Metabolic Unit 2 Practice Exam

What RPE ranges would correspond to vigorous, aerobic intensity for 6-20 scale and 1-10 scale?

*6-20* Vigorous: 15-17 Moderate: 12-13 Light: 9 AT: >17 *1-10* Vigorous: 7-8 Moderate: 5-6 Light: 3-4 AT: >8

How do you get from VO2 (L/min) to kcal/min? to VO2 (ml/kg/min)

1 L/min x 4.9 kcal/LO2 = 4.9 kcal/min 1 L/min x 1000 ml/L/kg = 1000 ml/kg/min

A 176 (80 kg) man exercises at 4.5 METs for 20 minutes on the treadmill and 4 METs for 15 minutes on the cycle ergometer. He also did a 5 minute warm-up at 2.5 METs and a 5 minute cool down at 2 METs. Calculate his total caloric expenditure for the exercise session.

1 MET = 1 kcal/kg/hr 4.5 kcal/kg/hr x 80 kg / 60 min x 20 min = 120 kcal 4 kcal/kg/hr x 80 kg / 60 min x 15 min = 80 kcal 2.5 kcal/kg/hr x 80 kg /60 min x 5 min = 16.67 kcal 2 kcal/kg/hr x 80 kg / 60 min x 5 min = 13.33 kcal Total kcal = 120 + 80 + 16.67 + 13.33 = 230 kcal

What is 1 MET equal to?

1 MET = 3.5 ml/kg/min 1 MET = 1 kcal/kg/hr

A 140 lb (63.6 kg) woman expends 300 kcal while running for 25 minutes. What is her absolute VO2 per minute (L O2/min)? For the total exercise session (LO2)?

1 VO2 (L O2/min) = 4.9 kcal/min 300 kcal / 25 min = 12 kcal/min / 4.9 kcal/min = 2.45 L O2/min Total session: 2.45 L O2/min x 25 min = 61.2 L O2

Assume VO2max is estimated for a 30 yr old man by drawing a line through the HR values measured during a submax GXT and extrapolating to his age adjusted max HR from the Tanaka equation. What direction is the error if his true HRmax is 180 bpm?

208 - 0.7 x 30 = 187 bpm This would overestimate his true VO2max

What if a 145 lb (65.1 kg) walks on an outdoor track at a 15 min/mile pace for 25 minutes? What is her VO2 (ml/kg/min) and MET cost for this activity? What is the total caloric expenditure? What is her net kcal? What would you wish to consider before advising whether she should run or walk for exercise?

25 min / 15 min/mil = 1.67 miles / 25 minutes = 0.067 mile/min x 60 = 4 mph x 26.8 m/min = 107.4 m/min Walking VO2 = (0.1 x S) + (1.8 x S x G) + 3.5 VO2 = (0.1 x 107.4 m/min) + (1.8 x 107.4 m/min x 0.01) + 3.5 = 10.74 + 1.93 + 3.5 = 16.1 ml/kg/min 16.1 ml/kg/min / 3.5 ml/kg/min = 4.6 METs 4.6 kcal/kg/hr x 65.1 kg / 60 min x 25 min = 124.8 kcal = gross 124.8 kcal - 27.5 kcal = 97.3 kcal I would like to know if she has any major disease or risk factors that might need to be evaluated

A 145 lb (65.1 kg) woman runs on an outdoor track at an 8 min/mile pace for 25 minutes. What is her VO2 (ml/kg/min) and MET cost for this activity? What is her total caloric expenditure? Net kcal?

25 min / 8 min/mile = 3.125 miles / 25 min x 60 = 7.5 mph x 26.8 m/min = 201 m/min Running VO2 = (0.2 x S) + (0.9 x S x G) +3.5 VO2 = (0.2 x 201 m/min) + (0.9 x 201 m/min x 0.01) + 3.5 = 40.2 + 1.809 + 3.5 = 45.5 ml/kg/min MET = 45.5 ml/kg/min / 3.5 ml/kg/min = 13 MET 1 MET = 1 kcal/kg/hr 13 kcal/kg/hr x 65.1 kg /60 min x 25 min = 352.7 kcal = Gross EE 1 kcal/kg/hr x 65.1 kg / 60 min x 25 min = 27.1 kcal = resting Net kcal = 352.7 kcal - 27.1 kcal = 325.6 kcal

What is the relative oxygen consumption in ml/kg/min for 4.5 METs?

