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THANK YOU Dr. Bo Fernhall Dr. Bo Fernhall Dr. David Pendergast Dr. David Pendergast Thomas Rowland M.D. Thomas Rowland M.D. Dr. Vish Unnithan Dr. Vish Unnithan
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Physiologic Correlates to Swimming Performance in the 50, 100, 200, 500, and 1000 Yard Freestyle in Elite Adolescent Female Swimmers J.D. Holohan 1, B. Fernhall 1, T. Rowland 2 J. Wylegala 3, D.Pendergast 3, J. Wylegala 3, D.Pendergast 3, and V.B. Unnithan 1 1 Exercise Science Department, Syracuse University, 2 Department of Pediatrics, Baystate Medical Center, Springfield, MA and 3 Center for Research and Education in Special Environments Laboratory, University of Buffalo, NY, USA
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INTRODUCTION Swimming performance at the elite level depends on a variety of factors including: Swimming performance at the elite level depends on a variety of factors including: –aerobic capacity –anaerobic capacity –stroke-specific muscular strength –stroke specific muscular endurance –swimming technique –training –psychological fitness –(Bar-Or 1994, Pendergast 2000).
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INTRODUCTION The contribution of these variables to elite swimming performance in young athletes is unclear. The contribution of these variables to elite swimming performance in young athletes is unclear. Therefore, a more complete understanding of the physiologic correlates to elite swimming performance in young swimmers is necessary. Therefore, a more complete understanding of the physiologic correlates to elite swimming performance in young swimmers is necessary.
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PURPOSE Examine elite young female swimmers while they were swimming in an annular pool. Examine elite young female swimmers while they were swimming in an annular pool. To determine the relationship between: To determine the relationship between: –Peak oxygen consumption –Fractional utilization (Fu, % peak VO 2 ) –Peak blood lactate – PP, MP, MIN P –Swimming economy AND AND Time and National Rank in the 50-1000 Freestyle 50-1000 Freestyle
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METHODS Subjects : – –Elite adolescent female swimmers with at least one time ranked nationally in the 87 th percentile or higher according to USA Swimming’s National Motivational Time Table. – –n= 10 – –Ages 11-19 – –Tanner Stage (#) 3(3), 4(4), 5(3)
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METHODS Procedures: – –Wingate Anaerobic Arm Cranking Test. The test was performed on the Sport Excalibur stationary ergometer while seated in and belted to a chair. – –The braking force used was 0.04 g/kg body mass, which was multiplied by the subject’s body mass (kg) (BASES 1988).
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SWIM TESTING Swimmers swam in a ring-shaped swimming pool The swimmer’s velocity was paced from a moving platform (Prampero 1974) The velocity every three minutes by (.1m/sec) for stages 1-3 Stages 4 – test completion v every two minutes Oxygen uptake was determined by standard open circuit method Serial lactate measurements were recorded at 3 min intervals post exercise for 9 minutes
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STASTICAL ANALYSIS Descriptive statistics (means, SD) for peak blood lactate, peak oxygen consumption, fractional utilization, and power measures were computed for each subject. Pearson Product Moment correlation coefficients were calculated for each variable with time and national rank for all the event distances used in this study.
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RESULTS
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Swim Tested Subject Mean Data Characteristics and Results
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Peak VO 2 Peak VO 2 was expressed in absolute terms and also normalized for mass (mL·kg -1 ·min -1 ) and body surface area (L·min -1 ·m -2 ). Only the correlation coefficient between Peak VO 2 (mL·kg -1 ·min -1 ) and nr 200 were significant (r= 0.67, p<.05). Peak VO 2 was expressed in absolute terms and also normalized for mass (mL·kg -1 ·min -1 ) and body surface area (L·min -1 ·m -2 ). Only the correlation coefficient between Peak VO 2 (mL·kg -1 ·min -1 ) and nr 200 were significant (r= 0.67, p<.05).
