Postexercise hypotension due to resistance exercise is not mediated by autonomic control: A systematic review and meta-analysis.

Changes in autonomic control have been suggested to mediate postexercise hypotension (PEH). We investigated through meta-analysis the after-effects of acute resistance exercise (RE) on blood pressure (BP) and autonomic activity in individuals with normal and elevated BP. Electronic databases were searched for trials including: adults; exclusive RE interventions; and BP and autonomic outcomes measured pre- and postintervention for at least 30 min. Analyses incorporated random-effects assumptions. Thirty trials yielded 62 interventions (N = 480). Subjects were young (33.6 ± 15.6 yr), with systolic BP (SBP)/diastolic BP (DBP) of 124.2 ± 8.9/71.5 ± 6.6 mm Hg. Overall, RE moderately reduced SBP (normal BP: ~1 to 4 mm Hg, p < 0.01; elevated BP: ~1 to 12 mm Hg, p < 0.01) and DBP (normal BP: ~1 to 4 mm Hg, p < 0.03; elevated BP: ~0.5 to 7 mm Hg, p < 0.01), which was in general parallel to sympathetic increase (normal BP: g = 0.49 to 0.51, p < 0.01; elevated BP: g = 0.41 to 0.63, p < 0.01) and parasympathetic decrease (normal BP: g = -0.52 to -0.53, p < 0.01; elevated BP: g = -0.46 to -0.71, p < 0.01). The meta-regression showed inverse associations between the effect sizes of BP vs. sympathetic (SBP: slope - 0.19 to -3.45, p < 0.01; DBP: slope - 0.30 to -1.60, p < 0.01), and direct associations vs. parasympathetic outcomes (SBP: slope 0.17 to 2.59, p < 0.01; DBP: slope 0.21 to 1.38, p < 0.01). In conclusion, changes in BP were concomitant to sympathetic increase and parasympathetic decrease, which questions the role of autonomic fluctuations as potential mechanisms of PEH after RE.

Influence of Different Treadmill Inclinations on V̇o2max and Ventilatory Thresholds During Maximal Ramp Protocols.

ABSTRACT: Silva, SC, Monteiro, WD, Cunha, FA, and Farinatti, P. Influence of different treadmill inclinations on V̇o2max and ventilatory thresholds during maximal ramp protocols. J Strength Cond Res 35(1): 233-239, 2021-Ramp protocols for cardiopulmonary exercise testing (CPET) lack precise recommendations, including optimal treadmill inclination. This study investigated the impact of treadmill grades applied in ramp CPETs on maximal oxygen uptake (V̇o2max), ventilatory thresholds (VT1/VT2), and V̇o2 vs. workload relationship. Twenty-one healthy men (age 33 ± 8 years; height 176.6 ± 5.8 cm; body mass 80.4 ± 8.7 kg; and V̇o2max 44.9 ± 5.7 ml·kg-1·min-1) and 12 women (age 29 ± 7 years; height 163.3 ± 6.7 cm; body mass 56.6 ± 6.3 kg; and V̇o2max 39.4 ± 4.9 ml·kg-1·min-1) underwent ramp CPETs with similar speed increments and different treadmill grades: CPET0%, CPET2%, CPET3.5%, and CPET5.5%. The V̇o2max was similar across protocols (42.8-43.2 ml·kg-1·min-1, p = 0.76), albeit duration of CPETs shortened when treadmill inclination increased (CPET0% 12.7 minutes; CPET2% 9.1 minutes; CPET3.5% 8.0 minutes; and CPET5.5% 6.6 minutes; p < 0.01). The %V̇o2max corresponding to VT1 was slightly lower in CPET0% (63.6%) and higher in CPET5.5% (75.8%) vs. CPET2% (67.8%) and CPET3.5% (69.5%; p < 0.05), whereas VT2 was not affected by treadmill inclination (95.1-95.8% V̇o2max; p > 0.05). V̇o2max and ventilatory thresholds were similar in CPETs performed with different treadmill inclinations and similar initial/final speeds. However, linear regressions between workload and V̇o2 were closer to the identity line in CPETs performed with smaller (CPET0% and CPET2%) than with greater (CPET3.5% and CPET5.5%) inclinations. These data suggest that in healthy young adults, ramp CPETs performed with inclinations of 0-2% degree should be preferred over protocols with greater inclinations.

