scholarly journals Effect of short moderate intensity exercise bouts on cardiovascular function and maximal oxygen consumption in sedentary older adults

2020 ◽  
Vol 6 (1) ◽  
pp. e000672 ◽  
Author(s):  
Karani Magutah ◽  
Kihumbu Thairu ◽  
Nilesh Patel
Keyword(s):  
Blood Pressure ◽  
Older Adults ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Systolic Blood Pressure ◽  
Maximal Oxygen Consumption ◽  
Cardiovascular Function ◽  
Moderate Intensity ◽  
Group Differences ◽  
Moderate Intensity Exercise

AimTo investigate effect of <10 min moderate intensity exercise on cardiovascular function and maximal oxygen consumption (V˙ O2max) among sedentary adults.MethodsWe studied 53 sedentary urbanites aged ≥50 years, randomised into: (1) male (MS) and (2) female (FS) undertaking three short-duration exercise (5–10 min) daily, and (3) male (ML) and (4) female (FL) exercising 30–60 min 3–5 days weekly. Resting systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate and V˙ O2max were measured at baseline and 8 weekly for 24 weeks.ResultsAt baseline, 50% MS, 61.5% ML, 53.8% FS and 53.8% FL had SBP ≥120 mm Hg, and 14.3% MS, 53.8% ML, 23.1% FS and 38.5% FL had DBP ≥80 mm Hg. At 24 weeks, where SBP remained ≥120 mm Hg, values decreased from 147±19.2 to 132.3±9.6 mm Hg (50% of MS), from 144±12.3 to 128±7.0 mm Hg (23.1% of ML), from 143.1±9.6 to 128.0±7.0 mm Hg (53.8% of FS) and from 152.3±23.7 to 129±3.7 mm Hg (30.8% of FL). For DBP ≥80 mm Hg, MS and FS percentages maintained, but values decreased from 101±15.6 to 84.5±0.7 mm Hg (MS) and 99.0±3.6 to 87.7±4.9 mm Hg (FS). In ML and FL, percentage with DBP ≥80 mm Hg dropped to 15.4% (86.1±6.5 to 82.5±3.5 mm Hg) and (91.4±5.3 to 83.5±0.71 mm Hg). V˙ O2max increased from 26.1±4.4 to 32.0±6.2 for MS, from 25.8±5.1 to 28.8±5.4 for ML (group differences p=0.02), from 20.2±1.8 to 22.7±2.0 for FS and from 21.2±1.9 to 24.2±2.7 for FL (groups differences p=0.38).ConclusionAccumulated moderate intensity exercise bouts of <10 min confer similar-to-better cardiovascular and V˙ O2max improvements compared with current recommendations among sedentary adults.

Oxygen Consumption, Heart Rate, Rating of Perceived Exertion, and Systolic Blood Pressure with Water Treadmill Walking

2008 ◽  
Vol 16 (1) ◽  
pp. 14-23 ◽  
Author(s):  
David R. Dolbow ◽  
Richard S. Farley ◽  
Jwa K. Kim ◽  
Jennifer L. Caputo
Keyword(s):  
Blood Pressure ◽  
Older Adults ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Systolic Blood Pressure ◽  
Perceived Exertion ◽  
Cardiovascular Responses ◽  
Treadmill Walking ◽  
Rating Of Perceived Exertion ◽  
Water Treadmill

The purpose of this study was to examine the cardiovascular responses to water treadmill walking at 2.0 mph (3.2 km/hr), 2.5 mph (4.0 km/hr), and 3.0 mph (4.8 km/hr) in older adults. Responses to water treadmill walking in 92 °F (33 °C) water were compared with responses to land treadmill walking at 70 °F (21 °C) ambient temperature. After an accommodation period, participants performed 5-min bouts of walking at each speed on 2 occasions. Oxygen consumption (VO2), heart rate (HR), systolic blood pressure (SBP), and rating of perceived exertion (RPE) were significantly higher during therapeutic water treadmill walking than during land treadmill walking. Furthermore, VO2, HR, and RPE measures significantly increased with each speed increase during both land and water treadmill walking. SBP significantly increased with each speed during water treadmill walking but not land treadmill walking. Thus, it is imperative to monitor HR and blood pressure for safety during this mode of activity for older adults.

