Hypertension is the most common, costly, and preventable cardiovascular disease risk factor. Numerous professional organizations and committees recommend exercise as initial lifestyle therapy to ...prevent, treat, and control hypertension. Yet, these recommendations differ in the components of the
F
requency,
I
ntensity,
T
ime, and
T
ype (FITT) principle of exercise prescription (Ex R
x
); the evidence upon which they are based is only of fair methodological quality; and the individual studies upon which they are based generally do not include people with hypertension, which are some of the limitations in this literature. The purposes of this review are to (1) overview the professional exercise recommendations for hypertension in terms of the FITT principle of Ex R
x
; (2) discuss new and emerging research related to Ex R
x
for hypertension; and (3) present an updated FITT Ex R
x
for adults with hypertension that integrates the existing recommendations with this new and emerging research.
Objectives
To examine the effects of exercise training on cognitive function in individuals at risk of or diagnosed with Alzheimer's disease (AD).
Design
Meta‐analysis.
Setting
PubMed, Scopus, ...ClinicalTrials.gov, and ProQuest were searched from inception until August 1, 2017.
Participants
Nineteen studies with 23 interventions including 1,145 subjects with a mean age of 77.0 ± 7.5 were included. Most subjects were at risk of AD because they had mild cognitive impairment (64%) or a parent diagnosed with AD (1%), and 35% presented with AD.
Intervention
Controlled studies that included an exercise‐only intervention and a nondiet, nonexercise control group and reported pre‐ and post‐intervention cognitive function measurements.
Measurements
Cognitive function before and after the intervention and features of the exercise intervention.
Results
Exercise interventions were performed 3.4 ± 1.4 days per week at moderate intensity (3.7 ± 0.6 metabolic equivalents) for 45.2 ± 17.0 minutes per session for 18.6 ± 10.0 weeks and consisted primarily of aerobic exercise (65%). Overall, there was a modest favorable effect of exercise on cognitive function (d+ = 0.47, 95% confidence interval (CI) = 0.26–0.68). Within‐group analyses revealed that exercise improved cognitive function (d+w = 0.20, 95% CI = 0.11–0.28), whereas cognitive function declined in the control group (d+w = −0.18, 95% CI = −0.36 to 0.00). Aerobic exercise had a moderate favorable effect on cognitive function (d+w = 0.65, 95% CI = 0.35–0.95), but other exercise types did not (d+w = 0.19, 95% CI = −0.06–0.43).
Conclusion
Our findings suggest that exercise training may delay the decline in cognitive function that occurs in individuals who are at risk of or have AD, with aerobic exercise possibly having the most favorable effect. Additional randomized controlled clinical trials that include objective measurements of cognitive function are needed to confirm our findings.
The Eighth Joint National Committee guideline on the management of adult hypertension was recently released. Rather than recommending specific lifestyle modifications as in the Seventh Joint National ...Committee guideline, the Eighth Joint National Committee endorsed the recommendations of the American Heart Association/American College of Cardiology 2013 Lifestyle Work Group. The Lifestyle Work Group report included systematic reviews and meta-analyses of randomized controlled trials or controlled clinical trials from 2001 through 2011 of "fair to good" quality. In total, 11 reviews qualified for inclusion in the report, 6 of which included blood pressure (BP) as the primary outcome. Three reviews did not find significant reductions in BP, and BP status was not reported in 5. When BP was reported, only 22% of the patients had hypertension. Yet, the group concluded with a strength of evidence categorized as "high" that aerobic exercise training reduces BP by 1 to 5 mm Hg in individuals with hypertension and that the most effective exercise interventions on average included aerobic physical activity of moderate to vigorous intensity for at least 12 weeks, 3 to 4 sessions per week lasting 40 minutes per session. The exercise prescription recommendations of the Lifestyle Work Group deviate from those of other professional organizations and committees including the Seventh Joint National Committee, another American Heart Association scientific statement, the American College of Sports Medicine, the European Society of Hypertension/European Society of Cardiology, and the Canadian Health Education Program. The purposes of this review are to present the existing exercise recommendations for hypertension, discuss reasons for differences in these recommendations, discuss gaps in the literature, and address critical future research needs regarding exercise prescription for hypertension.
Background
Aerobic exercise (AE) is recommended as first‐line antihypertensive lifestyle therapy based on strong evidence showing that it lowers blood pressure (BP) 5 to 7 mm Hg among adults with ...hypertension. Because of weaker evidence showing that dynamic resistance training (RT) reduces BP 2 to 3 mm Hg among adults with hypertension, it is recommended as adjuvant lifestyle therapy to AE training. Yet, existing evidence suggests that dynamic RT can lower BP as much or more than AE.
