We Don't Exercise as Much as We Say

The Wall Street Journal

Men More Likely to Inflate Levels of Physical Activity

By ANN LUKITS Jan. 6, 2014 6:21 p.m. ET

Danny Schwartz

Just in time for those New Year's exercise resolutions: A new study suggests the amount of physical activity men and women actually do is significantly less than they say they do.

Researchers found a wide variation in physical activity reported on questionnaires compared with objectively measured exercise time during a weeklong study reported in the January issue of Medicine & Science in Sports & Exercise. Men were more likely than women to overestimate vigorous exercise activities, the study found, while both sexes underestimated their sedentary times.

Researchers recruited 1,751 men and women, ages 18 to 84, from 10 regions of Norway. Close to half, 47%, were overweight or obese. Each participant was mailed a questionnaire and an accelerometer, an activity monitor worn on the wrist. The questionnaire assessed low, moderate and vigorous physical activity as well as sitting time over seven consecutive days. The accelerometer measured the subjects' physical activity levels during the same period, minus the hours from midnight to 6 a.m.

The total time spent on physical activity measured by the accelerometer wasn't significantly different between the sexes, but men reported 56 additional minutes of walking and moderate exercise on questionnaires than was actually recorded by the accelerometer. Women reported 52 additional minutes.

Self-reported vigorous activity also conflicted with accelerometer data, which categorized activity levels according to number of steps recorded. Men and women reported 20 minutes and 12 minutes of vigorous activity, respectively, on the questionnaires, but the accelerometer times were 2.9 and 2.4 minutes, respectively.

As for sedentary times, men reported 439 minutes of sitting on questionnaires but the accelerometer time was 565 minutes. Women's self-reported sitting time was 401 minutes and the accelerometer time was 535 minutes. The oldest subjects, ages 64 to 84, underreported sedentary times by approximately 210 minutes.

Education influenced exercise self-reports. Participants without a college or university degree reported 18% less sitting time than those with a college or university degree, but the difference between the groups was 6% based on the accelerometer data.

Caveat: As questionnaires and accelerometers were mailed, the data may not represent the same seven days for all subjects, researchers said.

Title: Comparison of Self-reported versus Accelerometer-Measured Physical Activity

Microcirculation: A simple test that measures how quickly blood flows through the tiny arteries of the retina may help pinpoint patients at risk of developing coronary atherosclerosis, or hardening of the arteries in the heart, says a pilot study in the current issue of Atherosclerosis.

About 20% of patients who undergo cardiac angiography, a common diagnostic heart procedure, have abnormally slow blood flow in the coronary arteries but no obvious vessel narrowing or stenosis, researchers said.

Faster blood flow in the retina is associated with lower coronary blood flow, the study found.

Researchers recruited 28 patients from the Tel Aviv Medical Center in Israel. The patients, who were about 59 years old and overweight, had been referred for diagnostic angiography because of chest pain and other abnormal heart symptoms. The angiogram tests found no apparent abnormalities in the subjects' coronary arteries, but coronary blood flow was classified as slow in 15 and normal in 13. The patients' retinal blood flow was assessed using an imaging technology that can detect early changes in retinal function.

The velocity of retinal blood flow was about 24% faster in patients with slow coronary blood flow compared with the normal blood-flow group. The difference in velocity can be explained by the diameters of the blood vessels, researchers said. When large coronary vessels become constricted and lose their elasticity, the velocity of blood flow is reduced. But the effects are reversed in the small retinal vessels, which have to distribute the same volume of blood, causing an increase in velocity, they said.

Caveat: The study was small.

Title: Inverse correlation between coronary and retinal blood flows in patients with normal coronary arteries and slow coronary blood flow

Allergies in bed: Teenagers may be sensitized to food allergens by simply hanging out in their bedrooms, as teens like to do, says a study in the January issue of Clinical & Experimental Allergy. Ingestion of various foods is believed to be the most common route of exposure to potential food allergens in the general population, researchers said. This study suggests mattresses can also be important reservoirs of dust and food allergens.

From 2005 to 2007, inspections were carried out at 143 family homes in Oslo, Norway. The families were participants in a larger study of childhood asthma and each had a 13-year-old boy or girl at the time of the present study. About half the teens had asthma.

A special dust-collecting vacuum was used to vacuum the teens' mattresses, with the sheets off, for four minutes. The dust was analyzed for milk, egg, peanut and fish proteins, which were categorized as probable or confirmed based on the levels detected.

Parents reported the mattress age, teens' bed-making habits, household-cleaning practices and the presence of furry pets. Floor plans, building materials, signs of dampness, and the types of ventilation systems were recorded.

Peanut allergens were confirmed in 41% and deemed probable in 34% of the 143 mattress dust samples. Milk allergens were confirmed in 39% and probable in 29%, while egg was confirmed in 22% and probable in 27%. Allergens from codfish, a popular Norwegian food, were confirmed in 46% of the samples and probable in 29%. All four allergens were found in 7% of the 143 samples and three of the four in 15%. Only three mattresses were free of any food allergens.

Mattresses in girls' bedrooms had significantly higher levels of peanut and egg allergens than those in boys' bedrooms. Girls may be more likely to eat in their bedrooms or have decorative pillows and stuffed toys that act as dust and allergen reservoirs, researchers said. About 90% of the teens had unmade beds during the day, the study found.

