Average blood pressure was in the normotensive range, defined as systolic blood pressure lower than 140 mm Hg and diastolic pressure below 90 mm Hg, in 52 study groups. Sixteen groups were classified as hypertensive at baseline. The training-induced weighted net change of blood pressure averaged −7.4 (−10.5;−4.3)/−5.8 (−8.0;−3.5) mm Hg in the hypertensives and −2.6 (−3.7;−1.5)/−1.8 (−2.6;−1.1) mm Hg in the normotensives.
We identified 10 randomized trials in which the influence of diet was compared with that of exercise alone and/or with the combined effects of diet and exercise in mostly overweight subjects (2,7,16,19,23,26,45,49,51,59). Two of these studies did not include a nonexercise nondiet control group (19,59), so that the results have not been adjusted for control data in the meta-analysis. Study duration ranged from 4 to 52 wk (median = 38). Table 3 summarizes the results for the paired comparison of exercise and diet (11 study groups). Only physical training increased peak oxygen uptake. The reduction in BMI was significantly more pronounced in the diet groups than in the exercise groups. Finally the reduction of blood pressure with diet alone (−5.9/−4.2 mm Hg) was superior to that of exercise alone (−3.6/−2.7 mm Hg).
The results on the comparison of combined exercise and diet intervention with diet alone are shown in Table 4 (N = 11). Only the combined intervention increased peak oxygen uptake. Diet alone was less effective in reducing BMI. Nevertheless, there was no evidence that adding physical training to diet was more effective for blood pressure control than diet alone.
Several epidemiological studies suggest that the incidence of hypertension is less in physically fit or active people than in unfit or sedentary subjects (3,18,43,47). This relationship was independent of baseline BMI or body fat (3,18,47). However, Paffenbarger et al. (43) reported that the inverse relationship between exercise and the incidence of hypertension was more evident for overweight than for lean Harvard alumni.
The results from cross-sectional studies on the associations between physical activity, fitness, and blood pressure are not quite consistent (12,13). Whereas several studies did not observe significant independent relationships, others did find that blood pressure was lower in fitter or more active subjects. On the whole, the differences in blood pressure between the most and the least fit or active rarely exceeded 5 mm Hg after controlling for confounding factors such as age and body size (12,13). It remains difficult, however, to ascribe differences in blood pressure within a population to differences in levels of physical activity or fitness because of the possible confounding factors which cannot be accounted for. Therefore, longitudinal intervention studies are more appropriate to assess the effect of physical exercise on blood pressure. The present meta-analysis of 44 randomized controlled trials involving 68 study groups indicates that dynamic aerobic exercise reduces blood pressure at rest by an average of 3.4 mm Hg for systolic and 2.4 mm Hg for diastolic pressure above blood pressure changes in nonexercising control groups or periods. Baseline BMI did not affect the blood pressure response: the change in blood pressure was indeed similar in overweight and lean participants. However, the lowering of blood pressure was more pronounced in hypertensive subgroups than in the normotensives. The exercise programs led to decreases of BMI (61), particularly in the overweight and obese subjects, but these changes did not determine the blood pressure response.
Although a large number of trials were controlled and applied randomization techniques, other important scientific criteria have not always been observed. The following shortcomings were identified in a variable number of training studies: lack of regular follow-up of the control subjects; no advice to keep diet or lifestyle, or both, constant throughout the study periods; a high number of drop-outs; inadequate statistical analyses and lack of adjustment for confounding variables; failure to blind the person who measured the blood pressure to the treatment or to use stationary or ambulatory automated blood pressure devices; and lack of use of an appropriate cuff size in the obese. Future studies should address these issues. However, it should be realized that it is difficult to blind the participants to the treatment in training studies; the inclusion of low-level exercise as placebo treatment is controversial.
The results on hemodynamic changes in response to dynamic training are conflicting; some authors claim that the lowering of blood pressure is based on a reduction of systemic vascular resistance whereas others observed a decrease of cardiac output. Most studies found a decrease of plasma noradrenaline concentrations suggesting a reduction in autonomic nervous activity. Other possible blood pressure lowering mechanisms have been addressed only rarely in randomized controlled exercise trials. Future studies, particularly in the obese, should not only focus on blood pressure but also on mechanisms involved in blood pressure regulation such as the renin-angiotensin-aldosterone system, prostaglandins, endothelial relaxing factor and endothelin, the sympathetic nervous system, insulin sensitivity and finally, genetic polymorphisms that might influence the blood pressure response to physical training.
The authors gratefully acknowledge the secretarial assistance of N. Ausseloos. R. Fagard is holder of the Prof. A. Amery Chair in Hypertension Research, founded by Merck, Sharp, and Dohme (Belgium).