Four-second dynamic exercise testing (T4S) for the assessment of cardiac vagal modulation in obese adolescents.

BACKGROUND: Reduced vagal activity is often present in obese adolescents. Simple and practical strategies for the assessment of isolate parasympathetic outflow in this population are therefore useful. OBJECTIVES: To compare the methods derived from heart rate variability (HRV) analysis at rest and 4 s exercise testing (T4S) for the assessment of cardiac parasympathetic modulation in adolescents classified as obese (OB) or with normal weight (NW). Additionally, associations between total and trunk fat versus autonomic modulation determined by the two methods were calculated. APPROACH: A cross-sectional study was conducted with 50 adolescents (26 OB and 24 NW, 14.7 ± 1.5 years), comparing autonomic indices provided by HRV and T4S. Body fractioning was determined employing dual-energy x-ray absorptiometry (DXA). MAIN RESULTS: The cardiac vagal index (CVI) obtained from T4S and standard time- and frequency-domain HRV measures were lower in OB versus NW (P ⩽ 0.05). Correlations between CVI and HRV indices of cardiac vagal modulation were as follows: CVI versus RMSSD (r = 0.44; P = 0.003); CVI versus pNN50 (r = 0.32; P = 0.04); CVI versus HF (r = 0.35; P = 0.02). Associations between body fat, android/gynoid ratio, and percent trunk fat versus CVI were of similar magnitude and direction than versus HRV indices. SIGNIFICANCE: The T4S proved to be adequate to detect cardiac parasympathetic impairment in obese adolescents. Moreover, vagal modulation assessed by HRV and T4S inversely correlated with visceral adipose tissue. These findings along with the simplicity and safety of the T4S should encourage its use in the assessment of cardiac parasympathetic modulation in obese pediatric populations.

Optimizing a Treadmill Ramp Protocol to Evaluate Aerobic Capacity of Hemiparetic Poststroke Patients.

Bernardes, WL, Montenegro, RA, Monteiro, WD, de Almeida Freire, R, Massaferri, R, and Farinatti, P. Optimizing a treadmill ramp protocol to evaluate aerobic capacity of hemiparetic poststroke patients. J Strength Cond Res 32(3): 876-884, 2018-A correct assessment of cardiopulmonary capacity is important for aerobic training within motor rehabilitation of poststroke hemiparetic patients (PSHPs). However, specific cardiopulmonary exercise testing (CPET) for these patients are scarce. We proposed adaptations in a protocol originally developed for PSHPs by Ovando et al. (CPET1). We hypothesized that our adapted protocol (CPET2) would improve the original test, by preventing early fatigue and increasing patients' peak performance. Eleven PSHPs (52 ± 14 years, 10 men) performed both protocols. CPET2 integrated changes in final speed (100-120% vs. 140% maximal speed in 10-m walking test), treadmill inclination (final inclination of 5 vs. 10%), and estimated test duration (10 vs. 8 minutes) to smooth the rate of workload increment of CPET1. Peak oxygen uptake (V[Combining Dot Above]O2peak) (20.3 ± 6.1 vs. 18.6 ± 5.0 ml·kg·min; p = 0.04), V[Combining Dot Above]O2 at gas exchange transition (V[Combining Dot Above]O2-GET) (11.5 ± 2.9 vs. 9.8 ± 2.0 ml·kg·min; p = 0.04), and time to exhaustion (10 ± 3 vs. 6 ± 2 minutes; p < 0.001) were higher in CPET2 than in CPET1. Slopes and intercepts of regressions describing relationships between V[Combining Dot Above]O2 vs. workload, heart rate vs. workload, and V[Combining Dot Above]O2 vs. heart rate were similar between CPETs. However, standard errors of estimates obtained for regressions between heart rate vs. workload (3.0 ± 1.3 vs. 3.8 ± 1.0 b·min; p = 0.004) and V[Combining Dot Above]O2 vs. heart rate (6.0 ± 2.1 vs. 4.8 ± 2.4 ml·kg·min; p = 0.05) were lower in CPET2 than in CPET1. In conclusion, the present adaptations in Ovando's CPET protocol increased exercise tolerance of PSHPs, eliciting higher V[Combining Dot Above]O2peak and V[Combining Dot Above]O2-GET, preventing earlier fatigue, and providing better physiological relationships along submaximal workloads.

