Physiological and Stroke Parameters to Assess Aerobic Capacity in Swimming

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Purpose: To identify the speed corresponding to anaerobic threshold using the D-max method for both blood lactate and biomechanical stroke parameters determined in an incremental swimming test and to compare this information with the speed corresponding to the maximal lactate steady state (S-MLSS). Methods: Five male long-distance swimmers and 8 triathletes (N = 13; age 23.8 +/- 9.5 y, height 1.76 +/- 0.1 m, weight 71.3 +/- 9.8 kg) performed the following protocols: maximal 400-m test to determine maximal aerobic speed (S-400); 7 x 200-m incremental test to determine the speed corresponding to the D-max point on the blood lactate (S-La), stroke-rate (S-SR), stroke-length (S-SL), and stroke-index (S-SI) responses; and two to four 30-min submaximal tests to determine the S-MLSS. Results: S-LA (1.18 +/- 0.08 m/s), S-SI (1.18 +/- 0.08 m/s), S-SR (1.17 +/- 0.1 m/s), and S-SL(1.16 +/- 0.09 m/s) were not significantly different from each other or from S-MLSS (1.13 +/- 0.08 m/s). There were high correlations between S-LA, S-SI, S-SR, S-SL, and S-MLSS (r = .91, .89, .85, and .80, respectively). The typical errors of estimate for S-LA (3.2%), S-SI (3.7%), S-SR (4.1%), and S-SL (4.7%) suggest good validity of these variables to predict S-MLSS. Furthermore, all physiological and biomechanical variables were moderately to highly correlated with S-400 (r = .73-.95). Conclusions: It is possible to obtain a physiological index of aerobic capacity and performance using simple biomechanical measurements during an incremental test without performing blood lactate analyses.