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Human beings are not programmed to be physically inactive. In fact, the "sedentary death syndrome" is a major risk factor for countless global diseases and millions of premature deaths each year.1] Studies have shown that long-lived species are more efficient at cell maintenance than short-lived species, suggesting that improving the body's maintenance systems can slow down the aging process. As aging results from the accumulation of cellular damage, changing inappropriate lifestyles can prevent damage, stimulate repair, and therefore increase life expectancy. In fact, about two-thirds of the leading causes of death are largely lifestyle-related. As reported by Mokdad et al. found that physical inactivity and poor diet are the main "real causes of death" [2,3].
Although a sedentary lifestyle is important in the pathogenesis of many chronic diseases/disorders, little is known about the mechanisms by which physical activity reduces their incidence. Since calorie restriction (CR) is the only paradigm that permanently increases lifespan in flies, worms, mice, rats, etc., a panel of aging experts investigated "whether changes in exercise behavior and body composition produce changes similar to those found in dietary restriction and whether these changes can be used to replace or enhance the beneficial effects of dietary restriction"  Although no definitive conclusions have been drawn, future research will determine whether changes in physical activity and body composition act as CR mimetics.
Physical inactivity leads to the so-called "disuse syndrome" (i.e., premature aging, obesity, cardiovascular vulnerability, musculoskeletal frailty, and depression)  As this reproducible syndrome applies to young and middle-aged people as well as the elderly, old age per se is not fully responsible for many of the diseases/disorders attributed to it. "So disease as we see it has another component that is not due to disease per se or the effects of time, but to disuse, the third dimension"  In fact, around 15% of the 1.6 million chronic illnesses diagnosed each year are due to physical inactivity.7](table 1). In addition, physical activity also improves balance, flexibility, mental health and overall quality of life. Indeed, “physical inactivity accelerates the aging process for many people, while increased physical activity slows it down for others”  Therefore, the earlier in life someone becomes and remains physically active, the greater the lifelong benefits.
physical activity guidelines
The 1995 Recommended Guidelines state that at least 30 minutes of moderate-intensity physical activity on most but preferably all days of the week would result in significant health benefits.9,10] However, these guidelines were updated in 2007  Therefore, all healthy adults between the ages of 18 and 65 require at least 30 minutes of moderate-intensity aerobic physical activity (i.e. endurance) five days a week, or at least 20 minutes of vigorous physical activity three days a week. week. Although recommendations for seniors are similar, there are some differences, including: aerobic intensity should take into account the elderly's aerobic fitness, include activities that maintain or increase flexibility, and balance exercises for those at risk of falls  Moderate intensity is classified as burning 3.5 to 7.0 kcal/minute (eg, walking 3.0 to 4.5 mph on level ground or cycling 5.0 to 9.0 mph). Severe intensity is classified as burning 7.0 or more kcal/minute (ie, running > 5.0 mph; cycling > 10.0 mph). To meet current guidelines, people must walk at least 3,000 steps in 30 minutes, five days a week. But three sessions of 1,000 steps in ten minutes a day also meet the recommended goal. Recently, Wen et al. prospectively examined 416,175 men and women between 1996 and 2008  Compared with the inactive group, those who exercised 15 minutes a day had a 14% lower risk of all-cause mortality and a 3-year longer life expectancy. Every additional 15 minutes of daily exercise reduces all-cause mortality by 4% and cancer mortality by 1%.
Physical Inactivity: Associated Diseases/Disorders
Gait speed (meters/second) has also been studied in relation to survival in the elderly.14] This analysis of 9 cohort studies enrolled 34,485 older adults with baseline gait speed data and was followed for periods ranging from 6 to 21 years. The authors concluded that "...gait speed was associated with survival in older adults". Unfortunately, at least 26% of American adults are sedentary and more than 50% are not regularly active at the minimum recommended level.15] the goals ofhealthy people 2010that at least 50% of American adults engage in regular moderate to vigorous exercise, as approximately 250,000 premature deaths occur each year in the United States as a result of physical inactivity.sixteen].
To assess the dose-response relationship between physical activity, various chronic diseases, and all-cause mortality, Lee et al. parameters of dose, volume, intensity, duration and frequency of physical activity in 44 published studies  Their results showed that: (a) there is "conclusive evidence" that there is an inverse relationship between levels of physical activity and all-cause mortality rates in men, women, young and old; (b) adherence to current minimum physical activity guidelines is associated with a 20-30% reduction in all-cause mortality; and (c) greater risk reductions occur with increased energy consumption.
Although health professionals are strongly encouraged to encourage more physical activity in older adults, many feel unprepared to prescribe a specific exercise program.18] In fact, a report by the Centers for Disease Control indicates that only 19% of physicians advise their patients about exercise  Lack of exercise among children and young people is also a big problem. For example, Kim et al. possible black and white girls for 10 years (ages 9-19)  Mean activity values for black and white girls were 27.3 and 30.8 metabolic equivalent times (METs)/week at baseline, respectively. In year 10, they were reduced to 0.0 and 11.0 METs/week (100% reduction in black girls, 64% reduction in white girls). Additionally, one-third of US high school students did not participate in the recommended minimum level of moderate or vigorous physical activity in 2003 , and only 55.7% were enrolled in some physical education class, where only 28.4% attended classes daily .