Continuous and Accumulated Bouts of Cycling Matched by Intensity and Energy Expenditure Elicit Similar Acute Blood Pressure Reductions in Prehypertensive Men.

Fonseca, GF, Farinatti, PTV, Midgley, AW, Ferreira, A, de Paula, T, Monteiro, WD, and Cunha, FA. Continuous and accumulated bouts of cycling matched by intensity and energy expenditure elicit similar acute blood pressure reductions in prehypertensive men. J Strength Cond Res 32(3): 857-866, 2018-This study investigated differences in postexercise hypotension (PEH) after continuous vs. accumulated isocaloric bouts of cycling. Ten prehypertensive men, aged 23-34 years, performed 2 bouts of cycling at 75% oxygen uptake reserve, with total energy expenditures of 400 kcal per bout. One exercise bout was performed continuously (CONTIN) and the other as 2 smaller bouts each expending 200 kcal (INTER1 and INTER2). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and cardiac autonomic control were monitored in a supine position for 10 minutes before and 60 minutes after each exercise bout, and during a control session. Compared with control, blood pressure was significantly reduced after CONTIN (SBP: [INCREMENT] - 3.4 mm Hg, p < 0.001; MAP: [INCREMENT] - 2.5 mm Hg, p = 0.001), INTER1 (SBP: [INCREMENT] - 2.2 mm Hg, p = 0.045), and INTER2 (SBP: [INCREMENT] - 4.4 mm Hg, p < 0.001; DBP: [INCREMENT] - 2.7 mm Hg, p = 0.045; MAP: [INCREMENT] - 3.3 mm Hg, p = 0.001). The PEH was similar in CONTIN and INTER2, whereas INTER2 elicited greater PEH than INTER1 (SBP and MAP: [INCREMENT] - 2.0 and [INCREMENT] - 1.8 mm Hg, respectively, p ≤ 0.05). Increases in sympathovagal balance from baseline were inversely related to changes in SBP and DBP after CONTIN and INTER2 (r = -0.64 to -0.71; p = 0.021-0.047). These findings indicate that similar amounts of PEH are observed when exercise is performed as a single 400-kcal exercise bout or 2 × 200-kcal bouts and that the exercise recovery pattern of cardiac autonomic activity may be important in eliciting PEH.

Long Term Home-Based Exercise is Effective to Reduce Blood Pressure in Low Income Brazilian Hypertensive Patients: A Controlled Trial.

