Exercise Physiology Lab exam HSS 408L

Karvonen Formula (intensity)

(220 - age)- RHR= HRR or (HRR x Intensity)+RHA=THR

age predicting formula

220-__ = Max HR +/-15

Take a moment and reflect on the last 4 weeks in 408L. What is something you have learned during the CRF unit that you did not know before the unit started? Furthermore, list one skill/aspect associated with CRF that you feel you need to continue to work on moving forward. Please answer this question individually for each member of the lab group

After the last 4 weeks of lab, I have learned a lot about exercise physiology and cardiorespiratory fitness. I learned that it does not matter what you necessarily look like, however, the inner workings of our bodies are more important to our health. Someone who is skinny might have lower cardiorespiratory health than someone who is a little bigger. Health is determined by the way our systems interact; our blood, muscles, skeletal, and nervous systems. I also learned how intense a maximal test really is. Poor Ellie was about to fall over while she ran her hardest on the treadmill. I feel like I could improve on the understanding of all the numbers the cart puts out during maximal testing.

State the Age Predicted Formula and Karvonen Formula. Identify the difference(s) between the two formulas and why one formula may be more advantageous than the other

Age Predicted Formula: (220-age) +/- 15 bpm, Karvonen formula: (HRR x Intensity)+RHA Karvonen takes age and resting heart rate into account so this is more reliable over age predicted formula because this simply uses your age and no other factors.

Explain the difference between direct and indirect measures of VO2? How might a technician decide which measure is best when trying to assess one's CRF?

An indirect measure of VO2 would be an estimate of a person's oxygen consumption volume. A direct measure of VO2 would be as close to an exact measurement as possible. An indirect measurement would look like the submaximal testing without the headgear like we did in the submax YMCA and Bruce protocols, and without the technology telling us immediate VO2 values. During this, we calculated the max with manual heart rate and blood pressure values as well as equations. Using the data we obtained and plugging it into an equation we got estimated values. A direct measure of VO2 looks like what we did on the treadmill. The participant has headgear on to breathe into the machine and the machine would determine VO2 with much more precision than manually getting data and predicting it. A technician measuring cardiovascular fitness might decide which one is best depending on the circumstances and how accurate they need their numbers to be. It might also depend on whether they want their participant to do maximal exercise or not. If maximal exercise could be dangerous for a patient they would simply estimate it.

What effect would a person's body weight have on blood pressure readings? Why?

Body weight such as being overweight can put strain on the heart because there is a need to increase vascular resistance and work has to increase to pump blood. This increases the risk of high blood and can damage blood vessels

Explain the concept of cardiac drift during aerobic exercise. Be specific

Cardiac drift is the term that refers to the changes in our heart rate, cardiac output, blood pressure, and stroke volume during sustained periods of exercise. This occurs, for example, by undergoing a long walk in which we maintain a pretty even pace. During these instances, our heart rate will show a steady increase, stroke volume, and blood pressure will decrease while maintaining a constrained cardiac output. The decrease in stroke volume can be attributed to the increase in heart rate (tachycardia) which decreases the fill time of the ventricles. There is less blood going into the ventricles therefore less blood leaving the ventricles into the lungs and body decreasing stroke volume. The stroke volume and blood pressure have many variables that lead to their decreases one main one is dehydration. This will cause the stroke volume to decrease due to the fact our blood is mostly water. We also initiate vasodilation which reduces blood pressure by allowing thermoregulation and more volume for blood to file. With the decrease in stroke volume and blood pressure, the heart rate will slowly increase to compensate; maintaining healthy ranges of variables.

