Study Questions Lab 7 VO2 Max Flashcards
- Compare the results obtained using computerized method vs. manual method. List sources of errors for each method. Give an explanation for any differences in results
- Results obtained using the computerized method give smaller VO2 values than those from the manual method.
- Sources of error in the automated method include the quality and reliability of
equipment being used. - Sources of error in the manual method include proper manipulation of the
equipment (e.g. beginning gas sampling on time or ending gas sampling without losing air). Other sources include differences in timing for balloon to cool to room temp., experience of experimenter, experimenter accuracy in taking readings, etc.
- Which method do u think it more accurate? Explain
The automated method may be more accurate due to less human error. Due to more manual manipulation of the equipment, there’s greater variability btwn experiments.
- From data collected in this lab, do u think subject reached his/her VO2 max at end of exercise test? Explain
For the data collected in the automated method, it’s more likely the subject reached their VO2max. Treadmill exercises use more muscle than ergometer exercises, also, readings show that VO2 ceases to inc with increasing work rate and the subject could go no farther. In the manual method, VO2max is assumed to be reached when the subject fatigues, and no measure of VO2 is available (can’t see if it plateaus).
- Define VO2max
Maximum O2 uptake (VO2max) is the highest rate of O2 utilization that a healthy person can attain during exhaustive (“maximal”) muscular exercise of approx 6-12 mins duration, when breathing air at approx sea level and performing exercise that activates large muscle groups.
- Give 3 reasons why kinesiologist might measure person’s VO2max
- Good measure of CARDIORESPIRATORY FITNESS e.g. fxnal capacity of the circulation
- Evaluation of ENDURANCE TRAINING PROGRAM
- SCREENING of people for various tasks – work, sport, etc
- Also, clinical evaluation of patients cardiovascular and/or pulmonary disease.
- A good VO2max test protocol should meet certain criteria. Give 6
- Work should involved LARGE MUSCLE GROUPS
- CONTINUOUS WORK performed at GRADUALLY INC INTENSITIES. Thus, the approach of fxnal limitations should be detectable w/sufficient discriminatory accuracy
- Work INTENSITY should be selected so that the subject will be EXHAUSTED in 7-10 mins AFTER WARM-UP
- WORK RATE should be sufficiently heavy so that O2 uptake doesn’t entirely correspond w/nrg requirement of work load (non-steady work)
- WORK RATE must be MEASURABLE and REPRODUCIBLE
- Test conditions must be such that RESULTS are COMPARABLE and REPRODUCIBLE
- Give 5 criteria used to determine whether subject reached VO2max
- O2 consumption ceases to inc linearly w/rising work and approaches plateau or drops slightly, the last 2 values agreeing w/in +/- 125 mL (1.5-2.0 mL/kg)
- Blood lactate levels 8.0 mM/L or greater, 3-5 mins after cessation of exercise
- HR close to predicted max (220-age)
- RER greater than 1.15
- Subjective fatigue, exhaustion, and an inability to continue
- Will we measure RQ or RER?
- RER = respiratory exchange ratio
- aka VCO2/VO2 at the lung level
- What is normal value for RER at rest? During heavy exercise?
More carbs and low fats the higher.
Rest: 0.8-0.9
Exercise: 1.15
- Sometimes RER is greater than RQ. How can this be?
- RER > RQ during hyperventilation
- RER can be greater than RQ, meaning that CO2 produced from cellular respiration is less than what’s expired from lungs, because additional CO2 is evolved from the body’s stores via the bicarbonate buffer system.
- In what units is VO2 usually expressed?
mL/kg/min
(includes body weight is relative measure of VO2 vs. absolute with L/min) two people can have same absolute measure but if one person 50 lbs heavier their VO2max is a lot lower taking into consideration
- List 6 reasons for stopping VO2max test
· Subject unable/unwilling to proceed for any reason
· Evidence of physiological de-compensations:
o Complaint of increasing angina
o Severe dyspnea (difficulty breathing)
o Severe fatigue
o Faintness
o Nausea
o Caludication (cramp or severe pain in legs; cause is same as angina)
· Signs suggestive of an impending emergency situation, including:
o Pale skin
o Cold, moist skin
o Cyanosis (blue lips or nail beds)
o Mental confusion
o Shakiness
o Abnormal EKG
- Would u expect a subject to obtain exactly same VO2max value in VO2max test performed 3 days apart? Explain
- No
- Test is subjective to environmental and situational factors including subjects fatigue level, nutritional level, mental well-being, temperature (heat/cold) among others
- These values fluctuate with ease (extrinsic factors fluctuate)
- Extrinsic:
1. Training status
2. Time of day
3. Sleep deprivation
4. Dietary intake
5. Nutritional status
6. Environment
- You have been hired to evaluate maximal aerobic power of a group of Canadian rowers. The results of test may be used as one of the criteria for choosing members of Canadian national team. Would it be valid to measure VO2max of these athletes using uphill treadmill running protocol?
You want to use whatever sport they do regularly. Rowers use upper body muscles, where O2 utilization may be greater, thus the exercise should involve working upper body muscle groups.
- Why is pale, cool, or blue skin suggestive of impending CV limitations in heavy exercise?
B/c blood is diverted from cutaneous vessels to
those supplying working muscle. This effect is known as shunting.
-> Suggests heart is working at max capacity and blood needs to be diverted to active skeletal muscle to meet energy demands