Physical inactivity and all-cause mortality
Life expectancy based on age and sex alone is of limited value because survival is also significantly influenced by health and functional capacity. In fact, around 65% of the leading causes of death are lifestyle-related.2,3] While those with lower health risks generally live longer than those with higher health risks, there is a common concern that longer life expectancy could lead to greater disability and higher medical costs. However, the morbidity compression hypothesis suggests that it is possible to reduce morbidity throughout life and therefore increase life expectancy.23] In fact, a study of college alumni showed that those with high health risks (eg, low patterns of physical activity, smoking, obesity) had twice the cumulative disability of those with low health risks after 32 years of follow-up.24] Thus, "not only do individuals with better health habits survive longer, but in them disability is postponed and compressed into fewer years at the end of life". was not studied was, Dunstan et al. adult tv time25] After controlling for important variables, the hazard ratio for each hour of increase in daily television time was 1.11 for all-cause mortality and 1.18 for cardiovascular mortality. Compared with watching less than 2 hours a day, the hazard ratio for all-cause mortality was 1.13 for 2 to 4 hours a day and 1.46 for more than 4 hours a day. For cardiovascular mortality, the corresponding hazard ratios were 1.19 and 1.80.
A previous study compared physical activity with all-cause mortality in 16,936 Harvard alumni  After 16 years of follow-up, the death rate steadily declined as energy expenditure increased. A subsequent prospective study of Harvard graduates showed a graded inverse relationship between total physical activity and all-cause mortality.27] The third study from this group showed that distance walked and floors climbed were independent predictors of longevity .
Blair et al. compared the level of physical fitness with all-cause and cause-specific mortality in men and women over an 8-year period.29] Here, the age-adjusted all-cause mortality rate decreased across fitness quintiles from 64/10,000 person-years in the least fit men to 18.6/10,000 in the fittest men (relative risk 3.4) and 39.5 /10,000 person-years for 8.5/10,000 for women (relative risk, 4.7). A follow-up study examined the association between changes in fitness and mortality risk in men.30] Each man underwent two clinic visits (median interval, 4.9 years) to assess changes in fitness associated with mortality risk during the follow-up period. The highest age-adjusted all-cause mortality rate was present in those who did not qualify for any of the tests; the lowest mortality rate was in physically fit men in both surveys. Additionally, men who improved from unfit to fit between the two assessments also had a lower mortality rate. In a recent review of physical activity and all-cause mortality in women, the authors concluded that "women can delay mortality by following current physical activity guidelines and consuming about 4200 kJ (about 1000 kcal) of energy per week " .
Because little was known about mortality risk and physical activity among the elderly, Bijnen and colleagues surveyed 802 Dutch retirees at baseline  The 10-year all-cause mortality in the highest tertile decreased with increasing physical activity (relative risk 0.77). More intense physical activity was associated with a greater reduction in mortality. In addition, walking or cycling for 20 minutes at least three times a week significantly reduced all-cause mortality compared with the physically inactive (relative risk 0.70). Recently, Newman et al. examined the long-term positive effects of older adults completing a 400-meter walk at baseline  After an average of 4.9 years, those who failed to complete the walk had a significantly increased risk of mortality, coronary artery disease, disability and reduced mobility. Each additional minute of running time to complete the walk was associated with the following hazard ratios: mortality, 1.29; incidence of coronary artery disease, 1.20; impaired mobility 1.52; and disability, 1.52. Those in the bottom quartile had a significantly higher risk of death than those in the top quartile.
Others have assessed daily energy expenditure and mortality in high-functioning elderly over an average period of 6.15 years.34] Energy expenditure during leisure activities was divided into three tertiles: less than 521 kcal/day; 521 to 770 kcal/day; and more than 770 kcal/day. After adjusting for various confounders, those in the group with the highest tertile of energy expenditure had a significantly lower risk of all-cause mortality than those in the lowest tertile. In fact, the least active group was three times more likely to die. Benetos et al evaluated the role of physical activity and other risk factors in elderly people who can live up to 80 years for men and 85 for women.35] Their data showed a significantly greater chance of reaching this age if they were regularly physically active. Wang et al. added more support for recommending physical activity among older people  In this 13-year prospective study, running club members aged 50 years and older were compared with sedentary controls. Their results showed significantly lower levels of disability among members of running clubs, and the death rate in the control group was 3.3 times higher. A recent meta-analysis of 33 all-cause mortality studies also showed that better cardiorespiratory fitness (CRF) was associated with a significantly lower risk of all-cause mortality.37].
A recent study also suggests that recreational physical inactivity can accelerate the aging process.38] These researchers assessed the physical activity, smoking, and socioeconomic status of male volunteers and determined the telomere length of their white blood cells. After adjusting for age, gender, BMI, smoking, socioeconomic status, and physical activity at work, telomere length was positively associated with recreational physical activity, possibly delaying the aging process.
Heart disease: primary prevention
Heart disease has been the leading cause of death in the United States for the past four decades.39] In 2007, cardiovascular disease (CVD) accounted for 33.6% of all US deaths; 2,200 Americans die every day from cardiovascular disease  Furthermore, the myth that heart disease is just a "man's disease" has been debunked. In fact, it is the leading cause of death for women worldwide, accounting for a third of all female deaths. In many countries, including the United States, more women die from cardiovascular disease than men.41] Primary prevention of heart disease, a reduction in risk factors for coronary artery disease (CAD) in healthy people, results in a four-fold reduction in mortality from coronary heart disease than secondary prevention (i.e., a reduction in risk factors). risk in people with existing CAD)  Although approximately 40% of adults in their 40s will develop heart failure during their lifetime, the Physicians' Health Study indicates that maintaining a healthy lifestyle is associated with a significantly lower risk of heart failure .