4.5 METS x 3.5 ml/kg/min = 15.75 ml/kg/min

A 176 lb (80 kg) man is playing cricket at 5 METs. What is his absolute VO2 (L O2/min)? If he plays for 45 minutes, how many kcals will he expend? Net? Gross?

5 METs = 17.5 ml/kg/min = 5 kcal/kg/hr VO2 (L O2/min) = 17.5 ml/kg/min / 1000 ml x 80 kg = 1.4 L O2/min 45 minutes: 5 kcal/kg/hr x 80 kg / 60 min x 45 min = 300 kcal (gross) Resting EE = 1 kcal/kg/hr x 80 kg / 60 min x 45 min = 60 kcal Net EE = 300 kcal - 60 kcal = 240 kcal

How much O2 will a female athlete who weighs 110 lbs (50 kg) consume running for 20 minute at 6 mph at 5% in ml/kg/min, ml/min, kcal/min, and total kcal? at 8%? Speculate on this woman's aerobic fitness to accomplish this work?

6 mph x 26.8 m/min = 160.8 m/min VO2 = (0.2 x S) + (0.9 x S x G) + 3.5 = (0.2 x 160.8 m/min) x (0.9 x 160.8 m/min x 0.05) + 3.5 = (32.16) + (7.236) + 3.5 = 42.9 ml/kg/min = 12.3 MET 42.9 ml/kg/min x 50 kg = 2145 ml/min 12.3 MET = 12.3 kcal/kg/hr 12.3 kcal/kg/hr x 50 kg / 60 min = 10.2 kcal/min 10.2 kcal/min x 20 min = 204.3 This woman has to be extremely fit

A 154 lb (70 kg) man has an avO2 difference of 70 ml O2/L blood and has a Q of 4200 ml blood/min. Calculate his absolute and relative VO2. What do you think he is doing?

70 ml O2/L blood / 1000 ml = 0.07 ml O2/ml blood = avO2 difference VO2 = Q x avO2 difference VO2 = 4200 ml blood/min x 0.07 ml O2/ml blood = 294 ml O2/min / 1000 ml = 0.294 L O2/min VO2 (ml/kg/min) = 294 ml/O2/min / 70 kg = 4.2 ml/kg/min This is barely above resting (3.5 ml/kg/min), so he is probably at rest or moving slightly.

How many METS is a 121 lb (55 kg)woman working at when she is doing synchronized swimming? What is her gross energy expenditure in kcal/min? What is her gross kcal for 30 minutes? What is her net energy expenditure in kcal/min? What is her net kcal for 30 minutes?

8 METS = 1 kcal/kg/hr Gross EE = 8 kcal/kg/hr / 60 minutes x 55 kg = 7.3 kcal/min For 30 minutes: 7.3 kcal/min x 30 minutes = 219 kcal Net EE = Gross EE - Resting EE where Resting EE = 1 kcal/kg/hr / 60 minutes x 55 kg = 0.92 kcal/min Net EE = 7.3 kcal/min - 0.92 kcal/min = 6.38 kcal/min For 30 minutes: 6.38 kcal/min x 30 minutes =191.4 kcal

Generally speaking, explain how a new field test for CRF would be developed and validated, and how the test would be used to predict VO2max once validated.

A new field test would have to be developed for a certain population, whether it be a general or specific population. You would have to first use a max test using the same general motions that you would want the field test to exhibit. Peak heart rates from each stage would be collected in order to create a criterion that the field test could be compared to. You would then perform the field test that you want to validate and create a regression equation based on the HR measured at the end of the field test. If the HR, BP, and RPE shown from the regression equation predicts VO2 max with an r >0.7 and a small SEE (<3 ml/kg/min or less than 3%), you would be able to validate the test for VO2max. It could then be used in the field for the population it was used for to ensure data continuously aligns with the prediction, and from there begin to extrapolate equations for populations other than the population that it was validated for.

