Recent investigations have revealed simply working out and exercising, greatly reduces in the risk of death from any cause and from cardiovascular disease. For instance, being fit or active was associated with a greater than 50% reduction in risk.
Furthermore, an increase in energy expenditure from physical activity of 1000 kcal per week or an increase in physical fitness of 1 MET (metabolic equivalent) was associated with a mortality benefit of about 20%.
Physically inactive middle-aged women (engaging in less than 1 hour of exercise per week) experienced a 52% increase in all-cause mortality, a doubling of cardiovascular-related mortality and a 29% increase in cancer-related mortality compared with physically active women.
These relative risks are similar to those for hypertension, hypercholesterolemia, and obesity, and they approach those associated with moderate cigarette smoking.
Moreover, it appears that people who are fit yet have other risk factors for cardiovascular disease may be at lower risk of premature death than people who are sedentary with no risk factors for cardiovascular disease.

Metabolic Equivalents, a unit used to express the energy cost of physical activity relative to resting metabolism.
- One MET is defined as the energy it takes to sit quietly, equivalent to 3.5 ml of oxygen per kilogram of body weight per minute.
- Calories burned = METs x body weight (kg) x time (hours)
(Running, at a 7.5mph pace (8-minute mile) = ~11.5 METs)

- Example:
We are running! 7.5mph, for 30 min. Say you hypothetically weigh
84kg (185lbs). We multiply that (84kg) x 11.5 x .5 (half an hour)
That gets us a TEE of 483 calories burned.
That small run, now solidifies ourselves in the middle of the graph. Were still half as likely to develop numerous diseases and illness compared to people who exercise very little or at all.
Now, compound this daily.
You are practically Superman.

This chart basically showcases the benefits of exercising, and how exercising (especially regularly) will DRASTICALLY decrease your chances of developing disease. Even among those who are low risk, but don’t work out.
Relative risks of death from any cause among participants with various risk factors (e.g., history of hypertension, chronic obstructive pulmonary disease [COPD], diabetes, smoking, elevated body mass index [BMI ≥ 30] and high total cholesterol level [TC ≥ 5.70 mmol/L) who achieved an exercise capacity of less than 5 METs (metabolic equivalents) or 5–8 METs, as compared with participants whose exercise capacity was more than 8 METs.

According to this study,
Both men and women who reported increased levels of physical activity and fitness were found to have reductions in relative risk (by about 20%–35%) of death.

here is evidence that intensity of physical activity is inversely and linearly associated with mortality.14 Early work by Paffenbarger and associates106 revealed that regular physical activity (expending > 2000 kcal [8400 kJ] per week) was associated with an average increase in life expectancy of 1 to 2 years by the age of 80 and that the benefits were linear even at lower levels of energy expenditure. Subsequent studies have shown that an average energy expenditure of about 1000 kcal (4200 kJ) per week is associated with a 20%–30% reduction in all-cause mortality.14,106,107
Currently, most health and fitness organizations and professionals advocate a minimum volume of exercise that expends 1000 kcal (4200 kJ) per week and acknowledge the added benefits of higher energy expenditures