Morris and others. reported in the early 1950s that active drivers on double-decker buses in London were protected from CAD compared with seated bus drivers [44,45] Likewise, postmen were protected against CHD compared to less active civil servants. Three decades later, Paffenbarger and colleagues interviewed 16,936 Harvard alumni about CAD-related lifestyle and longevity experiences  Those who spent 2000 kcal/week walking, climbing stairs and exercising had a 39% lower risk of coronary heart disease than less active former students, and there would be 16% fewer deaths from coronary heart disease if everyone had the same amount of energy in some way. form. exercise is over. Since then, there has been increasing interest in using gait speed to assess functional status and motor performance in the elderly.3208 elderly men and women were followed for an average of 5.1 years.47] Here, people who walked slowly had a three times greater risk of cardiovascular death compared to people who walked faster.
In their study of the association between the distance covered by a 400-meter runner and all-cause mortality in the elderly, Newman et al.33] In this case, the inability to complete the walk was associated with a significantly increased risk of CHD. For those who completed the walk, each additional minute was associated with a hazard ratio of 1.2 for an incident of CHD. Others have examined the impact of different levels of physical activity on overall life expectancy with and without CHD in men and women  Compared with low physical activity, moderate and vigorous activity resulted in 1.3, 3.7, 1.1 and 3.5 more overall life expectancy and 1.3 and 3.3 more years without CAD, respectively.
As the role of walking versus vigorous exercise in preventing coronary artery disease, particularly in women, remains controversial, healthy postmenopausal women were studied prospectively.49] Results showed that increasing quintiles of energy expenditure had age-adjusted relative risks of coronary events of 1.00, 0.73, 0.69, 0.68, and 0.47, respectively. To better understand these variables, Duncan et al. 492 sedentary adults to 1 of 4 conditions of exercise advice or a comparison group with medical advice  The duration (30 minutes) and type (walking) of exercise were held constant, while the intensity and frequency of exercise varied from moderate intensity - low frequency (3-4 days/week) to high intensity - high frequency (5 days/week). /week). -7 days/week). ). week) existed. . After 24 months, participants in the high-intensity exercise group showed a significant increase in cardiorespiratory fitness.
Although exercise capacity is an important prognostic factor in people with CHD, it is unclear whether it predicts mortality in healthy people as well. To assess this, Myers and colleagues studied 6713 men referred for treadmill exercise trials  Participants were divided into two groups: 3,679 had an abnormal stress test result, a history of CHD, or both; 2,534 had a normal stress test result and had no history of CHD. Maximum exercise capacity, measured in metabolic equivalents (METs), was the strongest predictor of death between the two groups. Each MET increase in exercise capacity resulted in a 12% improvement in survival.
To assess increased physical activity in frail older adults, Ehsani et al randomized frail octogenarians to either a sedentary control group or an exercise group on a 6-month exercise program followed by 3 months of more intense aerobic exercise.52] Compared with the sedentary group, the exercised group showed a 14% increase in both maximal oxygen consumption and cardiac output during exercise. The authors concluded that "although frail octogenarians have a reduced ability to improve aerobic performance in response to exercise, this adaptation is most strongly mediated by an increase in Q (maximum exercise cardiac output) during maximal exertion."
Heart disease: secondary prevention
Although rest and physical inactivity have been recommended for patients with CAD that have existed for decades, it is important to recognize that recent studies clearly show that the benefits of physical activity and physical conditioning also apply to patients with coronary artery disease and other vascular diseases. For example, a recent prospective study on the health of nurses showed that regular exercise significantly reduces the risk  In fact, the absolute risk of sudden cardiac death associated with moderate to vigorous exercise was "remarkably low". A prospective study of US male physicians also showed that regular vigorous exercise "reduces the risk of sudden death during vigorous exercise"  The following reports further document the importance of physical activity in patients with established CAD.
A British study involving men with existing CHD compared the relative risk of death from cardiovascular and all-cause disease with level of physical activity.55] Compared with the inactive or occasionally active group, the relative risks (RR) were as follows: mild activity, 0.42; moderate activity, 0.47; and moderately vigorous or vigorous activity, 0.63. In addition, recreational activities of four or more hours per week, moderate or intensive gardening, and regular walking for 40 minutes or more per day were also associated with a significant reduction in mortality. Those who were initially sedentary but started a light or more active program also lived longer (RR, 0.58). Likewise, Hung et al. studied the effect of aerobic exercise (AT) or the combination of AT and resistance exercise (CT) on maximal aerobic power (peak VO2), distance covered in 6 minutes, maximal strength of upper and lower limbs and quality of life in elderly women with CHD  Subjects randomized to AT or CT exercised 3 days a week for 8 weeks. Both AT and CT improved similarly in VO2 max, 6-minute walk distance, lower extremity strength, and emotional and global quality of life.
As the relationship between long-term outcomes and the number of cardiac rehabilitation sessions attended was unknown, Hammill et al. 30,161 elderly patients who attended at least one session over a four-year period  After adjusting for several confounders, the results showed that those who attended 36 sessions had a 14% lower risk of death and a 12% lower risk of myocardial infarction than those who attended 24 sessions; 22% lower risk of death and 23% lower risk of heart attack than those who attended 12 sessions; and a 47% lower risk of death and a 31% lower risk of heart attack than those who attended a session. In an initial meta-analysis of 48 clinical trials of patients with CAD, exercise-based cardiac rehabilitation reduced all-cause mortality (20%), cardiac mortality (26%), non-fatal myocardial infarction (21%) and coronary artery bypass graft surgery (13%) and percutaneous coronary angioplasty (19%) .
Flynn et al. tested the effects of physical training on the health status of people with heart failure  This multicenter, randomized, controlled study recruited outpatients with stable heart failure, 1172 of whom completed usual care plus aerobic exercise consisting of 36 supervised sessions followed by home exercise. The control group received only usual care. The researchers concluded that "exercise training produced modest but statistically significant improvements in self-reported health status compared with usual care without exercise."