Caveat: The study didn't assess the effect of food allergens on the severity of asthma or other allergic conditions.

Title: Food allergens in mattress dust in Norwegian homes – a potentially important source of allergen exposure

Grandmother love: The sight of one's own grandchild activates parts of a grandmother's brain that are separate from the brain regions associated with maternal love, indicating the two types of love may differ, suggests a small study in the current issue of Brain Research.

Studies have shown mothers have different brain responses to viewing photos of their child compared with strangers, but little is known about the neural activity underlying grandmotherly love, researchers said.

For the study, 17 Japanese grandmothers in their early 60s viewed six videos of children, ages 1 to 2½ years old. Each video consisted of a 30-second blank display followed by a 30-second clip of a grandchild or an unfamiliar child with a neutral expression. This was followed a 30-second clip of the grandchild or the other child smiling, and 30 more seconds of blank display. The grandchild and unfamiliar child were each featured in three videos.

During the viewing, probes attached to the participants' foreheads measured their cerebral oxygen-hemoglobin concentrations, an indicator of blood flow in the brain, using a neuroimaging technique that identifies changes in brain activity. After each video, the grandmothers rated their feelings of love.

Oxygen-hemoglobin concentrations increased in the anterior prefrontal cortex, an area of the brain that regulates executive function, or personality, planning and decision-making, when grandmothers viewed videos of their own grandchild but not the unfamiliar child, regardless of the child's expression.

The sight of the smiling grandchild increased brain activity in another region of the prefrontal cortex related to cognition and focused concentration. Brain activations were strongly associated with the grandmothers' emotional ratings. By comparison, maternal love is associated with brain areas related to emotion and spontaneous pleasure.

Researchers noted older adults are often motivated to focus on positive things that have emotional meaning in life. This so-called positivity shift may partly explain the grandmothers' unique brain response to their grandchild's face, they said.

Caveat: It isn't known if the activated brain regions are specific to grandmother love or associated with other positive emotions.

Title: I love my grandkid! A NIRS study of grandmaternal love in Japan

Mourning pets: Euthanizing a pet dog triggers intense grief reactions similar to those experienced after the loss of friends and family members, says a report in the February issue of Death Studies.

The study, at the Ben-Gurion University of Negev in Israel, involved recorded interviews with 29 people who had euthanized a pet dog in the previous two weeks. The dogs were six to 18 years old and had been sick for at least two years. About 41% of the animals were cremated while 27.6% of owners buried the dog themselves. Owners were asked if they'd had time to prepare for the dog's death, why they chose to euthanize the dog or felt guilty about it, if they had other pets, and if friends and relatives understood their grief.

Most pet owners were still mourning the dog after two weeks but only 17% regretted the decision to euthanize. A few reported nightmares, vomiting and other physical reactions to the dog's death. Photos, leashes, and collars were still visible in 38% of households.

Dying dogs often received special attention in the form of treats and baths. Families with children drew pictures of the dogs or wrote goodbye letters in preparation for euthanasia. About two-thirds of owners reported positive support from veterinarians, family members and friends.

The calmest owners were those who performed a burial ceremony for their dogs, researchers said.

Caveat: The study was small and conducted over a short period. Grief responses were self-reported.

Title: Grief and Bereavement of Israeli Dog Owners: Exploring Short-Term Phases Pre- and Post-Euthanization

—Write to researchreport@WSJ.com.

A Snow Shovel That's Better For Your Back

Using an ergonomic snow shovel, which minimizes bending, reduced the workload on the lower back by 16.5% compared with a traditional snow shovel during a simulated snow-clearing study reported in the March issue of Applied Ergonomics. Lower-back injuries from over-exertion account for more than a third of the estimated 12,000 snow-shoveling injuries reported in the U.S. every year, according to a 2011 study.

A new study pits a traditional snow shovel, pictured, against an ergonomic one. Sentinel-Tribune/Associated Press

In the latest study, University of Ottawa researchers compared the biomechanical effects of a bent-shaft snow shovel and a straight-shaft shovel on the lumbosacral joint, a common site of degenerative spinal conditions, in five men and three women about 29 years old. They were 5 feet 8 inches tall, on average, and weighed just over 160 pounds.

Reflective markers were attached to their lower body and torso while they stood on a platform that measured the biomechanical forces acting on each foot. Seven cameras tracked the position of each marker as subjects shoveled a 6.5-pound bag of sand 10 times, five times with each shovel, with a one-minute rest between shoveling. The subjects lifted the shovel to waist height and tossed the bag to the left so only the lifting portion of the shoveling movement was analyzed, researchers said. The marker and foot force data were used to calculate mechanical loads on the lower back.

Seven subjects experienced significantly reduced mechanical load with the bent-shaft shovel compared with the standard shovel. The maximum load was reduced by 11.8% with the bent-shaft shovel, possibly the result of reduced upper-body bending, the researchers said.

Caveat: The study was small, used sand instead of snow and included rest periods between shoveling motions.

Title: Influence of snow shovel shaft configuration on lumbosacral biomechanics during a load-lifting task

—A.L.