What does ACSM recommend as the best way to predict HRmax and what is the SEE of this prediction?

ACSM recommends we use the Tanaka equation to predict HRmax. The SEE is 10-15 bpm

What are the 3 universal psychological needs that naturally incline us towards growth and development according to Self-Determination Theory? Provide these needs along with a general description.

Autonomy: need to be in control of life Competency: need to be good at what we do Relatedness: need to be connected to others

What are 3 general differences between a Balke and a Bruce protocol?

Balke doesn't have a predictive equation for females with a strong r value. Balke uses a constant speed, while Bruce uses increasing speeds and increasing grades. Balke progresses through stages every minute, while Bruce progresses every 3 minutes.

Using indirect calorimetry, what gases are monitored and what else must be measured by the metabolic cart?

CO2 and O2 expiration is monitored in indirect calorimetry. Heart rate and RER are also measured by the metabolic cart.

What are the important anchor points when using the 6-20 RPE scale? Which values roughly correspond to moderate exercise? Vigorous exercise below AT? Vigorous exercise at and above AT?

Comfortable walk/light exercise: 9 Moderate: 13 Vigorous below AT: 15 Vigorous at AT: 16-17 Vigorous above AT: >17

Rank the order from the most intense to the least intense exercise test we have done in class?

Direct max test, indirect max tesk, submax steady state GXT, single stage GXT, field tests

Numerous GXT can be used for either direct or indirect determination of VO2max. Explain how each of these would work.

Direct tests measure VO2max through expiration of CO2 and O2. Indirect tests measure VO2max through time or power

What is the difference between a field test protocol and a submax GXT steady state protocol? In which situations would you prefer one over the other?

Field test: better for large groups and requires little equipment and is relatively cheap. SS: provides more information and is more accurate, but the protocol has to be followed rigidly. Better for screening for CVD, but have to be careful to not cross AT

*Critique the following test and include justifications for you comments based on class lecture, labs, and textbook info:* The Texas Step Test was developed for older adults (65 yrs+). It requires subjects to step at a cadence of 100 bpm (25 cycles/min) using a bleacher-style 16.25 inch step. The test length is 2 minutes. Immediately after a test, a 15 second post HR is measured. A prediction equation has been generated by relating this HR to VO2max as determined by the Rockport walking test. The regression analysis that provided the prediction equation yielded a correlation coefficient r = 0.54 and SEE = 25%. Would you use this test? Why or why not?

I would not use this test because it's not very valid. First, the cadence/intensity for the step is extremely fast for older adults as compared to the Queens College Step Test, where the cadence is 96 steps/min for men and 88 steps/min for women. Additionally, the step is likely too high for someone of that age, especially if they're not used to climbing bleachers regularly. Second, the Rockport walk test is not a criterion test for VO2max, a regression equation shouldn't be used to create a prediction equation. Lastly, r is <0.7, showing a weak correlation that's not valid for prediction of VO2max, and SEE is 25%, which will give a wide variability in predicted VO2max, making the output likely inaccurate.

Distinguish between intrinsic and extrinsic motivation. How do these motivation sources relate to the durability of change?

Intrinsic motivation: doing something because you have a desire to and is driven by universal psychological needs Extrinsic motivation: doing something due to an outside force Extrinsic motivation can help get started on making a change, but ultimately intrinsic motivation is what allows the change to be durable and maintained

What is the importance of the max, direct determination of VO2max? Why don't we use this every time in determining VO2max?

It's important to determine VO2max through direct tests so that we have a criterion that we can compare our true VO2max to. We can also use it to determine the validity and accuracy of our other, non-direct or submaximal VO2 tests. We don't do this every time because it's costly and highly uncomfortable to the participant.