In 2008, stroke was the third leading cause of death in the United States , and an estimated 795,000 people suffer a new or recurrent stroke each year  However, physical activity has been shown to reduce the risk of ischemic stroke in both women and men. For example, Hu et al. the association between physical activity and stroke risk in 72,488 women  At eight years of follow-up, the relative risks of ischemic stroke for increasing metabolic equivalent tasks from lowest to highest quintile were 1.00, 0.87, 0.83, 0.76, and 0.52. Similarly, Lee and Blair examined the association between cardiorespiratory fitness and stroke mortality in men over a ten-year period.63] After accounting for age and other risk factors, fit men had a 68% lower risk and moderately fit men had a 63% lower risk of stroke mortality compared with men with low physical fitness.
Recent studies confirm the importance of physical activity in reducing the risk of stroke. For example, a prospective cohort of stroke-free older adults in the Northern Manhattan Study showed that moderate-to-vigorous physical activity protects against the risk of ischemic stroke in men but not in women.64] However, the subsequent study found that increased levels of physical activity were associated with a lower risk of silent stroke in both men and women.sixty-five].
Aging is accompanied by cardiovascular changes, including decreased elasticity and increased stiffness of the coronary arteries, which increases afterload on the left ventricle and leads to systolic hypertension. Unfortunately, high blood pressure is a major public health problem and it appears to be on the rise. For example, Vasan et al. in a prospective community-based study, the lifetime risk of developing hypertension in 55- to 65-year-old subjects who did not have hypertension at baseline  The lifetime residual risk of developing hypertension was 90% in both groups. Compared with an earlier period, the risk of high blood pressure remained unchanged in women, but increased by about 60% in men.
As exercise is the cornerstone of therapy to prevent, treat, and control high blood pressure, lifestyle changes are recommended. In an early study of 14,998 male Harvard graduates, those who didn't exercise vigorously had a 35% higher risk of high blood pressure than those who did.67] In addition, increased BMI, weight gain since college, parental history of hypertension, and lack of strenuous exercise independently predicted increased risk. The following year, Blair et al. on the association between physical fitness and arterial hypertension in men and women over a period of one to twelve years  Low fitness subjects had a relative risk of 1.52 compared to the high fitness group. As reported by Brennan et al. found that most elderly women have isolated systolic hypertension.69] To assess the possible effect of less physical exertion on blood pressure, they studied 109 elderly women, 63.3% of whom were hypertensive. Mean systolic blood pressure was lower in women who exercised 5 hours or more a day than in women who exercised less than 5 hours a day. Others conducted a similar randomized controlled trial of six months of combined aerobic and resistance training in subjects with untreated systolic blood pressure of 130-159 mmHg or diastolic blood pressure of 85-99 mmHg  While mean diastolic blood pressure was significantly reduced, systolic blood pressure was not, suggesting that "older people may be resistant to exercise-induced reductions in systolic blood pressure", possibly due to "lack of improvement in aortic stiffness...". Based on current evidence, the American College of Sports Medicine recommends 30 minutes or more of moderate-intensity physical activity for people with high blood pressure on most but preferably all days of the week.71].
Type 2 diabetes mellitus
Aging is often associated with a higher incidence of insulin resistance and type 2 diabetes mellitus. Unfortunately, the number of diagnosed cases in the US increased from 1.5 million in 1958 to 17.9 million in 2007, and in 2009, 23, 6 million Americans had type 2 diabetes  Diabetes is currently the seventh leading cause of death in the United States. However, as it is also a major risk factor for cardiovascular, cerebrovascular and peripheral vascular disease, hypertension and kidney disease, its actual cause of death is much higher.
Type 2 diabetes accounts for 92% to 96% of all diabetes cases. For decades, it was called "late-onset diabetes" because it was rare before age 40. She was also commonly known as "3-Fs": female, fat, and forty. However, due to significant lifestyle changes over the last few decades, the disease is now common among men, teenagers and young adults. In fact, the main risk factors for type 2 diabetes are abdominal obesity and physical inactivity. A familial risk factor is often present, but much less important than lifestyle.
Numerous studies have clearly shown that exercise improves glucose metabolism. To evaluate the effect of lifestyle interventions, the Diabetes Prevention Program Research Group assigned 3234 middle-aged non-diabetic subjects with elevated fasting and afterload plasma glucose concentrations into one of three groups: placebo, metformin, or modification of the Lifestyle.73] After a median follow-up of 2.8 years, the lifestyle intervention reduced incidence by 58% and metformin use by 31%. Furthermore, after a median follow-up of 23.1 years, the Physicians Health Study reported that the hazard ratios for inactive men with normal BMI, overweight, and obese were 1.41, 3.14, and 6.57, respectively.74] Active but overweight and obese men had hazard ratios of 2.39 and 6.22, respectively.
In an initial study, Pan et al. 577 Chinese men and women with glucose intolerance in a control group or one of three treatment groups: diet only, exercise only, or diet plus exercise  After six years of follow-up, 67.7% of the control group developed diabetes, compared with 43.8%, 41.1%, and 46.0% in the diet only, exercise only, and diet plus exercise groups. Similarly, 522 Finnish middle-aged overweight/obese individuals with glucose intolerance were randomly assigned to either an intervention group or a control group.76] Each member of the intervention group received advice on weight loss, improving diet and increasing physical activity. After 4 years of follow-up, the incidence of diabetes was 11% in the intervention group and 23% in the control group.
Hu et al. followed 84,941 nurses who were free of cardiovascular disease, diabetes, and cancer at baseline for 16 years  They concluded that 91% of the 3,300 new cases of type 2 diabetes were due to poor lifestyles. Although overweight/obesity was the most important risk factor, physical inactivity was the second most important factor. Similar findings have also been reported in children  In this study, insulin resistance was examined in obese and lean children aged 9 to 11.5 years. As in adults, total and central obesity were positively associated with increased insulin resistance, while physical activity was negatively associated with insulin resistance.
