Abstract
Objective To perform a large-scale pairwise and network meta-analysis on the effects of all relevant exercise training modes on resting blood pressure to establish optimal antihypertensive exercise prescription practices. Design Systematic review and network meta-analysis. Data sources PubMed (Medline), the Cochrane library and Web of Science were systematically searched. Eligibility criteria Randomised controlled trials published between 1990 and February 2023. All relevant work reporting reductions in systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) following an exercise intervention of ≥2 weeks, with an eligible non-intervention control group, were included. Results 270 randomised controlled trials were ultimately included in the final analysis, with a pooled sample size of 15 827 participants. Pairwise analyses demonstrated significant reductions in resting SBP and DBP following aerobic exercise training (-4.49/-2.53 mm Hg, p<0.001), dynamic resistance training (-4.55/-3.04 mm Hg, p<0.001), combined training (-6.04/-2.54 mm Hg, p<0.001), high-intensity interval training (-4.08/-2.50 mm Hg, p<0.001) and isometric exercise training (-8.24/-4.00 mm Hg, p<0.001). As shown in the network meta-analysis, the rank order of effectiveness based on the surface under the cumulative ranking curve (SUCRA) values for SBP were isometric exercise training (SUCRA: 98.3%), combined training (75.7%), dynamic resistance training (46.1%), aerobic exercise training (40.5%) and high-intensity interval training (39.4%). Secondary network meta-analyses revealed isometric wall squat and running as the most effective submodes for reducing SBP (90.4%) and DBP (91.3%), respectively. Conclusion Various exercise training modes improve resting blood pressure, particularly isometric exercise. The results of this analysis should inform future exercise guideline recommendations for the prevention and treatment of arterial hypertension.
Generated Summary
This study is a large-scale systematic review and network meta-analysis of randomized controlled trials (RCTs) to investigate the effects of various exercise training modes on resting blood pressure. The research aimed to determine optimal exercise prescription practices for managing hypertension. The methodology involved a comprehensive search of PubMed (Medline), the Cochrane library, and Web of Science for relevant RCTs published up to February 2023. Inclusion criteria specified studies reporting reductions in systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) following an exercise intervention lasting two or more weeks, with an eligible non-intervention control group. The study employed pairwise meta-analyses and Bayesian network meta-analyses (NMAs) to compare the effectiveness of different exercise modes. The researchers also performed separate baseline blood pressure-stratified analyses to assess the effects of each exercise mode on individuals with varying blood pressure classifications. The study adheres to the PRISMA guidelines and is registered with PROSPERO (CRD42022326565).
Key Findings & Statistics
- The initial search identified 14,553 trials, with 270 ultimately included, encompassing a sample of 15,827 participants (7,632 controls).
- The analysis involved 358 effect sizes, including 182 AET (Aerobic Exercise Training), 57 RT (Dynamic Resistance Training), 46 CT (Combined Training), 49 HIIT (High-Intensity Interval Training), and 24 IET (Isometric Exercise Training).
- Pairwise analyses revealed significant reductions in resting SBP and DBP following aerobic exercise training (-4.49/-2.53 mm Hg, p<0.001), dynamic resistance training (-4.55/-3.04 mm Hg, p<0.001), combined training (-6.04/-2.54 mm Hg, p<0.001), high-intensity interval training (-4.08/-2.50 mm Hg, p<0.001) and isometric exercise training (-8.24/-4.00 mm Hg, p<0.001).
- Significant reductions in SBP were observed following AET with an overall reduction of 4.49 mm Hg (95%CI 3.5 to 5.5, Z=8.8, Prandom<0.001), 2.85mm Hg for walking, 6.88 mm Hg for cycling and 6.83 mm Hg for running.
- There were significant reductions in SBP following RT by 4.55 mm Hg (95%CI 3.2 to 5.9, Z=6.6, Prandom<0.001), and CT by 6.04mm Hg (95%CI 3.2 to 8.9, Z=4.1, <0.001).
- While there were significant SBP reductions following overall HIIT by 4.08 mm Hg (95% CI 2.6 to 5.5, Z=5.5, Prandom<0.001) and SIT by 5.26mm Hg, AIT did not significantly change.
- All IET modes produced significant reductions in SBP, with an overall reduction of 8.24 mm Hg (95% CI 6.5 to 10.0, Z=9.0, prandom<0.001), 7.10mm Hg for IHG, 10.05 mm Hg ILE and 10.47 mm Hg for IWS.
- Significant reductions in DBP following all modes of AET, with an overall reduction of 2.53 mm Hg (95% CI 1.8 to 3.2, Z=7.3, prandom<0.001), 1.44mm Hg for walking, 3.20 mm Hg for cycling and 5.67 mm Hg for running.
