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Does swimming lower blood pressure?

Swimming and water exercise lower blood pressure by about 4 to 9 mmHg in trials, with the biggest drops in people who already have high blood pressure.

Published October 2026

Short answer

Yes. Trials of swimming and water exercise show blood pressure drops of about 4 to 9 mmHg, biggest in people with high blood pressure. Evidence is graded limited: trials were short and pressure is a marker, not heart attacks or strokes. Evidence grade C (Limited). Meta-analyses of randomised trials and several individual trials agree that blood pressure falls; starts at A, downgraded to B because blood pressure is a surrogate marker (not heart attacks or strokes) and to C for inconsistency (systolic heterogeneity, no significant systolic effect in prehypertension, and one trial where swimming raised pressure versus walking).

Key takeaways

  • In a 2018 review of 14 trials with 452 people, regular water exercise lowered systolic blood pressure by 8.4 mmHg and diastolic by 3.3 mmHg on average [1].
  • A 12-week swimming trial in 43 adults over 50 lowered casual systolic pressure from 131 to 122 mmHg [2]; a 20-week trial in 100 postmenopausal women with stage 2 high blood pressure lowered both readings by 9 mmHg [3].
  • After a single 45-minute water workout, older women with high blood pressure had readings about 5 mmHg lower over 21 hours than after a land session [4].
  • One 6-month trial found the opposite for older women with normal pressure: swimming raised systolic pressure by about 4 to 6 mmHg compared with walking [5].
  • Pooled cohort studies link swimming to a 24% lower risk of dying early, but one large 2026 analysis of two cohorts found no such link [6][7].

The short version

Swimming and other water exercise can lower blood pressure. In a review of 14 trials with 452 people, regular water exercise lowered systolic pressure by 8.4 mmHg and diastolic by 3.3 mmHg on average [1]. Trials in people who already have high blood pressure found drops of about 4 to 9 mmHg [2][3][8], and the systolic drops look similar to those from land exercise such as walking or cycling [9][10]. The evidence is graded limited: the trials were short, one large trial found swimming raised pressure compared with walking in older women with normal pressure [5], and no trial measured heart attacks or strokes [1].

What the studies show

Pooled evidence. A 2018 meta-analysis pooled 14 randomised trials with 452 adults who did water exercise or no exercise; systolic pressure fell by 8.4 mmHg and diastolic by 3.3 mmHg on average, with significant drops in people with high blood pressure and in programmes that were not swimming-only [1]. A second 2018 meta-analysis looked at upright water training (water aerobics and similar, not swimming) and found lower systolic and diastolic pressure than no training; the systolic drop was significant in people with high blood pressure but not in prehypertension, and systolic results were similar to land training [9]. In a 2026 network meta-analysis of 74 trials in mostly postmenopausal women, water exercise produced the largest estimated drops (systolic 11.6 mmHg, diastolic 7.7 mmHg), but that estimate came from only three study arms and the authors call it exploratory [11]. In adults with type 2 diabetes, a 2023 meta-analysis of 12 studies found blood pressure 5.55 mmHg (systolic) and 4.99 mmHg (diastolic) lower after water training [12].

Swimming trials. In a 12-week trial, 43 adults over 50 with prehypertension or stage 1 high blood pressure swam three to four times a week; casual systolic pressure fell from 131 to 122 mmHg, daytime and central readings fell too, and an artery-flexibility measure improved by 21% [2]. In a 20-week trial of 100 postmenopausal women with stage 2 high blood pressure, systolic and diastolic pressure each fell by 9 mmHg more than in the control group, along with a drop in arterial stiffness [3]. A 12-week trial in 52 postmenopausal women with high blood pressure found systolic pressure fell from 136 to 124 mmHg with water aerobics — about the same as the land-training group — while the control group did not change [10]. In 62 women with mild high blood pressure, 15 weeks of either interval swimming or longer steady swims lowered systolic pressure by 6 and 4 mmHg [8]. In patients with osteoarthritis, 12 weeks of swimming improved artery function at least as much as cycling [13].

After a single session. In 24 older women with high blood pressure, a 45-minute water workout left pressure about 5 mmHg lower over the next 21 hours than a land session [4]. A pooled analysis of four small trials found no difference in the 24-hour average compared with land exercise, but night-time systolic pressure was 8.6 mmHg lower after water exercise [14].

Beyond blood pressure. Pooled cohort studies link swimming to a 24% lower risk of dying during follow-up [6]. A 2026 analysis of two large cohorts (about 111,000 people) found swimming was the one activity with no link to lower death rates [7], while another large cohort found only a small link [15]. Water training also lowered HbA1c, a measure of average blood sugar, by 0.62% across 12 studies in type 2 diabetes [12].