Importantly, diabetic adults aged 18 years and older who walked at least two hours a week had a 39% lower all-cause mortality rate and a 34% lower cardiovascular mortality rate compared to those with a sedentary lifestyle.79] Death rates were lower in people who walked for three to four hours a week. The authors concluded that "one death per year could be prevented for every 61 people who could be persuaded to walk at least 2 hours a week".
Cancer is the second leading cause of death in the United States, Canada and most of Europe. Along with poor diet and tobacco use, physical inactivity is a major risk factor for many types of cancer. In fact, “adopting an active lifestyle can reduce all-cause cancer rates by up to 46%”  Although the mechanisms by which regular physical activity prevents site-specific cancers are unknown, evidence suggests that components of the innate immune system are involved, as well as a better overall lifestyle, less body fat, a faster transit time, shorter stool length, lower estrogen, and improved antioxidant enzyme systems  The main types of cancer related to physical inactivity are listed inTable 2.
1. Prostate cancer
Studies on the link between physical activity and prostate cancer are conflicting. A review of the literature between 1989 and 2001 identified 13 cohorts of American and international studies, nine of which showed an association between increased physical activity and reduced risk of prostate cancer.82] Five out of 11 case-control studies also showed that a high level of physical activity reduced the risk of prostate cancer. Of all studies between 1976 and 2002, 16 of 27 reported a reduced risk in the most active men. More specifically, a recent Chinese case-control study showed that moderate physical activity was inversely associated with prostate cancer risk.83] There was also a dose-response relationship. However, a Canadian population-based case-control study reported mixed evidence of an association between prostate cancer risk and physical activity.84] Although occupational activity reduced the risk, only vigorous physical activity reduced the risk.
Neilsen and others. prospectively examined the association between physical activity and prostate cancer in 29,110 Norwegian men.85] After 17 years of follow-up, a multivariate analysis showed that exercise frequency and duration were inversely associated with the risk of advanced prostate cancer and death from cancer. However, results from a follow-up study of health professionals showed no association between total prostate cancer and complete, vigorous, or non-strenuous physical activity, although men aged 65 years and older had a lower risk in the highest level of activity category. vigorous for advanced and advanced patients. fatal prostate cancer86].
Since intense activity after diagnosis has been reported to be inversely associated with prostate cancer-specific mortality, Richman et al. Vigorous activity and brisk walking in 1455 men with clinically localized prostate cancer  After 2,750 person-years, men who walked 3 hours a week or more briskly had a 57% lower rate of progression than men who walked less than 3 hours a week at an easy pace.
2. Breast Cancer
Studies clearly show that increased physical activity reduces the risk of breast cancer. Although the beneficial effect of exercise applies to both premenopausal and postmenopausal women, the association is stronger for the latter.88] In women in the French E3N cohort, there was a linear decrease in breast cancer risk with greater amounts of moderate (P<0.01) and vigorous (P<0.0001) recreational activities.89] Additionally, women in the Female Contraceptive and Reproductive Experiences Study, which included white and black women with newly diagnosed breast cancer, were compared with women without cancer of the same age, race/ethnicity, and study setting  Here, the risk of breast cancer was significantly reduced in all women with higher lifetime physical activity. Likewise, John et al. conducted a population-based case-control study of breast cancer in African-American, Latino, and Caucasian women to assess the association with a lifetime of moderate and vigorous physical activity.91] The results showed a significant reduction in the risk of breast cancer in premenopausal and postmenopausal women and were similar across all three racial/ethnic groups.
Interestingly, the Women's Health Initiative Observational Study of older women reported that those who engaged in vigorous physical activity three or more times a week and sweated at age 35 had a relative risk of breast cancer of 0.86 compared with women who did not. .92] Therefore, "an hour of moderate to strenuous activity per day offers the greatest benefit." It should also be noted that obesity, which can be largely controlled by physical activity, is also an important risk factor for postmenopausal breast cancer.93].
3. Colon cancer
There is a strong inverse association between colon cancer risk and physical activity. In a case-control study, data on physical activity at work and leisure at ages 20, 30, 40, 50, and 60 years of patients with colorectal cancer were compared with a control group without cancer.94] For lifetime physical activity, the multivariate odds ratio for the highest quartile was 0.37. For high-quality trainers compared to non-trainers, the odds ratio was 0.26.
Others have examined the association between work- and leisure-time physical activity and colorectal cancer in a cohort of male smokers.95] After 12 years of follow-up, the relative risks for light and moderate work were 0.60 and 0.45, respectively. Furthermore, the relative risk of distal colon cancer for moderate/heavy work was 0.21. For rectal cancer, the relative risk reductions for light and moderate/heavy work were 0.71 and 0.50, respectively. Slatterley et al. also reported that vigorous physical activity reduces the risk of rectal cancer in men and women.96].
Although the incidence of colorectal cancer in Japan is among the highest in the world, increased work-related physical activity in men is associated with a significant reduction in the risk of cancer of the distal colon and rectum.97] However, only complete and moderate or "heavy" physical activity outside of work prevented a positive effect on rectal cancer. In women, work-related physical activity and moderate or "heavy" physical activity outside of work were protective only in the distal colon. In a recent review of 52 studies, 37 found a significant association between physical activity level and reduction in colorectal cancer .
4. Lung cancer
Population studies on the association between physical activity and lung cancer have produced conflicting results. For example, Back et al. the relationship between physical activity and risk of lung cancer in a Danish cohort aged 50 to 64 years  After adjusting for smoking, educational level, possible occupational exposure to carcinogens, and diet, "there was no convincing protective effect of physical activity on lung cancer risk." Similarly, a large European study showed "no consistent protective association of physical activity with lung cancer risk" .