Methods and Results
We meta‐analyzed 64 controlled studies (71 interventions) to determine the efficacy of dynamic RT as stand‐alone antihypertensive therapy. Participants (N=2344) were white (57%), middle‐aged (47.2±19.0 years), and overweight (26.8±3.4 kg/m2) adults with prehypertension (126.7±10.3/76.8±8.7 mm Hg); 15% were on antihypertensive medication. Overall, moderate‐intensity dynamic RT was performed 2.8±0.6 days/week for 14.4±7.9 weeks and elicited small‐to‐moderate reductions in systolic BP (SBP; d+=−0.31; 95% CIs, −0.43, −0.19; −3.0 mm Hg) and diastolic BP (DBP; d+=−0.30; 95% CIs, −0.38, −0.18; −2.1 mm Hg) compared to controls (Ps<0.001). Greater BP reductions occurred among samples with higher resting SBP/DBP: ≈6/5 mm Hg for hypertension, ≈3/3 mm Hg for prehypertension, and ≈0/1 mm Hg for normal BP (Ps<0.023). Furthermore, nonwhite samples with hypertension experienced BP reductions that were approximately twice the magnitude of those previously reported following AE training (−14.3 mm Hg 95% CIs, −19.0, −9.4/−10.3 mm Hg 95% CIs, −14.5, −6.2).
Conclusions
Our results indicate that for nonwhite adult samples with hypertension, dynamic RT may elicit BP reductions that are comparable to or greater than those reportedly achieved with AE training. Dynamic RT should be further investigated as a viable stand‐alone therapeutic exercise option for adult populations with high BP.
Advancements in wearable technology have provided practitioners and researchers with the ability to conveniently measure various health and/or fitness indices. Specifically, portable devices have ...been devised for convenient recordings of heart rate variability (HRV). Yet, their accuracies remain questionable.
The aim was to quantify the accuracy of portable devices compared to electrocardiography (ECG) for measuring a multitude of HRV metrics and to identify potential moderators of this effect.
This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles published before July 29, 2017 were located via four electronic databases using a combination of the terms related to HRV and validity. Separate effect sizes (ESs), defined as the absolute standardized difference between the HRV value recorded using the portable device compared to ECG, were generated for each HRV metric (ten metrics analyzed in total). A multivariate, multi-level model, incorporating random-effects assumptions, was utilized to quantify the mean ES and 95% confidence interval (CI) and explore potential moderators.
Twenty-three studies yielded 301 effects and revealed that HRV measurements acquired from portable devices differed from those obtained from ECG (ES = 0.23, 95% CI 0.05-0.42), although this effect was small and highly heterogeneous (I
= 78.6%, 95% CI 76.2-80.7). Moderator analysis revealed that HRV metric (p <0.001), position (p = 0.033), and biological sex (β = 0.45, 95% CI 0.30-0.61; p <0.001), but not portable device, modulated the degree of absolute error. Within metric, absolute error was significantly higher when expressed as standard deviation of all normal-normal (R-R) intervals (SDNN) (ES = 0.44) compared to any other metric, but was no longer significantly different after a sensitivity analysis removed outliers. Likewise, the error associated with the tilt/recovery position was significantly higher than any other position and remained significantly different without outliers in the model.
Our results suggest that HRV measurements acquired using portable devices demonstrate a small amount of absolute error when compared to ECG. However, this small error is acceptable when considering the improved practicality and compliance of HRV measurements acquired through portable devices in the field setting. Practitioners and researchers should consider the cost-benefit along with the simplicity of the measurement when attempting to increase compliance in acquiring HRV measurements.
: Aerobic exercise training and, to a lesser degree, dynamic resistance training, are recommended to lower blood pressure (BP) among adults with hypertension. Yet the combined influence of these ...exercise modalities, termed concurrent exercise training (CET), on resting BP is unclear.
This study aimed to meta-analyze the literature to determine the efficacy of CET as antihypertensive therapy.
Electronic databases were searched for trials that included the following: adults (>19 yr), controlled CET interventions, and BP measured pre- and postintervention. Study quality was assessed with a modified Downs and Black Checklist. Analyses incorporated random-effects assumptions.
Sixty-eight trials yielded 76 interventions. Subjects (N = 4110) were middle- to older-age (55.8 ± 14.4 yr), were overweight (28.0 ± 3.6 kg·m), and had prehypertension (systolic BP SBP/diastolic BP DBP = 134.6 ± 10.9/80.7 ± 7.5 mm Hg). CET was performed at moderate intensity (aerobic = 55% maximal oxygen consumption, resistance = 60% one-repetition maximum), 2.9 ± 0.7 d·wk for 58.3 ± 20.1 min per session for 19.7 ± 17.8 wk. Studies were of moderate quality, satisfying 60.7% ± 9.4% of quality items. Overall, CET moderately reduced SBP (db = -0.32, 95% confidence interval CI = -0.44 to -0.20, -3.2 mm Hg) and DBP (db = -0.35, 95% CI = -0.47 to -0.22, -2.5 mm Hg) versus control (P < 0.01). However, greater SBP/DBP reductions were observed among samples with hypertension in trials of higher study quality that also examined BP as the primary outcome (-9.2 mm Hg 95% CI = -12.0 to -8.0/-7.7 mm Hg 95% CI = -14.0 to -8.0).
Among samples with hypertension in trials of higher study quality, CET rivals aerobic exercise training as antihypertensive therapy. Because of the moderate quality of this literature, additional randomized controlled CET trials that examine BP as a primary outcome among samples with hypertension are warranted to confirm our promising findings.
