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Purpose: To verify whether excess body mass influences 24-h ambulatory heart rate variability (HRV) after a moderate-intensity continuous exercise (MICE) session. Method: Participants included 27 non-trained young men that were divided into two groups, 1) normal-weight (n = 10) and 2) overweight and obese (n = 17). Participants underwent a single MICE session of 30 minutes at 50-60% of heart rate reserve (HRR), and a control session (CT). Heart rate (HR) and HRV indices were recorded at 60-minute intervals and were used to obtain the area under the curve (AUC) for 24-h ambulatory measurements following MICE or CT. SDNN (standard deviation of RR intervals in milliseconds) and RMSSD (root mean square of successive differences between adjacent RR interval in milliseconds), Ln-LF (log-transformed values of the absolute power of the low-frequency band) and HF (log-transformed values of the absolute power of the high-frequency band) were analyzed. Results: The overweight and obese group presented higher AUC of RMSSD (p = 0.006), Ln-LF (p = 0.002), and Ln-HF (p = 0.005) indices after MICE than CT. Nighttime periods were more responsive to the effects of MICE on RMSSD and Ln-HF indices (p < 0.05), regardless of group. Conclusion: MICE promoted an increase in the 24-h ambulatory cardiac autonomic modulation in the group overweight and obese, mainly at nighttime during sleep. These results revealed a potential benefit of MICE on the cardiac autonomic modulation for young men with overweight and obesity.

Purpose: To evaluate whether excess body mass influences the heart rate variability (HRV) indexes at rest, and to correlate adiposity indicators and the aerobic fitness with cardiac autonomic variables in metabolically healthy young adults. Method: In all, 41 untrained males (M[subscript age] = 21.80, SD = 2.14 years), 14 normal weight (M[subscript BMI] = 22.28, SD = 1.86 kg·m[superscript-2]), 11 overweight (M[subscript BMI] = 26.95, SD = 1.43 kg·m[superscript-2]), and 16 obese (M[subscript BMI] = 33.58, SD = 3.06 kg·m[superscript -2]) metabolically healthy (normal values of blood pressure, fasting blood glucose, triglycerides, and total cholesterol), underwent evaluations of the HRV at rest and of the peak oxygen consumption (VO[subscript 2] peak) during maximal exercise on a cycle ergometer. Results: Blood pressure, heart rate, HRV indexes, casual blood glucose, oxidative stress, and antioxidant activity did not differ among the groups. The VO[subscript 2] peak (mL·kg[superscript -1]·min[superscript-1]) was lower in the obese group compared with the normal weight and overweight groups. The body mass (r = -.40 to -.45) and abdominal circumference (r = -0.39 to -0.52) were slightly to moderately correlated with SD1, SD2, RMSSD, SDNN, pNN50, LF, and HF indexes and total power. The VO[subscript 2] peak (mL·kg[superscript -1]·min[superscript -1]) was slightly to moderately correlated (r = 0.48 to 0.51) with SD2, SDNN, and LF indexes in the individuals with excess body mass. Conclusion: Cardiac autonomic modulation at rest was preserved in metabolically healthy obese young men. However, the indicators of adiposity, as well as the aerobic fitness were correlated with cardiac autonomic modulation in the individuals with excess body mass.

This study investigated the acute blood pressure (BP) effects of different exercise modalities in older adults with hypertension. Sixty volunteers were randomly assigned (n = 15/group) into different exercise protocols: resistance, bike, water-based exercise (WE), and a control session—all for ∼45 min. Clinic BP measurements were taken before, immediately after, and 15 and 30 min after protocols. The data were analyzed by one-way analysis of variance; generalized estimating equations, following Bonferroni post hoc (p <.05). Immediately after exercise, the systolic BP (SBP) increased in all exercise protocols (resistance exercise = Δ10.3, bike exercise = Δ5.8, WE = Δ9.5 mmHg; p <.001), while the diastolic BP was not altered. Afterward, the SBP reached the value observed before exercise. In Minute 30, only WE presented a significant reduction for SBP (WE = Δ−4.6 mmHg; p <.05). This study has important clinical implications in hemodynamic safety for acute BP increases immediately after exercises, as well as, in the SBP, reduction benefits for older adults with hypertension. [ABSTRACT FROM AUTHOR]

