Tag Archives: walking

 An interesting study looked at what the act of walking does to our brain, and found that it can modify and increase the amount of blood that’s sent to the brain (which is viewed as beneficial for brain function). The study, performed by researchers at New Mexico Highlands University in the United States, found that the foot’s impact on the ground while walking sends pressure waves through the arteries, which can increase the blood supply to the brain. This is referred to as cerebral blood flow or CBF.

These results may help explain other studies that find those that walk frequently (about 6 to 9 miles per week) have "less cognitive impairment" or cognitive decline, fewer memory problems, and greater brain volume with aging.  Another good reason to get out and walk - good for the heart, the body, and the brain. From Science Daily:

How walking benefits the brain

You probably know that walking does your body good, but it's not just your heart and muscles that benefit. Researchers at New Mexico Highlands University (NMHU) found that the foot's impact during walking sends pressure waves through the arteries that significantly modify and can increase the supply of blood to the brain. The research will be presented today at the APS annual meeting at Experimental Biology 2017 in Chicago.

Until recently, the blood supply to the brain (cerebral blood flow or CBF) was thought to be involuntarily regulated by the body and relatively unaffected by changes in the blood pressure caused by exercise or exertion. The NMHU research team and others previously found that the foot's impact during running (4-5 G-forces) caused significant impact-related retrograde (backward-flowing) waves through the arteries that sync with the heart rate and stride rate to dynamically regulate blood circulation to the brain.

In the current study, the research team used non-invasive ultrasound to measure internal carotid artery blood velocity waves and arterial diameters to calculate hemispheric CBF to both sides of the brain of 12 healthy young adults during standing upright rest and steady walking (1 meter/second). The researchers found that though there is lighter foot impact associated with walking compared with running, walking still produces larger pressure waves in the body that significantly increase blood flow to the brain. While the effects of walking on CBF were less dramatic than those caused by running, they were greater than the effects seen during cycling, which involves no foot impact at all.

 Makes sense that not driving to work in a car, but using mass transit (public transport), cycling, or walking to work results in lower body mass index (BMI) and body fat. They're moving more! From Science daily:

Public transport, walking and cycling to work are all associated with reductions in body fat for adults in mid-life

Adults who commute to work via cycling or walking have lower body fat percentage and body mass index (BMI) measures in mid-life compared to adults who commute via car, according to a new study incThe Lancet Diabetes & Endocrinology journal. Even people who commute via public transport also showed reductions in BMI and percentage body fat compared with those who commuted only by car. This suggests that even the incidental physical activity involved in public transport journeys may be important.

The study looked at data from over 150000 individuals from the UK Biobank data set, a large, observational study of 500000 individuals aged between 40 and 69 in the UK. The study is the largest to date to analyse the health benefits of active transport.

The strongest associations were seen for adults who commuted via bicycle, compared to those who commute via car. For the average man in the sample (age 53 years; height 176.7cm; weight 85.9kg), cycling to work rather than driving was associated with a weight difference of 5kg or 11lbs (BMI difference 1.71 kg/m2). For the average woman in the sample (age 52 years; height 163.6cm; weight 70.6kg), the weight difference was 4.4kg or 9.7lbs (BMI difference 1.65 kg/m2). After cycling, walking to work was associated with the greatest reduction in BMI and percentage body fat, compared to car-users (BMI difference 0.98 kg/m2 for men; 0.80 kg/m2 for women). For both cycling and walking, greater travelling distances were associated with greater reductions in BMI and percentage body fat.

Commuters who only used public transport also had lower BMI compared to car-users (BMI difference of 0.70kg/m2 for men), as did commuters who combined public transport with other active methods (BMI difference 1.00 kg/m2 for men; 0.67 kg/m2 for women). The effect of public transport on BMI was slightly greater than for commuters who combined car use with other active methods (BMI difference 0.56 kg/m2 for men). The link between active commuting and BMI was independent of other factors such as income, area deprivation, urban or rural residence, education, alcohol intake, smoking, general physical activity and overall health and disability.

  Research found that more time spent standing rather than sitting is associated with improved blood sugar, fats in the blood and cholesterol levels, and replacing time spent sitting with time walking is associated with a smaller waistline and body mass index (BMI)The researchers' motto: Stand Up, Sit Less, Move More. And activity adds up over the course of a day as Dr.Lopez-Jimenez of the Mayo Clinic points out: "A person walking while at work for two hours, standing for another four hours, and performing some daily chores at home for another hour will burn more calories than jogging or running for 60 minutes. From Medical Xpress:

Get up for your heart health and move for your waistline

More time spent standing rather than sitting could improve your blood sugar, fats in the blood and cholesterol levels, according to a new study published today (Friday) in the European Heart Journal. The study also shows that replacing time spent sitting with time walking could have additional benefits for your waistline and body mass index (BMI).

