Physiological bases for training colorado springs

1,068 views

Published on

2004 USA Cycling 1st Biannual International Cycling Summit, Colorado Springs, CO.

Published in: Sports, Technology, Business
0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,068
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
47
Comments
0
Likes
2
Embeds 0
No embeds

No notes for slide

Physiological bases for training colorado springs

  1. 1. “The science of exercise and the art of coaching”
  2. 2. Outline for talk 1. Brief review of energy systems 2. Determinants of endurance performance 3. Muscle fiber type and recruitment 4. Energy systems part II: what they didn’t teach you in Ex. Phys. 101 5. Application to interval training
  3. 3. Adenosine triphosphate (ATP): the “energy currency” of cells ATP ADP + Pi
  4. 4. Resynthesis of ATP: three energy systems • Phosphagen system: PCr + ADP Cr + ATP ADP + ADP ATP + AMP • Non-aerobic glycolysis: glucose 2 lactate + 2H+ + 2ATP • Aerobic metabolism: glucose + 6O2 6CO2 + 6H20 + 36ATP palmitic acid + 23O2 16CO2 + 16H20 + 130ATP
  5. 5. Three energy systems: relative contributions From: Gastin PB. Energy system interaction and relative contribution during maximal exercise. Sports Med 31:725, 2001
  6. 6. VO2, heart rate, lactate, and RPE vs. power VO2 Blood lactate RPE Heart rate VO2 (L/min), lactate (mMol/L), or RPE (U) 180 8 160 7 6 140 VO2max 120 5 100 4 80 3 OBLA 2 60 40 Lactate threshold 1 0 20 0 0 50 100 150 200 250 Power (W) 300 350 400 450 HR (beats/min) 9
  7. 7. Importance of LT From: Coyle EF et al. Physiological and biomechanical factors associated with elite endurance cycling performance. MSSE 23:93, 1991.
  8. 8. VO2 vs. power (economy/efficiency) 5 y = 0.0112x + 0.4543 R2 = 0.9967 VO2 (L/min) 4 y = 0.0106x + 0.4575 R2 = 0.9975 3 2 1 0 0 50 100 150 200 Power (W) 250 300 350 400
  9. 9. Effect of efficiency on performance From: Horowitz JF, Sidossis LS, Coyle EF. High efficiency of type I fibers improves performance. Int. J. Sports Med. 15:152, 1994.
  10. 10. Human skeletal muscle fiber type characteristics Type I Type IIa Type IIb(x) Size of muscle fiber Smallest Larger Largest # of fibers in motor unit Smallest Larger Largest Size of alpha motor neuron Smallest Larger Largest Order of recruitment First Next Last Force at zero velocity (per unit area) Same Same Same Speed of contraction Slowest Faster Fastest Force/power at velocity greater than zero Lowest Higher Highest PCr content Lowest Higher Highest Glycolytic enzyme activities Lowest Higher Highest Glycogen content Lowest Higher Highest Triglyceride content Highest Lower Lowest Mitochondrial enzyme activities Highest Lower Lowest Capillarization Highest Lower Lowest Fatigue resistance Highest Lower Lowest
  11. 11. Factors affecting fiber type recruitment 1. Exercise intensity 2. Exercise duration 3. Cadence?
  12. 12. Fiber type recruitment as a function of intensity % fibers recruited at onset of exercise 100 Total 80 60 Type I 40 Type IIa 20 Type IIb 0 25 50 75 100 % of VO2max From: Vollestad NK et al. Effect of varying exercise intensity on glycogen depletion in human muscle fibers. Acta Physiol Scand 125:395, 1985.
  13. 13. Energy systems part II: What they didn’t teach you in Exercise Physiology 101
  14. 14. Three energy systems: relative contributions From: Gastin PB. Energy system interaction and relative contribution during maximal exercise. Sports Med 31:725, 2001
  15. 15. Three energy systems: absolute contributions From: Gastin PB. Energy system interaction and relative contribution during maximal exercise. Sports Med 31:725, 2001
  16. 16. Three energy systems: all-out vs. constant intensity From: Gastin PB. Energy system interaction and relative contribution during maximal exercise. Sports Med 31:725, 2001
  17. 17. Half-time of PCr resynthesis
  18. 18. Half-lives of physiological responses Power (force and/or velocity) (0 s) Heart rate/cardiac output: ~25 s Sweating: ~25 s VO2: ~30 s VCO2: ~45 s Ventilation: ~50 s Temperature (core): ~70 s
  19. 19. Metabolic response to “micro” intervals
  20. 20. Energy metabolism during 30 s sprints mmol of ATP 1000 Lactate production PCr breakdown Aerobic metabolism 750 59% 500 21% 16% 15% 250 63% 26% 0 1 2 3 Sprint bout number From: Putman CT et al. Skeletal muscle pyruvate dehydrogenase activity during maximal exercise in humans. Am J Physiol 269:E458, 1995.
  21. 21. Analysis of different interval training sessions • LT intervals: 2 x 20:00/5:00 • VO2max intervals: 6 x 5:00/2:30 • LT intervals: 8 x 5:00/1:00 • Anaerobic capacity intervals: 10 x 1:00/3:00
  22. 22. LT intervals: 2 x 20:00/5:00
  23. 23. VO2max intervals: 6 x 5:00/2:30
  24. 24. LT intervals: 8 x 5:00/1:00
  25. 25. Anaerobic capacity intervals: 10 x 1:00/3:00

×