ANAEROBIC THRESHOLD MEASUREMENT IN YOUNG SWIMMERS IS DIFFICULT

Sousa, M., Vilas-Boas, J. P., & Fernandes, R. (2012). Comparison between individual and averaged methodologies for anaerobic threshold assessment of age-group swimmers. Presentation 1281 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.

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This study compared the anaerobic threshold swimming velocity of 10-11 years-old swimmers assessed by individualized protocols (step and critical velocity tests) and by the traditional blood lactate concentration of 4 mmol/l value.

Age-group swimmers (N = 15) performed a 5 x 200 m front crawl step test (increments of 0.05 m/s per step, and one-minute rest intervals). Earlobe capillary blood samples for lactate analysis were collected at rest, after each step, and at the end of the test, which allowed the assessment of the vAnTStep through the lactate/velocity curve modeling method, and velocity at 4 mmol/l by linear interpolation. Critical velocity was obtained through the slope of the linear relationship of time versus distance based on the times of 100 and 400 m competitive events.

The velocity at anaerobic threshold in the step test and critical velocity were significantly lower than the velocity at 4 mmol/l. The differences equate to a five-second gap in a 100 m front crawl effort. The lactate value corresponding to anaerobic threshold in the step test was 2.3 0.59 mmol/l.

Implication. The velocity of swimming at 4 mmol/l does not represent the individual velocity at anaerobic threshold in children involved in competitive swimming, A 200 m step incremental protocol to determine the precise point of the rise in lactate and critical velocity might yield more accurate measures. However, since young people (10-11 years) are underdeveloped in anaerobic capacity, conducting such an analysis would serve little practical purpose. [This study was conducted with traditional training characteristics of long work bouts and recovery periods and therefore might not be associated with the best form of swimming training and development.]

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