Physiological Concepts of Training

• Physiological Concepts of Adaptation: Synthesising appropriate proteins

  • Proteins continually turned over / recycled
  • How regulation occurred
  • Number & type of proteins driven by STRESS signals
  • Can increase or decrease protein production
• Physiological Concepts of Adaptation: Synthesising appropriate proteins

  • How to get more protein?

  1. Stress signals activate specific pathways/cascades
  2. Which activate transcription factors
  3. That switches on/off genes to produce code for new proteins (mRNA)
  4. That makes specific proteins
  5. Proteins made by ribosomes using this code
• How to get more Protein:

  • Multiple types of stimuli drive innumerable pathways
• Turning on / off Synthetic Pathways:

  • Number of things:
  • Physical, humeral
  • That are sensed
  • AMP signals low energy state of cell
  • ATP / ADP signals high energy state of cell
  • pH
  • Amount of glycogen (single transduction, cascade effect)
  • To up regulate protein synthesis
• Regulation & Timing:

  • Signalling is prerequisite for protein synthesis
  • Need signalling first but not enough need building blocks
  • But protein synthesis is not guaranteed, eg need:
  • Amino acids to make the protein
  • Machinery (usable DNA, nuclei, ribosomes)
  • mRNA response peaks in hours
  • Back to baseline by ~24 hrs
  • So, need to repeat an appropriate stress
  • Protein synthesis slower
  • Usually weeks to see measurable/functional effects
  • Individual differences!
  • Proteins lost over days to months
• Regulation & Timing:

  • Neural adaptations far more robust
  • Gain fast, lose slowly
  • They persist
• Fitness develops from repeated stress that causes sufficient strain
• How perform exercise going to affect the amount of strain
• Nature & Extent of Adaptation Dependent on Many Factors:

  1. Exercise parameters (FITT)
  2. Determines nature & extent of stress signals (esp intensity)
  3. Personal
  4. Genes
  5. 1000s of genes (protein codes)
  6. Sex effects (anabolic hormones)
  7. Age
  8. Children; less anabolic sex & steroid hormone
  9. Old age; blunted cell signalling, & increased inflammation (reduce hormones too)
  10. Clinical status
  11. Some diseases (eg lack enzymes like phosphorylase to break stuff down)
  12. Diet
  13. Availability of substrates for new protein, energy state, stored substrates
• Training Specificity (from Swimming):

  • Some central, mainly CV, adaptations that would also aid running
  • Little cross-adaptation
  • Better improvement in what specifically trained for
  • Using different muscle fibres, specific to that activity
  • CV: diff in muscle so those can use more oxygen, total active muscle greater for running than swimming
  • More CV strain in running than swimming
• Individual Responses:

  • Respond differently to given training stimulus
  • Initial fitness level has an influence
  • Those with lower fitness achieve greatest training improvements
  • Genetics predisposing for physical parameters, protein synthesis, hormones, metabolic etc. affect adaptability (rate) & ceiling
  • Epigenetics = environmental factors (incl. nutrition, energy balance, PA etc) turn on/off gene transcription & / or translation
• Interference - Time:

  • Acting in opposition to what trying to achieve
  • Eg for strength vs endurance, or training vs recovery, or nutritional req.
  • Don’t have time to do both
  • Focus on training time rather than recovery - don’t have enough time to replete
  • To get what you want & for nutrients to be stored in system (to be incorporated into these functional elements)
• Interference - Functional due to physiological effects eg hypertrophy:

  • Dilution effects
  • Exchange into & out of blood (such as plasma volume)
  • Relative area of contractile vs mitochondrial proteins
  • Increase contractile but not mitochondria → may not help VO2 capacity
  • Mass to be carried
  • Inertia (increased mass)
  • Energy used
  • Increase glycogen use to move
  • Thermal (mostly negative)
  • Produce more heat, AND harder to get rid of it
  • Compounds SNS activation, dehydration
  • All decrease endurance
• Interference

  • Signalling pathways activated by endurance / prolonged or RHIE exercise can inhibit hypertrophy pathway
  • ‘Resistance’ & ‘aerobic’ training can impair each other (concurrent training)
  • Do resistance training LAST; better yet use different muscle groups
  • Still some interference even if leaving it last
  • Can interference be beneficial?
  • (obtain neural without hypertrophy effects)
  • May not want to achieve hypertrophy (greater muscle mass)
• Constitutes of an Quality Training Session:

  • Does it maximises load (stress) or response (strain)?
  • Easier to measure load; can get good measure of strain (HR)
  • What type of strain is more important?
  • Purpose of training?
  • Performance, lose weight (increase energy utilisation)
  • Specificity required?
  • Key aspect of training most important to desired outcome
  • Basis of periodisation?
  • What & how?
  • Does it minimise interference (time, cell signalling pathways or physiol. demands)
  • Note: Many ExRx drives multiple, valuable forms of strain and fitness development
• Recovery in Active part of Training:

  • Energetically expensive, & anabolic processes take time to occur
  • Between sets:
  • Eg to replenish Phosphagens esp Type IIx; decrease H+
  • Phosphagens: get creatine phosphate back up
  • Type IIx: are slower to recover
  • H+: want acidity to turn around; if acidic breakdown creatine phosphate instead of building it back up
  • Between sessions:
  • Eg to remodel protein content, resolve inflammation, restore glycogen + IMTG
• Training-related aspects of Recovery:

  • Recovery affected by exercise, personal & environmental factors
  • Commercial focus (nutritional & methods)
  • Popular, but think critically about if want to hasten it
  • Or strain to be prolonged (for adaptation)
  • Ample blood supply critical eg:
  • O2 for phosphagens, glucose for glycogen resynthesis (insulin dependent)
  • Plays a role + does contraction
  • Protein for myofibrillar synthesis, & enzymes
  • Need for essential amino acids, greater protein need if CHO inadequate
  • Some amino acids are glucogenic (can be used like glucose)