INTRODUCTION: Home-based exercise programs may increase adherence to physical activity among groups with poor access to exercise facilities. However, their effectiveness to lower blood pressure of hypertensive patients remains undefined. AIMS: This controlled clinical trial investigated the influence of a home-based exercise program upon blood pressure, blood metabolic profile, and physical fitness in a Brazilian cohort of low income patients diagnosed with hypertension. METHODS: Twenty-nine patients (22 women, age: 53 ± 11 years) underwent 16 months of home-based exercise, including 30 min of moderate intensity walking and stretching exercises. Fourteen patients (9 women, age: 48 ± 5 years) composed a non-exercise control group. Primary outcomes were assessed each two months. RESULTS: Body mass (3.6 ± 0.2 kg; P = 0.03) and sum of skinfolds (3.0 ± 1.2 cm; P = 0.04) increased in controls vs. baseline. Mean compliance to home-based exercise was 83 ± 7 %, which induced significant improvements from baseline vs. controls in body mass (-5.4 ± 2.0 kg; P = 0.04), body fat (-4.7 ± 0.3 %; P = 0.03), waist circumference (-6.1 ± 1.2 cm; P = 0.03), sum of skinfolds (-14.8 ± 3.7; P = 0.02); aerobic efficiency reflected by slopes of relationships between heart rate and workload (-0.05 ± 0.01; P = 0.05), trunk flexibility (7.8 ± 1.7 cm; P = 0.02), HDL (1.8 ± 0.9 mg/dL; P = 0.04), triglycerides (-12.3 ± 1.0 mg/dL; P = 0.03), and glucose (-6.9 ± 2.9 mg/dL; P = 0.05). Systolic and diastolic BP decreased until the sixth month of intervention vs. baseline and controls, remaining stable at lower levels thereafter (systolic blood pressure: -4.5 ± 0.3 mmHg; P = 0.03; diastolic blood pressure: -2.5 ± 0.6 mmHg; P = 0.05). CONCLUSIONS: Low income hypertensive patients complied with a long-term home-based exercise program, which was effective for improving their functional capacity, blood metabolic profile, and blood pressure.

Hemodynamic responses during and after multiple sets of stretching exercises performed with and without the Valsalva maneuver.

OBJECTIVE: This study investigated the acute hemodynamic responses to multiple sets of passive stretching exercises performed with and without the Valsalva maneuver. METHODS: Fifteen healthy men aged 21 to 29 years with poor flexibility performed stretching protocols comprising 10 sets of maximal passive unilateral hip flexion, sustained for 30 seconds with equal intervals between sets. Protocols without and with the Valsalva maneuver were applied in a random counterbalanced order, separated by 48-hour intervals. Hemodynamic responses were measured by photoplethysmography pre-exercise, during the stretching sets, and post-exercise. RESULTS: The effects of stretching sets on systolic and diastolic blood pressure were cumulative until the fourth set in protocols performed with and without the Valsalva maneuver. The heart rate and rate pressure product increased in both protocols, but no additive effect was observed due to the number of sets. Hemodynamic responses were always higher when stretching was performed with the Valsalva maneuver, causing an additional elevation in the rate pressure product. CONCLUSIONS: Multiple sets of unilateral hip flexion stretching significantly increased blood pressure, heart rate, and rate pressure product values. A cumulative effect of the number of sets occurred only for systolic and diastolic blood pressure, at least in the initial sets of the stretching protocols. The performance of the Valsalva maneuver intensified all hemodynamic responses, which resulted in significant increases in cardiac work during stretching exercises.

Hemodynamic responses during and after multiple sets of stretching exercises performed with and without the Valsalva maneuver

OBJECTIVE: This study investigated the acute hemodynamic responses to multiple sets of passive stretching exercises performed with and without the Valsalva maneuver. METHODS: Fifteen healthy men aged 21 to 29 years with poor flexibility performed stretching protocols comprising 10 sets of maximal passive unilateral hip flexion, sustained for 30 seconds with equal intervals between sets. Protocols without and with the Valsalva maneuver were applied in a random counterbalanced order, separated by 48-hour intervals. Hemodynamic responses were measured by photoplethysmography pre-exercise, during the stretching sets, and post-exercise. RESULTS: The effects of stretching sets on systolic and diastolic blood pressure were cumulative until the fourth set in protocols performed with and without the Valsalva maneuver. The heart rate and rate pressure product increased in both protocols, but no additive effect was observed due to the number of sets. Hemodynamic responses were always higher when stretching was performed with the Valsalva maneuver, causing an additional elevation in the rate pressure product. CONCLUSIONS: Multiple sets of unilateral hip flexion stretching significantly increased blood pressure, heart rate, and rate pressure product values. A cumulative effect of the number of sets occurred only for systolic and diastolic blood pressure, at least in the initial sets of the stretching protocols. The performance of the Valsalva maneuver intensified all hemodynamic responses, which resulted in significant increases in cardiac work during stretching exercises. .

