Applied Exercise PhysiologyExam III Study Guide Aerobic capacity 1. 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: maximal oxygen uptake for use at cellular level or max aerobic capacity: -It integrates aspects of O2 transportation like ... Pulmonary V-e, Hemoglobin concentration, Blood vol. and Stroke vol., Blood flow, Aerobic metabolism. -As well as integration of respiration, CV system, and neuromuscular system - Can be continuous or discontinuous, graded exercise, verbal encouragement needed due to psychological impact due to perception of effort• VO2max is determined while the test subject is exercising at max intensity and reaches a plateau of oxygen consumption. It is then that we know VO2max has been reached. Yet because not all test subjects are trained athletes and factors of discomfort come into play while tests are being run. - Additional criteria, to find VO2max include (1-3 must be met together):1. +/- 10 beats of max heart rate (220-age)2. RPE is 18 or greater3. RER over 1.1 because CO2 is formed from buffering lactic acid- Others include: lack increase of 2.1 ml.kg-1.min-1 with an increase in workload, Blood lactate levels of 8 – 10 mmol or higher2. What are some of the factors that can affect VO2 max?- Mode of Exercise: different types and modes of workouts have different muscle masses activated during such activity. -Modality criteria: to activate large muscle groups, intensity and duration for continuous adaptations, independent of subject skill, strength, size, and speed -Treadmill tests is the most common used mode for evaluating fitness. Easy to quantify and regulate intensity- Heredity: changes related to genotype. In general most physical fitness characteristics demonstrate high heritability.-Identical vs. Fraternal twins: studies showed that heredity accounted for 93% of VO2max. The capacity for short-term glycolitic energy system indicated a genetic determination of approx. 81%, while max HR showed 86% genetic determination - State of training: a person’s state of training can contribute between 5-20% of variation in VO2 max. -Improved training can affect: Aerobic Enzymes, capillary density around muscle, cross section of Slow Twitch fibers, Oxidative capacity of Fast Twitch fibers, glycogen stores- Gender: Women typically have 15-30% (untrained) and 15% (trained) lower VO2 max scores compared to men, as well as hemoglobin concentrations -Why: most women have more body fat and less muscle mass- Body size and composition: - Age: VO2max decreases steadily after age 25 at a rate of about 1% per year. Oxygen uptake and endurance decrease3. Explain some of the factors responsible for the improvement in VO2 max through exercise. Include the cardiovascular changes one might expect to see with exercise training.• When we exercise on a regular basis and improve our strength and endurance, certain factors are improved that in turn help improve VO2max:- Central Factors: -Cardiac Output: when we become more efficient at pumping blood through the body, we deliver oxygen ore efficiently, therefore delaying the plateau of VO2max -Heart Rate: a lower HR during exercise, yet delivering a high amt. of blood to body -Stroke Vol.: larger volume of blood ejected per beat- Local Factors: -a-vO2diff.: endurance training can improve number and size of Mitochondria, increase Capillary Beds near trained muscles, increase myoglobin levels in muscles. All these improve a-vO2diff (ability of muscle to extract O2 from blood), which increase oxygen levels in muscles, therefore improving VO2max. The greater the a-vO2diff at max work, the better the VO2 improvement.4. 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.- To be accurate about measuring improvements in VO2max the same type of exercise must be carried out in all trials. Research has shown that subjects when tested for VO2 max on various modes of exercise (i.e. Treadmill running vs bench stepping vs cycling, etc), the greatest VO2max value is achieved when tested using treadmill running. VO2max values obtained from tests using other exercise modes produced max values short of the value acquired from treadmill running tests. However this dynamic can change with elite athletes of a specific sport that involve high activity of particular muscle groups not highly stressed during treadmill running. - For example, a cyclist can achieve a better VO2max measurement when tested using a cycling protocol as opposed to any other mode. So this would also obviously influence the type of equipment you would use. Fitness status is another important factor to consider when testing for VO2max. In lab we tested VO2max two ways, one was maximal and one was a submaximal. YOu must take into consideration practical difference. Would you stick someone who has been sedentary on a treadmill and run a maximal VO2max test on him? No, you would use a submaximal test. 5. What factors account for gender differences in VO2 max? - Included in #2Training Principles for aerobic exercise 1. Be familiar with factors which affect the aerobic training response (intensity, duration, etc).- Initial Level of Aerobic Fitness: Magnitude of training response greatly depends on initial level of fitness. Someone with a low level of fitness has great room for improvement; if capacity is already high, magnitude of improvement remains small. - Training Intensity: training-induced adaptations depend primarily on intensity of overload. The relative stress on a person’s physiologic system establishes exercise intensity. Intensity usually relates to some break-point for steady rate exercise (ex: lactate threshold) or some percentage of max physiologic capacity (ex: VO2max, HRmax). Generally, intensity is set after direct measurement of VO2max and then assigns an exercise level; normally, the higher the training intensity above threshold, the greater the training improvements for VO2max.* upper-body exercise produces lower HRmax than leg exercise- Training Duration: No threshold duration per workout exists for optimal aerobic improvement. If it does exist, it is likely depends on total work done, intensity,
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