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nr 200 to Peak VO 2 R 2 = 0.4521 40 50 60 70 80 90 100 20253035404550556065 Peak VO 2 (mL·kg -1 ·min -1 ) nr 200 nr200= national rank by percentile in the 200 yard freestyle
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Correlation Coefficients for all Peak VO 2 data with time or national rank for the 50 through 1000 yard freestyle events
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WINGATE RESULTS No significant correlation coefficients between PP, MP, Min P, and Rate of Fatigue with: No significant correlation coefficients between PP, MP, Min P, and Rate of Fatigue with: –Time –National Rank
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[BLOOD LACTATE] No significant correlation between blood lactic acid concentration and - Time No significant correlation between blood lactic acid concentration and - Time - National rank
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FRACTIONAL UTLIZATION (Fu, % Peak VO 2 ) Fractional utilization (Fu) was determined at velocities of.9 m/sec, 1.0 m/sec, 1.1 m/sec, and 1.2 m/sec. Fractional utilization (Fu) was determined at velocities of.9 m/sec, 1.0 m/sec, 1.1 m/sec, and 1.2 m/sec. The strongest significant single correlation coefficient occurred at a velocity of 1.1 m/sec between Fu and t200 (r= 0.86, p<.01). The strongest significant single correlation coefficient occurred at a velocity of 1.1 m/sec between Fu and t200 (r= 0.86, p<.01).
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Fu (%) at 1.1 m/sec and t200
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Fu with Time and National Rank Time or Rank Fu @ v=.9 m/sec Fu@ v=1 m/sec Fu@ v=1.1 m/sec Fu@ v=1.2 m/sec t50 0.29NS 0.38 NS 0.48 NS 0.03 NS t100 0.38NS 0.56NS 0.64 p<.05 0.22 NS t200 0.68 p<.05 0.58NS 0.86 p<.01 0.65 p>.05 t500 0.58NS 0.32NS 0.53 NS 0.65 p<.05 t1000 0.66 p<.05 0.32NS 0.59 NS 0.69 p<.05 r50 -0.21 NS -0.46 NS -0.63 p<.05 -0.12 NS r100 -0.28 NS -0.65 p<.05 -0.80 p<.01 -0.30 NS r200 -0.46NS -0.53 NS -0.76 p<.05 -0.62 NS r500 -0.38NS -0.62 NS -0.83 p<.01 -0.76 p<.05 r1000 -0.37NS -0.45 NS -0.7 2 p<.05 -0.83 p<.05
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MAJOR FINDINGS Our results showed a lack of significant correlation between: Our results showed a lack of significant correlation between: –Peak blood lactate –Power measures –Peak VO 2 AND Time and National Rank
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Fu numerous significant correlations coefficients with time and national rank. Fu numerous significant correlations coefficients with time and national rank. Fu at a given submaximal velocity = time for the 100-1000 yard freestyle AND Fu at a given submaximal velocity = time for the 100-1000 yard freestyle AND national rank in the 50-1000 yard distances. national rank in the 50-1000 yard distances.
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DISCUSSION Question: What does Fu mean in swimming? Question: What does Fu mean in swimming?
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DISCUSSION Consider the following: Consider the following: –Work in swimming is often measured as swimming velocity. –Large variation in the energy cost of swimming at a given velocity among swimmers (Pendergast 1977). –Given that the energy cost varies widely among swimmers we can infer that velocity may not be an accurate way to compare the workload between swimmers.
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DISCUSSION Speculate: Speculate: - the swimmer with the more efficient stroke will use less energy to swim at a given velocity. - this would be reflected in a lower percentage of peak VO 2 (lower Fu) at that velocity. Therefore: Therefore: - monitoring the changes in Fu (% peak VO 2 ) that result from stroke alterations may be an effective way to determine the usefulness of the modification in technique.
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CONCLUSION In Elite Adolescent Female Swimmers: In Elite Adolescent Female Swimmers: –Fu reflects stroke efficiency. –Anaerobic capacity as determined by the Wingate Anaerobic Arm Cranking Test does not correlate with swimming time or national rank. –[Blood Lactate] does not correlate with time or national rank. –Aerobic Fitness (Peak VO 2 ) does not correlate with swimming success.
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LIMITATIONS Small number of subjects. Small number of subjects. No measure of stroke mechanics. No measure of stroke mechanics.
