Developmental Essentials by IYCA, (07) Energy Management and Bioenergetics, Notes

Post date: May 4, 2016 12:37:53 PM

Developmental Essentials by IYCA

Energy Management and Bioenergetics

• 1. Questions

     1. Why do coaches concentrate so much on conditioning?

     2. When is it appropriate to involve adult type training with youth athletes?

     3. Take a current program and modify based on chapter content.

     4. Outline a training day for a pee wee program, high school and college.

     5. How would you integrate principles involved in anaerobic and aerobic metabolism to program work to rest rations for games of tag?

  2. Introduction

• • 1. Explore various means by which the body obtains energy and effects of training and developmental age.

    2. Energy: carried in adenosine triphosphate when broken down, energy is released.

    3. 2 issues

       1. longitudinal change in metabolic efficiency - a power due to growth and maturation

       2. effect of training on these factors

    4. metabolic systems never work in isolation - one system is usually dominant (intensity)

    5. identify principal factors in biological development and effects of training

    6. page 187 - figure 7-1 overview between aerobic and anaerobic

• 3. oxidative (steady state) metabolism

• • 1. aerobic use of oxygen in activity - body’s preferred method of providing energy

    2. fatty acids are major source of fuel along with some carbohydrate and even protein

    3. energy is high yield and steady

    4. kreb’s cycle and electron transport chain represent major metabolic machinery

    5. substrates for Keb cycle include:

       1. blood glucose

       2. glycogen from liver and muscle

       3. protein

• • • 1. fatty acids transformed into acetyl CoA(coenzyme a)

• • 1. page 187 - description of krebs cycle

    2. yield- slow glycolysis

       1. fatty acid nets hundreds of adenosine triphosphate molecules

    3. Control-

• • • 1. intensity determines aerobic or anaerobic dominance

      2. anaerobic threshold - maximal rate of steady state activity -- limiting factor is availability of substrate

      3. figure 7-2 aerobic metabolism

• • 4. substrate depletion and recovery

• • • 1. during steady state exercise depletion available substrate will occur at level of muscle and liver

      2. prepubertal child favors fatty acids as a substrate and oxidative mechanisms during exercise

• • 5. development and aerobic performance

• • • 1. increases with development

      2. factors

         1. mechanisms used

         2. amount of muscle mass

         3. efficiency of internal machinery

         4. changes in cardiorespiratory system

      3. VO2max (highest level of steady state available) improves slightly throughout childhood and significantly during puberty

• • 6. cardiac output - amount of oxygenated blood pumped out by the heart each minute and oxygen consumption by the body (Vo2) have an intimate relationship

• • • 1. VO2 = CO (aO2 - VO2)

      2. page 189 - Fick equation

      3. related to stroke volume - amount of blood pumped with each beat

• • 7. VO2max and peak - peak of calculation in a maximum test protocol

• • • 1. VO2max is lower in prepubertal as compared to adults

      2. stroke volume is determining factor in VO2max

      3. increase in muscle in puberty is correlated to increase in physical capacity

• • 8. training effects on endurance capabilities

• • • 1. VO2 max can be improved in children

      2. most effective is three times /week at 85% of VO2 peak

      3. both high and medium intensity improves movement skills and metabolic efficiency

      4. trainers should spend more time improving running skill, neuromuscular coordination and strength rather than reinforce poor running mechanics

• 1. Anaerobic (short burst) activity - high intensity performed less than 3 minutes

     1. duration determined by intensity

        1. energy provided by phosphagen system

           1. jumping, short sprints

        2. energy from fast glycolytic

• • • • 1. sprints between 100 and 880 meters begin to bring in

• 1. 2. phosphagen - 0-30 seconds, quick energy

     3. overview

• • • 1. rate of adenosine triphosphate supply is high but yield is low

      2. creatines kinase - synthetic enzyme for phosphate system

      3. myokinase reaction is immediate source of energy

• 1. 4. control

• • • 1. increase in adenosine diphosphate will increase creatine kinase activity (positive feed forward)

      2. will stay during high intensity to allow time for glycolytic glycolysis

      3. as adenosine triphosphate increases in sarcoplasm (inside muscle cell) it inhibit creatine kinase activity

