Adaptations to Exercise Training

1. Adaptations to Exercise Training

2. Introduction • Exercise training can be defined as participation in chronic, organized physical activity, with the goal of improving athletic performance or specific health and fitness parameters

3. Principles of Exercise adaptation • Specificity of Training • A specific exercise elicits a specific training response • Overload Principle • Improvement in performance capacity occur when regular physical activity is increased above the level that the performer usually experiences • Three factors • Frequency • Intensity • duration

4. The Principle of Individual Differences • No two individuals are the same • Unique motor performance profile, and training strategies may need to be customized to match the individual’s rate of improvement

5. Types of Anaerobic Exercise Training • Increases in muscular strength generally require exercise intensities of least 30% of maximal voluntary contractile strength (MVC) • Isometric Exercise • No change in joint position • Desirable in some rehab. situation • Little or no equipment • Can be done almost anywhere • Better to perform at various joint angles % strength gain 35 ° 45 ° 55° Joint angle

6. Dynamic Resistance Exercise • Changes in muscle length and joint angles • Concentric muscle contractions can offer very forces and thus an appropriate overload stimulus • Eccentric muscle produce more muscular force than that obtained during an isometric muscle contraction • Eccentric or lengthening muscle contractions is both highly fatiguing and highly susceptible to muscle soreness

8. Assessing Success of Anaerobic Exercise Training • Dynamic muscle strength can be estimated using the 1 RM (repetition maximum) • Anaerobic power maximum amount of force that can be generated over a period of time • Margaria power test or Wingate cycling terst

9. Exercise Tests

10. Aerobic Exercise Training • Low intensity or relatively low force levels • Continuous training • One type of aerobic exercise training • Exercise at a low intensity for a duration sufficient for creating an aerobic overload • Workload may be estimated as a percentage of maximum heart rate or a percentage of VO2max • Aerobic exercise should be performed at an intensity of about 60 to 80% of maximal heart rate

12. Rating of Perceived Exertion • Borg (1970s) discovered that our sense of effort bears a close relationship to actual workload • Borg’s scale correlates well with heart rate and VO2max

13. Rating of Perceived Exertion

14. Interval Training • Alternating higher-intensity exercise bouts with rest periods, overload stimuli can be applied that stress the intermediate energy systems and long-term aerobic systems • Major advantage is that more total work can be done by dividing it into several bouts than by performing it continuously

15. Other Types of Exercise Training • Fartlek training • Designed by Swedish exercise • A type of alternating fast-slow training • Hollow sprints • Alternate periods of sprint, jogging, and walking

16. Long-Term Adaptations to Anaerobic Exercise Training • Muscle Strength • Muscle strength to increase with long-term resistance exercise training • Initial strength increase can be dramatic • Most of gain occurs during the first month, subsequent gains much more slow, • Strength decrease as detraining persists

17. Major part of initial gain in strength originates in the nervous system • Learn how to activate more motor units in the muscles responsible for action or how to activate them more efficiently • Nervous system learns task in a more coordinated fashion

18. Training the Brain • Thinking about performing a maximal voluntary muscle contraction on a regular basis can improve muscular strength

19. Muscle Fiber Adaptations • Slow twitch muscle fibers are recruited or brought into action first, with the fast twitch muscle fibers recruited as the force increases • Fast-twitch fibers to hypertrophy even more than slow-twitch fibers

20. Long-Term Adaptations to Aerobic Exercise Training • An expect of VO2max to increase as the aerobic training program progress • Increase the efficiently of the oxygen utilization system • Respiratory Adaptations • Lung become more capable at extracting from the inhaled air and exchanging it for CO2

21. Oxygen-Carrying Adaptations • Increase myoglobin in muscle with endurance exercise, facilitating the delivery of O2 to mitochondria • Blood-Delivery Adaptations • Endurance training increases the size of the heart • Total blood volume increases helps O2 delivery and regulation of body temperature • An increase in the number of RBC helps to provide more oxygen-carrying hemoglobin • Stroke volume increases with training

22. Energy Production Adaptations • More mitochondria in the trained individuals • Enzymes for aerobic metabolism increase in concentration and efficiency • Muscle learns to contain more glycogen • Beta-oxidation increases to better use fat stores for energy

23. Other Aerobic Adaptations • Increase in the proportion of slow-fibers • Increase fatigability of most muscle fibers • Better handle the heat produced

24. Summary of Anaerobic and Aerobic Training Adaptations • The specificity and overloadprinciples are key to understanding and predicting adaptations that occurs with training • Floor-and-ceiling effect of hemoglobin

25. Antagonism between Anaerobic and Aerobic Training • Training aerobically may hinder anaerobic performance and vice versa • Strength training decrease muscle myoglobin content • Resistance exercise training increase the proportion of fast-twitch muscle fibers

26. Detraining • Once training stops, the positive effects of resistance exercise or endurance training wear off at about the same rate that training occurred

27. The Space Environment • 30 days of space flight, • muscle may atropy as much as 20%, • muscle strength decrease by about 20% • Bone mass decrease about 1 to 2 % per month • Problems in balance and postural control • VO2max can decrease by as much as 25% after 20 day of bed rest

28. Percent change in gastrocnemius and soleus muscle volume from preflight to postflight recovery days 4 (R+4) and 19 (R+19). *P < 0.05 vs. preflight. †P < 0.05 vs. gastrocnemius. Scott Trappe et al., 2009

29. Overtraining • Overtraining is a physical, behavioral, and emotional condition that occurs when the volume and intensity of an individual's exercise exceeds their recovery capacity. • They cease making progress, and can even begin to lose strength and fitness. • Overtraining is a common problem in weight training, but it can also be experienced by runners and other athletes.

30. Overtraining

31. General adaptation syndrome • Hans Selye (1950s), stressed and allowed to recover, rats grew stronger, if repeatedly stressed without sufficient time for recovery, rats grew weaker • Cure for overtraining • Reduce the intensity, duration, frequency of exercise • Training levels should be increased slowly and regular rest period • Maintain adequate diet and plenty of sleep

32. Tapering • Refers to the practice of reducing exercise in the days just before an important competition. • Tapering is customary in many endurance sports, such as the marathon, athletics and swimming. • For many athletes, a significant period of tapering is essential for optimal performance. The tapering period frequently lasts as much as a week or more

33. Tapering

34. Swimmers decrease their training for 15 days resulted in a 25% increase in muscular power and 4% performance improvement • Reducing training volume several weeks before big meet to enhance performance • Tapering may be one way of compensating for overtraining during part of the training period

35. Discussion • What biochemical changes may occur each bout during interval training (glucose, lactate etc.) and why. • Can you using the University’s campus, (gymnasiums, stadiums, buildings etc.) to plan a Fartlek training (drawing a running course) for distance runner. • How do you do to detect subjective and objective overtraining to athletes.