Physical Activity Prolongs Life – Jesse Santiano M.D.

I initially posted on August 15, 2020. This article is updated with more information.

This article shows several studies that show that minor improvements in the level of physical activities can make a difference in life expectancy no matter what age or gender.

Highlights

Exercise lowers the risk of dying early from all causes. “All causes” means any cause of death, including severe infections, cancer, trauma, heart attacks, strokes, neurodegenerative diseases, and whatever else.
The benefits obtained from physical activity are dose-dependent—the more intense, the greater the rewards.

The following are studies and start with the least to the highest effort.

Light Activity

The study Leisure-time physical activity of moderate to vigorous intensity and mortality: an extensive pooled cohort analysis followed 654,827 individuals, 21–90 y of age for ten years.[1]

The group that walked 75 minutes per week lived longer for 1.8 years than those who did not. The group that walked more for more than 450 minutes per week lived 4.5 years longer.

Higher levels of physical activity were associated with greater gains in life expectancy, with a gain of 4.5 years at the highest level (22.5+ MET-hour/week, equivalent to brisk walking for 450+ min/wk).

Substantial gains were also observed in each BMI group. In joint analyses, being active (7.5+ MET-h/wk) and normal weight (BMI 18.5-24.9) was associated with a gain of 7.2 years of life compared to being inactive (0 MET-h/wk) and obese (BMI 35.0+).

Sedentary is Bad; Vigorous Activity is Better

Exercise intensity and longevity in men. The Harvard Alumni Health Study involved 17,321 Harvard Alumni men. Followed up for 20 – 26 years.[2]

The men were divided into low, moderate, and vigorous physical activity groups. The group with the least physical activity died earlier than the medium group, but the group that exercised the most lived the longest.

Total energy expenditure and energy expenditure from vigorous activities, but not energy expenditure from nonvigorous activities, related inversely to mortality.

Light activity is better than none.

Objectively Measured Physical Activity, Sedentary Behavior, and All-cause Mortality in Older Men: Does the Volume of Activity Matter More than the Pattern of Accumulation? Evaluated 1,655 older men (aged 71–92 years) with five years follow-up.

An accelerometer worn by the subjects measured the steps per minute (intensity). The more steps per minute, the higher the intensity. The group that walked faster for at least 10 minutes lived longer than the slow walkers. [3]

Among older men there are sustained benefits to longevity from physical activity of all intensities, from Low Intensity Physical Activity upwards.

In older British men, accumulating more minutes of activity from light intensity upwards was associated with lower all cause mortality.

There was no evidence to suggest that accumulating moderate to vigorous activity in bouts lasting ≥10min lowered risk of mortality compared with accumulating activity in shorter bouts, nor that breaking up sedentary time was associated with lower mortality risks.

Walking faster is better.

Another study, The self-rated walking pace, and all-cause, cardiovascular disease and cancer mortality: individual participant pooled analysis of 50225 walkers from 11 British population cohorts., showed that people who walk faster have a reduced risk of dying from all-cause, cardiovascular disease, and cancer and tend to live longer. [4]

Walking benefits health. Assuming causality, these analyses suggest that increasing walking pace could reduce risk for all-cause and CVD mortality.

Walking pace could be emphasised in public health messages, especially in situations when increase in walking volume or frequency is less feasible.

Recreational Activities Increases Life Span

The De Elfstedentocht is a 200-kilometer ice skating race covering 11 cities in Holland. Finishing the ice-skating tour is one of the highest achievements for a Dane. The study The Longevity of Men Capable of Prolonged Vigorous Physical Exercise: a 32-year follow-up of 2259 participants in the Dutch eleven cities ice skating tour, followed 2259 athletes that participated in the 1956 race and followed up after 32 years.[5]

The skaters that finished within 2 hours of the first-place winner of the 200-kilometer skate in one day lived longer than the slower rest. The participants who did more intense physical activity lived longer than the other competitors.

The capacity for prolonged and vigorous physical exercise, particularly if the exercise is recreational, is a strong indicator of longevity.

Cardiovascular Fitness and Life Span

Physical Fitness as a Predictor of Cardiovascular Mortality in Asymptomatic North American men. The Lipid Research Clinics Mortality Follow-up Study.[6]

This study involved 4,276 men, 30 to 69 years of age, followed for an average of 8.5 years. Cardiorespiratory fitness was measured by the subjects’ duration on the exercise treadmill.

The Bruce protocol stress test on the exercise treadmill has three stages. The subjects run at 1.7 miles per hour and a 10% incline in Stage One. Stage 2 is 2.5 mph and 12%, while Stage 3 goes to 3.4 mph and 14%.

We conclude that a lower level of physical fitness is associated with a higher risk of death from coronary heart disease and cardiovascular disease in clinically healthy men, independent of conventional coronary risk factors.

The fittest has the lowest death rate from all causes

Physical fitness as a predictor of mortality among healthy, middle-aged Norwegian men. Study population: 1,960 healthy men 40 to 59 years of age. [7]

The study duration of 16 years showed a more significant difference in mortality between the different fitness levels.

