Is our modern lifestyle slowly killing us? We all know that we should exercise for good health every day, and most of us have heard the recommendations for 30 minutes of exercise a day. But our lifestyle is becoming more and more sedentary, as most of us spend hours in front of the computer and TV, work the entire day behind a desk, and drive where we need to go.

And to top it off, many of us do not have time or inclination to exercise with consistency.

Perhaps it is time to (literally) get moving for health. A recent study published this month in the The Lancet of 400,000 people followed for an average of eight years shows that small amounts of exercise help people live longer. The study showed that if sedentary people increased their physical activity by just 15 minutes per day, they could reduce their risk of death by 14 percent and increase their life expectancy by three years. The study compared inactive people with active people who engaged in varying levels of physical activity.

Studies have shown that even among those who exercise, having a sedentary lifestyle is bad for health. Case in point , a July 2010 study of more than 120,000 people, published in the Journal of Epidemiology, showed that being sedentary significantly increased the risk of death. What was interesting is that this study looked at time spent in leisure activity (TV, computer, driving) regardless of amount of exercise. The more leisure time spent sitting, the more likely people were to have died, especially from cardiovascular disease, even if they also exercised.

Women who sat six or more hours a day were 37 percent more likely to have died than were women who spent fewer than three hours a day sitting. Men's risk was 18 percent higher. And women who were inactive and did not exercise had a 94 percent increased risk of dying (inactive men had a 48 percent increased risk of dying).

And finally, another study in January 2010 studying 8,800 people showed that each hour spent in front of a TV increased the risk of dying by 11 percent, and those who watched more than four hours a day had a 46 percent higher risk of death from all causes.

Take-home message? We need to find ways to bring more and more activity in our day-to-day living, sitting less and walking more even in our regular activities in our jobs and homes. We need to exercise with consistency , even 15 minutes a day is a good start. We need to walk or bike more and drive less. We need to watch less TV , the less the better. The health rewards are well worth it.