Verifying Physiological and Biomechanical Parameters during Continuous Swimming at Speed Corresponding to Lactate Threshold

Abstract

<jats:p>The purpose of this study was to verify the physiological responses and biomechanical parameters measured during 30 min of continuous swimming (T30) at intensity corresponding to lactate threshold previously calculated by an intermittent progressively increasing speed test (7 × 200 m). Fourteen competitive swimmers (18.0 (2.5) years, 67.5 (8.8) kg, 174.5 (7.7) cm) performed a 7 × 200 m front crawl test. Blood lactate concentration (BL) and oxygen uptake (VO2) were determined after each 200 m repetition, while heart rate (HR), arm-stroke rate (SR), and arm-stroke length (SL) were measured during each 200 m repetition. Using the speed vs. lactate concentration curve, the speed at lactate threshold (sLT) and parameters corresponding to sLT were calculated (BL-sLT, VO2-sLT, HR-sLT, SR-sLT, and SL-sLT). In the following day, a T30 corresponding to sLT was performed and BL-T30, VO2-T30, HR-T30, SR-T30, and SL-T30 were measured after the 10th and 30th minute, and average values were used for comparison. VO2-sLT was no different compared to VO2-T30 (p &gt; 0.05). BL-T30, HR-T30, and SR-T30 were higher, while SL-T30 was lower compared to BL-sLT, HR-sLT, SR-sLT, and SL-sLT (p &lt; 0.05). Continuous swimming at speed corresponding to lactate threshold may not show the same physiological and biomechanical responses as those calculated by a progressively increasing speed test of 7 × 200 m.</jats:p>

Lactate Threshold Evaluation in Swimmers: The Importance of Age and Method

“…In this case, the slope of the straight line may be greater, and the maximal perpendicular distance from the lactate curve may correspond to a higher point of the speed vs. lactate concentration curve, with a higher predicted lactate concentration as a result. A similar disa-greement between BL corresponding to LT compared to MLSS has been previously reported using LT F and LT int methods in adult swimmers [10,24]. Indeed, this is also confirmed in the current study between LT F and MLSS methods in children and adolescents.…”

“…Moreover, the participants in most of the cycling or running studies investigating the comparison of LT calculation methods are "healthy" [21], "moderately-trained" [15], or at a non-defined competitive level [13,36]. Well-trained swimmers participated in the current study and previous studies with swimmers [4,24,37]. The competitive level of participants may affect the physiological responses, altering the exercise intensity versus lactate concentration curve and all subsequent calculations for LT and sLT [3,10].…”

“…Fingertip capillary blood was collected (Lactate Scout + , SensLab GmbH, Leipzig, Germany) in the first 30-s of recovery after each repetition of the incremental test. Individual speed vs. lactate concentration curves were drawn and used for the determination of sLT using five methods: i) LT int , calculation of the x-axis projection of the intersection of the lines connecting the higher and lower points of the speed vs. lactate curve [7,24] (▶Fig. 1a), ii) LT v , by visual inspection, locating the point at the curve where BL increase rapidly [25].…”

Particularities of the changes in young swimmers’ body adaptation to the stimuli of physical and mental stress in sports training process

“…To determine the anaerobic capacity in training, the capillary blood test was used for measuring the blood lactate (mmol L −1 ) and blood glucose (mmol L −1 ) before effort and after effort, when the 8x100 m specialized swimming stroke was used (motor test-MT1), start at 150 s, with a pause of 1 min approximately; the competition events were split 2x50 m (MT2), with 5 s pause; in the 5th and 15th minute after effort for the assessment of the quality of the recovery capacity after effort. The Lactate Pro portable analyzer with Lactate Pro Test Strips was used to determine the blood lactate, which was generally less than +/-2.0 mM over the physiological range of 1.0-18.0 mM (range of mean difference: −0.06 mM to 0.52 mM), Mean Squared Error and correction for Bias indicated that both the Edge and Xpress had low 'total' error (∼0-2 mM) for lactate concentrations <15 mM (e.g., Bonaventura et al, 2015); the blood glucose was determined by means of the portable analyzer Accu-Chek Performa Nano glucometer with Accu-Chek Performa test strips, Detection limit (lowest value displayed): 10 mg/dL (0.6 mmol/L) for the test strip, System measurement range: 10-600 mg/dL (0.6-33.3 mmol/L), Sample size: 0.6 µL, Test time: 5 s (Salgau, 2017;Ferreira et al, 2019;Arsoniadis et al, 2020a;Arsoniadis et al, 2020b). The time in the motor tests was measured with the help of the Professional Timer Stopwatch, Digital Sports Stopwatch with Countdown Timer, 100 Lap Memory, 0.001 Second Timing (water resistant, multi-functional stopwatch for swimming, running, training).…”

“…The anaerobic threshold tests measure the concentration of lactate in timed repetitions series, swimming at progressive speeds. The lactate concentration depending on the swimming speed shows the results of one of the most used blood tests (Bitang & Dulceanu, 2014;Nikitakis et al, 2019;Arsoniadis et al, 2020a;Arsoniadis et al, 2020b).…”