What is the VO2 and MET cost for a 130 lb (59 kg) man who is working at 100 W on a cycle ergometer? What if he weighs 160 lb (72.7 kg)? Why do the metabolic values change based on weight given the subject is doing the same external work?

Leg ergometry VO2 = (1.8 x power / mass) + 7 100 W = 600 kg m/min VO2 = (1.8 x 600 kg m/min / 59 kg) + 7 = 18.3 + 7 = 25.3 ml/kg/min 25.3 ml/kg/min / 3.5 ml/kg/min = 7.2 MET VO2 = (1.8 x 600 kg m/min / 72.7 kg) + 7 = 14.8 + 7 = 21.9 ml/kg/min 21.9 ml/kg/min / 3.5 ml/kg = 6.26 METs The values change based on weight because VO2 in METs and ml/kg/min are weight dependent units. the heavier individual is doing roughly the same amount of external work but are using less work relative to the amount of mass they have to perform that work (heavier people use smaller percentage of muscles)

What is the difference between a ramp max indirect protocol and a submax graded SS protocol? In which situations would you prefer one over the other?

Max ramp tests determine max aerobic power by increasing work intensity every minute until exhaustion and is based on total time or power output. SS is based on steady state heart rate and have longer stages. You would want to do a max test to determine true VO2, but if screening for CVD or person is not used to exercise, you would want to do a submax test.

Numerous GXTs can be used for a max or submaximal indirect prediction of VO2max. Explain how each of these work.

Max: predicts VO2max based on time or power Submax: predicts VO2max based on steady state heart rate

What are the general parameters of the Storer-Davis test?

Mode: cycling Intensity: starts at 30 W and increases 15 W every minute. Must maintain cadence above 50 rpm. Ramp test

What is the percent of O2 and CO2 in inspired air?

O2 = 20.93% CO2 = 0.04%

What are the key ideas to share with a client when teaching him/her how to report RPE?

On the 6-20 scale, RPE corresponds with heart rate (6 is 60 bpm, 10 is 100 bpm, etc). Additionally there are several good anchor points. 9: comfortable walk with feeling of exertion 13: moderate intensity (can tell you're working but not uncomfortable. Increase in breathing and sweating) 15: vigorous intensity (little uncomfortable but sustainable) 17: anaerobic threshold (as hard as you can work but still sustain for 15 minutes) 20: max

List the ACSM criteria for low risk populations for terminating an exercise test.

Onset of angina/symptoms Drop in BP > 10 mmHg from baseline despite increasing intensity Excessive rise in BP >250 mmHg SBP or >115 mmHg DBP Extreme shortness of breath, leg cramps, claudication Signs of poor perfusion Failure to increase heart rate with increasing intensity Noticeable change in heart rhythm Request by subject to stop Manifestation of severe fatigue Failure of testing equipment

What are the stages of change in the transtheoretical model? Provide each stage along with a general description.

Precontempation: not considering change in the next 6 months Contemplation: seriously considering change in the next 6 months Preparation: taking steps/intent to change in next month Action: 6 months following change of unhealthy behavior Maintenance: changed behavior lasting more than 6 months

What are the pros and cons of maximal exercise testing?

Pros: gives most accurate VO2max, relatively short stages so short testing, allow for the assumption that person has average movement economy and anaerobic thershold Cons: Expensive, uncomfortable for participant, higher risk for adverse events

What are the signs that a true VO2max has been reached during a max, direct VO2max test?

RER >1.15 HR is very close or exceeds predicted HRmax VO2 levels plateau even with increases in work rate Participant can't continue any longer due to fatigue

Mike has a VO2max of 9 METs. About how long do you think he could run at 5 mph? Justify your answer.

Running at 5 mph is around 8.3 METs, which is very near his max. He won't be able to run at this speed very long

What is a SMART goal? What is the difference between a behavioral goal and an outcome goal?

SMART goal: specificity, meaningful, action oriented, realistic, timely Behavioral goal: goals and behaviors that allow you to move closer to your outcome goal Outcome goal: long term, big picture goal that you want to achieve through changing behaviors

What is the only kind of VO2max test that is based on extrapolation/theory?

