B.Sokolova, G.Sokolovas

Lithuanian Institute of Physical Education,
Kaunas, Lithuania

INTRODUCTION. The blood lactate concentration perform the activity of the anaerobic glycolysis by athletes. In enduarance sports the scientists use often so-called "lactate curve" - dependence between lactate concentration and exercice intencity. This curve shows the aerobic and anaerobic capacity by athletes. The term anaerobic threshold represents the speed where aerobic metabolism and lactate removing are at near maximum capacity. It is a border between aerobic zones (1 and 2) and anaerobic zones (3, 4 and 5). Zone 3 correspond to mix - aerobic-anaerobic energy system. Zone 4 - to anaerobic glycolize energy system, zone 5 - to anaerobic creatinphosphate energy system (Brooks G.A. etc., 1996; Maglischo E., 1993).

The aim of this study was to analize lactate accumulation to swimming velocity and evaluate anaerobic threshold by swimmers.

METHODS. 25 male swimmers different age participated to this study. Age of these sujects was between 12 and 19 years. They were good trained to Lithuanian age group level. The swimmers performed incremental test with each load step duration 300 m. It was five steps. Last step was with maximum effort. The swimming velocity on 300 m diatance correspond to: 1 step - 85%, 2 step - 90%, 3 step - 95%, 4 step - 100%. The break duration between steps was about 1 min. - time for blood sample. Blood samples were taken from fingertip. In according to test results were evaluate lactate curves - dependencies between lactate accumulation and swimming velocity.

After last step were taken blood samples at 5, 10 and 15 minutes of recovery. In according to these were evaluate dependencies between lactate accumulation and recovery time. Lactate measurement were carried out by lactate analyser (company of Dr. Bruno Lange, Germany).

The lactate threshold was determined from the lactate curve and lactate decreasing curve in recovery time (Stegmann H., Kindermann W., 1981).

RESULTS. The maximal blood lactate concentration was very different by swimmers: from 3,23 till 20 mmol/l. It shows different anaerobic capacity by athletes. This depend on age and workability of swimmers. The dynamic of lactate accumulation to swimming velocity was evaluated as exponentional regression (figure 1).

Lactate threshold depends on working-capacity of swimmers, their age and individual adaptation to workload. Our investigations showed dynamic of lactate threshold with age: the younger athletes are, the less they can accumulate lactate. Some times they accumulate maximum only 6-8 mmol/l.

After last swimming step with maximum effort we evaluated lactate accumulation in recovery. The decreasing of lactate concentration in recovery was evaluated as exponentional function. We determinated dependencies of lactate amount and recovery time. Coefficient "b" showed recovery velocity of lactate amount. This index was different for swimmers: from 0,025 to 0,117 minutes^-1.

Individual lactate threshold we determinated in according to Stegmann H., Kindermann W. (1981) methods. These indexes by swimmers were from 2,6 to 5,2 mmol/l.

Figure 1. The dynamic of lactate accumulation to swimming velocity by swimmer.

DISCUSSION. This study has shown that lactate concentration to swimming velocity depends on different factors: age, workability and distance orientation of swimmers. In according to individual anaerobic threshold were determinated borders of intensity zones as swimming velocity for each swimmer. Individual anaerobic threshold by young swimmers is rather lower than 4 mmol/l, which is as general index of anaerobic threshold. The analysis of dynamic’s of lactate accumulation to swimming velocity need individualization: the swimmers have different lactate accumulation speed to swimming velocity, different maximal blood lactate concentration, different recovery of lactate concentration, different individual lactate threshold.

1. Exercise physiology / G.A.Brooks, T.D.Faley, T.P.White. - Mayfield Publishing Company, California, 1996.

2. Stegmann H.,Kindermann W. Bestimung der individuellen anaeroben Schwelle bei unterschiedlich Ausdauertrainierten aufgrund der Arbeits- und Erholungsphase // Dt. Ztschr. f. Sportmedizin (1981), 8.

3. Maglischo E. Swimming Even Faster. Bakersfield, California, Mayfield Publishing Company, 1993.

При любом использовании данного материала ссылка на первоисточник обязательна!

Sokolova, B. Investigation of "lactate curve" by swimmers / Sokolova B., Sokolovas G. // Человек в мире спорта : Новые идеи, технологии, перспективы : Тез. докл. Междунар. конгр. - М., 1998. - Т. 1. - С. 117-118.