The purposes of this study were to compare the hypotensive effects of treadmill running (TR) and resistance exercise (RE) performed by hypertensive subjects and to verify if the hypotensive effects of these exercises are maintained during a regular white-collar workday. Fifteen white-collar workers (42.9 [+ or -] 1.6 years), treated with antihypertensive medication, accomplished three different sessions: 20 minutes of TR (~70-80% of heart rate reserve), 20 minutes of circuit training RE (20 repetitions at 40% of 1 repetition maximum), and a control session without exercise (CON). The systolic blood pressure (BP), diastolic BP, heart rate, and blood lactate were measured at resting (Rest) and after sessions at 15th (R15), 30th (R30), 45th (R45), and 60th (R60) min, as well as after lunch (AL), four (R4h) and seven (R7h) hours of recovery at the participants' workplace. In relation to rest, a higher decrease of systolic BP after TR (-11.1 [+ or -] 7.6 mm Hg) and RE (-12.6 [+ or -] 7.3 mm Hg) was observed respectively at the R30 and R45. For diastolic BP, the highest decreases after TR (-4.0 [+ or -] 6.4 mm Hg) and RE (-9.0 [+ or -] 7.0 mm Hg) were observed respectively at the R45 and R30. The systolic BP and mean BP after TR and RE differed significantly from CON session (p < 0.05), and lower post-exercise values could be observed over the workday. In conclusion, both 20 minutes of TR and RE resulted in postexercise hypotension, and were able to reduce BP throughout 7 hours after exercise, even throughout the subject's regular occupational activities. Also, the RE promoted higher cardiac protection and can be a useful model of physical exercise prescription for hypertension individuals. KEY WORDS exercise, postexercise hypotension, aerobic training, circuit resistance training

The purpose of this study was to compare different methods to identify the lactate threshold (LT) and glucose threshold (GT) on resistance exercise for individuals with type 2 diabetes. Nine men with type 2 diabetes (47.2 [+ or -] 12.4 years, 87.6 [+ or -] 20.0 kg, 174.9 [+ or -] 5.9 cm, and 22.4 [+ or -] 7.2% body fat) performed incremental tests (ITs) on the leg press (LP) and bench press (BP) at relative intensities of 10, 20, 25, 30, 35, 40, 50, 60, 70, 80, and 90% of one-repetition maximum (1 RM) at each 1 -minute stage. During the 2-minute interval between stages, 25 [micro]l of capillary blood were collected from the earlobe for blood lactate [Lac] and blood glucose [Gluc] analysis (YS12700S). The LT in the LP and BP was identified at IT by the inflexion in [Lac] response as well as by an equation originated from a polynomial adjustment (LTp) of the [Lac]/% 1RM ratio responses. The lowest [Gluc] during the IT identified the GT. The analysis of variance did not show differences among the 1RM at the thresholds identified by different methods in the LP ([LT.sub.Lp] = 31.0% [+ or -] 5.3% 1RM; [GT.sub.LP] = 32.1% [+ or -] 6.1% 1RM; LT[p.sub.LP] = 36.7% [+ or -] 5.6% [+ or -] 1RM; p > 0.05) and BP ([LT.sub.BP] 29.9% [+ or -] 8.5[+ or -] 1RM; [GT.sub.BP] = 32.1% [+ or -] 8.5% 1RM; LT[p.sub.BP] = 31.8% [+ or -] 6.7% 1 RM; p > 0.05). It was concluded that it was possible to identify the LT and GT in resistance exercise by different methods for individuals with type 2 diabetes with no differences between them. The intensities (kg) corresponding to these thresholds were between 46% and 60% of the body weight on the LP and between 18% and 26% of the body weight on the BP, in which the exercise prescription would be done to this intensity in 3 sets of 20 to 30 repetitions each and 1 minute of rest while alternating the muscle groups for blood glucose control for individuals with characteristics similar to the participants. KEY WORDS anaerobic threshold, prescription of resistance exercise, glucose control