However, other studies have shown that physical activity reduces the risk of lung cancer. For example, an Iowa Women's Health Study found that physically active women were less likely to develop lung cancer than relatively inactive women.101] Similarly, a case-control study of women from the Czech Republic reported an inverse association between smoking and exercise in lung cancer.102] Furthermore, researchers in a large Norwegian study reported that men who exercised four or more hours a week had a lower lung cancer risk for small cell adenocarcinoma and adenocarcinoma than men who did not exercise (relative risk, 0.71 ) .
Furthermore, in a subcohort of these men who were assessed twice for physical activity, the relative risk of lung cancer for the most active men at both assessments was 0.39. Furthermore, in a meta-analysis of "all relevant published reports from 1966 to October 2003", the odds ratios for lung cancer were 0.87 for moderate recreational physical activity and 0.70 for vigorous activity .
5. Ovarian cancer
Increased physical activity may reduce the risk of ovarian cancer by reducing circulating sex hormones, ovulation frequency, body fat or chronic inflammation. To investigate this possible association, Hannan et al. a prospective cohort study of 27,365 women conducted by  Although there was no significant overall association between physical activity and ovarian cancer in the past year, "the results suggest an inverse association." However, in the Copenhagen City Heart Study, "a highly significant inverse association was found between vigorous recreational physical activity and ovarian cancer..."  Similarly, a Canadian case-control study reported that women in the top tertile were at significantly lower risk compared to women in the bottom tertile with moderate, intense, and full recreational activity.107] In a Chinese case-controlled study, the risk of ovarian cancer also decreased with increasing duration of strenuous exercise and the frequency of "activity-induced sweating in premenopausal women...".  Furthermore, a review of the literature concluded that "physical activity protects against postmenopausal breast, endometrial, and ovarian cancer, regardless of BMI" .
6. Endometrial cancer
Results of an initial population-based case-control study of physical activity at work and outside of work showed that non-retired women who had a sedentary job or lifestyle had a "slightly increased risk of endometrial cancer".110] Similarly, authors of an early UK study concluded that "physically inactive women may have an increased risk of endometrial cancer because they are more likely to be overweight or obese" .
Recently, Moradi et al. on the results of a population-based case-control study in "the entire Swedish female population aged 50-74 years..."  Compared with the lowest levels of exercise, there was a significant reduction in endometrial cancer in those with the highest levels of exercise. Another population-based case-control study that examined the association between endometrial cancer and physical activity through exercise, housework, and transportation showed the following: Participation in physical activity in adolescence and adulthood reduced the risk of cancer in 40%; Postmenopausal women who began exercising in adulthood significantly reduced their risk of cancer; and reductions in risk were found for household chores and walking for transportation  A review of physical activity and individual cancer risk concluded that "a convincing reduction in the risk of colon cancer and estrogen-dependent malignancies such as breast and endometrial cancer was found" .
By age 50, most people realize that they are losing muscle endurance and strength due to loss of muscle mass and adaptability (sarcopenia). The most obvious causes are underutilization, depletion of muscle regenerative stem cells, decrease in anabolic hormones, and decrease in physical activity. As a result, muscle strength declines by approximately 50% between the ages of 30 and 80.115], and in the seventh and eighth decade of life, maximal willpower in the proximal and distal muscles is reduced by 20-40% in men and women .
A recent study evaluated the effects of aging on morphological and functional characteristics of cardiac, skeletal, and intestinal muscles and on oxidative status in mice to determine whether a lifelong moderate exercise regimen would protect against some deleterious effects of aging.117] In fact, a moderate treadmill throughout the mouse's lifetime reversed all the effects of aging on intestinal, skeletal and cardiac muscles. It also prevented increased lipid peroxidation and sarcopenia.
Raguso et al investigated the association between physical activity and body composition in healthy elderly men and women.118] After a 3-year period, increased physical activity was associated with greater muscle mass and less trunk fat. Exercise not only reverses age-related declines in muscle mass, but also in muscle strength.119] After 12 weeks of physical training, approximately 40% of the 10-year loss of strength and 75% of the loss of muscle mass were recovered.
Only modest strength gains in older people are achieved with low-intensity training. However, progressive resistance training shows similar or even greater strength gains compared to youth. For example, after a 12-week progressive training program in older men, extension strength more than doubled, flexion strength more than tripled, and total muscle area increased by 11.4% [120,121] Strength training also leads to significant improvements in muscle strength in frail people age 90 and older.122] After eight weeks of high-intensity resistance training, strength gains averaged 174%, mid-thigh muscle area increased by 9%, and average tandem walking speed improved by 48%.
osteoporosis and fractures
Osteoporosis, a very common problem in postmenopausal and elderly women, is associated with a decrease in bone mineral density (BMD) and an increase in fractures, leading to a high percentage of disability and death in old age. Sadly, 20 million Americans have osteoporosis and another million will develop the disease if preventative measures are not taken.123] An estimated 26% of American women age 65 and older and more than 50% of those age 85 and older have osteoporosis.124] However, osteoporosis is not just a female disease. Although men are commonly affected, it is not highly regarded by the medical community. In fact, two million American men have osteoporosis compared to eight million women.125] Additionally, 24% of men over age 45 will suffer an osteoporosis-related fracture, versus 47% of females, and 31% will die within a year, versus 17% of females. Osteoporosis is responsible for more than 1.5 million fractures in the United States each year, resulting in 500,000 hospital admissions, 800,000 emergency room visits, 2.6 million physician visits, 180,000 nursing home admissions and $12 to $ 18 billion in healthcare costs.
