1 / 29

Effect of Stroke Rate Manipulation on Oxygen Uptake in Constant Speed Swimming

Effect of Stroke Rate Manipulation on Oxygen Uptake in Constant Speed Swimming. Scott McLean, Ph.D. Collaborators. Southwestern University, Georgetown, TX, USA Jimmy Smith, Ph.D. Graham Ice Institute for Exercise and Environmental Medicine, Dallas, TX, USA Dean Palmer, M.S.

lbranch
Télécharger la présentation

Effect of Stroke Rate Manipulation on Oxygen Uptake in Constant Speed Swimming

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Effect of Stroke Rate Manipulation on Oxygen Uptake in Constant Speed Swimming Scott McLean, Ph.D.

  2. Collaborators Southwestern University, Georgetown, TX, USA Jimmy Smith, Ph.D. Graham Ice Institute for Exercise and Environmental Medicine, Dallas, TX, USA Dean Palmer, M.S. Robert Wiskera, B.A. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, Netherlands. Martin Truijens, Ph.D.

  3. Optimization of human movement Cavanagh & Williams (1982) • Gait • Choose SR/SL that minimizes O2 uptake • Cycling • Choose higher cadence than most economical • Minimize muscle stress? Running shorter step longer step Marsh & Martin (1993) Cycling faster cadence slower cadence

  4. SR and Oxygen Uptake Pawelczyk et al. (1991) • Swaine and Reilly (1983) swim bench • Pawelczyk et al. (1991) • swim in flume @ ~1.0 m/s • Manipulated SR • HR& • Combination of SL and SR to minimize metabolic cost • Smaller effect than in running • Intensity? • 8 min swims • Blood lactates 6-7 mmol • Stroke Rate Control? • Metronome • CV 5-7%

  5. Purpose • To examine the manipulation of stroke rate on oxygen uptake in submaximal, constant speed swimming • It was hypothesized that deviations from the preferred stroke rate (SR) would increase oxygen uptake when swimming at a constant submaximal speed.

  6. Measures • Stroke Rate • controlled using a Finis Tempo Trainer • monitored with time needed to complete 10 strokes. • Oxygen Uptake • Monitored on breath-by-breath system to identify steady state • Measured using Douglas bag technique • Heart Rate • Polar™ HR monitor • Kick Rate • computed using the time needed to complete 30 kicks • determined from underwater video • RPE

  7. Methods • Nine competitive swimmers • 33.3±13.6 yrs • 175.3±8.6 cm • 74.9±12.2 kg • Swim in flume at 1.0 m/s

  8. Accommodation • Heart Rate monitor applied • 5-min warm-up swim in a flume at 1.0 m/s • Headgear and mouthpiece fitted to subject • 5 minute swim at 1.0 m/s • participant accommodated to equipment • determine preferred SR

  9. -10% +20% +10% -20% Preferred SR Protocol • Randomized order • Each trial continued for 1-min after steady state was verified (~4-5 min) • VO2, HR, and KR measured during the final min of each trial • RPE was reported immediately after each trial.

  10. Steady State

  11. Oxygen Uptake * *

  12. Heart Rate * *

  13. RPE * *

  14. Kick Rate * *

  15. Summary • These data suggest that these swimmers preferred to swim at the slowest SR (or the longest stroke length) that did not require an increase in KR and thus an increase in VO2.

  16. Now Where? • SR x S relationship • Training to increase SL • Changes in SR/SL during the season or phases of the season

  17. Grimston and Hay, 1985 • “long-limbed individuals with large hands and feet have a predisposition to success in swimming” *p<0.05

  18. Representative Data McLean et al., 2003 • S depended on ΔSR and ΔSL (Craig and Pendergast, 1976)

  19. 200 free • SL tends to decrease through a race (Letzelter and Freitag, 1982; Hay et al., 1983) • SL negatively correlated with S (r=-0.59, p<0.05) but not SR (r=0.08) (Hay et al.,1983)

  20. WHY SR and SL? Easy to measure Useful during training and competition

  21. What do we know? Stroke Length (SL) Stroke Rate (SR)

  22. Anthropometrics Stroke Length (SL) Stroke Rate (SR)

  23. Changes with speed Anthropometrics Stroke Length (SL) Stroke Rate (SR)

  24. Changes with speed Anthropometrics Stroke Length (SL) Stroke Rate (SR) Changes during race

  25. Changes with speed Anthropometrics Stroke Length (SL) Stroke Rate (SR) Changes during race Differences b/w strokes

  26. What’s missing from these studies? • Physiological cost • Relationship of SR, SL, S and metabolic cost? • Limited ability to describe this relationship • Need ability to control stroke characteristics • Flume

  27. Effect of Stroke Rate Manipulation on Oxygen Uptake in Constant Speed Swimming Scott McLean, Ph.D.1, Dean Palmer, M.S2, Graham Ice1, Robert Wiskera, B.A2, Martin Truijens, Ph.D.3, and Jimmy Smith, Ph.D.1. 1Southwestern University, Georgetown, TX, USA 2Institute for Exercise and Environmental Medicine, Dallas, TX, USA 3Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, Netherlands.

More Related