Bibiano Madrid

Lactate Threshold Prediction by Blood Glucose and Rating of Perceived Exertion in People with Type 2 Diabetes

The validity of rating of perceived exertion (RPE) in predicting lactate threshold during an incremental test was analyzed in 15 men with type 2 diabetes (M age = 53.4 yr., SD = 12.9). Blood glucose, lactate, and minute ventilation (VE)/VO2 responses identified the lactate, ventilatory, and glucose thresholds. Workloads (W) corresponding to RPEs 12, 13, 14, and 15 were determined. Second-order polynomials fit to VE/W and [lac]/W ratios corresponding to RPEs of 9–10, 12–13, and 16–17 also identified workloads above which there was an overproportional increase in VE and [lac]. These workload breakpoints did not differ, although at RPE 12 underestimated and at RPE 15 overestimated lactate threshold. RPE 13 and 14 and the responses of VE/W and [lac]/W to submaximal exercise accurately predicted lactate threshold.

Circulating miR-1, miR-133a, and miR-206 levels are increased after a half-marathon run.

Abstract Context: Circulating miRNAs are potential biomarkers that can be important molecules driving cell-to-cell communication. Objective: To investigate circulating muscle-specific miRNAs in recreational athletes. Materials and methods: Three miRNAs from whole plasma before and after a half-marathon were analyzed by qPCR. Results: MiR-1, −133a, and −206 significantly increased after the race. Discussion: Increased levels of miRNAs after exercise point to potential biomarkers and to the possibility of being functional players following endurance training. Conclusion: These miRNAs are potential biomarkers of muscle damage or adaptation to exercise.

Relação da circunferência do pescoço com a força muscular relativa e os fatores de risco cardiovascular em mulheres sedentárias

OBJECTIVE To verify the relation of neck circumference and relative muscle strength and cardiovascular risk factors in sedentary women. METHODS A cross-sectional study with 60 premenopausal women (33.9±9.1 years; 67.4±13.6kg; 1.57±0.6cm and 27.2±5.3kg/m²). Based on the neck circumference, the sample was divided into two groups: Group Circumference <35cm (n=27) and Group Circumference >35cm (n=33) to compare relative muscle strength and cardiovascular risk factors. The correlation between variables was tested by Pearson and Spearman correlations, with a significance level established at p<0.05. RESULTS The findings revealed that women with neck circumference >35cm presented higher values of body mass, waist circumference, body adiposity index, body mass index, systolic blood pressure, blood glucose, glycated hemoglobin and volume of visceral fat when compared with the group with neck circumference <35cm. Additionally, the group with larger neck circumference presented lower values of relative strength. CONCLUSION Neck circumference seems to be an important predictive factor of cardiovascular risk and of relative strength loss in middle-aged sedentary women.

Reliability of Vertical Jump Performance evaluated with contact mat in elderly women

The aim of this study was to evaluate the reliability of the vertical jump (VJ) using a contact mat in elderly women. Thirty‐one physically active women aged 69·5 ± 5·6 years participated in this study. Jump performance was evaluated with a contact mat. The first testing session (s1) consisted of four countermovement jumps interspersed with 40 s rest intervals. After a period of 5–7 days, volunteers performed the second session (s2) utilizing the same procedures. The intersession statistical analysis was calculated considering the two highest jumps, one obtained in each section. The intra‐session analysis utilized all eight jumps, all four from each section, and the differences between means were calculated by repeated measures ANOVA. Reliability was tested using the intra‐class correlation coefficient (ICC) and agreement by the Bland–Altman method. The intra‐ and inter‐subject variation percentage was calculated by the coefficient of variation (CV). Results: The intersession results displayed a high ICC (0·91; P<0·001) and a good agreement verified by the Bland–Altman method. There was a significant difference in the intra‐session analysis only in s2 between the jumps 2 and 4. Both in s1 and s2, the ICC was high (0·96; P<0·001; 0·95; P<0·001), and the within session reliability CV was low (10·14% and 9·07%). Conclusion: In physically active elderly women, VJ evaluation using a contact mat is a reliable method and could be used to estimate jump height. Additionally, the results of this study could serve as reference values in similar samples evaluated with the same procedures.