Numerous studies have shown that physical activity is an important factor in reducing/preventing osteoporosis. In addition, increased physical activity in childhood and adolescence is an important preventive factor. For example, athletically active teens have greater bone mass than their sedentary counterparts.126] In addition, weight-bearing physical activity during the years of peak bone formation (ages 12 to 18 years) "appears to have sustained benefits for the lumbar spine and proximal femoral BMD (areal bone mineral density) in postmenopausal women. menopause". Similarly, a study from eastern Finland that compared distance walked between 9 and 11 years of age with femoral BMD in perimenopausal women showed that the greater the distance walked, the greater the BMD.127].
Others have examined the effect of daily physical activity on the proximal femur in 35- to 40-year-old women  At 12 months, there was a significant association between physical activity and proximal femur BMD. Similarly, after comparing the BMD of male long-distance runners with age-matched healthy controls, the runners had significantly higher BMD in the calcaneus, lower extremity, femoral neck, pelvis, and lumbar trabecular spine.129] However, a meta-analysis of 10 studies examining the effect of walking on BMD in postmenopausal men and women showed that walking alone had a significant beneficial effect on lumbar BMD, but the effect was not significant on the femur or calcaneus.130] However, when combined with a weight-bearing program, the results are more significant. For example, in a 12-month prospective randomized study, older women assigned to the exercise group showed significant increases in Ward's triangle BMD, improvement in gait speed, and isometric grip strength .
The risk of becoming frail and disabled increases significantly with age. An early study compared predictors of disability among members of a running club aged between 50 and 80 years and a college population.132] The running club members had significantly better overall health and fewer disabilities at baseline and six years later. Predictors of greater subsequent disability were greater initial disability, medication, years of smoking and age, as well as increased blood pressure, arthritis and less physical activity. Similarly, a six-year prospective longitudinal study of disability compared older men and women with members of the general community.133] The authors concluded that "older people who engage in vigorous running and other aerobic activities have lower mortality rates and slower development of disability than members of the general population."
To better assess the benefits of aerobic exercise on disability and mortality in the elderly, Wang and others investigated whether regular exercise could lead to morbidity later in life.134] Compared with the control group, their results showed the following: (a) disability levels were significantly lower among running club members; (b) relative disability was deferred by 8.7 years; (c) running club membership and participation in other aerobic activities protected from mortality; and (d) controls had a 3.3 times higher mortality rate in each disease category.
Physical inactivity and obesity are important public health problems in developed countries. Indeed, obesity and physical inactivity independently contribute to all-cause and cause-specific mortality in young and middle-aged adults.135] These researchers compared obesity with physical activity to predict mortality over a 24-year period in 116,564 women who did not have cancer or coronary artery disease at baseline. Compared with physically active lean women, the multivariable relative risk of death was 1.55 for inactive lean women, 1.91 for active obese women, and 2.42 for inactive obese women. Furthermore, a BMI greater than 25 and physical activity less than 3.5 hours per week combined accounted for 31% of all premature deaths. Because it was unclear how much physical activity is needed to prevent long-term weight gain in the elderly, Lee and colleagues conducted a 15-year prospective study in 34,079 healthy women  At the end of the study, the average weight gain was 2.6 kg. However, those who managed to maintain a normal weight and gain less than 2.5 pounds averaged 60 minutes of moderate-intensity activity (mainly walking) per day.
Menik et al. studied 3,345 adolescents over a five-year period and found that those who participated in various bicycle-related extracurricular activities (eg, riding a bicycle) did so more than four times a week.137] In addition, on each day of the week, students who participate in the physical education curriculum are 5% less likely to become overweight adults; Attending physical education classes every day of the week reduced the odds by 28%.
The HALE project investigated the individual and combined effects of the Mediterranean diet, physical activity, moderate alcohol consumption, and non-smoking on all-cause and cause-specific mortality in elderly Europeans.138] At 10 years of follow-up, the hazard ratios were as follows: adherence to the Mediterranean diet, 0.77; moderate alcohol consumption, 0.78; physical activity 0.63; and non-smokers, 0.65. Combining these risk factors reduced the all-cause mortality rate to 0.35. Indeed, Mokdad et al found that the combination of physical inactivity and obesity/poor diet was the second leading "true" cause of death in the United States in 1990 and 2000 [2,3].
depression and dementia/Alzheimer's disease
Depression is reported to be the leading cause of non-fatal medical disability in developed countries among people aged 15 to 44 years.139] In fact, depression is the leading cause of suicide, the 10th leading cause of death in the United States. Although aging is strongly associated with loss of function and depression, increased physical activity has been shown to delay these disorders. For example, 158 men and women aged 50 years and older with major depressive disorder were randomly assigned to a program of aerobic exercise, antidepressants, or a combination of exercise and medication.140] Although those receiving medication alone had the fastest initial response, exercise was just as effective in reducing depression after 15 weeks.
Recently, Lindwall et al. the association between light and strenuous physical activity and depression in older Swedish men and women  Here, inactive older adults had higher depression scores for light and strenuous physical activity. Furthermore, those who were continuously active had lower depression scores than those who were continuously inactive and those who switched from active to inactive in the previous year. Similarly, a Finnish study found that those who exercised at least two to three times a week experienced significantly less depression, anger, cynical distrust, and stress than those who exercised less often or did not exercise at all.142] Others have examined the effects of walking on a treadmill in a group of American men and women with a major depressive episode  Following a pattern of interval training, running on a treadmill for 30 minutes a day for 10 days resulted in "significant improvement in patients with major depressive disorder."