SS GXT since you only need 2 data points

Why are there no valid ACSM metabolic equations for swimming? For basketball?

Swimming: it would be difficult to measure actual VO2max because participants are holding their breath during the majority of the event. Additionally, you would need a waterproof HR monitor since it would be impossible to take a carotid HR while they're performing this activity. Basketball: it would be difficult to measure actual VO2max because participants are performing at different intensities at unpredictable times, which will cause a wide variation in heart rate over the course of the game.

How should we take an exercising heart rate?

Take an exercising heart rate with heart rate monitor or carotid artery. Use 15 seconds and count the beats. You could also use the time it takes to get to 30 beats.

Assuming everything goes well, how do you know when to terminate the 1 mile walk, the Queens college step, the Astrand single stage, the ebbeling single stage, the YMCA GXT, and the Bruce GXT?

Terminate the 1 mile walk at the end of 1 miles Terminate the Queens College Step test at the end of 3 minutes Terminate the Astrand single stage test after 3 minutes if steady state heart rate thats above 125 and below 170 has been achieved, or continue until steady state heart rate has been achieved. Terminate the Ebbeling Single Stage test after 4 minutes if steady state HR has been achieved, or until steady state HR has been achieved Terminate the YMCA GXT when 2 stages of 2 consecutive steady state HRs above 50% HRmax and below 85% HRmax have been achieved that are above 110 bpm Terminate the Bruce GXT when 2 stages of 2 consecutive steady state HRs have been achieved that are above 110 bpm

What is the main assumption we make when performing a max, direct determination of VO2max?

That the participant is working as hard as they can for as long as they can.

What is the best test to use if you are organizing a community health fair at the IMU for 30 UI food serve employees, most of who are middle aged women?

The Rockport Walk Test

Describe a scenario when YMCA bike test would be your test of choice and a scenario when you might select the Rockport one mile walk instead.

The YMCA bike test is a good test for one participant. It more accurately measures VO2max at a wider variety of intensities. It's good for people who have arthritis, osteoporosis, or people who use cycling as their mode of exercise. It has been validated with the general population, but is best with females The Rockport walk test is better used with a larger group of people who might not be as physically fit and are used to walking as their mode of exercise. It's also a good test for a general population with a wide variety of ages.

Explain the abstinence violation effect. What do you think is meant by the quote "if something is worth doing, it's worth doing poorly"?

The abstinence violation effect is how a person reacts in the event of a relapse. While a relapse may occur, a person can choose to move past it or give up and fall back into old habits. The quote means that doing something a little bit is better than not doing it at all. Even baby steps to reach a goal is considerably better than not trying to attain a goal.

What is the optimal duration range for a max, direct VO2max test? Why is this range optimal?

The ideal test is somewhere between 6 and 20 minutes, with some data indicating that 8-10 minutes is optimal. If the test is <6 minutes, aerobic systems might not reach full power output and that failure is caused by excessive anaerobic contributions and local muscular fatigue. If the test is >20 minutes, performance may be negatively affected by mental fatigue, increases in body temperature, and nutrient depletion rather than maximal oxygen consumption.

What assumptions are necessary in order for a max, indirect test of CRF to be valid? What variable is used to predict VO2max?

Variables are time or power. Max indirect tests assume that movement economy and lactate threshold are average. You also assume that they're giving their true max effort

Which 3 variables are actually measured by our metabolic cart? Explain how these variables, as well as known constants and assumptions, are used to determine VO2max.

Variables measured are air flow and exhaled CO2 and O2. Since the proportion of O2 and CO2 inspired is constant (O2 around 20.9% and CO2 around 0.04%) we don't need to account for those, only the exchange of oxygen and production of CO2. Using the known inspiration and variating expiration as well as air flow, we can calculate VO2max at any given point in time, as well as the RER to know when AT is reached, indicating fatigue in the near future.The assumption that the participant is working as hard as they can for as long as they can is important because VO2max is predicted based on max effort to fatigue. The assumption that HR increases linearly with VO2max after 110 bpm will also allow us to create regression equations later on that can determine VO2max without maximal effort.