scholarly journals Objective and subjective measures of exercise intensity during thermo-neutral and hot yoga

2018 ◽  
Vol 43 (4) ◽  
pp. 397-402 ◽  
Author(s):  
Corinne N. Boyd ◽  
Stephanie M. Lannan ◽  
Micah N. Zuhl ◽  
Ricardo Mora-Rodriguez ◽  
Rachael K. Nelson
Keyword(s):  
Oxygen Consumption ◽  
Light Intensity ◽  
Exercise Intensity ◽  
Perceived Exertion ◽  
Maximal Oxygen Consumption ◽  
Rating Of Perceived Exertion ◽  
Moderate Intensity ◽  
Subjective Measures ◽  
Moderate Intensity Exercise ◽  
Constant Intensity

While hot yoga has gained enormous popularity in recent years, owing in part to increased environmental challenge associated with exercise in the heat, it is not clear whether hot yoga is more vigorous than thermo-neutral yoga. Therefore, the aim of this study was to determine objective and subjective measures of exercise intensity during constant intensity yoga in a hot and thermo-neutral environment. Using a randomized, crossover design, 14 participants completed 2 identical ∼20-min yoga sessions in a hot (35.3 ± 0.8 °C; humidity: 20.5% ± 1.4%) and thermo-neutral (22.1 ± 0.2 °C; humidity: 27.8% ± 1.6%) environment. Oxygen consumption and heart rate (HR) were recorded as objective measures (percentage of maximal oxygen consumption and percentage of maximal HR (%HRmax)) and rating of perceived exertion (RPE) was recorded as a subjective measure of exercise intensity. There was no difference in exercise intensity based on percentage of maximal oxygen consumption during hot versus thermo-neutral yoga (30.9% ± 2.3% vs. 30.5% ± 1.8%, p = 0.68). However, exercise intensity was significantly higher during hot versus thermo-neutral yoga based on %HRmax (67.0% ± 2.3% vs. 60.8% ± 1.9%, p = 0.01) and RPE (12 ± 1 vs. 11 ± 1, p = 0.04). According to established exercise intensities, hot yoga was classified as light-intensity exercise based on percentage of maximal oxygen consumption but moderate-intensity exercise based on %HRmax and RPE while thermo-neutral yoga was classified as light-intensity exercise based on percentage of maximal oxygen uptake, %HRmax, and RPE. Despite the added hemodynamic stress and perception that yoga is more strenuous in a hot environment, we observed similar oxygen consumption during hot versus thermo-neutral yoga, classifying both exercise modalities as light-intensity exercise.

scholarly journals Cortisol, blood pressure, and heart rate responses to food intake were independent of physical fitness levels in women

2015 ◽  
Vol 40 (11) ◽  
pp. 1186-1192 ◽  
Author(s):  
Sisitha U. Jayasinghe ◽  
Susan J. Torres ◽  
Steve F. Fraser ◽  
Anne I. Turner
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Food Intake ◽  
Physical Fitness ◽  
Maximal Oxygen Consumption ◽  
Physical Activity Guidelines ◽  
Time Treatment ◽  
Fitness Levels

This research tested the hypothesis that women who had higher levels of physical fitness will have lower hypothalamo–pituitary–adrenal axis (cortisol) and sympatho-adrenal medullary system (blood pressure and heart rate) responses to food intake compared with women who had low levels of physical fitness. Lower fitness (n = 22; maximal oxygen consumption = 27.4 ± 1.0 mL∙kg−1·min−1) and higher fitness (n = 22; maximal oxygen consumption = 41.9 ± 1.6 mL∙kg−1·min−1) women (aged 30–50 years; in the follicular phase of the menstrual cycle) who participated in levels of physical activity that met (lower fitness = 2.7 ± 0.5 h/week) or considerably exceeded (higher fitness = 7.1 ± 1.4 h/week) physical activity guidelines made their own lunch using standardised ingredients at 1200 h. Concentrations of cortisol were measured in blood samples collected every 15 min from 1145–1400 h. Blood pressures and heart rate were also measured every 15 min between 1145 h and 1400 h. The meal consumed by the participants consisted of 20% protein, 61% carbohydrates, and 19% fat. There was a significant overall response to lunch in all of the parameters measured (time effect for all, p < 0.01). The cortisol response to lunch was not significantly different between the groups (time × treatment, p = 0.882). Overall, both groups showed the same pattern of cortisol secretion (treatment p = 0.839). Systolic blood pressure, diastolic blood pressure, mean arterial pressure, or heart rate responses (time × treatment, p = 0.726, 0.898, 0.713, and 0.620, respectively) were also similar between higher and lower fitness women. Results suggest that the physiological response to food intake in women is quite resistant to modification by elevated physical fitness levels.