Under normal conditions, neuron production (ie, neurogenesis) occurs only in the hippocampus and olfactory system of the adult brain. As aging causes changes in the hippocampus, the elderly may experience a decline in cognition. However, several studies have shown that regular exercise improves some of the detrimental morphological and behavioral outcomes in aged mice, thereby increasing the potential for neurogenesis.144–147] Furthermore, as in mice, exercise has been shown to have a primary effect on dentate gyrus cerebral blood volume, which correlates with cardiopulmonary and cognitive function in humans.148].
Recognizing that increased physical activity can also maintain cognitive function in older adults, Weuve and colleagues examined the association between regular long-term physical activity such as walking and cognitive function in 18,766 older women  They found that when tests of cognition, verbal memory, category fluency and attention were combined, women in the most active quintile had a 20% lower risk of cognitive decline. In fact, an American study found that increased energy expenditure protects against cognitive decline in a dose-responsive manner.150] However, as low-intensity physical activity such as B. walking has not been studied in relation to dementia, Abbott et al. this association in men aged 71 to 93 years  After five years of follow-up, those who walked less than 0.25 miles a day had a 1.8 times greater risk of dementia than those who walked two or more miles a day.
Colcombe et al reported that greater cardiovascular fitness leads to better functioning of the brain's attentional network during a cognitively challenging task.152] In this case, the aerobically trained or physically fit individuals showed greater task-related activity of the prefrontal and parietal cortices compared with the non-aerobically trained or low-fitness control group. They recently reported a significant increase in brain volume in subjects aged 50 to 79 years who participated in aerobic exercise compared to those who participated in the non-aerobic group .
Alzheimer's disease (AD) is the sixth leading cause of death in the United States. Major risk factors include age, family history, educational level, and presence of the apolipoprotein E (APOE) e4 genotype.154] One of the main explanations for AD is the increase in brain beta-amyloid protein. It is important to note that Lazarov et al. recently reported that environmental enrichment decreases amyloid protein accumulation and alters changes in gene expression in a double transgenic mouse model.155] These genetically engineered mice were placed in an "enriched" environment that included exercise equipment and toys, as well as food, water and bedding for control mice. After five months, the brains of mice housed in the enriched environment showed a significant reduction in amyloid protein, mainly related to increased physical activity.
Around the same time, Podewills and colleagues reported that people who regularly engage in a variety of physical activities can reduce their risk of developing AD by up to 50%  Increased physical activity also reduced the risk of all-cause dementia and ischemic dementia. However, physical activity did not affect APOE4 carriers, a gene variant that increases the risk of AD. Others have also reported that recreational physical activity in middle age is associated with a reduced risk of AD.157] Therefore, "Regular physical activity may reduce the risk or delay the onset of dementia and AD, particularly in genetically susceptible individuals."
Both physical activity and diet were recently evaluated in a prospective study of two cohorts composed of community-dwelling older adults without dementia at baseline  After 14 years, the hazard ratio for "some" physical activity was 0.75 and for "a lot" physical activity was 0.67. A review of the literature on the beneficial effects of exercise on brain aging and cognition was published .
inflammation and atherosclerosis
Although the pathogenesis of atherosclerosis is not fully understood, inflammation is a widely accepted mechanism. Since coronary heart disease is the leading cause of death in the United States and most other Western countries, and cerebrovascular disease is the third, preventing or delaying these diseases would not only improve quality of life but also increase longevity. Since 2005, 22 prospective epidemiological studies have shown that elevated blood levels of highly sensitive C-reactive protein (hs-CRP), a sensitive marker of inflammation, are a strong predictor of future CAD. Other studies have also shown that physical activity reduces the inflammatory process. For example, a group of 197 CD patients were randomized to a comprehensive lifestyle program (regular physical activity, low-fat diet, smoking cessation) or usual care with routine follow-up for 6 months.160] Regardless of diet and smoking, exercise capacity was significantly and inversely correlated with levels of C-reactive protein, interleukin-6, and soluble cell adhesion molecule-1 in CAD patients, "possibly delaying the atherosclerotic process."
Aging is often accompanied by a decline in immune function, which can lead to an increased incidence of infectious diseases, malignancies, and autoimmune diseases; hence the immunological theory of aging. As the aging process does not uniformly affect the immune system, a possible explanation could lie, at least in part, in differences in physical activity. In fact, numerous studies have shown that moderate physical exercise attenuates immune senescence in the elderly. For example, Chubak et al. The effects of moderate-intensity physical activity on the risk of colds and upper respiratory tract infections in overweight and obese sedentary postmenopausal women.161] After a few months, the risk of catching a cold was three times higher in the control group than in the students.
While regular, moderate physical activity benefits the immune system by increasing resistance to infections and some cancers, long-term vigorous exercise (eg, running a marathon) appears to have a negative effect. For example, susceptibility to upper respiratory tract infection (URTI) after chronic exercise of varying intensity is described by a "J" shaped curve. In this review article, Nieman presented data from several studies suggesting that people who participate in marathon events and/or very heavy training are at increased risk for URTI .
Regular exercise also accelerates wound healing in the elderly. For example, in a group of healthy elderly men and women, wound healing occurred significantly faster in the exercise group than in the sedentary group.163].
Metabolic syndrome is a combination of cardiometabolic risk factors, including central obesity, insulin resistance, glucose intolerance, dyslipidemia, hypertension, hyperinsulinemia, and microalbuminuria. Sisson et al., investigated the association of sedentary leisure behavior (LTSB) and habitual work/home activity with risk factors for metabolic syndrome and cardiovascular disease (CVD) in men and women.164] At four years, the odds of developing metabolic syndrome were 1.94 in men with four or more hours/day of LTSB compared with one or less hours/day. LTSB of four or more hours a day was also associated with increased waist circumference, lower HDL cholesterol levels, high blood pressure, and high blood sugar levels in men. In women, high LTSB alone was associated with increased risk of metabolic syndrome.