Researchers in Australia gave activity monitors to 782 men and women, aged 36-80 years, who were taking part in the Australian Diabetes, Obesity and Lifestyle Study. The monitors were capable of determining, very accurately, how long each participant spent sleeping, sitting or lying down, standing and stepping (which includes walking and running)....participants each wore an activity monitor on their thigh for 24 hours a day over a seven-day period. .

An extra two hours per day spent standing rather than sitting was associated with approximately 2% lower average fasting blood sugar levels and 11% lower average triglycerides (fats in the blood). Extra standing time was also associated with 0.06 mmol/L higher average levels of the "good" type of cholesterol, HDL, and a 6% lower average total/HDL cholesterol ratio, which indicates an improvement in the total amount of HDL cholesterol in relation to "bad" LDL cholesterol.

Replacing two hours a day of sitting time with stepping was associated with an approximately 11% lower average BMI and a 7.5cm smaller average waist circumference. In addition, average blood sugar levels fell by approximately 11% and average triglycerides by 14% for every two hours spent walking rather than sitting, while HDL cholesterol was 0.10 mmol/L higher. There was no significant effect on BMI or waistline of replacing sitting time with standing.

"However, it is important to say that not all sitting is bad; but if people can incorporate alternatives to sitting wherever possible, it may benefit their heart and metabolic health. Our message is to 'Stand Up, Sit Less, Move More'."She said the study had also produced evidence of how common standing is during the waking day. "Standing takes up nearly a third of waking hours, and among this group of participants who could choose when they sat, stood or walked, the standing had health benefits.

Get up every hour from your seat and walk a few minutes, and cut your risk of early death by 33% (by 41% in those with chronic kidney disease). Standing won't do it - have to move. Just make sure that little walk is not to the refrigerator. Other studies have found that sitting for long periods may increase the risk for chronic disease and early death. From Scientific American:

A Little Bit of Walking Can Add up to Improve Your Health

Want to reduce your risk of dying at a young age? Try walking casually for as little as 2 minutes per hour.While it is well known that intense exercise can help you get fitter, a new study has found that even a little exercise can still go a long way. Study participants who traded time on the sofa for a total of 30 minutes of walking during the day reduced their risk of dying over a three-year period by 33 percent.

For the participants with chronic kidney disease, the risk of dying was reduced by more than 40 percent, according to the findings, published today (April 30) in the Clinical Journal of the American Society of Nephrology.

The Physical Activity Guidelines for Americans, a complement to the government's diet guidelines, recommend that people do at least 75 minutes of high-intensity aerobic physical activity (such as running, swimming or biking), or 150 minutes of moderate-intensity activity (such as brisk walking) every week to reduce the risk of obesity, diabetes and other chronic diseases. But the researchers on the new study wanted to know what the minimum threshold was—the lowest amount of physical activity that could still provide health benefits, said Dr. Srinivasan Beddhu, a kidney specialist at the University of Utah School of Medicine in Salt Lake City and lead author of the new study. [How Many Calories Am I Burning? (Infographic)]

"This study specifically looked at what intensity of activity should be used to replace sedentary activity.... being sedentary is an active choice to indulge in activities that barely raise the energy expenditure above basal metabolic rate." That threshold of intensity, Beddhu said, appears to be low. The study found that "light-intensity activities," such as casual walking, are beneficial. In contrast, activities that are "low intensity," such as standing or writing at a desk, aren't enough to provide any meaningful health benefits, the study found.

For this study, Beddhu and his colleagues at the University of Utah and the University of Colorado used information from the National Health and Nutrition Examination Survey, which includes data collected from an accelerometer, a device that measures motion. This enabled the researchers to study the activities of more than 3,600 adults representing the general U.S. population, including 383 adults with chronic kidney disease. Over the course of three years, 137 of these participants died as a result of various causes. In general, those who exercised more were less likely to die during the study period.

Positive effects of exercise could be seen down to the level of 30 minutes per day of any kind of light activity....it could be attained merely by getting up to move around a few minutes every hour. The finding could be particularly beneficial for people with kidney disease, who tend to be sedentary and inactive throughout most of the day, Beddhu added.