1. Albright, C. L., A. C. King, C. B. Taylor, and W. L. Haskell. Effect of a six-month aerobic exercise training program on cardiovascular responsivity in healthy middle-aged adults. J. Psychosomat. Res. 36: 25–36, 1992.
2. Anderssen, S., I. Holme, P. Urdal, and I. Hjermann. Diet and exercise intervention have favourable effects on blood pressure in mild hypertensives: The Oslo Diet and Exercise Study (ODES). Blood Press. 4: 343–349, 1995.
3. Blair, S. N., N. N. Goodyear, L. W. Gibbons, and K. H. Cooper. Physical fitness and incidence of hypertension in healthy normotensive men and women. JAMA 252: 487–490, 1984.
4. Blumenthal, J. A., W. C. Siegel, and M. Appelbaum. Failure of exercise to reduce blood pressure in patients with mild hypertension. JAMA 266: 2098–2104, 1991.
5. Braith, R. W., M. L. Pollock, D. T. Lowenthal, J. E. Graves, and M. C. Limacher. Moderate- and high-intensity exercise lowers blood pressure in normotensive subjects 60 to 79 years of age. Am. J. Cardiol. 73: 1124–1128, 1994.
6. Coconie, C. C., J. E. Graves, M. L. Pollock, M. I. Phillips, C. Sumners, and J. M. Hagberg. Effect of exercise training on blood pressure in 70- to 79-yr-old men and women. Med. Sci. Sports Exerc. 23: 505–511, 1991.
7. Cox, K. L., I. B. Puddey, A. R. Morton, V. Burke, L. J. Beilin, and M. McAleer. Exercise and weight control in sedentary overweight men: effects on clinic and ambulatory blood pressure. J. Hypertens. 14: 779–790, 1996.
8. De Geus, E. J. C., C. Kluft, A. C. W. De Bart, and L. J. P. Van Doornen. Effects of exercise training on plasminogen activator inhibitor activity. Med. Sci. Sports Exerc. 24: 1210–1219, 1992.
9. De Plaen, J. F. and J. M. Detry. Hemodynamic effects of physical training in established arterial hypertension. Acta Cardiol. 35: 179–188, 1980.
10. Duncan, J. J., J. E. Farr, S. J. Upton, R. D. Hagan, M. E. Oglesby, and S. N. Blair. The effects of aerobic exercise on plasma catecholamines and blood pressure in patients with mild essential hypertension. JAMA 254: 2609–2613: 1985.
11. Duncan, J. J., N. F. Gordon, and C. B. Scott. Women walking for health and fitness. JAMA 266: 3295–3299, 1991.
12. Fagard, R. H. The role of exercise in blood pressure control: supportive evidence. J. Hypertens. 13: 1223–1227, 1995.
13. Fagard, R. H. Physical activity, fitness and blood pressure. In:Handbook of Hypertension: Epidemiology of Hypertension
. W. H. Birkenhäger, J. L. Reid, and C. J. Bulpitt (Eds.). Amsterdam: Elsevier(in press).
14. Fagard, R. H., J. A. Staessen, and L. Thijs. Advantages and disadvantages of the meta-analysis approach. J. Hypertens. 14(Suppl. 2): S9-S13, 1996.
15. Fagard, R. H. and C. M. Tipton. Physical activity, fitness and hypertension. In: Physical Activity, Fitness and Health. C. Bouchard, R. J. Shephard, T. Stephens (Eds.). Champaign, IL: Human Kinetics, 1994, pp. 633–655.
16. Fortmann, S. P. W. L. Haskell, P. D. Wood, and the Stanford Weight Control Project Team. Effects of weight loss on clinic and ambulatory blood pressure in normotensive men. Am. J. Cardiol.
17. Gettman, L. R., M. L. Pollock, J. L. Durstine, A. Ward, J. Ayres, and A. C. Linnerud. Physiological responses of men to 1, 3, and 5 day-per-week training programs. Res. Q. 47: 638–645, 1976.
18. Gillum, R. F., H. L. Taylor, J. Anderson, and H. Blackburn. Longitudinal study (32 years) of exercise tolerance, breathing response, blood pressure, and blood lipids in young men. Arteriosclerosis 1: 455–462, 1981.
19. Gordon, N. F., C. B. Scott, and B. D. Levine. Comparison of single versus multiple lifestyle interventions: are the antihypertensive effects of exercise training and diet-induced weight loss additive? Am. J. Cardiol. 79: 763–767, 1997.
20. Hagberg, J. M., S. J. Montain, W. H. Martin, and A. A. Ehsani. Effect of exercise training in 60- to 69-year-old persons with essential hypertension. Am. J. Cardiol. 64: 348–353, 1989.