      4. negative feedback

• 1. 5. substrate depletion and recovery

• • • 1. phosphagen system makes use of the donor creatine phosphate to make adenosine triphosphate from adenosine diphosphate and hydrolyzes adenosine triphosphate

• 1. 6. the phosphagen system and development

• • • 1. figure 7-3 - phosphagen system in children - page 191

      2. children exhibit less power due to less enzyme activity and less ability to phosphorylate adenosine diphosphate to adenosine triphosphate

      3. special note: creatine is naturally produced. IYCA does not promote supplementation. Long term effects of supplementation are unknown

      4. hormonal changes and increase in body size play a role in power output

• 1. 7. glycolysis

• • • 1. glycolytic system provides energy for sustained bouts of high intensity exercise (6 sec to 3 minutes)

      2. fast glycolysis = absence of oxygen

      3. slow glycolysis = presence of oxygen = pyruvate in krebs cycle

• 1. 8. slow versus fast

• • • 1. pyruvate converted into lactic acid

      2. slow pyruvate transported into mitochondria where fed into krebs (citric acid ) cycle in presence of oxygen

      3. yield

         1. one molecule of glucose = 2-3 molecules of adenosine triphosphate

      4. control - inhibited

• • • • 1. glycolysis is by acidic conditions secondary to ischemia and the production of lactate and positive hydrogen ions/ Possibly inhibited by increases in adenosine triphosphate, CRPO4, citrate and free fatty acids

        2. primary control is achieved via phosphorylation of glucose to hexokinase (type of sugar with different structure)

        3. another factor is the breakdown rate of glycogen (stored form of glucose)

        4. major limiting step is conversion of fructose - 6- phosphate to fructose - 1, 6-bisphosphate by phosphofructokinase

        5. adenosine monophosphate produced by phosphagen energy system will stimulate glycolysis via an increase in phosphofructokinase activity

        6. presence of secondary to deamination of proteins will also increase phosphofructokinase activity - - breakdown of proteins (and possibly muscle tissue - after 2 hours of exercise amino acids are consumed as fuel

• • • 5. development and the anaerobic system

• • • • 1. lactate threshold is the point at which the body begins to rely on anaerobic mechanisms preferentially

        2. increase in intensity puts the body closer to onset of blood lactate accumulation

           1. point at which lactate is produce at a rate faster than the body can buffer and clear waste

        3. children experience lower peaks in lactic acid

        4. active recovery speeds lactate clearance - lactate not just a waste product but also an energy source

        5. in children lactate threshold occurs at an increased percentage of peak oxygen consumption than in non athletic adults - behave more like athletically trained adults)

        6. relationship between sedentary and active children not yet studied

        7. increase in activity of glycolytic enzymes during growth and maturation

        8. page 193, Figure 7-4. Anaerobic glycolysis in children

• • • 6. training effects on short burst activities and anaerobic metabolism

• • • • 1. circumpubertal boys (11-13) - increase in activity of phosphofructokinase post training

        2. increase in maximum anaerobic power range from 4% to 14%

        3. neuromuscular coordination and muscular strength will determine amount of improvement in training

• • • 7. selected special populations

• • • • 1. movement should be a part of any medical prescription

        2. asthma - dyspnea and bronchospasm secondary to exercise induced hyperventilation

           1. exercise reduces incidence and dependence on medication

           2. deconditioned athletes more prone to attack

           3. importance of accurate assessment and appropriate progressions

           4. start with short burst activity with appropriate rest

        3. obesity

• • • • • 1. young children can lose weight rapidly due to increased propensity to lose weight than adults

          2. avoid high impact activity

• • • • 4. deconditioned - non-obese - no research

• • • • • 1. avoid indoor entertainment

          2. send kids outside more

          3. go for a walk, play, slowly build work capacity

• • • 8. conclusion

• • • • 1. focus on acquisition of basic movement skills

           1. move well, then move often

        2. as technique improves, slowly look to build work capacity

        3. important to consider all forms of varied training - aerobic and anaerobic demands when programming training

        4. ages 6-11 respond best to game situations (tag related)

• • • • • 1. practice skills through games