Influence of exercise order on the number of repetitions, oxygen uptake, and rate of perceived exertion during strength training in younger and older women.

The study investigated the effect of resistance exercise order on the number of repetitions, oxygen uptake (VO(2max)) and rate perceived exertion (RPE) in younger (YG: N = 10; 22 ± 2 years; VO(2peak) 42.2 ± 2.9 ml·kg(-1)·min(-1)) and older (EG: N = 8; 69 ± 7 years; VO(2peak)22.7 ± 2.5 ml·kg(-1)·min(-1)) women. The subjects performed 3 sets of each exercise until fatigue using 10 repetition maximum in 2 sequences of opposite order: (a) sequence A (SEQA): bench press (BP), machine shoulder press (SP), pulley triceps extension (TE); (b) sequence B (SEQB): TE-SP-BP. The VO(2) was assessed during the exercises, rest intervals, and 20 minutes after sequences (postexercise oxygen consumption [EPOC]). The number of repetitions decreased in both groups (p < 0.05) throughout sets. No difference (p > 0.22) was found between sequences for total VO(2) (exercise sequences + EPOC) in YG (SEQA = 25.41 ± 6.51 L vs. SEQB = 24.81 ± 4.08 L) and EG (SEQA = 26.45 ± 5.24 L vs. SEQB = 26.91 ± 4.62 L). In both groups, the VO(2) within the sequences was higher during BP when it was placed at the end of SEQB, the same occurring with TE in SEQA (p < 0.05). The VO(2) within sequences and RPE were higher in SEQB compared with SEQA (p < 0.05) in EG but not in YG. In conclusion, the exercise order did not affect total VO(2). The VO(2) within a given sequence was always lower when an exercise was performed first as compared with last regardless of the exercise order. Accumulated fatigue reflected by the VO(2) within sequences and RPE was influenced by the exercise order only in EG, suggesting that to prevent early fatigue, resistance training sessions in this group should preferably progress from large toward small-muscle group exercises.

Determination of Best Criteria to Determine Final and Initial Speeds within Ramp Exercise Testing Protocols.

This study compared strategies to define final and initial speeds for designing ramp protocols. V(O(2)max ) was directly assessed in 117 subjects (29 ± 8 yrs) and estimated by three nonexercise models: (1) Veterans Specific Activity Questionnaire (VSAQ); (2) Rating of Perceived Capacity (RPC); (3) Questionnaire of Cardiorespiratory Fitness (CRF). Thirty seven subjects (30 ± 9 yrs) performed three additional tests with initial speeds corresponding to 50% of estimated V(O(2)max ) and 50% and 60% of measured V(O(2)max ). Significant differences (P < 0.001) were found between V(O(2)max ) measured (41.5 ± 6.6 mL·kg(-1)·min(-1)) and estimated by VSAQ (36.6 ± 6.6 mL·kg(-1)·min(-1)) and CRF (45.0 ± 5.3 mL·kg(-1)·min(-1)), but not RPC (41.3 ± 6.2 mL·kg(-1)·min(-1)). The CRF had the highest ICC, the lowest SEE, and better limits of agreement with V(O(2)max ) compared to the other instruments. Initial speeds from 50%-60% V(O(2)max ) estimated by CRF or measured produced similar V(O(2)max ) (40.7 ± 5.9; 40.0 ± 5.6; 40.3 ± 5.5 mL·kg(-1)·min(-1) resp., P = 0.14). The closest relationship to identity line was found in tests beginning at 50% V(O(2)max ) estimated by CRF. In conclusion, CRF was the best option to estimate V(O(2)max ) and therefore to define the final speed for ramp protocols. The measured V(O(2)max ) was independent of initial speeds, but speeds higher than 50% V(O(2)max ) produced poorer submaximal relationships between workload and V(O(2) ).