21. Halbert, J. A., C. A. Silagy, P. Finucane, R. T. Withers, P. A. Hamdorf, and G. R. Andrews. The effectiveness of exercise training in lowering blood pressure: a meta-analysis of randomised controlled trials of 4 weeks or longer. J. Hum. Hypertens. 11: 641–649, 1997.
22. Hamdorf, P. A., R. T. Withers, R. K. Penhall, and M. V. Haslam. Physical training effects on the fitness and habitual activity patterns of elderly women. Arch. Phys. Med. Rehabil. 73: 603–608, 1992.
23. Hellénius, M. L., U. de Faire, B. Berglund, A. Hamsten, and I. Krakau. Diet and exercise are equally effective in reducing risk for cardiovascular disease: results of a randomized controlled study in men with slightly to moderately raised cardiovascular risk factors. Atherosclerosis 103: 81–91, 1993.
24. Jennings, G., L. Nelson, P. Nestel, et al. The effects of changes in physical activity on major cardiovascular risk factors, hemodynamics, sympathetic function, and glucose utilization in man: a controlled study of four levels of activity. Circulation 73: 30–40, 1986.
25. Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. The 6th
report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC VI). Arch. Int. Med. 157: 2413–2446, 1997.
26. Katzel, L. I., E. R. Bleecker, E. G. Colman, E. M. Rogus, S. D. Sorkin, and A. P. Goldberg. Effects of weight loss vs aerobic exercise training on risk factors for coronary disease in healthy, obese, middle-aged and older men. JAMA 274: 1915–1921, 1995.
27. King, A. C., W. L. Haskell, C. B. Taylor, H. C. Kraemer, and R. F. De Busk. Group- vs home-based exercise training in healthy older men and women: a community-based clinical trial. JAMA 266: 1535–1542, 1991.
28. Kingwell, B. A. and G. L. Jennings. Effects of walking and other exercise programs upon blood pressure in normal subjects. Med. J. Aust. 158: 234–238, 1993.
29. Kokkinos, P. F., P. Narayan, J. A. Colleran, et al. Effects of regular exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension. N. Engl. J. Med. 333: 1462–1467, 1995.
30. Kukkonen, K., R. Rauramaa, E. Voutilainen, and E. Länsimies. Physical training of middle-aged men with borderline hypertension. Ann. Clin. Res. 14(Suppl 34): 139–145, 1982.
31. Länsimies, E., E. Hietanen, J. K. Huttunen, et al. Metabolic and hemodynamic effects of physical training in middle-aged men: a controlled trial. In: Exercise and Sport Biology, P. V. Komi, R. C. Nelson, and C. A. Morehouse (Eds.). Champaign, IL: Human Kinetics, 1979, pp. 199–206.
32. Leon, A. S., D. Casal, and D. Jacobs. Effects of 2,000 kcal per week of walking and stair climbing on physical fitness and risk factors for coronary heart disease. J. Cardiopulm. Rehabil. 16: 183–192, 1996.
33. Lindheim, S. R., M. Notelovitz, E. B. Feldman, S. Larsen, F. Y. Khan, and R. A. Lobo. The independent effects of exercise and estrogen on lipids and lipoproteins in postmenopausal women. Obstet. Gynecol. 83: 167–172, 1994.
34. Mann, G. V., H. L. Garrett, A. Farhi, H. Murray, and F. T. Billings. Exercise to prevent coronary heart disease: an experimental study of the effects of training on risk factors for coronary disease in men. Am. J. Med. 46: 12–27, 1969.
35. Marceau, M., N. Kouamé, Y. Lacourci re, and J. Cléroux. Effects of different training intensities on 24-hour blood pressure in hypertensive subjects. Circulation 88: 2803–2811, 1993.
36. Martin, J. E., P. M. Dubbert, and W. C. Cushman. Controlled trial of aerobic exercise in hypertension. Circulation 81: 1560–1567, 1990.
37. Meredith, I. T., G. L. Jennings, M. D. Esler, et al. Time course of the antihypertensive and autonomic effects of regular endurance exercise in human subjects. J. Hypertens. 8: 859–866, 1990.
38. Meredith, I. T., P. Friberg, G. L. Jennings, et al. Exercise training lowers resting renal but not cardiac sympathetic activity in humans. Hypertension 18: 575–582, 1991.
39. Myrtek, M. and U. Villinger. Psychologische und physiologische Wirkungen eines fünfwöchigen Ergometertrainings bei Gesunden. Med. Klin. 71: 1623–1630, 1976.
40. Nelson, L., M. D. Esler, G. L. Jennings, and P. I. Korner. Effect of changing levels of physical activity on blood-pressure and haemodynamics in essential hypertension. Lancet 2: 473–476, 1986.
