Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision ...Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and 3 methods of VT determination by gas analysis.Methods: Twenty-four professional basketball players(age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold(VT1) was determined by ventilatory equivalent(VE) and HRV and second ventilatory threshold(VT2) was determined by 3 methods of gases analysis(V-slope, VE and gas exchange ratio(R), and HRV). Pearson's coefficient(r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement.Results: The results showed no significant differences in HR and oxygen consumption(VO2) at VT1 between the 2 methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation in HR values was higher between R and HRV(r = 0.96) and VE and HRV(r = 0.96) than V-slope and HRV(r = 0.90).Conclusion: These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.展开更多
We compared the levels of ventilatory threshold (VT) between subjects with and without pro-teinuria. We used data of 402 men and 413 women who were not taking any medications, aged 20 - 77 years, in this cross-section...We compared the levels of ventilatory threshold (VT) between subjects with and without pro-teinuria. We used data of 402 men and 413 women who were not taking any medications, aged 20 - 77 years, in this cross-sectional in-vestigation study. Aerobic Parameters at VT i.e. oxygen uptake, work rate and heart rate, and exercise habits were evaluated, which are con-sidered to be cardio respiratory fitness. Pro-teinuria was measured by using urine strip de-vices. Forty three men (10.7%) and 29 women (7.0%) were diagnosed as having the proteinuria (± ≦). There were no significant relationships between proteinuria and exercise habits in both sexes after adjusting for age. Oxygen uptake at VT in subjects with proteinuria was significantly lower than that in subjects without proteinuria after adjusting for age in men. However, such link was not noted in women after adjusting for age (p = 0.9964). Finally, associations were at-tenuated after adjusting for age and exercise habits in both sexes. Among Japanese not tak-ing medications, proteinuria might be a modifi-able factor of VT, especially in Japanese men.展开更多
Purpose: The present study aimed to investigate the reliability of the non-exhaustive double effort(NEDE) test in running exercise and its associations with the ventilatory thresholds(VT_1 and VT_2) and the maximal la...Purpose: The present study aimed to investigate the reliability of the non-exhaustive double effort(NEDE) test in running exercise and its associations with the ventilatory thresholds(VT_1 and VT_2) and the maximal lactate steady state(MLSS).Methods: Ten healthy male adults(age: 23 ± 4 years, height: 176.6 ± 6.4 cm, body mass: 76.6 ± 10.7 kg) performed 4 procedures:(1) a ramp test for VT_1 and VT_2 determinations measured by ratio of expired ventilation to O_2 uptake(VE/VO_2) and expired ventilation to CO_2 output(VE/VCO_2) equivalents, respectively;(2) the NEDE test measured by blood lactate concentration(NEDE_(LAC)) and heart rate responses(NEDE_(HR));(3) a retest of NEDE for reliability analysis; and(4) continuous efforts to determine the MLSS intensity. The NEDE test consisted of4 sessions at different running intensities. Each session was characterized by double efforts at the same running velocity(E1 and E2, 180 s), separated by a passive recovery period(90 s rest). LAC and HR values after E1 and E2(in 4 sessions) were used to estimate the intensity equivalent to"null delta" by linear fit. This parameter represents, theoretically, the intensity equivalent to maximal aerobic capacity.Results: The intraclass correlation coefficient indicated significant reliability for NEDE_(LAC)(0.93) and NEDE_(HR)(0.79)(both p < 0.05). There were significant correlations, no differences, and strong agreement with the intensities predicted by NEDE_(LAC)(10.1 ± 1.9 km/h) and NEDE_(HR)(9.8 ± 2.0 km/h) to VT_1(10.2 ± 1.1 km/h). In addition, despite significantly lower MLSS intensity(12.2 ± 1.2 km/h), NEDE_(LAC) and NEDE_(HR) intensities were highly correlated with this parameter(0.90 and 0.88, respectively).Conclusion: The NEDE test applied to running exercise is reliable and estimates the VT_1 intensity. Additionally, NEDE intensities were lower but still correlated with VT_2 and MLSS.展开更多
Purpose： The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically,...Purpose： The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically, it was hypothesized that the catecholamine, lactate, and ventilatory thresholds is the point at which significant improvements in speed of cognitive function are observed. Methods： We compared mean effect sizes for threshold studies and for those studies where exercise intensity was classed as moderate （40%-- 79% VO2 or equivalent） but in which the thresholds were not measured. Results： Random effects meta-analysis showed significant, moderate, mean effect sizes for studies at the threshold （g = 0.58, Z = 2.98, p 〈 0.003） and for those during moderate intensity exercise but in which the threshold was not measured （ g = 0.54, Z = 5.0l, p 〈 0.001）. There was no significant difference between mean effect sizes, which suggests that the thresholds are unlikely to represent a trigger point. Conclusion： Moderate intensity exercise, even below the thresholds, can induce improved speed of cognition, possibly due to a combination of increased peripheral catecholamine concentrations inducing vagal/nucleus tractus solitarii pathway activation and central increases due to perceptions of stress.展开更多
文摘Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and 3 methods of VT determination by gas analysis.Methods: Twenty-four professional basketball players(age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold(VT1) was determined by ventilatory equivalent(VE) and HRV and second ventilatory threshold(VT2) was determined by 3 methods of gases analysis(V-slope, VE and gas exchange ratio(R), and HRV). Pearson's coefficient(r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement.Results: The results showed no significant differences in HR and oxygen consumption(VO2) at VT1 between the 2 methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation in HR values was higher between R and HRV(r = 0.96) and VE and HRV(r = 0.96) than V-slope and HRV(r = 0.90).Conclusion: These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.
