HOW MAXIMUM LACTATE STEADY-STATE IS DETERMINED GOVERNS THE ASSOCIATED VELOCITY OF SWIMMING

Oliveira, M. F., Caputo, F., Dekerle, J., Denadai, B. S., & Greco, C. C. (2010). Technical and physiological changes during continuous vs. intermittent swims at and above maximal lactate steady state. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 1619, 2010.

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This study aimed to verify whether maximum lactate steady-state determined using continuous (MLSSc) or intermittent (MLSSi) protocols represented a boundary above which not only physiological but also technical changes occurred. Endurance swimmers (N = 13; ~23 years) performed four to eight 30-minute sub-maximal tests, to determine the MLSSc and MLSSi (12 x 150 seconds with 30 seconds of passive recovery). The time to complete five stroke cycles was used to calculate one stroke rate value per 100 m. Stroke length was calculated as the ratio between velocity and stroke rate. Blood lactate, stroke rate, and stroke length were analyzed at minutes 10 and 30 of each test.

Velocities at MLSSi (fastest) and MLSSc were significantly different (3.2%) while the blood lactate concentrations were similar. Stroke rate increased during MLSSi. Stroke length decreased during both protocols. Stroke rate and stroke length changed from minute 10 to 30 of the interval exercise and was greatest at a velocity of 102.5% MLSSc when compared to the actual MLSSc. There was no significant correlation of the percent change in lactate with changes in stroke rate and stroke length.

Implication. Swimming technique changes over time when swimming above and at maximum lactate steady-state in both continuous and intermittent forms despite a steady state in blood lactate concentrations. However, these changes seem to be more pronounced in continuous swimming. Changes in stroke technique can be dissociated from changes in blood lactate concentrations in intermittent swimming.

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