A STEP-TEST GIVES A ROUGH PREDICTION OF A PROTOCOL-DEPENDENT MEASURE

Barber, J., W., Robinson, T. L., Smith, E. R., & Vitale, D. A. (1999). Anaerobic threshold determination for breaststroke and butterfly in competitive adolescent swimmers. Medicine and Science in Sports and Exercise, 31(5), Supplement abstract 1398.

This study evaluated a field test for anaerobic threshold (AT) in breaststroke (BS) and butterfly (BF) swimming. A step-test was used to determine AT: 4 x 100 m swims of BS or BF at increasing velocities until failure. The average times of the set of 4 x 100 m preceding failure were used to predict AT. The step test was compared with a criterion blood lactate test when predicting AT. The blood lactate test consisted of 4 x 200 m swims of increasing velocity, with lactate sampled immediately after each swim. The lactate breakpoint curve served as the AT criterion.

Ss swam BS (N = 6) or BF (N = 5). There were no significant differences between criterion or predicted AT for either stroke. Significant correlations between blood lactate test and step-test for predicting AT were revealed (r = .91 for BS; r = .94 for BF). It should be noted that a rough estimate of predictive accuracy of these tests is 82 and 88% respectively.

The authors propose the step-test as a good predictor of AT speeds for both BS and BF. However, since AT is dependent upon the protocol and repetition distance used, one has to question the external validity of this proposal. Exactly what the numbers from the step-test represent is debatable.

Implication. A specific step-test protocol is moderately related to one method for estimating anaerobic threshold in breaststroke and butterfly swimming. Is such a restricted activity useful?

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