Despite the growing evidence for the beneficial effects of high-intensity interval exercise (HIIE) on vascular health of overweight and obese individuals, it is not clear whether the autonomic stress promoted by HIIE during the ambulatory period is higher than that by moderate-intensity continuous exercise (MICE). Therefore, this study compares the 24 hour (h) ambulatory heart rate variability (HRV) following HIIE and MICE in young overweight and obese men. Eleven untrained men aged 23.2 ± 1.9 years, with average body mass index (BMI) of 31.6 ± 3.9 kg/m² (three overweight and eight obese), underwent three exercise sessions: HIIE, MICE and Control (CT). HRV was recorded in the laboratory and for the next 24 h following laboratory recovery. There were no differences in HRV indices in the rest period between the sessions (p >.05). During the ambulatory period, the area under the curve (AUC) of the low-frequency band transformed into natural logarithm (Ln-LF) during sleep was higher after HIIE than after CT (43.31 ± 8.59 vs. 41.11 ± 7.28 ms²*h, p =.034). The HRV followed by MICE did not differ from other sessions (p >.05). In conclusion, the 24 h ambulatory HRV did not differ after HIIE and MICE. However, despite the small effect, HIIE increased the cardiac autonomic modulation during the sleep period, as a protector of cardiovascular system. 24 h ambulatory HRV could add important information about the cardiovascular safety of the exercise protocols in overweight and obese individuals. There was no disturbances in the cardiac autonomic modulation during the awake period, regardless of the exercise protocol. LnLF index was higher in HIIE compared to CT in the sleep period. 24 h ambulatory HRV did not differ between the HIIE and MICE sessions. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Kineanthropometry & Human Performance is the property of Brazilian Journal of Kineanthropometry & Human Performance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Medicina do Esporte is the property of Redprint Editora Ltda. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Ciência e Movimento: RBCM is the property of Revista Brasileira de Ciencia e Movimento and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate the reproducibility of the heart rate variability threshold (HRVT) by different HRV indexes and determination criteria. 68 untrained participants, 17 women (24.09 ± 4.91 years old; 21.54 ± 1.97 kg⋅m-2) and 51 men (24.52 ± 3.52 years old; 26.51 ± 6.31 kg⋅m-2)), were evaluated on 2 different days (test and retest). The HRVT was determined during an incremental exercise test using 2 indexes (SD1 and RMSSD) and criteria (HRTV1, first intensity of physical effort with index < 3 ms, and HRVT2, first intensity of physical effort, in which the index presents a difference < 1 ms between 2 consecutive intensities). There was no significant difference (p < 0.05) between the test and retest for any of the variables evaluated. All variables, except for the rate of perceived exertion at HRVT2, presented moderate to high intraclass correlation coefficient (HRVT1: 0.55-0.85 and HRVT2:0.58-0.69). All variables at HRVT1 and the heart rate at HRVT2 showed coefficient of variation ~ 10 %. The HRVT, regardless of criteria and HRV index used, showed satisfactory reproducibility. Thus, these criteria can be used to assess clinically autonomic cardiac modulation and aerobic capacity, and to analyze the effect of different interventions. [ABSTRACT FROM AUTHOR]

This study compared maximum oxygen consumption (VO2max) on a 20-meter multistage shuttle run test (20-Srt) with a cardiopulmonary exercise test (CPET) to determine a VO2max prediction equation for a 20-Srt in children aged 6-10 years. Eighty healthy children performed the CPET on a treadmill, while the 20-Srt took place on a sports court. Heart rate (HR) was measured and the expired gases were continuously measured breath-by-breath using a portable gas analyzer. The VO2max was lower (p < 0.05) in CPET than 20-Srt for all, female, and male participants, respectively (46.3 ± 7.9 vs. 48.7 ± 4.6; 42.7 ± 7.8 vs. 46.7 ± 4.8; 49.3 ± 6.8 vs. 50.4 ± 3.9, mL ⋅ kg-1 ⋅ min-1). The standard error estimates were between 3.0 and 3.6 and considered as not clinically relevant if less than 5 mL ⋅ kg-1 ⋅ min-1. The intraclass correlation coefficient between the VO2 in CPET and in 20-Srt was 0.74 (CI95 % 0.55-0.84) and considered moderately reliable. The linear multiple regression excluded sex, body mass index and fat-free mass and retained the maximum speed and age in the predictive equation. The 20-Srt estimates the VO2max with moderate reliability and the predictive equation was VO2maxpred = 4.302 + (maximum speed * 5.613)-(age * 1.523) for children aged 6-10 years. [ABSTRACT FROM AUTHOR]

Background: Obesity and aerobic fitness influence resting (HR) and heart rate recovery (HRR), and the evaluation of these parameters show a relevant clinical application. Purpose: This study aimed to evaluate the influence of body mass index (BMI) and aerobic fitness on HRR after maximal exercise in healthy young men. Methods: Twenty nine untrained men (21.37 ± 2.11 years) were divided according to BMI (normal weight ≤24.9, overweight ≥25 and obese ≥30 kg m) and subsequently divided into higher aerobic fitness (125.00 ± 21.71 W) and lower aerobic fitness (72.69 ± 24.38 W), based on the median (105 W) aerobic fitness assessed through the workload at the heart rate variability threshold (HRVT). Results: There were no differences ( p > 0.05) for HR, aerobic fitness or HRR between the three BMI groups. Blood glucose and lipid profile were similar among groups, regardless of BMI and aerobic fitness. However, the young men with higher aerobic fitness showed lower HR (70.48 ± 6.54 vs 81.54 ± 6.46 bpm), HRR (163.1 ± 9.2 vs 170.1 ± 7.6 bpm), HRR (147.2 ± 7.4 vs 154.6 ± 8.1 bpm) and HRR (139.2 ± 6.9 vs 145.8 ± 8.0 bpm), compared to their pairs with lower aerobic fitness. Additionally, HR and the HRVT workload were significantly ( p < 0.05) associated with HRR ( r 0.49 and −0.49), HRR ( r 0.60 and −0.53), HRR ( r 0.53 and −0.47) and HRR ( r 0.48 and −0.47). Conclusions: Aerobic fitness influenced HR and HRR in untrained young men, regardless of BMI. [ABSTRACT FROM AUTHOR]