The relationship between oxygen uptake reserve and heart rate reserve is affected by intensity and duration during aerobic exercise at constant work rate.

The relationship between the percentage of heart rate reserve (%HRR) and percentage of oxygen uptake reserve (%VO2R) has been recommended for prescribing aerobic exercise intensity. However, this relationship was derived from progressive maximal exercise testing data, and the stability of the relationship during prolonged exercise at a constant work rate has not been established. The main aim of this study was to investigate the stability of the %VO2R-%HRR relationship during prolonged treadmill exercise bouts performed at 3 different constant work rates. Twenty-eight men performed 4 exercise tests: (i) a ramp-incremental maximal exercise test to determine maximal heart rate (HR(max)) and maximal oxygen uptake (VO2(max)) and (ii) three 40-min exercise bouts at 60%, 70%, and 80% VO2R. HR and VO2 significantly increased over time and were influenced by exercise intensity (p < 0.001 and p = 0.004, respectively). A 1:1 relationship between %HRR and %VO2R, and between %HRR and %VO2(max), was not observed, with mean differences of 8% (t = 5.2, p < 0.001) and 6% (t = 4.8, p < 0.001), respectively. The VO2 values predicted from the ACSM running equation were all significantly higher than the observed VO2 values (p < 0.001 for all comparisons), whereas a difference for HR was observed only for the tenth min of exercise at 80% VO2R (p = 0.041). In conclusion, the main finding of this study was that the %HRR-%VO2R relationship determined by linear regression, obtained from progressive maximal exercise testing, did not apply to prolonged treadmill running performed at 3 work rates.

Cardiovascular responses to passive static flexibility exercises are influenced by the stretched muscle mass and the Valsalva maneuver.

BACKGROUND: The respiratory pattern is often modified or even blocked during flexibility exercises, but little is known about the cardiovascular response to concomitant stretching and the Valsalva maneuver (VM) in healthy subjects. OBJECTIVES: This study evaluated the heart rate (HR), systolic blood pressure (SBP), and rate-pressure product (RPP) during and after large and small muscle group flexibility exercises performed simultaneously with the VM. METHODS: Asymptomatic volunteers (N = 22) with the following characteristics were recruited: age, 22 ± 3 years; weight, 73 ± 6 kg; height, 175 ± 5 cm; HR at rest, 66 ± 9 BPM; and SBP at rest, 113 ± 10 mmHg. They performed two exercises: four sets of passive static stretching for 30 s of the dorsi-flexion (DF) of the gastrocnemius and the hip flexion (HF) of the ischio-tibialis. The exercises were performed with (V+) or without (V-) the VM in a counterbalanced order. The SBP and HR were measured, and the RPP was calculated before the exercise session, at the end of each set, and during a 30-min post-exercise recovery period. RESULTS: The within-group comparisons showed that only the SBP and RPP increased throughout the sets (p < 0.05), but no post-exercise hypotension was detected. The between-group comparisons showed that greater SBP increases were related to the VM and to a larger stretched muscle mass. Differences for a given set were identified for the HR (the HFV+ and HFV- values were higher than the DFV+ and DFV- values by approximately 12 BPM), SBP (the HFV+ value was higher than the DFV+ and DFV- values by approximately 12 to 15 mmHg), and RPP (the HFV+ value was higher than the HFV- value by approximately 2000 mmHGxBPM, and the HFV+ value was higher than the DFV+ and DFV- values by approximately 4000 mmHGxBPM). CONCLUSION: Both the stretched muscle mass and the VM influence acute cardiovascular responses to multiple-set passive stretching exercise sessions.