Excellent for those who want to exercise more, but don't want something complex. This is so simple that there is NO excuse for not doing this: walk fast for 3 minutes, then 3 minutes of strolling, and repeat 5 times (total=30 minutes). From NY Times:

Walk Hard. Walk Easy. Repeat.

Intense, interval-style workouts — brief bouts of very hard exercise broken up by periods of recovery — have been shown to improve the health and fitness of people who exert themselves for only a few minutes a week. Such efficiency is alluring, and has helped this kind of conditioning attract widespread media attention in recent years (including in this column). But high-intensity interval training programs aren’t for everyone....That doubt is what makes some news out of Japan about a much-less-punishing form of interval training so welcome.

A decade ago, scientists led by Dr. Hiroshi Nose at the Shinshu University Graduate School of Medicine in Matsumoto, Japan, started developing walking programs. They knew that walking was physically the easiest (and also the most practical) exercise for those in middle age and older, but the researchers suspected that people might need to push themselves to achieve the greatest health benefits. So they created a regimen consisting of three minutes of fast walking at a pace that Nose says approximates a 6 or 7 on a scale of exertion from 1 to 10. Each “somewhat-hard” three-minute spell was followed by three minutes of gentle strolling.

In their original experiment, the results of which were published in 2007, walkers between the ages of 44 and 78 completed five sets of intervals, for a total of 30 minutes of walking at least three times a week. A separate group of older volunteers walked at a continuous, moderate pace, equivalent to about a 4 on the same exertion scale. After five months, the fitness and health of the older, moderate group had barely improved. The interval walkers, however, significantly improved aerobic fitness, leg strength and blood-pressure readings.

In their latest study, which came out in December in the Journal of Applied Physiology, Nose and his colleagues report that most of the participants stayed with the walking program long after their original five-month commitment ended. Two years later, almost 70 percent of the walkers with whom the researchers remained in contact were still following their regimen at least three times a week and had retained or improved their health gains. Those who quit often cited “family, health and job issues,” says Dr. Shizue Masuki, the new study’s lead author, but they rarely complained about the complexity or difficulty of the training.

So those who have considered high-intensity interval training but have been apprehensive about its demands should go for a walk. “Perform the training for 10 minutes in the morning, 10 minutes in the afternoon and 10 minutes in the evening,” Masuki suggests. Three days of exercise per week is best, but if that’s too challenging, she says, “do it on the weekend” and cram the workouts into two days. Doing so, Masuki adds, “can have a profound effect on physiological regulation.”

The bottom line: for better health be physically active at least is 2.5 hours of week. Note that HbA1c is a measure of glycated hemoglobin which identifies average plasma glucose concentration (and lower is better). From Medscape:

Exercise Tied to Cardiometabolic Markers in Clinic Patients 

Healthy, middle-aged outpatients who were physically active for at least 2.5 hours a week had better blood pressure and blood glucose levels than their sedentary peers in a large cross-sectional study in California. The differences were especially notable in women, in this study published online December 18, 2014 in Preventing Chronic Disease.

Men and women who were consistently physically active—defined as performing moderate to vigorous activity such as brisk walking for at least 150 minutes a week, as self-reported at all three outpatient visits in a 33-month period—had lower diastolic blood pressure, glucose, and HbA1c levels than patients not reporting exercise at that level.

Moreover, on a population level, the observed associations "were comparable to those needed to reduce the risk of coronary heart disease, stroke, and diabetes," they continue. "If healthcare providers would routinely assess the physical activity of their patients and refer those who are physically inactive to effective physical-activity programs, it may reduce the burden of future chronic diseases."

They analyzed electronic records from over 622,000 adults covered by Kaiser Permanente Southern California healthcare insurance who made at least three clinic visits between April 2010 and December 2012 and were not being treated for diabetes or hypertension.

The consistently active women had systolic and diastolic blood pressures that were 4.60-mm-Hg lower and 3.28-mm-Hg lower, respectively, than inactive women. Perhaps surprisingly, somewhat active women had slightly better blood-pressure values than the more active group.

