1 . Even light activity such as housework might help to keep the brain young, researchers say, adding to a growing body of evidence that, when it comes to exercise, every little helps.
Writing in the journal Jama Network Open, the international team of researchers report how they came to their findings by studying at least three days of activity-tracker data from 2,354 middle-aged adults from the US, together with the participants' brain scans.
From the latter, the researchers worked out individuals' brain volume, a measure linked to ageing: about 0.2% of the volume of the brain is lost every year after the age of 60. Loss or shrinkage (萎缩) of brain tissue is linked to dementia (痴呆), Spartano noted.
After taking into account factors including sex, smoking status and age, the team found that every extra hour of light physical activity per day was linked to 0.22% greater brain volume, equal to just over a year's less brain ageing. What's more, those who took at least 10,000 steps a day had a 0.35% greater brain volume than those who took, on average, fewer than 5,000 steps a day—equivalent to 1.75 years' less brain ageing.
However, the study has limitations. It used mainly white participants, and cannot prove cause and effect. The authors add that not all time spent sedentary is necessarily "bad" for the brain—particularly if people are engaged in a task that takes a lot of thinking.
Dr James Pickett, head of research at Alzheimer's Society, said, "Don't worry if you're not hill-running, but find something you enjoy and do it regularly, because we know that what's good for the heart is good for the head."
1. What can be inferred from the statistics in Paragraphs 3&4?| A．Loss of brain tissue is linked to disease. |
| B．Light physical activity raises the brain volume. |
| C．Taking 10000 steps per day is best for our brain. |
| D．Light physical activity slows down the brain ageing. |
| A．Sitting. | B．Walking. | C．Sleeping. | D．Working. |
| A．Doubtful. | B．Supportive. | C．Objective. | D．Indifferent. |
| A．Regular exercise makes you happy. |
| B．The more exercise, the better. |
| C．Doing what you like regularly is beneficial. |
| D．Light physical activities are the best. |
