Only a few studies have been published on the association between level of blood pressure and its development and physical activity. The observational studies before mid-1998 reviewed by Hagard  and some others [81,82] show quite consistently that higher levels of physical activity or fitness are associated with a lower blood pressure level and 30-70% lower incidence of hypertension.
The effects of exercise training on blood pressure show wide variation in different studies. A recent meta-analysis of 44 randomized controlled trials found that aerobic or endurance exercise on nor-motensive and hypertensive men and women resulted on average 3.4/2.4 mmHg net decrease in systolic and diastolic blood pressure, respectively, adjusted for control observations and for the number of trained participants . The effect depends on the initial blood pressure being greater in hypertensive subjects. Another meta-analysis of 10 randomized controlled trials on the effect of aerobic exercise on blood pressure of normotensive and hypertensive women revealed a 2/1 mmHg decrease in systolic and diastolic blood pressure, respectively . A comparable meta-analysis on the effect of progressive resistance exercise including 11 studies found an average 3/3 mmHg blood pressure decrease . Hagberg et al.  reported in their updated review of all studies on the effect of exercise training on hypertensive subjects an average blood pressure reduction of 11/8 mmHg and exercise was effective in approximately 75% of individuals with hypertension. The decreased systolic blood pressure was on average 142 mmHg and thus remained inside the hypertension range. The corresponding decreased diastolic blood pressure was on average 89 mmHg. The greater reduction of blood pressure found in this review as compared with the results of the three meta-analyses is likely to be mainly due to the fact that Hagberg and coworkers included studies on hypertensive subjects only and they included both randomized and non-randomized trials. The reviews largely agree on some important aspects. The effect of exercise on resting blood pressure seems to be independent of change of body weight, moderate and vigorous exercise is equally effective and the effects are seen in both men and women and across a wide range of age. In an additional analysis of randomized controlled trials focusing on dose-response relationships Fagard  found that the changes in blood pressure were not significantly related to training frequency (1-7 sessions per week, but in two-thirds of the studies the frequency was 3 sessions per week) or to time per session (15-70 min). Thus, on the basis of current evidence exercise regimens that vary greatly in their content can be effective in reducing blood pressure.
The mechanisms that are responsible for the blood pressure lowering effect of exercise training are not definitively known, but the possible mechanisms include attenuation of adrenergic sympathetic activity, increased cellular insulin sensitivity and decreased level of circulating insulin, decreased peripheral resistance, increased baroreflex sensitivity, changes in the renin-angiotensin aldosterone system and reduction in body fat. Improved relaxation and decreased tension and anxiety are examples of indirect mechanisms.
The risk of cardiovascular events associated with hypertension depends not only on the blood pressure level but to a large extent also on the presence of other risk factors. This is demonstrated by wide differences in the risk of cardiovascular mortality at the same absolute level of blood pressure in different populations . Therefore, it is important that exercise training improves, for example, the blood lipid profile and insulin sensitivity of hypertensive subjects to the same degree as in normotensive individuals. Some evidence also suggests that exercise training in hypertensive patients may result in regression of pathologic left ventricular hypertrophy and attenuate exaggerated
Fig. 3.2.9 Risk of developing cardiovascular (CV) disease for hypertensive individuals with different combinations of CV disease risk factors and the reductions in risk expected with exercise training. Case A: Average 10-year risk for a 50-year-old man and woman with systolic/diastolic blood pressure (BP) of 153/97 mmHg, cholesterol of 206 mg/dL, high density lipoprotein cholesterol (HDL-C) of 42 mg/dL, non-smoking and not having diabetes mellitus or left ventricular hypertrophy (LVH). Percentage risk reduction in these individuals is that resulting from usual CV disease risk factor changes with exercise training in patients with hypertension (DBP=-11/ -8 mmHg, DHDL-C=+3 mg/dL). Case B: Same man and woman as in case A except that both have type 2 diabetes mellitus (non-insulin-dependent diabetes mellitus, NIDDM). The type 2 diabetes mellitus is eliminated with exercise training in both the man and woman, and as in case A all other expected changes occur with exercise training. Case C: Same man and woman as in case A except that both have type 2 diabetes mellitus and LVH. Type 2 diabetes mellitus and LVH are eliminated with exercise training in both the man and the woman, and as in case A all other expected changes occur with exercise training. All risks are calculated using the equations of Anderson et al. based on the Framingham Study. (From , with permission.)
blood pressure response during physical exertion [86,88]. The recent finding that exercise training also decreases blood pressure response to mental stress in hypertensive subjects may be important in terms of the risk of developing end-organ damage .Taken together, the effects of exercise training may decrease the risk of acute cardiovascular complications and development of cardiovascular diseases (Fig. 3.2.9), reduce antihypertensive and other medication requirements and improve the quality of life of hypertensive patients.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...