4 . Barbara, 70, and me, at 71, have swum together for at least 50 years. We swim in a quiet cove (小海湾). It’s home to seagulls, a duck or two, and kayaks (独木舟) on occasion. The difficult summer drought of 2021 brought a burning sun that warmed the water. As the drought eased and the water cooled in late August, we decided to keep swimming. We have both read Bonnie Tsui’s Why We Swim, a fine book about cold-water swimming. We challenged ourselves to swim for as long as possible through September and into October.

I have long loved swimming, though the fear of being seen as fat has dogged me. I am one of those female bodies poorly displayed in bathing suits. Cold-water swimming deepened my sense of well-being and let me use my body. It became a ritual Barbara and I embraced as swimming sisters. When she returned to the United States immediately after our Canadian Thanksgiving, I did not know how I could continue our cold-water tradition. I wasn’t prepared to freeze alone.

But, I had to swim; there were larger commitments I should stick to. In the summer, we planned to cross from the cove to an island across the lake. I had to stay fit. We also planned to host a cold-water swimming race for locals in the fall. We would make it an annual event, improving our strength and endurance (耐力) so that, in our 80s, we might swim through October and into November.

With these plans in mind, I joined my local city pool. I had not been in a public pool for about 30 years. But my body said swim, my brain said swim and my heart, could not let go. So I went anyway.

I am swimming. I am alive to my love of the water, alive to my promise for the spring and the summer that will come. I intend to step back into the lake in May, and through September and October with Barbara. We are perfectly matched in our devotion, and increasingly aware of the miracle of being able-bodied enough to share the cold-water wonder side by side.

10 . The benefits of regular exercise are well documented but there’s a new bonus to add to the ever-growing list. New researchers found that middle-aged women who were physically fit could be nearly 90 percent less likely to develop dementia in later life, and as they did, it came on a decade later than less sporty women.

Lead researcher Dr. Helena Horder, of the University of Gothenburg in Sweden, said : "These findings are exciting because it’s possible that improving people's cardiovascular （心血管的）fitness in middle age could delay or even prevent them from developing dementia. "

For the study, 191 women with an average age of 50 took a bicycle exercise test until they were exhausted to measure their peak （最大值的） cardiovascular capacity. The average peak workload was measured at 103 watts.

A total of 40 women met the criteria for a high fitness level, or 120 watts or higher. A total of 92 women were in the medium fitness category; and 59 women were in the low fitness category, defined as a peak workload of 80 watts or less, or having their exercise tests stopped because of high blood pressure, chest pain or other cardiovascular problems.

These women were then tested for dementia six times over the following four decades. During that time, 44 of the women developed dementia. Five percent of the highly fit women developed dementia, compared to 25 percent of the women with medium fitness and 32 percent of the women with low fitness.

"However, this study does not show cause and effect between cardiovascular fitness and dementia, it only shows an association. More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important. " She also admitted that a relatively small number of women were studied, all of whom were form Sweden, so the results might not be applicable to other groups.