While a regimented fitness routine is certainly part of a healthy lifestyle, what you do outside the gym is equally important. Most adults spend 10 hours or more each day sitting, and research1,2 shows this level of inactivity cannot be counteracted with a workout at the end of the day. To maintain health, you really need mild but near-continuous movement throughout your waking hours.
One strategy that has been shown to have a positive impact is simply to stand up more. Increasing your daily walking is another key strategy that pays significant dividends, both short term and long term. According to the World Health Organization, inactivity is the fourth biggest killer of adults worldwide, responsible for 9 percent of premature deaths,3 and walking more could go a long way toward reducing this risk.
Walking Produces Beneficial Biochemical Changes in Your Body
The short video above reviews what happens in your body while walking. For starters, when you take your first few steps, your body releases chemicals that give your body a quick boost of energy. Once you get going, your heart rate will increase, from about 70 to about 100 beats per minute. This boost in blood flow will warm up your muscles. As you move, your body will also increase production of fluid in your joints, thereby reducing stiffness.
Walking for six to 10 minutes can raise your heartbeat to about 140 beats per minute and trigger your body to start burning up to six calories per minute. While your blood pressure will rise from the exertion, this increase is counteracted by chemicals that help expand your blood vessels, such as nitric oxide. This expansion in turn allows greater amounts of oxygen-rich blood to reach your muscles and organs, including your heart and brain. Over time, taking regular walks will help lower your blood pressure if it tends to be high.
Walking for 11 to 20 minutes results in an increase in body temperature and sweating as blood vessels closer to the surface of your skin expand to release heat. At this point, you start burning about seven calories per minute. The increase in heart rate also causes you to breathe deeper. Epinephrine (adrenaline) and glucagon also begin to rise at this point to boost muscle activity. Epinephrine helps relieve asthma and allergies, which helps explain why walking and other exercises tend to have a beneficial impact on these ailments.
At 21 to 45 minutes, you'll start burning more fat, courtesy of a drop in insulin. This is also when you'll start experiencing greater physical and mental relaxation as your brain starts to release "feel good" endorphins. Walking has also been shown to boost memory and creative problem-solving,4 so taking a walk when you're puzzling over a problem may allow you to come up with better solutions. One Stanford University study found walking increased creative output by an average of 60 percent, compared to sitting still.5
After 30 to 45 minutes, you're really oxygenating your whole body, burning more fat, strengthening your heart and cardiovascular system, and boosting your immune function. Provided you're walking outdoors and the weather complies, an hour of sunshine will also help boost your mood and provide a number of beneficial health effects associated with vitamin D production.
Those struggling with depression would do well to get out of the concrete jungle and into nature, as nature walks have been found to be particularly beneficial for your mood by decreasing rumination — the obsessive mulling over negative experiences.
Walking Boosts Health and Longevity
Several studies have confirmed that walking boosts health and longevity. For example:
•In one, walking for 20 to 25 minutes per day (140 to 175 minutes per week) was found to add anywhere from three to seven years to a person's life span.6
•Research7 published last year found that as little as two hours (120 minutes) of walking per week may reduce mortality risk in older adults, compared to inactivity. Meeting or exceeding the activity guidelines of 2.5 hours (150 minutes) of moderate activity per week in the form of walking lowered all-cause mortality by 20 percent.
•Research published in 2012 found brisk walking improved life expectancy even in those who are overweight.8
•Smokers may also increase their life span by nearly four years by engaging in physical activity9 such as walking. Former smokers who kept up their physical activity increased their life expectancy by 5.6 years on average, reducing their all-cause mortality risk by 43 percent.
Smokers who were physically active were also 55 percent more likely to quit smoking than those who remained inactive, and 43 percent less likely to relapse once they quit. A Norwegian study10 also showed that regular exercise is as important as quitting smoking if you want to reduce your mortality risk.
About 5,700 older men were followed for about 12 years in this study, and those who got 30 minutes of exercise — even if all they did was light walking — six days a week, reduced their risk of death by about 40 percent. Getting less than one hour of light activity per week had no effect on mortality in this study, highlighting the importance of getting the "dosage" right if you want to live longer.