Presentation on theme: "Review Questions Advanced Exercise Physiology – Lecture 10 Review and Beyond Dr. Moran 11.16.05."— Presentation transcript:
Review Questions Advanced Exercise Physiology – Lecture 10 Review and Beyond Dr. Moran 11.16.05
Review Question #1 Briefly explain the purpose of the Conconi Field Test. What is it attempting to assess? Is it a good coaching tool to employ? The Conconi Test is a field that has been adapted for numerous endurance sports: xc-skiing, distance running, cycling, etc. It attempts to find the precise exercise intensity in which to improve maximal oxygen uptake (max VO 2 ). Although it was originally reported to be a good field test and fairly accurate to laboratory measurements, more recent studies have shown that it is not a RELIABLE test. This indicates that if 1 athlete was tested within a short time frame the test would not give the same results. As a result this test is not recommended to field professionals, however, it could be beneficial for some athletes.
Review Question #2 Which of the following is NOT a valid term to describe the exercise intensity point in which removal of lactate is not adequate? a.) Lactate Threshold (LT) b.) Onset of Blood Lactate Accumulation (OBLA) c.) Anaerobic Threshold d.) Aerobic Threshold
Review Question #3 Training alters the % of VO 2 maximum in which OBLA occurs. For an untrained person where % of VO 2 max can OBLA be expected? How about a trained athlete? What physiological adaptations allow this substantial difference? For an untrained person OBLA can be expected to occur at ~55% of VO 2 max, while for a trained athlete it is more typical to record OBLA at ~ 85% VO 2 max. The trained athlete can operate at greater exercise intensities and remain below OBLA because of the following adaptations: Due to a blunted catecholamine response Catecholamines stimulate glycolysis but not oxidative enzymes Increased ability to deliver and extract oxygen Increased lactate utilization
Review Question #4 Describe two training techniques that can be used to improve LT. Steady-state (“tempo”) runs right below, at, or above the LT intensity help to create the best stimulus to bring about physiological adaptations that will increase the intensity at which OBLA occurs. The duration LT pace runs will be affected by training status, type of activity, and duration of goal event. Interval training are short runs greater than 45 seconds in duration much faster than LT pace. An adequate amount of rest is granted between intervals to allow blood lactate levels to return below the OBLA point. Again this short burst of lactate create a stimulus for the physiological system to adapt to handle the increased lactate levels.
Review Question #5 Briefly explain why the production of lactic acid through glycolysis is an elegant design? Be sure to describe the fate of lactic acid after it is produced. The production of lactate acid at the end of anaerobic metabolism is an elegant design because lactate can be used as an energy substrate by both the liver and the heart. A person producing lactate above the OBLA point indicates that they are exercising intensely. Obviously at this point of exercise the cardiac system will be under a significant amount of stress so the fact that lactate can be used by the heart as an energy substrate represents a great use for lactate. Lactate can also be taken up by the liver an used as a building block for glycogen, again an action that would help to prolong exercise.
Review Question #5 What is the “lactate shuttle” and how does endurance training improve it? The lactate shuttle describes the transport from muscle fibers primarily engaged in glycolytic metabolism. The produced lactate is shuttled to nearby muscle fibers via the “lactate shuttle” to fibers where it can be oxidized for energy. Monocarboxlate transporters (MCT) facilitate the transport of lactate from the cytosol into the mitochondria where it can be metabolized. Endurance training has been shown to increase the concentration of MCT. In a simplistic fashion this can be thought to occur between type II fibers to type I fibers.
Review Question #6 What is the overall goal of a tapering program? As a coach how should manipulate training frequency, intensity, volume? How long should you design a tapering program and what % of performance gains can be expected? The tapering goal is reduce psychological and physiological effects of everyday training with the thought that performance can be maximized by 0.5-6% over a short time frame. Research has not shown what is the best duration of a tapering program, although anywhere from 4-28d seems optimal. A coach should reduce training frequency by now more than 20% and volume by no more than 40% but maintain training intensity during the program. Four types of tapering programs have been described: linear, fast exponential, slow exponential, and step. It is still unclear which program is optimal for a given type of athlete.
Practical Application #1 Describe the contribution of each fuel substrate (carbohydrates, fat, protein, lactate) to the total energy production of an individual running at 75% VO 2 max (OBLA @ 70%). For the past two days, this person’s typical diet is 10% CHO, 40% fat, and 50% protein. After two months of intensive training, this same individual raises her OBLA point to 80% of VO 2 max. After the training, describe the contribution of each fuel substrate (CHO, Fat, Protein, Lactate) to the total energy production if she is running at 75% max VO 2 max. Be sure to include the control or feedback mechanisms responsible for dictating her fuel of choice in both cases and specific alterations associated with conditioning that may change the fuel substrate. After 3 hours of continuous running at 75% of VO 2 max, justify why she must slow her pace. Be specific. Describe the physiological mechanisms responsible for increasing her anaerobic threshold.