- Significant reductions in DBP following RT by 3.04 mm Hg (95% CI 2.2 to 3.9, Z=6.9, Prandom <0.001), and CT by 2.54mm Hg (95%CI 1.1 to 4.0, Z=3.4, prandom=0.001).
- While there were significant DBP reductions following overall HIIT by 2.50mm Hg (95% CI 1.2 to 3.8, Z=3.8, Prandom<0.001) and SIT by 3.29mm Hg (95%CI 0.1 to 6.5, Z=2.0, Prandom=0.043), AIT did not significantly change.
- All IET modes produced significant reductions in DBP, with an overall reduction of 4.0 (95% CI 2.7 to 5.3, Z=6.0, Prandom<0.001), 3.46mm Hg for IHG, 4.23 ILE and 5.33 for IWS.
- For SBP, the order of effectiveness based on SUCRA values were IET (SUCRA: 98.3%), CT (75.7%), RT (46.1%), AET (40.53%) and HIIT (39.44%).
- The secondary exercise mode SBP NMA included 282 two-arm studies, 21 multiarm trials and 21 direct comparisons. The order of effectiveness based on SUCRA values were IET IWS (90.4%), ILE (84.7%), IHG (73.1%), cycling (69.9%), running (66.1%), CT (57.6%), SIT (43.3%), other aerobic (40.1%), RT (38.2%), AIT (18.3%) and walking (17.4%).
- The primary exercise mode DBP NMA included 296 two-arm studies, 24 multiarm trials and 11 direct comparisons. The order of effectiveness based on SUCRA values were IET (89.0%), RT (67.6%), HIIT (51.5%), CT (46.7%) and AET (45.1%).
- The secondary exercise mode DBP NMA included 274 two-arm studies, 21 multiarm trials and 21 direct comparisons. The order of effectiveness based on SUCRA values (Figure S7) were running (91.3%), IWS (86.1%), IHG (57.1%), ILE (56.2%), cycling (54.3%), SIT (54.2%), RT (52.1%), AIT (48.1%), other aerobic (46.9%), CT (38.0%) and walking (14.7%).
Other Important Findings
- The study found that isometric exercise training (IET) was the most effective mode for reducing both systolic and diastolic blood pressure.
- The NMA meta-regression demonstrated a significant moderator effect of baseline SBP and DBP across the exercise modes.
- In secondary analyses, IWS and running were the most effective submodes for reducing SBP and DBP, respectively.
- HIIT produced clinically relevant reductions in both SBP and DBP but ranked as the least effective.
- The study suggests that the current exercise guideline recommendations may need updating based on the findings.
Limitations Noted in the Document
- The study acknowledges several limitations in the exercise training literature, including poor control group activity monitoring, missing intention-to-treat analyses, and participant and investigator awareness of group allocation.
- With a large analysis, the study inevitably included trials of varying participant populations, statistical and methodological processes, and exercise intervention specifics, leading to interstudy variability.
- Publication bias was found for overall AET SBP and DBP and IET DBP.
- The analysis of some novel exercise modes like SIT, AIT, ILE and IWS involved a smaller number of RCTs, which could not be stratified by baseline blood pressure status.
- The study’s compliance moderator analysis does not fully account for low attendance rates.
Conclusion
In this comprehensive systematic review and NMA, the optimal exercise prescription practices for managing resting arterial blood pressure were established. Pairwise analyses of 270 RCTs with a sample size of 15,827 demonstrated significant reductions in SBP and DBP across all exercise modes except AIT. The primary NMA found that IET was the most effective, followed by CT, RT, AET, and HIIT for SBP. For DBP, the ranking was IET, RT, HIIT, CT, and AET. IWS was the most effective submode for reducing SBP in secondary exercise mode analyses, followed by ILE, IHG, cycling, running, CT, SIT, other aerobic, RT, AIT, and walking, whereas running was the most effective submode for DBP reduction, followed by IWS, IHG, ILE, cycling, SIT, RT, AIT, other aerobic, CT and walking. The meta-regression analysis also showed that the exercise modes’ impact was significantly moderated by baseline blood pressure. The study’s findings support the role of exercise as a primary intervention for hypertension management. Notably, IET demonstrated superior effectiveness, which aligns with previous research. The study’s results suggest that current guidelines may require updates to reflect the impact of exercise mode and submode on blood pressure control, particularly the effectiveness of isometric exercise training. The analysis provides a data-driven framework that can inform future exercise guideline recommendations for the prevention and treatment of hypertension, highlighting the need for personalized exercise prescription based on the exercise mode and the individual’s blood pressure profile. These results could shift the emphasis from traditional aerobic exercise, offering a new approach to managing blood pressure through exercise.