Vo2max what does it really mean

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Webinar for USA Cycling Coaching Education program.

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<ul><li> VO2max: what does it really mean? Andrew R. Coggan, Ph.D. Cardiovascular Imaging Laboratory Washington University School of Medicine St. Louis, MO 63110 </li> <li> Maximal O2 uptake (VO2max) What is it? Why is it important? What determines it? How do you train it? How do you measure it? </li> <li> VO2max what is it? </li> <li> VO2max what is it? The highest rate of whole-body oxygen uptake (VO2) achievable during exercise that utilizes a large muscle mass (e.g., running). </li> <li> Plateau in VO2 with increasing exercise intensity </li> <li> VO2max what is it? The highest rate of whole-body oxygen uptake (VO2) achievable during exercise that utilizes a large muscle mass (e.g., running). An intrinsic biological characteristic of an individual at any particular point in time. </li> <li> VO2max why is it important? </li> <li> VO2max why is it important? VO2max is the best overall measure of cardiovascular fitness and sets the upper limit to the production of energy (ATP) via aerobic metabolism (i.e., mitochondrial respiration). As such, having an adequately high VO2max is a necessary but not a sufficient condition to be an elite endurance athlete. </li> <li> VO2max in different groups of athletes </li> <li> VO2max what determines it? </li> <li> VO2max what determines it? While there are numerous steps involved in the transport of the O2 from the atmosphere to the mitochondria where it is utilized, the primary limiting factor to VO2max is maximal cardiac output, and in particular, maximal stroke volume. </li> <li> The cardiovascular Fick equation: The Fick equation represents the relationship of the . . bodys oxygen consumption (VO2) to cardiac output (Q) and the arterial-mixed venous oxygen difference (a-vO2 . diff): . . VO2 = Q x a-vO2 diff . or VO2 = HR x SV x a-vO2 diff During maximal exercise: . VO2max = HRmax x SVmax x a-vO2 diffmax </li> <li> Relationship between VO2max and maximal cardiac output </li> <li> Stroke volumes (SV) for different states of training Subjects SV @ rest (ml) SV @ max (ml) Untrained 50-70 80-110 Trained 70-90 110-150 Highly trained 90-110 150-220 </li> <li> VO2max how do you train it? </li> <li> Role of genetics in determining baseline VO2max </li> <li> Role of genetics in determining trainability of VO2max From D. Prud'homme et al., 1984, Sensitivity of maximal aerobic power to training is genotype-dependent, Medicine and Science in Sports and Exercise 16(5): 489-493. Copyright 1984 by American College of Sports Medicine. Adapted by permission. </li> <li> Role of genetics in determining trainability of VO2max . Adapted, by permission, from C. Bouchard et al., 1999, Familial aggregation of VO 2max response to exercise training: Results from HERITAGE Family Study, Journal of Applied Physiology 87: 1003-1008. </li> <li> VO2max how do you train it? At least/especially in untrained persons, ordinary endurance exercise training, if of sufficient intensity (i.e., &gt;50-60% of VO2max), frequency, and duration will lead to an improvement in VO2max, but As an individual becomes more fit, it becomes progressively harder and harder to elicit further improvement, necessitating that the exercise intensity be increased if any further gains are to be achieved. </li> <li> VO2max how much can it be improved? Training program: Running all-out for 40 min/d, 3 d/wk. Cycling (on an ergometer) 6 x 5 min on, 2 min off, 3 d/wk. Power during intervals set so that subject achieved VO2max during each effort. Hickson, Bomze, and Holloszy. J Appl Physiol 1977; 42:372-376. </li> <li> Changes in VO2max over time in a world class team pursuit cyclist Jeukendrup AE, Craig NP, Hawley JA. J Sci Med Sport 2000; 3:414-433. </li> <li> VO2max how do you measure it? </li> <li> VO2max how do you measure it? By using a metabolic cart (gas analyzers, flow measuring device) to quantify respiratory gas exchange (VO2, CO2 production (VCO2)) across the lungs/at the mouth during an incremental exercise test. </li> <li> Subject performing VO2max test </li> <li> Characteristics of ideal VO2max test Total duration 8-12 min Stages typically 1-3 min in length Exercise intensity increased by</li></ul>