How can ventilatory anaerobic threshold be determined?

Ventilatory anaerobic threshold can be determined by looking at RER. If it's greater than 1 or >85% HRmax, you know you have reached anaerobic threshold. In untrained, it's 60% of predicted VO2max, in active it's >75% of predicted VO2max, and in trained it's >85% predicted VO2max

When choosing a GXT for use alongside the extrapolation technique for determination of VO2max, what are the important considerations? Explain scenarios that could result in poor results due to either MET-jumps that are too small or too large?

When choosing a GXT you want to consider both the correlation coefficient and the SEE. You'll also want to consider the population, mode, intensity, and assumptions that go along with each test. With GXT, you want to get 2 HR points >50% VO2max (110 bpm) that are within 5 beats of each other in 2 consecutive stages. MET jumps between stages are generally pretty large for some tests (around 3 METs/stage for Bruce), so you might progress from <110 bpm to between that and anaerobic threshold, and then above anaerobic threshold. This results in only 1 data point instead of 2. This can happen when somebody isn't used to doing aerobic exercise, resulting in poor fatigue resistance. With small jumps, you're predicting on points that are too close together so it won't be accurate

You are working with a client (female, 42 years old, 77 kg) who hates the treadmill and bike, but loves to do Zumba classes (3x/week, 60 minutes per class). She wants to know how many gross and net kcal she is burning per week. What techniques could you use to calculate these values?

You can use the physical activity compendium to find METs and then calculate with kcal/kg/hr METs = 6.5 = 6.5 kcal/kg/hr x 3 hrs = 19.5 kcals/kg x 77 kg = 1502 gross kcals/wk Resting kcals = 1 kcal/kg/hr x 77 kg x 3 hrs = 231 kcal/wk Net kcal = 1502 kcal/wk - 231 kcal/wk = 1271 kcal/wk

How is assessment of exercising BP different from resting BP?

You want to place the blood pressure cuff up higher on the arm and pump it a little more full than normal (160-180 mmHg). You also want to let the air out at about 5 mmHg instead of 2 mmHg

When might you prefer a treadmill test over a bike test?

You would want a treadmill test if person is used to/trains with walking/running. Treadmill tests are more accurate and minimize local muscular fatigue, so you should try to use them when you can. Treadmill: Bruce, Balke Ware, Ebbeling, Ellestad. modified Astrand Bike: YMCA cycle test, Storer Davis, Astrand rhyming

When might a single stage exercise test be preferred over a graded exercise test? Name and describe 2 single stage tests. How do they differ? How are they similar?

You would want to do a single stage test if you want a quick test and your population matches the validated population, but a GXT if you want a more accurate, flexible protocol. They both estimate VO2max based on heart rate, but GXT requires 2 data points to measure it, as well as calculation of starting and ending VO2. SS are valid only on the population that they measure and with a rigid protocol.

Describe a scenario when the Astrand-Rhyming test would be your test of choice and a scenario where you might select the submaximal Bruce treadmill test instead.

You would want to use the Astrand-Rhyming test with young, active adults. It's relatively quick, and best used with people who are relatively familiar with each mode, but not necessarily professionals.. The Bruce treadmill test is best used for people with CVD and has not been validated with the general population.

If Bob (100 kg) and Terry (50 kg) are doing the same treadmill test at the same speed and grade, how will their METs, kcals, and VO2 (both L/min and ml/kg/min) differ?

ml/kg/min is the same METs are the same This is because these equations are mass specific and accounting for their mass LO2 is higher for Bob Kcal is higher for Bob This is because Bob is bigger, so he's doing more work and will need more oxygen.

If Bob (100 kg) and Terry (50 kg) are doing the same bike test at the same power, how will their METs, kcals, and VO2 (both L/O2 and ml/kg/min) differ?

ml/kg/min: Terry is higher MET: Terry is higher This is because Terry is doing the same absolute work, but relative to his size, he's doing more L/O2 is same kcal is same This is because they're doing the same amount of absolute work