The aim was to examine the validity of heart rate variability (HRV) measurements from photoplethysmography (PPG) via a smartphone application pre- and post-resistance exercise (RE) and to examine the ...intraday and interday reliability of the smartphone PPG method. Thirty-one adults underwent two simultaneous ultrashort-term electrocardiograph (ECG) and PPG measurements followed by 1-repetition maximum testing for back squats, bench presses, and bent-over rows. The participants then performed RE, where simultaneous ultrashort-term ECG and PPG measurements were taken: two pre- and one post-exercise. The natural logarithm of the root mean square of successive normal-to-normal (R-R) differences (LnRMSSD) values were compared with paired-sample
-tests, Pearson product correlations, Cohen's
effect sizes (ESs), and Bland-Altman analysis. Intra-class correlations (ICC) were determined between PPG LnRMSSDs. Significant, small-moderate differences were found for all measurements between ECG and PPG: Base
(ES = 0.42), Base
(0.30), RE
(0.26), RE
(0.36), and RE
(1.14). The correlations ranged from moderate to very large: Base
(
= 0.59), Base
(
= 0.63), RE
(
= 0.63), RE
(
= 0.76), and RE
(
= 0.41)-all
< 0.05. The agreement for all the measurements was "moderate" (0.10-0.16). The PPG LnRMSSD exhibited "nearly-perfect" intraday reliability (ICC = 0.91) and "very large" interday reliability (0.88). The smartphone PPG was comparable to the ECG for measuring HRV at rest, but with larger error after resistance exercise.
Objectives
To develop an evaluation instrument to determine to what extent Tai Chi interventions aimed at improving the balance of older adults disclosed their exercise prescription (Ex Rx) and ...instructional methods and met best‐practice exercise recommendations for balance improvement.
Design
Review.
Setting
PubMed, Scopus, and CINAHL databases were searched from their inception until August 22, 2014.
Participants
Adults aged 60 and older without debilitating disease.
Measurements
Three electronic databases were searched to identify randomized controlled trials (RCTs) of Tai Chi interventions aimed at improving balance in older adults without severe debilitating diseases. Three Ex Rx (frequency, time, intervention length) and 10 instructional (e.g., style, number of forms) methods of the included RCTs were evaluated.
Results
Twenty‐seven interventions were identified from 26 RCTs. On average, Tai Chi was performed for a mean 56.5 ± 14.4 minutes per session for 2.8 ± 1.4 sessions per week for 19.7 ± 12.7 weeks. Most interventions reported all three Ex Rx methods items, with a mean reporting rate of 92.6 ± 19.2%. For the 10 instructional methods items, the mean reporting rate was 41.1 ± 18.0%, significantly lower than for the Ex Rx methods items (P < .001). Fewer than half of the interventions reported unsupervised practice (15%), progression (22%), or the use of breathing (30%) and relaxation (15%) techniques. The instructional methods items most important for targeting Tai Chi practice to improve balance were not routinely disclosed, with only 15% reporting names of forms and 52% reporting movement principles.
Conclusion
Most Tai Chi interventions disclosed their Ex Rx methods yet routinely failed to report instructional methods. To increase the effectiveness of Tai Chi to improve balance in older adults, future RCTs should disclose their Ex Rx and instructional methods, especially methods that target balance.
This study was conducted to investigate the systemic hemodynamic and vascular changes in women during and after two commonly used clinical blood flow restriction (BFR) pressures at rest. There are ...minimal data regarding the independent effects of BFR on hemodynamic and systemic vascular changes due to pressor response, particularly among women. Therefore, this study investigated BFR‐induced alterations in pressor response and systemic flow redistribution at rest during two commonly used pressures (50% and 80% limb occlusion pressure LOP). Fifteen women (22.1 ± 4.2 years) completed two randomised sessions involving 8‐min of bilateral, lower limb restriction at 50% or 80% LOP followed by 8‐min of recovery post‐deflation. Changes in vascular (arterial diameter DIA, time‐averaged mean velocity TAMV, volume flow VF, and area) and hemodynamic (heart rate HR and blood pressure) measures over time (pre‐, during, post‐occlusion) and by session (50% vs. 80% LOP) were tested using repeated measures analysis of variance. Repeated measures correlations (rrm) quantified common intraindividual associations between BFR‐induced hemodynamic and vascular responses. HR increased from baseline during 50% LOP and remained elevated during recovery (p < 0.05). HR increased from baseline during 80% LOP, while tibial VF and TAMV decreased (p < 0.03 for all). HR and TAMV values returned to baseline during recovery, while brachial artery VF decreased (p < 0.05). Changes in HR, brachial VF, and brachial TAMV were similar between 50% and 80% LOP (rrm = 0.32–0.70, p < 0.05 for all). At 80% LOP, changes in HR were positively correlated with brachial VF (rrm = 0.38) and TAMV (rrm = 0.43) and negatively correlated with tibial VF (rrm = −0.36) and TAMV (rrm = −0.30) (p < 0.05 for all). Results suggest that BFR at 80% LOP elicits an acute systemic pressor reflex without concomitant increases in brachial arterial flow, while 50% LOP elicits a subdued response.
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