Physical training and heart rate and blood pressure variability: a 5-yr randomized trial

2004 ◽  
Vol 286 (5) ◽  
pp. H1821-H1826 ◽  
Author(s):  
Arja L. T. Uusitalo ◽  
Tomi Laitinen ◽  
Sari B. Väisänen ◽  
Esko Länsimies ◽  
Rainer Rauramaa
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Blood Pressure Variability ◽  
Maximal Oxygen Consumption ◽  
Final Analysis ◽  
Peak Performance ◽  
Autonomic Modulation ◽  
The Mean ◽  
Time Point

We studied the effect of regular physical activity on cardiac and vascular autonomic modulation during a 5-yr controlled randomized training intervention in a representative sample of older Finnish men. Heart rate variability (HRV) and blood pressure variability (BPV) are markers of cardiac and vascular health, reflecting cardiac and vascular autonomic modulation. One hundred and forty randomly selected 53- to 63-yr-old men were randomized into two identical groups: an intervention (EX) group and a reference (CO) group, of which 89 men remained until the final analysis (EX: n = 47; CO: n = 42). The EX group trained for 30–60 min three to five times a week with an intensity of 40–60% of maximal oxygen consumption. The mean weekly energy expenditure of the training program for the 5-yr training period was 3.80 MJ, and 71% of the EX group exceeded the mean. The EX group had a significantly ( P < 0.01) higher oxygen consumption at ventilatory aerobic threshold (V̇o2VT) than the CO group at the 5-yr time point. V̇o2VT had a tendency to increase in the EX group and decrease in the CO group (interaction P < 0.001) from the baseline to the 5-yr time point. Peak performance did not change. Low-frequency power of R-R interval variability decreased in the EX group ( P < 0.01, by 6%) from the baseline to the 5-yr time point. BPV did not change. In conclusion, low-intensity regular exercise training did not prevent HRV from decreasing or change BPV in 5 yr in older Finnish men.

Impaired cardiovascular function in male rats with hypo- and hyperthyroidism: Involvement of imbalanced nitric oxide synthase levels

2020 ◽  
Vol 20 ◽  
Author(s):  
Nasibeh Yousefzadeh ◽  
Sajad Jeddi ◽  
Asghar Ghasemi
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Left Ventricular Pressure ◽  
Cardiovascular Function ◽  
Heart Tissue ◽  
Left Ventricular ◽  
Male Rats ◽  
Protein Levels

Background and Objective: All three isoforms of nitric oxide (NO) synthase (NOS) are targets for thyroid hormones in cardiovascular system. The aim of this study was to assess effects of hypoand hyperthyroidism on inducible (iNOS), endothelial (eNOS), and neural (nNOS) NOS levels in aorta and heart tissues of male rats. Methods: Rats were divided into control, hypothyroid, and hyperthyroid groups; hypo- and hyperthyroidism were induced by adding propylthiouracil (500 mg/L) and L-thyroxine (12 mg/L) to drinking water for a period of 21 days, respectively. At day 21, systolic blood pressure, heart rate, left ventricular developed pressure (LVDP), peak rate of positive and negative (±dp/dt) changes in left ventricular pressure as well as NO metabolites (NOx) and iNOS, eNOS, and nNOS protein levels in aorta and heart were measured. Results: Compared to controls, LVDP and ±dp/dt were lower in both hypo- and hyperthyroid rats. Compared to controls, heart rate and systolic blood pressure were lower in hypothyroid and higher in hyperthyroid rats. NOx levels in the heart of hypothyroid rats were lower (53%) whereas in the heart and aorta of hyperthyroid rats were higher (56% and 40%) than controls. Compared to controls, hypothyroid rats had lower levels of eNOS, iNOS, and nNOS in aorta (16%, 34%, and 15%, respectively) and lower iNOS and higher nNOS in heart tissue (27% and 46%). In hyperthyroid rats, eNOS levels were lower (54% and 30%) and iNOS were higher (63%, and 35%) in the aorta and heart while nNOS was lower in the aorta (18%). Conclusion: Hypothyroidism increased while hyperthyroidism decreased ratio of eNOS/iNOS in aorta and heart; these changes of NOS levels were associated with impaired cardiovascular function.