Outline the methods for manually assessing HR and BP. Also outline common mistakes made before and during the assessment and explain how you would avoid or correct these mistakes 1. HR 2. BP

HR: Use the tip of your index and middle finger to press gently against the subject's radial artery, this will be on the wrist under the thumb. Count the number of beats you feel for 15 seconds. Multiply this number by four to estimate the heart rate per minute. Pressing too hard will obstruct the blood flow and your reading will be incorrect. You should only be firm enough to feel the heartbeats. The subject should stay still during the reading. You should not move your finger after counting has begun as this can affect the accuracy. BP: First, the correct size cuff must be used. The incorrect size can lead to inaccurate readings. The cuff should be wrapped around the arm smoothly and snugly. The bladder should be over the brachial artery. The stethoscope bell should be lightly placed over the palpable brachial artery. Inflate the cuff to the predetermined level of pressure, we used 160 mmHg. Release the air at a slow and steady rate so it falls 2 to 3 mmHg per second. Be sure to have the stethoscope earpieces in correctly to listen for at least two consecutive sounds, this will be the systolic blood pressure. Note the number from the sphygmomanometer. Next, listen for the muffled sound or last sound, this will be the diastolic blood pressure. You should continue to listen 10-20 mmHg after the last sounds to confirm the reading. Then deflate the cuff completely. Record the blood pressure and the arm used. Repeat on the opposite arm to confirm the reading. (According to the Taking a Blood Pressure Reading Handout on Isadore) The arm of the subject should be relaxed, if tense while the reading is taking place it can be inaccurate. The one measuring can hold the wrist or the elbow to correct this. If the bladder is not over the brachial artery the blood pressure will be overestimated. The cuff should be on a bare arm, if clothing is in between the arm and cuff the reading may be incorrect.

Explain the rationale for measuring heart rate and blood pressure at REST and DURING exercise.

Heart rate and blood pressure are taken at rest to help identify any health problems and to gauge where the range should be while not at rest. Both indicate if the body is in good shape. While exercising there is an increase in cardiac stroke volume and heart rate which will increase cardiac output. This increase is caused by a need for oxygen in the working muscles. Both heart rate and blood pressure measure how well the heart flows blood to the extremities. This also provides a safety measure before exercising.

What are the criteria used to determine if an exercise test truly elicited a maximal physiological effort?

In order for a test to be considered to have reached maximal effort, it should result in one or more of the following; a plateau in oxygen consumption with increasing workload, a respiratory exchange ratio greater than 1.05-1.15, a blood lactate greater than 8-10 mMxL^-1, and/or a heart rate withing 10-12 beats of age predicted maximal heart rate. -a point where their oxygen consumption levels off or only increases by a small amount (less than 150 ml/min) despite higher exercise intensity, it is often considered a plateau in VO2 and an indication that they have achieved their maximal effort.

What is a typical physiological response to blood pressure during isometric exercise? Explain.

Isometric exercises consist of movements that are held for a period of time. For example planks, wall sits, and v-sits. During these isometric movements, blood pressure increases in order to profuse through the contracted muscles. This is mediated through central and peripheral afferent input and an increased cardiac output. This is important because it allows oxygen to reach the muscles during sustained contraction. BP has 2 values; SBP and DBP and they can respond differently. SBP will inc significantly w isometric exercise, leads to inc resistance in blood vessel and more forceful contraction. DBP will also inc.

What is the difference between "maximal" and "peak" oxygen consumption? When reviewing the Master Data sheet how many participants achieved max and how many achieved peak? Why does the field of exercise science utilize "maximal" and "peak" VO2 when describing a CRF exercise test?

Maximal oxygen consumption is the maximum amount of oxygen that is consumed during a period of exercise to exhaustion. Maximal oxygen consumption allows for more energy to be produced and it is considered the standard for overall fitness. The higher one's VO2 max is the more energy they are able to produce. Peak oxygen consumption occurs during a particular test and is the number that is below the maximal number. VO2 peak is used to determine the VO2 max if the max is not reached during exercise. VO2 peak can be used with formulas to determine one's VO2 max. The field of exercise science utilizes maximal and peak because if the maximal is not reached then the peak will be used. This means if you don't reach one you can use the other. Both numbers are important when it comes to oxygen consumption and maximal exercise. Peak tends to be very similar to the max so both are essential when it comes to maximal exercise testing. This language is utilized because it is during these values when participants are giving their all and push until they have nothing left to give. The peak can be very similar if not the same as the max. When reviewing the master data sheet there were 5 participants who reached max value and there were 7 who reached their peak.