The nuances

Who benefits most. The drops are clearest in people who already have high blood pressure [1][9]. In people with normal or slightly raised pressure the picture is weaker: one meta-analysis found no significant systolic effect in prehypertension [9], and a 6-month trial in 116 older women with normal pressure found swimming raised systolic pressure by about 4 to 6 mmHg compared with walking [5].

Doses used in the trials. Sessions ran 45 to 60 minutes, three or four days a week, for 12 to 20 weeks; interval swimming worked about as well as longer steady swims [4][8][3]. One water workout lowered pressure for most of the following day [4].

Safety. People in the blood pressure trials kept taking their medicines [10]. Adults with heart disease other than high blood pressure were not included in the main water-training review, so people with a heart condition should ask a doctor first [9]. In rare cases, open-water and race swimmers develop fluid in the lungs (swimming-induced pulmonary edema); a review of triathlon reports put the rate under 1.5% and listed cold water and tight wetsuits among the triggers [16]. Water exercise looked safe in pregnancy: in a trial of 320 pregnant women, those who exercised had no more complications than usual care [17], and a review of 10 trials with 1,949 women found no differences in birth weight, Apgar scores or preterm birth [18]. The Swimming page has the full safety list.

What this means for you

Systolic drops of about 4 to 9 mmHg are similar to what land exercise produces, and water supports your weight, which suits older adults and people with painful joints [10][2][13]. Blood pressure is a marker, though: no trial here measured heart attacks or strokes, so whether swimming prevents them is untested [1]. The trials kept people on their usual blood pressure medicines, and the drops happened on top of that [10]. If you have a heart condition or uncontrolled high blood pressure, talk to a doctor before starting a new exercise programme [9].

Go deeper

  • Swimming — Swimming and other water exercise lower blood pressure in trials — systolic pressure falls by roughly 4 to 9 mmHg, with the biggest drops in people who already…
  • Walking — Walking after a meal lowers the post-meal blood sugar rise: pooled crossover trials found walking soon after eating cut glucose more than sitting or walking be…

References

  1. The effect of regular aquatic exercise on blood pressure: A meta-analysis of randomized controlled trials.. Eur J Prev Cardiol, 2018.
  2. Effects of swimming training on blood pressure and vascular function in adults >50 years of age.. Am J Cardiol, 2012.
  3. The effects of swimming training on arterial function, muscular strength, and cardiorespiratory capacity in postmenopausal women with stage 2 hypertension.. Menopause, 2018.
  4. Postexercise Hypotension After Aquatic Exercise in Older Women With Hypertension: A Randomized Crossover Clinical Trial.. Am J Hypertens, 2018.
  5. Blood pressure rise with swimming versus walking in older women: the Sedentary Women Exercise Adherence Trial 2 (SWEAT 2).. J Hypertens, 2006.
  6. Health Benefits of Different Sports: a Systematic Review and Meta-Analysis of Longitudinal and Intervention Studies Including 2.6 Million Adult Participants.. Sports Med Open, 2024.
  7. Physical activity types, variety, and mortality: results from two prospective cohort studies.. BMJ Med, 2026.
  8. High-intensity intermittent swimming improves cardiovascular health status for women with mild hypertension.. Biomed Res Int, 2014.
  9. Aquatic Training in Upright Position as an Alternative to Improve Blood Pressure in Adults and Elderly: A Systematic Review and Meta-Analysis.. Sports Med, 2018.
  10. Aquatic exercise is as effective as dry land training to blood pressure reduction in postmenopausal hypertensive women.. Physiother Res Int, 2014.
  11. Exercise dose and modality for blood pressure reduction in predominantly postmenopausal women: a dose-response network meta-analysis.. Front Med (Lausanne), 2026.
  12. Aquatic training improves HbA1c, blood pressure and functional outcomes of patients with type 2 diabetes: A systematic review with meta-analysis.. Diabetes Res Clin Pract, 2023.
  13. Effects of Swimming and Cycling Exercise Intervention on Vascular Function in Patients With Osteoarthritis.. Am J Cardiol, 2016.
  14. Effects of Aquatic Exercise in Post-exercise Hypotension: A Systematic Review and Meta-Analysis.. Front Physiol, 2022.
  15. Association of Leisure Time Physical Activity Types and Risks of All-Cause, Cardiovascular, and Cancer Mortality Among Older Adults.. JAMA Netw Open, 2022.
  16. Swimming-induced pulmonary oedema in triathletes: A narrative review of epidemiology, risk factors and prevention.. Sports Med Health Sci, 2026.
  17. Effect of aerobic water exercise during pregnancy on epidural use and pain: A multi-centre, randomised, controlled trial.. Midwifery, 2021.
  18. Influence of prenatal aquatic activities on fetal outcomes and maternal physical and mental outcomes: a systematic review and meta-analysis.. BMC Pregnancy Childbirth, 2024.