scholarly journals Measuring Moderate-Intensity Exercise with the Apple Watch: Validation Study (Preprint)

2017 ◽  
Author(s):  
Grant Abt ◽  
James Bray ◽  
Amanda Clare Benson
Keyword(s):  
Oxygen Consumption ◽  
Exercise Intensity ◽  
Intraclass Correlation ◽  
Maximal Oxygen Consumption ◽  
Mean Difference ◽  
Moderate Intensity ◽  
Validity And Reliability ◽  
Moderate Intensity Exercise ◽  
Green Exercise ◽  
Left Hand

BACKGROUND Moderate fitness levels and habitual exercise have a protective effect for cardiovascular disease, stroke, type 2 diabetes, and all-cause mortality. The Apple Watch displays exercise completed at an intensity of a brisk walk or above using a green “exercise” ring. However, it is unknown if the exercise ring accurately represents an exercise intensity comparable to that defined as moderate-intensity. In order for health professionals to prescribe exercise intensity with confidence, consumer wearable devices need to be accurate and precise if they are to be used as part of a personalized medicine approach to disease management. OBJECTIVE The aim of this study was to examine the validity and reliability of the Apple Watch for measuring moderate-intensity exercise, as defined as 40-59% oxygen consumption reserve (VO2R). METHODS Twenty recreationally active participants completed resting oxygen consumption (VO2rest) and maximal oxygen consumption (VO2 max) tests prior to a series of 5-minute bouts of treadmill walking at increasing speed while wearing an Apple Watch on both wrists, and with oxygen consumption measured continuously. Five-minute exercise bouts were added until the Apple Watch advanced the green “exercise” ring by 5 minutes (defined as the treadmill inflection speed). Validity was examined using a one-sample t-test, with interdevice and intradevice reliability reported as the standardized typical error and intraclass correlation. RESULTS The mean %VO2R at the treadmill inflection speed was 30% (SD 7) for both Apple Watches. There was a large underestimation of moderate-intensity exercise (left hand: mean difference = -10% [95% CI -14 to -7], d=-1.4; right hand: mean difference = -10% [95% CI -13 to -7], d=-1.5) when compared to the criterion of 40% VO2R. Standardized typical errors for %VO2R at the treadmill inflection speed were small to moderate, with intraclass correlations higher within trials compared to between trials. CONCLUSIONS The Apple Watch threshold for moderate-intensity exercise was lower than the criterion, which would lead to an overestimation of moderate-intensity exercise minutes completed throughout the day.

Abstract P216: Co-ingestion of Dietary Nitrate and Caffeine Elevates Submaximal Oxygen Consumption and Oxygen-pulse Compared to Nitrate or Caffeine Alone

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Phillip M Armentrout ◽  
James M Smoliga ◽  
Kennedy Marshall ◽  
Colin R Carriker
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Moderate Intensity ◽  
Peak Power Output ◽  
Caffeine Intake ◽  
Placebo Control ◽  
Moderate Intensity Exercise ◽  
Double Blind ◽  
Dietary Nitrate ◽  
Oxygen Pulse