Variability of cardio-respiratory, electromyographic, and perceived exertion responses at the walk-run transition in a sample of young men controlled for anthropometric and fitness characteristics.

The cardio-respiratory (heart rate, HR; oxygen uptake, VO(2;) expired carbon dioxide, VCO(2); ventilation, VE), electromyographic (EMG; medial gastrocnemius, vastus lateralis, rectus femoralis, and anterior tibialis), and perceived exertion (PE) responses during a protocol for the determination of the walk-run transition speed (WRTS) were investigated. From an initial sample of 453 volunteers, 12 subjects matched for age, anthropometric characteristics [height, weight, lower limb length (LLL)], cardio-respiratory fitness (peak oxygen consumption, VO(2peak); ventilatory threshold, VT; maximal HR), and habitual physical activity levels were selected (age = 18.6 ± 0.5 years; height = 174.5 ± 1.4 cm; weight = 66.4 ± 1.1 kg; LLL = 83.3 ± 1.2 cm, VO(2peak) = 52.2 ± 2.2 ml kg(-1) min(-1); VT = 39.8 ± 2.6 ml kg(-1) min(-1)). The highly reproducible WRTS determination protocol (ICC = 0.92; p < 0.0001) consisted in 2-min warm-up at 5.5 km h(-1) followed by increments of 0.1 km h(-1) every 15 s. Between-subjects variability of the measured variables during 24 walking and 12 running velocities (from 80 to 120% of WRTS) was compared to WRTS variation. The coefficient of variation for WRTS was 7.8%, which was within the range of variability for age, anthropometric variables, VO(2peak), and maximal HR (from 5 to 12%). Cardio-respiratory responses at WRTS had a greater variation (VO(2) about 50%; VE/VCO(2) about 35%; VE/VO(2) about 45%; HR about 30%). The highest variation was found for PE (from 70 to 90%) whereas EMG variables showed the lowest variation (from 25 to 30%). Linear regression between EMG series and VO(2) data showed that VO(2) reflected the increase in muscle activity only before the WRTS. These results support the hypothesis that the walk-run transition phenomenon is determined by mechanical variables such as limb length and its relationship to biomechanical model rather than by metabolic factors.

Cardiovascular responses to passive static flexibility exercises are influenced by the stretched muscle mass and the Valsalva maneuver

BACKGROUND: The respiratory pattern is often modified or even blocked during flexibility exercises, but little is known about the cardiovascular response to concomitant stretching and the Valsalva maneuver (VM) in healthy subjects. OBJECTIVES: This study evaluated the heart rate (HR), systolic blood pressure (SBP), and rate-pressure product (RPP) during and after large and small muscle group flexibility exercises performed simultaneously with the VM. METHODS: Asymptomatic volunteers (N = 22) with the following characteristics were recruited: age, 22 ± 3 years; weight, 73 ± 6 kg; height, 175 ± 5 cm; HR at rest, 66 ± 9 BPM; and SBP at rest, 113 ± 10 mmHg. They performed two exercises: four sets of passive static stretching for 30 s of the dorsi-flexion (DF) of the gastrocnemius and the hip flexion (HF) of the ischio-tibialis. The exercises were performed with (V+) or without (V-) the VM in a counterbalanced order. The SBP and HR were measured, and the RPP was calculated before the exercise session, at the end of each set, and during a 30-min post-exercise recovery period. RESULTS: The within-group comparisons showed that only the SBP and RPP increased throughout the sets (p<0.05), but no post-exercise hypotension was detected. The between-group comparisons showed that greater SBP increases were related to the VM and to a larger stretched muscle mass. Differences for a given set were identified for the HR (the HFV+ and HFV- values were higher than the DFV+ and DFV- values by approximately 12 BPM), SBP (the HFV+ value was higher than the DFV+ and DFV- values by approximately 12 to 15 mmHg), and RPP (the HFV+ value was higher than the HFV- value by approximately 2000 mmHGxBPM, and the HFV+ value was higher than the DFV+ and DFV- values by approximately 4000 mmHGxBPM). CONCLUSION: Both the stretched muscle mass and the VM influence acute cardiovascular responses to multiple-set passive stretching exercise sessions.