文摘We compared the levels of ventilatory threshold (VT) between subjects with and without pro-teinuria. We used data of 402 men and 413 women who were not taking any medications, aged 20 - 77 years, in this cross-sectional in-vestigation study. Aerobic Parameters at VT i.e. oxygen uptake, work rate and heart rate, and exercise habits were evaluated, which are con-sidered to be cardio respiratory fitness. Pro-teinuria was measured by using urine strip de-vices. Forty three men (10.7%) and 29 women (7.0%) were diagnosed as having the proteinuria (± ≦). There were no significant relationships between proteinuria and exercise habits in both sexes after adjusting for age. Oxygen uptake at VT in subjects with proteinuria was significantly lower than that in subjects without proteinuria after adjusting for age in men. However, such link was not noted in women after adjusting for age (p = 0.9964). Finally, associations were at-tenuated after adjusting for age and exercise habits in both sexes. Among Japanese not tak-ing medications, proteinuria might be a modifi-able factor of VT, especially in Japanese men.
基金financially supported by the Fundacao de AmparoàPesquisa do Estado de Sao Paulo(FAPESP,protocol 2009/08535-5)
文摘Purpose: The present study aimed to investigate the reliability of the non-exhaustive double effort(NEDE) test in running exercise and its associations with the ventilatory thresholds(VT_1 and VT_2) and the maximal lactate steady state(MLSS).Methods: Ten healthy male adults(age: 23 ± 4 years, height: 176.6 ± 6.4 cm, body mass: 76.6 ± 10.7 kg) performed 4 procedures:(1) a ramp test for VT_1 and VT_2 determinations measured by ratio of expired ventilation to O_2 uptake(VE/VO_2) and expired ventilation to CO_2 output(VE/VCO_2) equivalents, respectively;(2) the NEDE test measured by blood lactate concentration(NEDE_(LAC)) and heart rate responses(NEDE_(HR));(3) a retest of NEDE for reliability analysis; and(4) continuous efforts to determine the MLSS intensity. The NEDE test consisted of4 sessions at different running intensities. Each session was characterized by double efforts at the same running velocity(E1 and E2, 180 s), separated by a passive recovery period(90 s rest). LAC and HR values after E1 and E2(in 4 sessions) were used to estimate the intensity equivalent to"null delta" by linear fit. This parameter represents, theoretically, the intensity equivalent to maximal aerobic capacity.Results: The intraclass correlation coefficient indicated significant reliability for NEDE_(LAC)(0.93) and NEDE_(HR)(0.79)(both p < 0.05). There were significant correlations, no differences, and strong agreement with the intensities predicted by NEDE_(LAC)(10.1 ± 1.9 km/h) and NEDE_(HR)(9.8 ± 2.0 km/h) to VT_1(10.2 ± 1.1 km/h). In addition, despite significantly lower MLSS intensity(12.2 ± 1.2 km/h), NEDE_(LAC) and NEDE_(HR) intensities were highly correlated with this parameter(0.90 and 0.88, respectively).Conclusion: The NEDE test applied to running exercise is reliable and estimates the VT_1 intensity. Additionally, NEDE intensities were lower but still correlated with VT_2 and MLSS.
文摘Purpose： The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically, it was hypothesized that the catecholamine, lactate, and ventilatory thresholds is the point at which significant improvements in speed of cognitive function are observed. Methods： We compared mean effect sizes for threshold studies and for those studies where exercise intensity was classed as moderate （40%-- 79% VO2 or equivalent） but in which the thresholds were not measured. Results： Random effects meta-analysis showed significant, moderate, mean effect sizes for studies at the threshold （g = 0.58, Z = 2.98, p 〈 0.003） and for those during moderate intensity exercise but in which the threshold was not measured （ g = 0.54, Z = 5.0l, p 〈 0.001）. There was no significant difference between mean effect sizes, which suggests that the thresholds are unlikely to represent a trigger point. Conclusion： Moderate intensity exercise, even below the thresholds, can induce improved speed of cognition, possibly due to a combination of increased peripheral catecholamine concentrations inducing vagal/nucleus tractus solitarii pathway activation and central increases due to perceptions of stress.
