her first 5K race in three months. She is interested in knowing how her respiratory, cardiovascular, and neuromuscular systems will react at rest and during exercise. Choose one of these systems to explain to your friend Megan, and compare its functioning at the resting and exercise state. In your response, address the following:
    • Identify the system you chose
    • Explain the major organs that make up this system
    • Compare how this system functions at rest to how it functions during exercise. Parameters to consider:
      • Respiratory System:
        • Tidal Volume
        • Minute ventilation
        • Depth and rate of ventilations
        • Gas exchange in the tissues
        • Ventilation limits
      • Cardiovascular System:
        • Heart rate
        • Stroke volume
        • Cardiac output
        • Blood pressure
        • VO2 Max
      • Neuromuscular System:
        • Chemical and mechanical action of the muscles
        • Oxygen uptake
        • Removal of waste products
        • Motor unit recruitment
        • Force of contraction
    • Explain two chronic adaptations in the system you chose that occurs with exercise.
    Use the text and one additional scholarly source to support your research and findings. All sources must be referenced and cited according to APA guidelines as outlined in the Ashford Writing Center. Your initial post should be at least 250 words in length and be submitted by Day 3 to the discussion forum.

    Guided Response: Due by Day 7. Read several of your classmates’ posts and respond to two students who have chosen a different system. In your response, address a limitation or dysfunction of this system that may hinder exercise performance. Each peer response should be at least 100 words in length and include one additional scholarly resource.
    Filter replies by unread
    • COLLAPSE SUBDISCUSSIONElizabeth Tsikitas
      Hello Megan, I believe that I will be greatly resourceful and will help you gain a deeper understanding of the cardiovascular system as it relates to exercise. I will begin with a brief introduction to the cardiovascular system. I will begin with a brief introduction to the cardiovascular system (Katch, McArdle, & Katch, 2015). The cardiovascular system consists of the heart, the arteries, the capillaries, and the veins. The heart plays an important role in ensuring that blood is circulated throughout the body. The arteries are high-pressure tubes that help deliver oxygenated blood to the tissues. Blood that is pumped from the left ventricle of the heart via the aorta is then supplied to various tissues in the body through arteries. Capillaries, on the other hand, consist of a network of microscopic blood vessels that are thin enough to allow blood cells to squeeze through (Katch, McArdle, & Katch, 2015). Veins help in maintaining the continuity of blood by ensuring that deoxygenated blood flows back to the heart. Veins contain about 65 percent of the total blood volume, and therefore they do not act as passive conduits. Evidently, the circulatory system is an interconnected system that delivers oxygenated blood to tissues and ensures that deoxygenated blood is then delivered back to the heart.When one is resting, the blood pressure differs significantly compared to when one is exercising. At rest, the highest pressure that results from pumping by the left ventricle reaches about 120 mm Hg. When the heart relaxes, the valves of the aorta shut. Continuous pressure is provided by the arteries’ natural recoil. During the diastole phase, the blood pressure reduces to about 70 to 80 mm Hg (Katch, McArdle, & Katch, 2015). However, the pressure can be affected by various factors, including the mineral and fat deposits within the walls of the arteries. The fat and mineral deposits create resistance and can result in a systole pressure of over 300 mm Hg and diastolic pressures of over 120 mm Hg. When one is exercising, the blood pressure rises. The rise in blood pressure helps supply the muscles with oxygenated blood. The result is a rise in the cardio output, which describes the number of heartbeats as well as the volume of blood that is pumped for every stroke of the heart.The oxygen used when one is exercising and at rest also differ. When one is at rest, the myocardium extracts 70 percent or 80 percent of oxygen from the blood (Katch, McArdle, & Katch, 2015). Many tissues at rest use about 25 percent of the oxygen available in the blood. At rest, one achieves near-maximum oxygen myocardium oxygen extraction. When one is exercising, coronary blood flow increases four to six times compared to when one is resting. As the rate of exercising increases, the myocardial flow also increases to ensure that oxygen supply is matched to the demand. One important factor that is important is the VO2max. The VO2 max is the measure of the maximum oxygen consumption when one is exercising. VO2max indicates one’s level of fitness (Ross et al., 2016). A higher VO2max is indicative of higher levels of aerobic fitness. With age, the VO2max declines. As you get older, it becomes increasingly difficult to handle extended periods of exercise (Ross et al., 2016). After exercising, the cardiovascular system slows down to attain normal. Evidently, two chronic adaptations to exercise are blood pressure and cardiac output. Cardiac output increases when one is exercising. The blood pressure also increases.ReferencesKatch, V., McArdle, W., & Katch, F. (2015). Essentials of exercise physiology. (5th ed.). Retrieved from https://www.vitalsource.com/ (Links to an external site.)Ross, R., Blair, S. N., Arena, R., Church, T. S., Després, J. P., Franklin, B. A., ... & Wisløff, U. (2016). Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a clinical vital sign: a scientific statement from the American Heart Association. Circulation, 134(24), e653-e699.

