RESUMO
BACKGROUND: The purpose of this study was to analyze the course of changes in the blood lactate (BL) concentration in response to the graded exercise test (GXT) and the modified Wingate test (MWT). METHODS: This study involved 23 male highly trained road cyclists (age: 16.2 ± 1.1 years; experience: 5.0 ± 2.1 years; VO2max 59.0 ± 3.5 mL × kg-1 × min-1). The analysis of BL concentration was conducted using an enzymatic-amperometric electrochemical technique. RESULTS: Our study provided the following information: (i) peak BL concentration in response to GXT (12.86 ± 2.32 mmol × L-1) and MWT (12.85 ± 1.47 mmol × L-1) is expected around the third minute after the completion of the trial; (ii) 60 min is not a sufficient period for BL concentration to return to resting values after GXT; (iii) post-GXT BL removal during the 60 min period is unsteady (3-20 min: -2.6 ± -0.6% × min-1; 20-60 min: -1.6 ± -0.3% × min-1; p-value for comparison < 0.01), whereas post-MWT BL removal during the 12 min period appears to be constant (3-6 min: -2.4 ± -5.6% × min-1, 6-9 min: -2.6 ± -1.8 % × min-1; 9-12 min: -3.1 ± -2.1 % × min-1; p-value for all comparisons < 0.01). CONCLUSIONS: When aiming to obtain valuable data regarding the course of changes in BL concentration during the post-exertion period, it is essential to consider the number of measurements and the time points in sample collection for analysis.
RESUMO
The objective of this study was to analyze the behavior of autonomic modulation before, during and after the Modified Wingate Test (WanMT), through the analysis of Heart Rate Variability (HRV). Six volunteers between the ages of 40 and 70, post-revascularization procedures (angioplasty and/or surgery, mean duration 10 months), were submitted to supervised training for at least 10 to 14 months. The following protocol, divided into 5 phases, was used: 1) Rest Phase (RP): 180 seconds; 2) Submaximum Phase (SP): 30 seconds; 3) Maximum Phase (MP): 30 seconds; 4) Active Recuperation Phase (ARP); 120 seconds and; 5) Passive Recuperation Phase (PRP): 180 seconds. For the WanMT Test, we selected the load of 3.75% of corporal weight for all volunteers. To analyze the HRV, we used the following parameters: the interval RRr, MNN, SDNN, RMSSD and PNN50. We only observed results for the group according to RMSSD parameters during the rest phase of the test protocol in which the group remained in vagal presence and during all other phases in vagal depression. However, when we analyzed the PNN50, we observed that the group was in medium vagal presence during all of the phases of the test though there was no statistically significant difference (p> 0.05) between the phases. Therefore, we can say that all of the individuals had a similar profile in the autonomic response to the WanMT, confirmed by the parameters studied in the analysis of the HRV in the time domain.