Influence of exercise order on oxygen uptake during strength training in young women.

This study investigated the effect of resistance exercise order on the oxygen uptake (Vo2) and energy expenditure (EE). Ten trained women (age, 22 +/- 2 years; body mass index, 21 +/- 2 kgxm; peak Vo2, 42.2 +/- 2.9 ml kg min) volunteered for the study. Data were collected in 5 nonconsecutive days: (day 1) assessment of the peak Vo2 in a maximum effort ramp treadmill protocol; (days 2 and 3) determination of 10 repetition maximum (10RM) for the bench press (BP), machine shoulder press (SP), and pulley triceps extension (TE); and (days 4 and 5) performing 3 sets of each exercise with 3-minute rest intervals between sets and exercises until fatigue using 10RM in 2 sequences of opposite order (sequence A [SEQA]: BP, SP, TE; sequence B [SEQB]: TE, SP, and BP). Total Vo2 was assessed during all exercises, recovery intervals, and for 20 minutes after the end of the sequences. Energy expenditure was estimated from net Vo2 by subtracting rest values from total Vo2. No difference was found between the sequences for the total Vo2 (p = 0.68) and net energy cost (p = 0.29) (SEQA: 25.41 +/- 6.51 l and 60.01 +/- 29.26 kcal; SEQB: 24.81 +/- 4.08 l and 57.02 +/- 15.25 kcal; mean +/- SD). Conversely, the Vo2 in the rest intervals between sets was higher for BP when it was placed at the end of SEQ B, and the same occurred with TE in SEQ A. In conclusion, the Vo2 was lower for a given exercise when it was performed first as compared with last in a training session for the upper limbs. However, these differences did not affect the overall Vo2 or EE during sequences performed in the opposite exercise order.

Comportamento de variáveis cardiorrespiratórias em idosos e jovens durante 15 minutos de recuperaçäo após esforços de diferentes intensidades / Behavior os cardiorespiratory variables in elderly and yong individual during 15 minute recovery after efforts of varying intensities

Sabe-se pouco sobre os efeitos do envelhecimento na recuperaçäo pós-esforço (RP). O estudo observou a RP em 15 idosos (GI, idade= 61 ± 1 anos) e 15 jovens (GJ, idade= 22 ± 2 anos) após atividades de três intensidades (IE) em cicloergômetro. Realizaram-se testes máximos, com incremento de 30W/min para GJ e de 25W/min após detecçäo de steadystate para GI. Posteriormente, os grupos pedalaram a 40 e 75o da carga máxima, respectivamente, 25 e 15 minutos. Foram acompanhados VOz, VCO, Vç e FC nos primeiros 15 minutos da RP nas três IE. O tratamento dos resultados compreendeu: a) teste de ajustamento das curvas experimentais a equações com uma ou duas exponenciais; b) cálculo do valor dos componentes para a equaçäo mais ajustada; c) análise das constantes extraídas. Os desvios de ajustamento foram inferiores para uma curva de duas exponenciais, definida por integral de tempo na forma A/a +B/(3. A/a designa a componente rápida da recuperaçäo e B/(3 a lenta. Quando comparados os grupos, GI mostrou constantes maiores que GJ, evidenciando recuperaçäo mais lenta nas duas fases. Subdividindo os componentes, em GI e GJ as constantes de velocidade de recuperaçäo rápida (1/a) para VO, e VC02 foram semelhantes nas três IE, enquanto para a constante lenta (I/(3), os valores para GI indicaram maior dependência em relaçäo à carga. A recuperaçäo da FC revelou-se extremamente dependente da IE para GJ. Para GI isso foi menos evidente, talvez...