        Carmen Greene

        Week 4 - Discussion (Respiratory System) Meghan, I'm so happy that you realize the importance of taking care of your bodies, especially as you age. Studies have shown that being inactive leads to many diseases, premature biological aging, and a weakened immune system (Stefanović, 2016). With all of these viruses going around, why not build up our immune system with exercise? You have chosen an excellent plan for getting started. A 5k in three months is achievable, fun, and the sense of accomplishment that you will feel will have you reaching for more! I like that you are only running three days a week; this will help you recover and decrease your injury risk. At first, you will feel that you are huffing and puffing and that your respiratory system cannot keep up. Do not get discouraged. With time and training, your respiratory system will adapt, and you will find yourself surprised that you can speak and run. Let me explain more about your respiratory system. We generally think of just the lungs, but there is more to this system. Your nose, mouth, larynx, trachea, two bronchi, bronchioles, and alveoli are all that make up your respiratory system. These components work together to supply the oxygen needed for metabolism and expel the carbon dioxide made in metabolism. They also help us retain the acid/base balance that our bodies require (Katch et al., 2015). When you are resting, you breathe in oxygen from the atmosphere from your nose and mouth, where it is warmed, filtered, and humidified as it flows through the larynx into the trachea. From the trachea, the oxygen flows into two bronchi that divide from the trachea and are part of your right and left lung. These bronchi divide further into bronchioles, where the air continues to travel into the alveoli, which are the respiratory tract's ending sacs, where gas exchange occurs. From the lungs, oxygen is sent out to the body for metabolism, and carbon dioxide waste returns to the lung to be expelled in exhalation (Katch et al., 2015) When you are new to running, the respiratory system must work harder to adjust to the new demand. At rest, your respiratory rate is about 12 breaths per minute. When you start running, it can go as high as 45. The amount of air moved with each breath you take is called your tidal volume. With increased exercise, your tidal volume rises. The amount of air you breathe each minute is called your minute ventilation, and it will also increase. At first, you will find yourself breathing hard and fast, but in time, your body will adapt, and your tidal volume will increase with only a minimal increase in respirations (Katch et al., 2015). Just as there is a gas exchange in your alveoli, there is also gas exchange in your tissues. Because you are running, your muscles need more energy, so they will use up more oxygen. The oxygen will flow into your muscle cells, and carbon dioxide will flow out to be returned to the heart to be delivered to your lungs to be expelled. Your body will keep up and not run out because most people tend to over-breathe to make up for it (Katch et al., 2015). Like I said before, your body in time is going to adapt beautifully to running. Two adaptation examples are increased respiratory muscle endurance and increased respiratory muscle strength. Your minute ventilation can increase 20-fold from what it is at rest, and your lungs will be able to handle the heavier demands of your training (McKenzie, 2012). As the lung muscles are able to work harder and longer with exercise, you will find yourself running faster and longer. I wish you much success, Meghan. ReferencesKatch, V., McArdle, W., & Katch, F. (2015). Essentials of exercise physiology. (5th ed.). Retrieved from https://www.vitalsource McKenzie, D. C. (2012). Respiratory physiology: adaptations to high-level exercise. British Journal of Sports Medicine, 6, 381..com/ Stefanović, R. (2016). Model of a Recreational Running Program for Beginners. Activities in Physical Education & Sport, 6(1), 132.
        • COLLAPSE SUBDISCUSSIONDominique Ivory
          Evening from Italy, Megan it is really great that you are taking your health more seriously. The saying that it is better to start late than to not start at all, applies to your awesome decision. Jogging 3 days a week is a great start and will give you a foundation for you to develop as a runner.
          • Cardiovascular System: The cardiovascular system is comprised of the heart, arteries, capillaries, and veins.
          There is an interconnected continuum of the vascular system that pumps the blood and distributes blood and oxygen to the rest of the body and vital organs. The heart muscle consists of two separate pumps. The right pump receives deoxygenated blood returning from the body and pumps blood to the lungs. The left pump receives oxygenated blood from the lungs and pumps blood into the aorta for distribution throughout the body.
          • Heart rate- This is the number of times the heart beats in the space of a minute. This is normally an important indicator of the health of the human body. The heart rate should be between 60-100 beats per minute while resting.
          • Stroke volume is the end diastolic and end systolic volumes. It is the volume ejected with each heartbeat. It is the volume of blood ejected during ventricular contraction or for each stroke of the heart.
          • Cardiac output is the heart rate and stroke volume being measure in liters per minute.
          • Blood pressure- The left ventricular contraction causes an amount of blood to enter the aorta which distending the vessel and creating pressure.
          • VO2 Max
          The increasing in the muscle thickness also increases the contractility, which increases the stroke volume at rest and during exercise. This increases blood supply to the body. Katch, V., McArdle, W., & Katch, F. (2015). Essentials of exercise physiology. (5th ed.). Retrieved from https://www.vitalsource.com/

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