Introduction: Previous studies have examined dietary nitrate's and caffeine’s combined effects on time-trial and peak power output with caffeine improving performance while nitrate exhibits no additive benefit with co-ingestion. However, less is known about their combined effect on submaximal intensity exercise. Dietary nitrate may reduce submaximal oxygen cost while caffeine may increase submaximal cost. Hypothesis: Co-ingestion of dietary nitrate may attenuate the rise in oxygen consumption following caffeine intake. Methods: Ten healthy individuals (4 males; 28 ± 10 years of age) and (6 females; 21 ± 3 years of age) participated in a double-blind, placebo controlled, crossover experiment. The first of five visits consisted of a maximal oxygen consumption (VO 2max ) treadmill test. Prior to visits 2 - 5, participants consumed either a dietary nitrate (~12.4 mmol, NIT) or placebo nitrate supplement (PLN) combined with either a caffeine (3 mg/kg, CAF) or placebo caffeine (PLC) dose for a total of 4 days. The final dose of NIT or PLN and CAF or PLC was consumed 2.5 and 1-hr pre-exercise, respectively. Visits 2 - 5 consisted of a 30-min treadmill run at ~65% VO 2max . During exercise, VO 2 and heart rate (HR) were measured continuously. A linear mixed effects model analysis was performed to determine how each supplementation influenced each dependent variable. Treatments (NIT+CAF, CAF+PLN, NIT+PLC, PLN+PLC) and exercise timepoints (10 and 30 min) served as fixed factors. If p<0.05, p ost-hoc pairwise comparisons were performed. Results: Exercise VO 2 was significantly elevated for NIT+CAF at 10 and 30 minutes (36.2±4.1 and 37.7±5.0 ml/kg/min, respectively) compared to placebo (33.4±3.4 and 35.3±3.8 ml/kg/min, respectively) (p<0.05). However, there was no difference in VO2 at either timepoint (10 or 30 minutes) for conditions CAF+PLN (34.3±3.9, 35.4±3.6, and 36.3±3.2 ml/kg/min, respectively) (p=0.07) and NIT+PLC (34.8±3.9, 36.0±4.2, and 36.6±4.4 ml/kg/min, respectively) (p=0.08) compared to PLN+PLC. No difference was observed for heart rate between conditions at any timepoint. However, oxygen-pulse (VO 2 /HR) at the end of exercise was elevated in NIT+CAF (15.1±2.5 ml/beat) compared to CAF+PLN, NIT+PLC, PLN+PLC (14.5±2.5, 14.2±2.5, 13.8±2.5 ml/beat, respectively). Conclusion: When consumed independently, a low-moderate dose of caffeine or dietary nitrate had no impact on oxygen consumption during 30 minutes of moderate intensity exercise. However, co-ingestion of dietary nitrate and caffeine elevated submaximal oxygen consumption compared to a placebo control; both overall (main effect) and at individual time points of 10 and 30 minutes. Additionally, oxygen-pulse was elevated with co-ingestion compared to all treatments perhaps due to enhanced tissue uptake or altered mitochondrial efficiency. Future work may examine such mechanisms.

Effects of self-contained breathing apparatus on ventricular function during strenuous exercise

2009 ◽  
Vol 106 (2) ◽  
pp. 395-402 ◽  
Author(s):  
Michael D. Nelson ◽  
Mark J. Haykowsky ◽  
Jonathan R. Mayne ◽  
Richard L. Jones ◽  
Stewart R. Petersen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Systolic Blood Pressure ◽  
Ventricular Function ◽  
Esophageal Pressure ◽  
Ventilation Rate ◽  
Strenuous Exercise ◽  
Protective Equipment ◽  
Breathing Apparatus

The purpose of this study was to investigate left-ventricular function during strenuous exercise with the self-contained breathing apparatus (SCBA). With the use of two-dimensional echocardiography, images of the left ventricle (LV) were acquired during sustained exercise (3 × 10 min) under two conditions: 1) SCBA, or 2) low resistance breathing valve. Twenty healthy men volunteered for the study, and in each condition subjects wore fire protective equipment. Heart rate, systolic blood pressure, cavity areas during systole and diastole (ESCA and EDCA, respectively), esophageal pressure, ventilation rate, oxygen consumption, perceived physical, thermal and respiratory distress, and core temperature were measured at regular intervals. Urine specific gravity (<1.020 g/ml) and hematological variables were used to infer hydration status. All subjects began both trials in a euhydrated state. No differences were found between conditions for heart rate, systolic blood pressure, ventilation rate, oxygen consumption, perceived distress, or any hematological variables. Peak expiratory esophageal pressure was always higher ( P < 0.05), while EDCA and stroke area (SA) were significantly lower ( P < 0.05) with the SCBA. ESCA, end-systolic transmural pressure (ESTMP), and LV contractility (ESTMP/ESCA) were similar between conditions. Sustained exercise with fire protective equipment resulted in significant reductions in EDCA, ESCA, and SA from the start of exercise, which was associated with a 6.3 ± 0.8% reduction in plasma volume, an increase in core temperature (37.0 ± 0.4 to 38.8 ± 0.3°C), and a significant increase in heart rate (146.9 ± 2.1 to 181.7 ± 2.4 beats/min) throughout exercise. The results from this study support research by others showing that increased intrathoracic pressure reduces LV preload (EDCA); however, the novelty of the present study is that when venous return is compromised by sustained exercise and heat stress, SA cannot be maintained.

