Background: While several studies have identified the anaerobic threshold (AT) through the responses of blood lactate, ventilation and blood glucose others have suggested the response of the heart rate variability (HRV) as a method to identify the AT in young healthy individuals. However, the validity of HRV in estimating the lactate threshold (LT) and ventilatory threshold (VT) for individuals with type 2 diabetes (T2D) has not been investigated yet. Aim: To analyze the possibility of identifying the heart rate variability threshold (HRVT) by considering the responses of parasympathetic indicators during incremental exercise test in type 2 diabetics subjects (T2D) and non diabetics individuals (ND). Methods: Nine T2D (55.6 ± 5.7 years, 83.4 ± 26.6 kg, 30.9 ± 5.2 kg.m^2(-1)) and ten ND (50.8 ± 5.1 years, 76.2 ± 14.3 kg, 26.5 ± 3.8 kg.m^2(-1)) underwent to an incremental exercise test (IT) on a cycle ergometer. Heart rate (HR), rate of perceived exertion (RPE), blood lactate and expired gas concentrations were measured at the end of each stage. HRVT was identified through the responses of root mean square successive difference between adjacent R-R intervals (RMSSD) and standard deviation of instantaneous beat-to-beat R-R interval variability (SD1) by considering the last 60 s of each incremental stage, and were known as HRVT by RMSSD and SD1 (HRVT-RMSSD and HRVT-SD1), respectively. Results: No differences were observed within groups for the exercise intensities corresponding to LT, VT, HRVT-RMSSD and HHVT-SD1. Furthermore, a strong relationship were verified among the studied parameters both for T2D (r = 0.68 to 0.87) and ND (r = 0.91 to 0.98) and the Bland & Altman technique confirmed the agreement among them. Conclusion: The HRVT identification by the proposed autonomic indicators (SD1 and RMSSD) were demonstrated to be valid to estimate the LT and VT for both T2D and ND.

Post-exercise hypotension (PEH), the reduction of blood pressure (BP) after a single bout of exercise, is of great clinical relevance. As the magnitude of this phenomenon seems to be dependent on pre-exercise BP values and chronic exercise training in hypertensive individuals leads to BP reduction; PEH could be attenuated in this context. Therefore, the aim of the present study was to investigate whether PEH remains constant after resistance exercise training. Fifteen hypertensive individuals (46±8 years; 88±16 kg; 30±6% body fat; 150±13/93±5 mm Hg systolic/diastolic BP, SBP/DBP) were withdrawn from medication and performed 12 weeks of moderate-intensity resistance training. Parameters of cardiovascular function were evaluated before and after the training period. Before the training program, hypertensive volunteers showed significant PEH. After an acute moderate-intensity resistance exercise session with three sets of 12 repetitions (60% of one repetition maximum) and a total of seven exercises, BP was reduced post-exercise (45–60 min) by an average of aproximately −22 mm Hg for SBP, −8 mm Hg for DBP and −13 mm Hg for mean arterial pressure (P0.05). In conclusion, our data demonstrate that PEH, following an acute exercise session, can indeed be attenuated after 12 weeks of training in hypertensive stage 1 patients not using antihypertensive medication.

The purpose of this study was to investigate postexercise hypotension (PEH) during a 4-month period of resistance training in hypertensive elderly women. Sixty-four women were divided into 2 groups: an experimental group (EG), which performed resistance training, and a control group (CG) that did not practice any exercise. The EG carried out the following steps: (a) 3 weeks of exercise adaptation and 1 repetition maximum (1RM) test (month 1); (b) resistance exercise at 60% 1RM (month 2); (c) resistance exercise at 70% 1RM (month 3); (d) resistance exercise at 80% 1RM (month 4); and (e) PEH analyses at the end of each month. Measurements of systolic (SBP) and diastolic blood pressure (DBP) were calculated each 5 minutes during a 20-minute resting period before the sessions and each 15 minutes during 1 hour of post-session recovery. Analysis of covariance for repeated measures showed a reduction in SBP of about 14 mm Hg (p ≤ 0.05) and in DBP of 3.6 mm Hg (p ≤ 0.05) between resting values after the training period. In the EG group, SBP showed acute PEH during months 2 and 3, whereas DBP showed acute PEH during months 2 and 4. The CG did not show acute PEH or variations during the 4-month period. Postexercise hypotension occurrence and chronic reduction of resting blood pressure observed in the EG may have a protective effect on the cardiovascular system of the study participants.