PET3380 Exam 3 Study GuideAerobic Capacity1. Explain the concept of VO2 max, include what it measures, how you determine if a subject has reached it, and explain clearly how this information can be used.- VO2max is a fundamental measure of physiologic functional capacity for exercise- VO2 max = Q max * avO2 difference at maxo HR max * SV max- VO2 max is the max uptake of max aerobic capacity (mg*kg-1*min-1 OR L*min-1)- highest VO2 max in individuals who engage most muscle mass (most in cross country skiers)- VO2 max is reached when you see a plateau on graph- integrates aspects of O2 transport systemo pulmonary VEo [Hb]o bV and Qo blood flowo aerobic metabolism- integrates respiration, CV system, and neuromuscular system- VO2 max can’t be manipulated, but it can sort of change it artificially with altitude, blood loss, temperature, training, etc- criteria for VO2 maxo lack of increase of 2.1 ml/kg*min with increase in workloado RER > 1.10o attainment of max HR +/- 10 bpmo blood lactate levels of 8-10 mmol or highero when these criteria are satisfied, VO2 max isn’t always reached (it’s hard to tell)o look for physiologic max: in spite of increase in work, O2 consumption does not increaseo VO2 peak: when plateau isn’t reached but O2 consumption increases; highest value of O2 consumption measured during a graded exercise test; when leveling off doesn’t occuror max performance appears limited by local muscular factors instead of central circulatory dynamics2. What are some of the factors that can affect VO2 max?- mode of exerciseo variations in VO2max with different forms of exercise generally reflect variations in quantity of muscle mass activated- state of trainingo person’s state of aerobic training contributes substantially to VO2 max, which normally varies between 5-20% depending on person’s fitness at time of testing- gendero women typically achieve scores 15-30% below males- heredityo changes seem to be related to genotypeo genetic effect for VO2 max is about 20-30%- body size and compositiono variations in body mass explain nearly 70% of differences in VO2max scores among individualso the size of the contracting muscle mass activated in exercise largely accounts for gender differences in aerobic capacity- ageo O2 consumption declines with age, which can’t really be prevented, so therefore VO2max declines with age as well3. Explain some of the factors responsible for the improvement in VO2 max through exercise. Include cardiovascular changes one might expect to see with exercise training.- sports or difference aspects of sports that engage person in different ways and challenge systems in different ways can alter a person’s max O2 consumption- a person’s state of training can contribute 5-20% of variation in VO2 max- improved training can affect: o aerobic enzymeso capillary densityo cross section of slow twitch fiberso oxidative capacity of fast twitch fiberso glycogen stores- can improve VO2 max through training4. How does the concept of specificity apply when talking about VO2 max? Here include; mode of exercise, subject fitness status, and different types of equipment one might use to measure VO2 max.- mode of exercise: o exercise modality affects VO2 max by amount of muscle mass during activity activate large muscle groups intensity and duration independent of subject skill, strength, size, and speedo 10-12% difference between tests on cycle or treadmillo treadmill tests are most commonly used because you can easily quantify as well as regulate exercise intensityo VO2 max tests can be continuous or discontinuous; they must be a graded exercise test and it has been shown that those given verbal encouragement are more likely to achieve their VO2 max than those with no encouragement max aerobic capacity was 9-10x higher than when not encouraged and time on treadmill was increased for those being encouraged this helps to truly reach a person’s physiologic max, which is one way to really guarantee a person reaches their VO2 max5. What factors account for gender differences in VO2 max?- women tend to have lower VO2 max than men- women have lower levels of hemoglobin, as well as differences in body composition between males and females- average male generates more total aerobic energy because he possesses more muscle mass and less fat than average female- men also have a higher hemoglobin concentration than women (perhaps due to more testosterone), which enables men to circulate more oxygen during exerciseTraining Principles for Aerobic Exercise1. Be familiar with factors which affect the aerobic training response (intensity, duration, etc).- factors improving heart:o training at higher heart rate (increasing intensity)o duration of exercise sessiono frequency of trainingo mode of trainingo initial level of fitnesso ALSO known as “FITT” (frequency, intensity, time, type)o these things can all be manipulated2. Maintenance of aerobic fitness gains.- with intensity held constant, frequency and duration required to maintain certain level of aerobic fitness remain considerably lower than that required to induce improvement- a small decline in intensity can decrease the VO2max\- therefore, intensity plays a crucial role in maintaining increased aerobic capacity achieved through training3. Understand various cardiovascular adaptations that occur with chronic training.- the higher the intensity trained at, the greater the cardiovascular achievements- the longer you spend training per session, the greater improvements you will see in VO2- the more times a week you train, the greater cardiovascular improvements will be- your initial level of fitness also has bearings on rate of which improvements occur- the key to improving cardiovascular health is the intensity at which a person trains- if you don’t stimulate the heart enough, you will see minimal effects on cardiovascular health- increased heart mass and volume with increased size of left ventricle and thickening of the heart walls- 12-20% increase in plasma volume, which enhances circulatory reserve and increases EDV, SV, O2 transport, VO2max, and temperature-regulating ability during exercise- lower resting heart rate and sub-max heart rate- increased SV during rest and exercise regardless of age or gender- increase in max cardiac output represents most significant function with aerobic training- increased quantity of O2 extracted from circulating blood (a-v O2 difference)-
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