What does respiratory exchange ratio (RER) mean in terms of exercise intensity and fuel utilization? How do RER values change as one moves through a maximal exercise test and why?

RER is a measure of the ratio between the volume of carbon dioxide exhaled and the volume of oxygen inhaled during respiration while exercising. During the maximal testing, the increase in intensity causes the body to recruit more muscles and create more work to continue running or cycling. The increase in work required increases the required oxygen for energy, therefore the stroke volume increases pumping more blood to the muscles and lungs. The need for oxygen increases as does the exchange ratio of O2 and CO2. This leads to an increase in the ratio overall because more oxygen is going in and more carbon dioxide (byproduct of metabolism) is coming out. RER is important for informing us of exercise intensity and fuel utilization during exercise.

What is the rating of perceived exertion (RPE)? Why do we measure this variable during CRF Testing?

Rating of perceived exertion is a scale that is used to understand how individuals experience the intensity of exercise and how it impacts their body and mind. Typically the Borg scale is used as it is a quantitative measure of perceived exertion. Based on ACSM's guidelines, RPE and exercise-related variables are relatively high. It also states that exercise professionals utilize this scale to clearly communicate with the individual on his/her own assessment level of exertion during exercise progression. Not only is it used with our numerical data it is also used to ensure the participant is doing okay during the exercise.

Explain the response in heart rate when an individual moves from a resting state to an exercising state. What physiological response takes place and why (think back to the content covered in HSS 307, utilized appropriate terms, and resources found on Isidore). 1

Resting heart rate is the heart rate an individual experiences at rest. In individuals aged 21 a healthy resting heart rate is between 60 and 100 bpm. There is a large range because of the variety of physiological factors to individuals resting heart rate. During the transition from rest to exercise state our brain is recruiting more muscle fibers and muscle groups perform work. Said work requires energy in the form of ATP, ATP is synthesized during cellular respiration which requires oxygen. The way we get oxygen to our muscles to perform work is through the blood and the more blood we pump the more oxygen is being delivered. Therefore, the increase in exercise/movement/work the more oxygen required, hence the increase in heart rate. Our heart rate increases in order to increase oxygenation of our muscles and other tissues which increases O2 utilization during activity. During sustained exercise, the heart rate will continue to gradually increase while stroke volume (done so by an increase/decrease force) and blood pressure will decrease, however, cardiac output will remain constant. The demands of our muscles send signals to the brain and then to the heart to create faster or larger beats to meet the growing demands during exercise. ROLE of the nervous system! Sympathetic stimulation!

What tissues and physiological variables determine VO2max (think about the equation discussed in lab)?

Some variables that influence VO2max are age, skeletal muscle, training status, body composition, genetics, the lungs, as well as the heart. VO2max typically declines with age along with other physiological systems. The capacity of one's skeletal muscles to utilize oxygen is an important factor in determining VO2max . Well-trained muscles can have increased oxygen delivery, this is why training can also be a factor. The ratio of lean body mass in regards to body composition can influence VO2 max . The lungs are the organ responsible for oxygen intake and carbon dioxide removal so the capacity they have to oxygenate the blood is important when looking at maximum oxygen consumption. Similarly, the heart is the organ that pumps oxygen-rich blood to muscles so a more effective, stronger heart can deliver more oxygen around the body.

Explain the response in blood pressure (systolic and diastolic pressures) when an individual moves from a resting to an exercising state. What physiological response takes place and why (Think back to the content covered in HSS 307, and utilize appropriate terms, and resources found on Isidore).

Systolic pressure is an estimation of the pressure on the arterial wall while the heart contracts. Diastolic is the measurement of pressure in the arterial wall while the heart relaxes and can show how easily blood flows through the whole circulatory system. During dynamic exercise diastolic blood pressure decreases from what it was at rest, this is caused by the decrease in vascular resistance. Heart rate increases to meet metabolic demands during exercise. During static exercise, the blood vessels compress compared to when they are at rest, and the reduction in blood flow means total peripheral resistance doesn't decrease. The increase in heart rate and cardiac output is less than dynamic exercise and the increase in systolic, diastolic, and MAP is more than dynamic exercise. During aerobic exercise heart rate increases to circulate blood faster and deliver oxygen to the muscles that are now working that weren't at rest. Systolic blood pressure increases and diastolic either remains constant or slightly decreases.