Identificação do lactato mínimo de corredores adolescentes em teste de pista de três estágios incrementais

OBJECTIVE: To analyze the possibility of determining the lactate minimum (LM) velocity in prepubertal runners applying only three incremental stages. METHODS: Eleven teens (13.7 ± 1.0 years; 47.3 ± 12.1 kg; 160.0 ± 1.0 cm; 18.3 ± 1.8 kg/m2) performed three run tests on athletic track field on different days: 1) performance at 3000m (Vm3000) 2) LM test consisting of a 500m sprint for hyperlactatemia induction, followed by 10min of recovery and six sets of 800m at intensities of 83, 86, 89, 92, 95 and 98% of Vm3000, 3) LM test with threestage (LMp3) similarly to the previous protocol; however, with only three sets of 800m at intensities of 83, 89 and 98% of Vm3000. During the first recovery minute between the second and third test stages, blood samples were collected in order to measure blood lactate. The following criteria were used to determine LM: a) visual inspection (LM), b) polynomial function of second order to LM six stages (LMp) and to three stages (LMp3). RESULTS: ANOVA showed no differences between speeds (m.min-1) identified in the studied methods (LM = 221.7 ± 15.4 vs. LMp = 227.1 ± 10.8 vs. LMp3 = 224.1 ± 11.2). High correlations were observed between the studied protocols and between these protocols and the Vm3000 (p <0.01). CONCLUSION: It was possible to identify the velocity corresponding to the LM in youth runners even when applying only three incremental stages for identification of the LM intensity (LMp3).

Functional capacity and obesity reflect the cognitive performance of older adults living in long-term care facilities

With the increase in life expectancy, the elderly Brazilian population has grown considerably. However, longevity is usually accompanied by problems such as the loss of functional capacity, cognitive decline, and deterioration in anthropometric parameters, particularly among those living in long‐term care facilities. We analyzed the relationship among cognitive performance, anthropometry, and functional capacity in institutionalized elderly individuals.

Reprodutibilidade do protocolo de lactato mínimo com intensidade do esforço prévio individualizado pela PSE

Abstract: The lactate minimum protocol (LM) is preceded by a maximum effort to induce hyperlactatemia. Objective: To verify the reliability of LM test with induced hyperlactatemia realized by exercise intensity individualized by the rating perceived effort (RPE). Methods: The sample was composed of 20 students, physically active (25.4 ± 4.1 years, 14.1 ± 5.0% fats) who were undertaken to two tests with identical methodology of LM. Induction of hyperlactatemia was performed by a test with four stages, lasting three minutes each, loads individualized by the PSE (levels 10, 13, 16 and 17-20 last stage until voluntary exhaustion). After eight minutes of recovery the progressive test started with initial load of 75W and 25W increments every 3 min until exhaustion. Results: The intensities of LM 1 (155.0 ± 23.8 W) and 2 (157.5 ± 27.0 W) did not differ statistically (p = 0.795) and showed good reliability (ICC = 0.79) and agreement [-2.5 W of mean difference and ± 41.8 W of bias]. Conclusion: The LM test, with loads for induction of hyperlactatemia individualized by the RPE, has shown to be reliable in physically active individuals.

Estimation of the Maximal Lactate Steady State Intensity by the Rating of Perceived Exertion

The maximal lactate steady state is the gold standard for evaluating aerobic capacity; however, it is time-consuming. The lactate minimum protocol is an easier alternative, but is not feasible and still expensive. This study investigated whether the rating of perceived exertion of 13 is an accurate predictor of lactate minimum and maximal lactate steady state intensities. Eleven physically active men performed three tests: (1) incremental exercise with workloads based on rating of perceived exertion of 10, 13, and 16 (experimental protocol – denominated RPE-13 test), (2) lactate minimum, and (3) maximal lactate steady state. No differences were observed among participants’ workloads corresponding to rating of perceived exertion 13, lactate minimum, and maximal lactate steady state intensities. Thus, the workload associated with the rating of perceived exertion of 13 was equivalent to the other two protocols investigated.