Predicting Lactate Threshold With Rate of Perceived Exertion in Young Competitive Male Swimmers

The purpose of this study was to verify the effectiveness of the rate of perceived exertion threshold (RPET) for predicting young competitive swimmers' lactate threshold (LT) during incremental testing. We enrolled 13 male athletes (M age = 16, SD = 0.6 years) in an incremental test protocol consisting of eight repetitions of a 100-meter crawl with 2-minute intervals between each repetition. We collected data for blood lactate concentration ([La]) and Borg scale rate of perceived exertion (RPE) at the end of each repetition. The results obtained were: M RPET = 4.98, SD = 1.12 arbitrary units (A.U.) and M lactate threshold = 4.24, SD = 1.12 mmol.L^-1, with [La] and RPE identified by the maximal deviation (Dmax) method without a significant difference (p > 0.05) and large correlations between DmaxLa and DmaxRPE at variables for time (r = 0.64), velocity (r = 0.67) and percentage of personal best time (PB) (r = 0.60). These results suggest that RPET is a good predictor of LT in young competitive swimmers.

PONTOS DE TRANSIÇÃO DA FREQUÊNCIA CARDÍACA NA MARCHA ATLÉTICA

RESUMO Introdução: A frequência cardíaca fornece informações úteis para os treinamentos de marcha atlética. Objetivo: O objetivo do estudo foi analisar o comportamento da frequência cardíaca (FC) e seus pontos de inflexão (PIFC) e deflexão (PDFC) em teste progressivo de marcha atlética (TPMA) antes e depois de 20 sessões de treinamento. Métodos: Participaram 13 jovens atletas (12,46 ± 1,61 anos, 44,29 ± 10,25 kg, 157,93 ± 12,03 cm, 24,39 ± 7,60 %G). O TPMA foi realizado em uma pista oficial de atletismo, antes e depois do treinamento. Os dados de FC e carga foram plotados a cada minuto para identificação dos PIFC e PDFC. Resultados: A FC apresentou comportamento sigmoide, com identificação dos pontos de transição (PT), sendo no pré-treinamento: a) oito sujeitos PIFC (5,31 km·h-1; 125 bpm) e PDFC (7,63 km·h-1; 169 bpm); b) um sujeito somente PIFC (7,00 km·h-1; 149 bpm); c) um sujeito somente PDFC (8,00 km·h-1; 170 bpm); d) três sujeitos sem detecção de PT e no pós-treinamento: a) em 12 sujeitos PIFC (5,46 km·h-1; 125 bpm) e PDFC (7,75 km·h-1; 168 bpm); b) um sujeito somente PDFC (7,50 km·h-1; 184 bpm). O PIFC foi encontrado em carga significativamente inferior ao PDFC no pré (p < 0,001) e no pós-treinamento (p < 0,001). Quando comparamos o PIFC e o PDFC pré e pós, não encontramos diferença significativa, seja em relação à carga (p = 0,87 e p = 0,61) ou FC (p = 0,60 e p = 0,99). Conclusão: Conclui-se que a FC tem relação curvilínea com a carga, sendo possível detectar os seus pontos de transição em TPMA.

Lactate threshold by muscle electrical impedance in professional rowers

Lactate threshold (LT) is one of the physiological parameters usually used in rowing sport training prescription because it indicates the transitions from aerobic to anaerobic metabolism. Assessment of LT is classically based on a series of values of blood lactate concentrations obtained during progressive exercise tests and thus has an invasive aspect. The feasibility of noninvasive LT estimative through bioelectrical impedance spectroscopy (BIS) data collected in thigh muscles during rowing ergometer exercise tests was investigated. Nineteen professional rowers, age 19 (mean) ± 4.8 (standard deviation) yr, height 187.3 ± 6.6 cm, body mass 83 ± 7.7 kg, and training experience of 7 ± 4 yr, were evaluated in a rowing ergometer progressive test with paired measures of blood lactate concentration and BIS in thigh muscles. Bioelectrical impedance data were obtained by using a bipolar method of spectroscopy based on the current response to a voltage step. An electrical model was used to interpret BIS data and to derive parameters that were investigated to estimate LT noninvasively. From the serial blood lactate measurements, LT was also determined through Dmax method (LT_Dmax). The zero crossing of the second derivative of kinetic of the capacitance electrode (Ce), one of the BIS parameters, was used to estimate LT. The agreement between the LT estimates through BIS (LT_BIS) and through Dmax method (LT_Dmax) was evaluated using Bland-Altman plots, leading to a mean difference between the estimates of just 0.07 W and a Pearson correlation coefficient r = 0.85. This result supports the utilization of the proposed method based on BIS parameters for estimating noninvasively the lactate threshold in rowing.

Can we Identify the Heart Rate Deflection Point and Rating of Perceived Exertion Threshold during the Yo-Yo Intermittent Recovery Test Level 1 in University Basketball Players? A Pilot Study

Purpose. The aim of the study was to identify the heart rate deflection point (HRDP) and the rating of perceived exertion (RPE) threshold (D

Rowing ergometer with the slide is more specific to rowers' physiological evaluation

This study investigated maximal and submaximal performance (power output) and physiological responses (oxygen uptake, heart rate and blood lactate concentration) of eight male rowers to two different incremental tests to exhaustion performed either in a rowing ergometer without (regular) or with the slide, as well as to a 2000 m race simulation, conducted in a randomized order. Peak oxygen uptake ([Formula: see text]O2peak) was statistically higher (3.4%) in the regular test (5.18 ± 0.44 L.min(-1)) compared with the slide condition (5.01 ± 0.37 L.min(-1); P = 0.005). Time for the on-water race simulation was significantly correlated with the slope of the [Formula: see text]O2-power relationship in the slide condition (r = -0.73, P = 0.043) and [Formula: see text]O2peak during the test in the slide condition was correlated to mean [Formula: see text]O2 at the on-water race simulation (r = 0.78; P = 0.024). Thus, the use of the slide is more beneficial than the regular test when evaluating rowers.

Narita target heart rate equation underestimates the predicted adequate exercise level in sedentary young boys

Purpose

Optimal training intensity and the adequate exercise level for physical fitness is one of the most important interests of coaches and sports physiologists. The aim of this study was to investigate the validity of the Narita et al target heart rate equation for the adequate exercise training level in sedentary young boys.

Methods

Forty two sedentary young boys (19.07±1.16 years) undertook a blood lactate transition threshold maximal treadmill test to volitional exhaustion with continuous respiratory gas measurements according to the Craig method. The anaerobic threshold (AT) of the participants then was calculated using the Narita target heart rate equation.

Results

Hopkin's spreadsheet to obtain confidence limit and the chance of the true difference between gas measurements and Narita target heart rate equation revealed that the Narita equation most likely underestimates the measured anaerobic threshold in sedentary young boys (168.76±15 vs. 130.08±14.36) (Difference ±90% confidence limit: 38.1±18). Intraclass correlation coefficient (ICC) showed a poor agreement between the criterion method and Narita equation (ICC= 0.03).

Conclusion

According to the results, the Narita equation underestimates the measured AT. It seems that the Narita equation is a good predictor of aerobic not AT which can be investigated in the future studies.