The subjects’ age, smoking status, serum lipids, blood pressure, resting heart rate, vital capacity, body mass index, physical activity level, glucose tolerance, and physical fitness were all compared with death as the endpoint. To sum up the findings, the authors said:

Thus, although physical fitness appears to be more closely associated with mortality from cardiovascular causes than with overall mortality, the men in the quartile with the highest level of fitness appeared to be protected from death from all causes.

The men in the most physically fit group lived longer than the less physically fit group! Even if they smoke, have high triglycerides, low HDL, reduced heart rate variability (bad), high blood pressure, low lung capacity, high body-mass index, and have diabetes.

nejm199302253280803_f1

The highest death rates in the lowest fitness group Quartile 1 and the lowest death rate in the fittest group Quartile 4. February 25, 1993, N Engl J Med 1993; 328:533-537

Physical fitness trumps cardiac risk factors

Influences of Cardiorespiratory Fitness and Other Precursors on Cardiovascular Disease and All-Cause Mortality in Men and Women. Twenty-five thousand three hundred forty-one men and 7,080 women. The study is about cardiac risk factors and physical fitness.[7] Conclusions for both sexes:

Fit persons with any combination of smoking, elevated blood pressure, or elevated cholesterol level had lower adjusted death rates than low-fit persons with none of these characteristics.

Low fitness is an important precursor of mortality. The protective effect of fitness held for smokers and nonsmokers, those with and without elevated cholesterol levels or elevated blood pressure, and unhealthy and healthy persons. Moderate fitness seems to protect against the influence of these other predictors on mortality.

The more fit, the lower the death rate

Physical Activity, Physical Fitness, and All-Cause and Cancer Mortality: A Prospective Study of Men and Women followed 7,080 women and 25,341 men for approximately eight years on average, including physical fitness and activity.[8]

After adjusting for baseline differences in age, examination year, cigarette habit, chronic illnesses, and electrocardiogram abnormalities, the authors found that the least physically fit died earlier. The fittest subjects have a lower death rate in both men and women.

The risk of dying from cancer was also decreased for the most able-bodied men. Being physically fit puts everything on a higher level.

More Muscular Strength lowers mortality in Both Sexes and All Ages.

Association Between Muscular Strength and Mortality in Men: Prospective Cohort Study involved eight thousand seven hundred sixty-two men aged 20-80. Average follow-up of 18.9 years.

In this study, total body strength was measured by quantifying the power of the large muscle groups of the lower and upper body using the leg and bench presses. The treadmill measured Cardiorespiratory fitness.

The graphs below show that the strongest group has the lowest cancer and all-cause mortality rate.

Age-adjusted-death-rates-per-10-000-person-years-from-all-causes-and-cancer-by-thirds — Bar Columns Depict Levels of Physical Fitness, Note the difference in all-cause and cancer mortality in the ≥60 years age group.

After adjusting for many differences between the groups like age, physical activity, smoking, alcohol intake, body mass index, baseline medical conditions, and family history of cardiovascular disease, the group capable of moving heavier weights with the leg press and bench press had the lowest death rate from all causes.

Muscular strength was independently associated with lower risk of death from all causes and cancer in men.

These findings are valid for men of normal weight, those who are overweight, and younger or older men, and are valid even after adjusting for several potential confounders, including cardiorespiratory fitness.

Muscular strength seems to add to the protective effect of cardiorespiratory fitness against the risk of death in men.

How does physical fitness prolong life?

Skeletal muscles produce myokines during activity. Myokine is a combination of muscle (myo) and cytokines. Myokines spread their benefits to the other organs of the body.

During intense exercise and weight-lifting, Type II muscle fibers are used. More capillaries are recruited, improving the blood supply to all organs and lowering blood pressure as there is less arterial resistance due to increased elasticity of the arteries. Arterial contractions during physical activity also increase nitric oxide and improve the inner lining of the arteries.

Type II muscle fibers or the “fast-twitch” fibers are essential even in the elderly so that they correct their balance or break a fall when they trip. I have seen many frail older people fall directly on their faces and suffer injuries with no signs of their hands breaking their fall. Someone with developed Type II fibers can easily adjust their balance or break their fall if they trip on something.

Biologic frailty due to sarcopenia or loss of muscle mass is a poor prognostic factor in older people in acute coronary syndrome, critical illness, and COVID-19. In contrast to physical fitness, frailty increases all-cause mortality.

Insulin sensitivity increases and blood sugar levels lower to prevent the damage caused by insulin resistance and high blood sugars. Exercise also decreases the harmful effects of free radicals.

Sweat is not only water and electrolytes. It also contains glucose, triglycerides, inflammatory cytokines, and toxic heavy metals.

Take-Away Message

Low, moderate, and high activity all prolong life. To go from inactivity to high activity is not an impossibility.

The journey to physical fitness can start a half push-up, a 15-minute walk, or a single partial-body squat that will signal the body to adapt to the increased physical demand to get you ready for more next time. The earlier you start, the more benefits you will get.

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