Today I'll point out the results from recent research into the intersection between exercise and aging. It is well known that undertaking physical activity correlates with a lower risk of mortality and age-related disease, and though the details vary by age, this relationship holds up all the way into late life. Even modest levels of activity, such as cleaning and gardening and walking, appear to have a sizable impact on health and mortality risk.
When using human data researchers can typically only establish correlations between exercise and health, which leaves open the possibility that people who are more robust and would have lived longer anyway tend to exercise more often. However, in studies using mice it is quite clear that exercise is the cause of improved health and extends average (but not maximum) life span. It would be surprising to find that this was not the case in other mammals, given the degree of similarity in the cellular and biochemical responses to exertion.
The question of whether more exercise is better is an interesting one, and hard to quantify in humans. There is good evidence to suggest that the usual recommendation of 150 minutes per week is too low, for example. Elite athletes live significantly longer than the rest of the population, but it is unclear as to whether this is a reflection of that fact that only unusually robust individuals can manage to become professional athletes, or perhaps that the effect is mediated by wealth, status, or other confounding relationships. Exercise has a dose-response curve and it is presently thought that there is such a thing as too much of it as well as too little, though where exactly that line is drawn is far from settled. Exercise may be too indirect a measure, as one of the papers here suggests, and aerobic fitness may be the important determinant of mortality. For this measure, it seems that more is always better.
Researchers retrospectively studied 122,007 patients who underwent exercise treadmill testing between Jan. 1, 1991, and Dec. 31, 2014, to measure all-cause mortality relating to the benefits of exercise and fitness. The study found that increased cardiorespiratory fitness was directly associated with reduced long-term mortality, with no limit on the positive effects of aerobic fitness. Extreme aerobic fitness was associated with the greatest benefit, particularly in older patients (70 and older) and in those with hypertension.
The risk associated with poor cardiorespiratory fitness was comparable to or even exceeded that of traditional clinical risk factors, such as cardiovascular disease, diabetes, and smoking. The study's findings emphasize the long-term benefits of exercise and fitness, even to extreme levels, regardless of age or coexistent cardiovascular disease. Several recent studies have suggested associations between extreme exercise and certain adverse cardiovascular findings, such as atrial fibrillation and coronary artery disease. However, the newly published study found that extreme fitness provided additional survival benefit over more modest levels of fitness, and that extremely fit patients lived the longest.
"We were particularly interested in the relationship between extremely high fitness and mortality. This relationship has never been looked at using objectively measured fitness, and on such a large scale."
Physical activity includes walking and other gentle forms of exercise. It is proven to improve health. Physical activity can lower the risk of many chronic diseases, including type 2 diabetes, heart disease, several cancers, and depression. Exercise also can improve your ability to perform your daily activities and can lower your risk of death from heart disease. In frail older adults, physical activity has been shown to improve strength, balance, agility (the ability to move quickly and easily), walking speed, and muscle mass (the amount of muscle you have in your body). These are all key functions tied to frailty.
Researchers recently reviewed a number of studies about exercise in frail older adults. The review found a number of studies that showed exercise helped reduce falls, improved walking ability, improved balance or increased muscle strength. However, we still don't know whether physical activity can reduce death among frail older adults. Researchers thus recently designed a study to fill that knowledge gap by exploring whether physical activity could lower the high rate of death associated with frailty in older people.
The 3,896 study participants aged 60 years and older were selected according to sex and age. Information was collected at the participants' homes through personal interviews, and physical examinations were performed by trained personnel. Researchers assessed how much physical activity the participants did by asking whether they were generally inactive during their leisure time, or engaged in physical activity occasionally, several times a month, or several times a week.
Compared with robust participants, pre-frail and frail people had a higher risk of death from cardiovascular disease. However, being physically active was linked to a lower risk for death among pre-frail and frail individuals. What's more, deaths from cardiovascular disease in people who were physically active but also frail were similar to levels for pre-frail and inactive people. The researchers said their findings suggest that physical activity might partly reduce the increased risk of death associated with frailty in older adults.