 Vews about exercise and aging have really changed over the last century. Bottom line: walk  - it's good for cognitive health, especially as you age. Try for at least 1 mile per day (1 mile = approx. 20 minutes brisk walk). From The Atlantic:

Walking for a Better Brain

 A “nerve specialist” from New York named J. Leonard Corning said in 1909 that he was opposed to “excessive exercise,” ... He thought that with the “over-cultivation of the physique the mentality suffered.”Corning wrote during a period when experts widely believed that brain cells didn’t regenerate. As a result, graceful aging was in large part a matter of learning to cope with gradually diminishing brain capacity. Modern science has shown that’s not the case; we do generate new brain cells throughout our lives, although the process can become increasingly imperfect and less efficient with age, as it does with much cellular activity.

One of the largest studies ever conducted was on a group of 121,000 nurses, who were surveyed on a wide range of their health and lifestyle habits starting in 1976. The survey was repeated every two years. This established a trove of valuable information, which public-health researchers have been fruitfully mining since. Among them is Rush University assistant professor Jennifer Weuve, who studied the data collected on 18,766 of the nurses, who were then ages 70 to 81, to unearth connections between exercise and cognitive ability. The results, published in The Journal of the American Medical Association, suggested that those who exercised the most—the group that maintained a median level of walking for six hours a week—were 20 percent less likely to show cognitive impairment than those who exercised the least.

Other long-term studies also show that even modest exercise can serve
 as a bulwark against dementia. A study started in 1989 with 299 elderly 
volunteers in the Pittsburgh area tracked mental acuity and exercise habits....The results, published in the journal Neurology, were sweeping and conclusive: Those who walked the most cut in half their risk of developing memory problems. The optimal exercise for cognitive health benefits, the 
researchers concluded, was to walk six to nine miles each week. That’s a mile to a mile and a half a day, without walking on Sundays if you’re inclined to follow Weston’s example of resting on the Sabbath. (This study concluded that walking an additional mile didn’t help all that much.)

A study written up in the Archives of Internal Medicine in 2001 tracked nearly six thousand women ages 65 and older for six to eight years. The women were given a cognitive test at the study’s beginning and end, the results of which were then correlated with how many blocks they walked daily. Those who walked the least had a drop of 24 percent in cognition. Those who walked the most still showed a decline, but of a lesser degree: 17 percent. The results were clear: “Women with higher levels of baseline physical activity were less likely to develop cognitive decline.”

Peter Snyder of Brown University’s Alpert Medical School, who studies the effects of aging on the brain, recently told National Public Radio that “what we’re finding is that of all of these noninvasive ways of intervening, it is exercise that seems to have the most efficacy at this point—more so than nutritional supplements, vitamins and cognitive interventions ... The literature on exercise is just tremendous,” he said.

Indeed, a 20-year-long study in 2010 found that walking just five miles per week “protects the brain structure” over a 10-year period in people with Alzheimer’s disease and in those who exhibit signs of mild cognitive impairment. “The findings showed across the board that greater amounts of physical activity were associated with greater brain volume,” the researchers concluded.

While different studies arrive at moderately different conclusions via various routes, the recent research of dozens of scientists more often than not converges at a single intersection. And that consistently suggests that if you exercise, your brain will be fitter than if you don’t. This applies to the young, those in the prime of their days, and especially to the elderly.

The 20-year 2010 study mentioned above, results from which were released by Cyrus Raji of the University of Pittsburgh, followed 426 older adults, including healthy people along with those showing mild cognitive impairment or the actual onset of Alzheimer’s. Across test subjects, more walking was shown to result in greater brain volume. “Unfortunately, walking is not a cure,” Raji said. “But walking can improve your brain’s resistance to [Alzheimer’s] disease and reduce memory loss over time.”

Good news! From Science Daily:

Taking short walking breaks found to reverse negative effects of prolonged sitting

Three easy -- one could even say slow -- 5-minute walks can reverse harm caused to leg arteries during three hours of prolonged sitting, researchers report. Sitting for long periods of time is associated with risk factors such as higher cholesterol levels and greater waist circumference that can lead to cardiovascular and metabolic disease. When people sit, slack muscles do not contract to effectively pump blood to the heart. Blood can pool in the legs and affect the endothelial function of arteries, or the ability of blood vessels to expand from increased blood flow.

The researchers were able to demonstrate that during a three-hour period, the flow-mediated dilation, or the expansion of the arteries as a result of increased blood flow, of the main artery in the legs was impaired by as much as 50 percent after just one hour. The study participants who walked for 5 minutes each hour of sitting saw their arterial function stay the same -- it did not drop throughout the three-hour period. Thosar says it is likely that the increase in muscle activity and blood flow accounts for this.