8 . Until we start to lose our balance, we barely notice that it’s there at all. “It starts for a lot of people with simple stuff,” says Dr Anna Lowe, an expert on healthy ageing and physical activity. “    1     It’s easy to either miss the signs or just put it down to ageing — but it really is something you can affect.”

The key, it is increasingly becoming clear, is to address the decline before it gets serious: and that can happen earlier than you might think.

What is balance? Technically, it’s the complex interaction of several different systems in your body — from muscles, nerves, eyesight and the inner ear to the sensory system that lets you recognise where your body is touching the ground, along with movement receptors within your joints that tell you where your body is in space.     2    

A lack of balance is, globally, associated with serious health problems. Earlier this year, the British Journal of Sports Medicine published the results of a decade-long study involving more than 1,700 middle-aged participants, which concluded that an inability to balance was associated with an almost twofold increase in risk of death.

“    3    ” agrees Lowe, an associate professor researching strength and balance in midlife. “Older women are far less active than older men, and general activity, just moving around and doing stuff, affects balance a lot. Single-legged movements, such as walking lunges, are a great test of dynamic (动态的) balance, but even bilateral movements, like squats (深蹲), can provide a challenge.”

    4     Resistance exercise, whether that means lifting weights or hiking with a backpack, comes with a host of other proven health benefits, from improved bone density to a reduced risk of Alzheimer’s. As Locker puts it: everyone’s told to save money for their retirement, and nobody’s taught to save their balance. But both are difficult to get back once they’re gone.

9 . My father decided to start learning French when he was 57. On the surface, his retirement hobby seems a little random — our family has no connection to French-speaking countries — but his ______ ran deeper than a passion for cakes. My grandmother developed signs of Alzheimer’s disease (阿尔兹海默症) in her early 70s, and studies suggest that being bilingual, that is, being able to speak two languages equally well, can ______ the start of the condition by up to five years. Drawn by that ______ benefit, many people have attempted to pick up a new language in adulthood.

Lots of activities are linked to better brain health in old age, like getting more education when you’re younger and physical activity. Experts say regularly speaking multiple languages may be especially ______ though. “We use language in all aspects of daily life, so a bilingual brain is ______ working,” said Mark Antoniou, a professor at Western Sydney University who specializes in bilingualism.

The age at which you learn another language appears to be less important than how ______ you speak it. The cognitive (认知的) benefit is from having to ______ your mother tongue, which your brain is forced to do if you’re trying to recall the right words in another language. So if the second language is used a lot, you’re getting that cognitive ______. That process is called cognitive inhibition. In theory, by improving these types of processes, the brain becomes stronger to the ______ caused by diseases like dementia. The stronger your mental power, the thinking goes, the longer you can function normally, even if your brain health starts to ______.

However, evidence for the benefits of learning a second language as a hobby in your 60s is ______. Research by Dr. Antoniou and colleagues found that while Chinese adults 60 and up improved on cognition tests after a six-month language learning program, people who played games like Sudoku did as well. Two more recent studies on the topic found virtually no ______ in cognitive performance after people took part in language-learning programs.

The scientists who conducted those studies offered a few potential ______. One is that the participants were highly motivated volunteers, who may have already been at peak performance for their age, making it hard to see any ______. Another is that the language interventions were perhaps too short. The handful of studies looking into the issue have used language lessons that were very different in their ______ and frequency. Some studies taught participants for eight months, others for just one very intense week.