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PRACTICAL IMPLICATIONS Fu (% peak VO 2 ) may be a valuable coaching tool, as a way to monitor the effectiveness of stroke modifications. Fu (% peak VO 2 ) may be a valuable coaching tool, as a way to monitor the effectiveness of stroke modifications. Swimming is a technique intensive sport and the training programs of young swimmers should include a substantial amount of technique work. Swimming is a technique intensive sport and the training programs of young swimmers should include a substantial amount of technique work.
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APPENDIX
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FRACTIONAL UTILIZATION (Fu) All Subjects.9 m/sec to 1.2 m/sec
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Table 1 Subject Characteristics
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Table 2 Training, Competition, and Performance Summary (all times are by electronic timing with an electronic start and touchpad stop)
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Table 3 Physiologic Variables: Peak O2, Peak blood [Lactate] and Wingate Anaerobic Arm Crank Results.
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Table 7 Correlation Coefficients for all Peak VO2 data with time or national rank for the 50 through 1000 yard freestyle events * Significant at p<.05 Abbreviations: LBW= lean body weight, [LA] = blood lactate concentration, mM= millimoles, t50-1000= time for the freestyle event distance listed, nr=national rank for the freestyle event distance listed, (mL·kgLBW-·min-1)= Peak oxygen consumption normalized per kg of lean body weight.
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Table 6: Recovery Blood Lactate Measurements and Peak Blood Lactate
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Table 3 Physiologic Variables: Peak VO 2, Peak blood [Lactate] and Wingate Anaerobic Arm Crank Results. Abbreviations: [LA] = blood lactate concentration, na= not applicable, (ml·kglbw-1· min-1) = Oxygen consumption normalized for kg of lean body weight.
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Muscular Efficiency= work/energy expenditure Delta efficiency change in work output between two loads/change in VO2 between the same two loads. pg 51 Brooks, Fahey and Dunn. Oxygen uptake is converted to caloric equivalent with RQ assumed at 1. At an RQ=1, 1 liter of O2= 5kcal. Running Economy used because actual work performed during treadmill running or walking is difficult to determine. Economy= O2 uptake/kg body mass at a given v or slope Measured during steady state exercise below individual lactate threshold. Running =progressive decline in weight-relative metabolic demand for a given submaximal exercise with increasing age. Children= increased energy cost of locomotion. Submaximal economy measured as VO2 per kg steadily improves as the child grows. In children submaximal economy is not a good predictor of field success in running. Karhenbuhl. As children grow they will exercise at the same submaximal speed at a progressively lower percentage of VO2 max. SWIMMING
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Pendergast: W= D.v where W=kgm/min D= kg v= m/min Efficiency increases linearly as a function of velocity for all levels of swimming skill. Muscle: >% ST fibers >#&Density of capillaries Smaller fiber diameters Shorter diffusion distances > SDH Determinants of Aerobic Power: HR and Q max 10-20% less than in running Bradycardia seen during immersion persists during X and is compensated for by >SV therefore Q remains relatively unchanged.
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VE does not seem to limit oxygen transport during swimming. VE is significantly lower than during running at all levels during of VO2. Underwater Torque (T') =[ force (feet tend to sink) X distance (feet to center of volume of the lung) ] (T') is linearly related to the energy cost of swimming front crawl. T' is one of the most important factors in determining the energy cost of swimming Cs. T' increases linearly with age slope higher with boys. Wtot = Wk + Wd Cs measured by [Steady State O2 cost /v m/sec] Cs was a function of velocity in all four strokes Increased exponentially in crawl and backstroke Cs in fly attained a min at the two lowest v to increase exponentially at higher v Cs in breaststroke was a linear function of v. Zampara T' is not a determinant of Cs at faster speeds only at the 400 (and maybe the mile?)
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Maximal performance depends on maximal metabolic power and on the economy of locomotion. Cs= the amount of metabolic energy spent to cover one unit of distance kJ km-1 Cs increases as a function of the speed and depends on: swimming style technical skill gender anthropometric features buoyancy passive and active drag propelling efficiency The energy equivalent of oxygen = 20.9 kJ lO2-1 RQ=.98 Determinants of the energy cost of swimming in children: Poujade: Cs= energy expenditure per unit of distance one of the most important factors effecting performance. Di Prampero 1986.
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