What is the difference between "absolute" and "relative" oxygen consumption? Why do we report both sets of units when discussing oxygen consumption?

The difference between absolute and relative oxygen consumption is that absolute oxygen consumption is the total amount of oxygen consumption regardless of any other factors. Relative oxygen consumption would be oxygen consumption based on factors such as the unit of mass or one kilogram (1 kg.). The unit of measurement for absolute oxygen consumption is (L/min) and for relative oxygen consumption is (mL/min/kg). We report both sets of units when discussing oxygen consumption because it allows for more accuracy and to get the appropriate numbers we may need. They both provide valuable information and can be used to understand weight loss through metabolic equivalents. Relative values also allow VO2 values to be compared across different body sizes

When reviewing the data collected during lab, do the indirect measures (submaximal testing) tend to over or under-predict VO2 when compared to the direct measures (maximal testing)? Why might these results be the case when comparing the values between participants?

The indirect measures of the Bruce test for females were larger than the direct measurement for VO2 but the heart rate for direct measurement was larger than the indirect measurement. For males, the direct measurement was larger than the indirect, Bruce test, measurement for both VO2 and heart rate. On the cycle females who reached peak showed direct measurement to be larger than indirect measurement for VO2 and heart rate, this was the same pattern shown in males on the cycle who reached peak. Females who reached max and value showed a larger indirect measurement, YMCA, than direct for VO2 . Overall, the indirect measurement overpredicted for females on the treadmill and females on the cycle who reached max and value. The indirect measurement was underpredicted for males on the treadmill, males on the cycle, and females who reached peak on the cycle. This is because indirect measurement is based on equations while direct measurements are in practice. The one-minute intervals for heart rate and three-minute intervals for blood pressure can be a cause of the prediction being incorrect. Another cause influencing the data on the male subjects could involve individual variation, since fewer males participated in this experiment than females the averages could be skewed since there is less data.

How might modality impact VO2 values (think about the physiological and mechanical differences between a treadmill and a cycle)?

Treadmill running is more weight-bearing than cycling therefore requires more muscles to maintain balance, sing arms, and hold posture. Cycling requires less muscle recruitment therefore less oxygen to perform the activity, therefore will have a lower VO2 max because it has a lower O2 requirement. Because oxygen consumption depends on the amount of muscle mass involved, exercise test modes like the treadmill and cross-country ski ergometer that use more muscle mass yield higher values than a cycle ergometer or step test. Specifically, when VO, is measured in most people on the treadmill versus the cycle ergometer, the value is 5-10 % higher on a treadmill.42 So, if one participant completes several exercise tests using different modes, the test that yields the highest VO, value would be used as the true maximal oxygen consumption (VO, max). Another term often used is peak oxygen consumption, which is measured.

Why do we measure one's VO2? What is the purpose of classifying an individual's results? Why do we utilize this system within the field of exercise science?

VO2 is widely accepted as the criterion measure of one's cardiorespiratory fitness and aerobic fitness. It is used to indicate the efficiency of one's body at utilizing oxygen. This CRF measurement is used to help set a baseline, create a fitness program, and track one's progress throughout the program. This type of testing indicates where the person stands in relation to cardiovascular health and cardiorespiratory health. We use VO2 and VO2 max as an indicator of one's respiratory health because it refers to the maximal amount of oxygen someone can use during intense or maximal-effort exercise. Classifying such results helps simplify the numbers into consumer-friendly terminology. Someone who has no idea what VO2 means will most likely not understand what 36.2 ml/kg/min means. Whereas they will definitely understand if they fit into the fair, good, poor, or excellent category. This classification system helps us determine where they need to go and has a motivation factor to it.

In the field of exercise science why is a heart rate range more advantageous than say a single heart rate value?

its advantageous to have a heart rate range compared to a single heart rate value. This is because of the diversity in human physiology in regard to resting heart rates, dose response to exercise, and one's capacity during exercise