41. Okumiya, K., K. Matsubayashi, T. Wada, S. Kimura, Y. Doi, and T. Ozawa. Effects of exercise on neurobehavioral function in community-dwelling older people more than 75 years of age. J. Am. Geriatr. Soc. 44: 569–572, 1996.
42. Oluseye, K. A. Cardiovascular responses to exercise in Nigerian women. J. Hum. Hypertens. 4: 77–79, 1990.
43. Paffenbarger, R. S., A. L. Wing, R. T. Hyde, and D. L. Jung. Physical activity and the incidence of hypertension in college alumni. Am. J. Epidemiol. 117: 245–257, 1983.
44. Posner, J. D., K. M. Gorman, L. Windsor-Landsberg, et al. Low to moderate intensity endurance training in healthy older adults: physiological responses after four months. J. Am. Geriatr. Soc. 40: 1–7, 1992.
45. Reid, C. M., A. M. Dart, E. M. Dewar, and G. L. Jennings. Interactions between the effects of exercise and weight loss on risk factors, cardiovascular haemodynamics, and left ventricular structure in overweight subjects. J. Hypertens. 12: 291–301, 1994.
46. Rogers, M. W., M. M. Probst, J. J. Gruber, R. Berger, and J. B. Boone. Differential effects of exercise training intensity on blood pressure and cardiovascular responses to stress in borderline hypertensive humans. J. Hypertens. 14: 1369–1375, 1996.
47. Sawada, S., H. Tanaka, M. Funakoshi, M. Shindo, S. Kono, and T. Ishiko. Five year prospective study on blood pressure and maximal oxygen uptake. Clin. Exp. Pharmacol. Physiol. 20: 483–487, 1993.
48. Staessen, J., R. Fagard, and A. Amery. The relationship between body weight and blood pressure. J. Hum. Hypertens. 2: 207–217, 1988.
49. Stefanick, M. L., S. Mackey, M. Sheehan, N. Ellsworth, W. L. Haskell, and P. D. Wood. Effects of diet and exercise in men and postmenopausal women with low levels of HDL cholesterol and high levels of LDL cholesterol. N. Engl. J. Med. 339: 12–20, 1998.
50. Suter, E., B. Marti, A. Tschopp, H. U. Wanner, C. Wenk, and F. Gutzwiller. Effects of self-monitored jogging on physical fitness, blood pressure and serum lipids: a controlled study in sedentary middle-aged men. Int. J. Sports Med. 11: 425–432, 1990.
51. Svendsen, O. L., C. Hassager, and C. Christiansen. Effect of an energy-restrictive diet, with or without exercise, on lean tissue mass, resting metabolic rate, cardiovascular risk factors, and bone in overweight postmenopausal women. Am. J. Med. 95: 131–140, 1993.
52. Tanabe Y, H. Urata, A. Kiyonaga, et al. Changes in serum concentrations of taurine and other amino acids in clinical antihypertensive exercise therapy. Clin. Exper. Hyper.: Theory and Practice A11: 149–165, 1989.
53. Tanaka, H., D. R. Bassett, E. T. Howley, D. L. Thompson, M. Ashraf, and F. L. Rawson. Swimming training lowers the resting blood pressure in individuals with hypertension. J. Hypertens. 15: 651–657, 1997.
54. Urata, H., Y. Tanabe, A. Kiyonaga, et al. Antihypertensive and volume-depleting effects of mild exercise on essential hypertension. Hypertension 9: 245–252, 1987.
55. Van Hoof, R., P. Hespel, R. Fagard, P. Lijnen, J. Staessen, and A. Amery. Effect of endurance training on blood pressure at rest, during exercise and during 24 h, during exercise and during 24 hours in sedentary men. Am. J. Cardiol. 63: 945–949, 1989.
56. Vroman, N. B., J. A. Healy, and R. Kertzer. Cardiovascular response to lower body negative pressure (LBNP) following endurance training. Aviat. Space Environ. Med. 59: 330–334, 1988.
57. Wang, J., C. J. Jen, and H. Chen. Effects of exercise training and deconditioning on platelet function in men. Arterioscler. Thromb. Vasc. Biol. 15: 1668–1674, 1995.
58. Wijnen, J. A. G., M. J. F. Kool, M. A. van Baak, et al. Effect of exercise training on ambulatory blood pressure. Int. J. Sports Med. 15: 10–15, 1994.
59. Wirth, A. and H. Kröger. Improvement of left ventricular morphology and function in obese subjects following a diet and exercise program. Int. J. Obes. 19: 61–66, 1995.
60. World Health Organization Guidelines Sub-Committee. WHO/ISH Guidelines for the Management of Hypertension. J. Hypertens. 17: 151–183, 1999.
61. Zachwieja, J. J. Exercise as treatment of obesity. Endocrinol. Metab. Clin. North Am. 25: 965–988, 1996.