scholarly journals Exercise Training Improved Body Composition, Cardiovascular Function, and Physical Fitness of 5-Year-Old Children With Obesity or Normal Body Mass

2017 ◽  
Vol 29 (2) ◽  
pp. 245-253 ◽  
Author(s):  
Sijie Tan ◽  
Cheng Chen ◽  
Mingyang Sui ◽  
Lunan Xue ◽  
Jianxiong Wang
Keyword(s):  
Heart Rate ◽  
Body Composition ◽  
Exercise Training ◽  
Physical Fitness ◽  
Body Mass ◽  
Cardiovascular Function ◽  
Moderate Intensity ◽  
Obese Children ◽  
Moderate Intensity Exercise ◽  
Lean Children

Objectives:To explore the effects of exercise training on body composition, cardiovascular function, and physical fitness in 5-year-old obese and lean children.Methods:42 obese and 62 lean children were randomly allocated into exercise and control groups separately. Body composition, cardiovascular function, and physical fitness were measured at baseline and the end of the intervention. The exercise groups participated in 10 weeks of supervised moderate intensity exercise training (at 50% of heart rate reserve), 50 training sessions in total.Results:The physical activity program was successfully completed and no sport injury occurred. Exercise training decreased BMI, waist circumference, body fat%, and fat mass; and slowed down the growth speed of body mass of both trained obese and lean children. Exercise training significantly decreased systolic blood pressure of obese children and decreased their heart rate responses during exercise. Trained obese children improved the performances of long jump, 10-m × 4 shuttle run, and 3-m balance beam walk; while trained lean children improved more items of physical fitness.Conclusions:10 weeks of moderate intensity exercise training is an effective and safe treatment for children aged 5 years, either obese or with normal body mass.

scholarly journals Microneurographic characterization of sympathetic responses during 1-leg exercise in young and middle-aged humans

2019 ◽  
Vol 44 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Catherine F. Notarius ◽  
Philip J. Millar ◽  
Connor J. Doherty ◽  
Anthony V. Incognito ◽  
Nobuhiko Haruki ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Uptake ◽  
Systolic Blood Pressure ◽  
Peak Oxygen Uptake ◽  
Moderate Intensity ◽  
Middle Aged ◽  
Burst Frequency ◽  
Leg Cycling ◽  
Leg Exercise

Muscle sympathetic nerve activity (MSNA) at rest increases with age. However, the influence of age on MSNA recorded during dynamic leg exercise is unknown. We tested the hypothesis that aging attenuates the sympatho-inhibitory response observed in young subjects performing mild to moderate 1-leg cycling. After predetermining peak oxygen uptake, we compared contra-lateral fibular nerve MSNA during 2 min each of mild (unloaded) and moderate (30%–40% of the work rate at peak oxygen uptake, halved for single leg) 1-leg cycling in 18 young (age, 23 ± 1 years (mean ± SE)) and 18 middle-aged (age, 57 ± 2 years) sex-matched healthy subjects. Mean height, weight, resting heart rate, systolic blood pressure, and percent predicted peak oxygen uptake were similar between groups. Middle-aged subjects had higher resting MSNA burst frequency and incidence (P < 0.001) and diastolic blood pressure (P = 0.04). During moderate 1-leg cycling, older subjects’ systolic blood pressure increased more (+21 ± 5 vs. +10 ± 1 mm Hg; P = 0.02) and their fall in MSNA burst incidence was amplified (−19 ± 2 vs. −11 ± 2 bursts/100 heart beats; P = 0.01) but because heart rate rose less (+15 ± 3 vs. +19 ± 2 bpm; P = 0.03), exercise induced similar reductions in burst frequency (P = 0.25). Contrary to our initial hypothesis, with advancing age, mild- to moderate-intensity dynamic leg exercise elicits a greater rise in systolic blood pressure and a larger fall in MSNA.

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