Are superagers simply those who ignore, even welcome, the pain and frustration that comes with intense mental effort? Or is there some other reason why they spend so much time and effort challenging themselves?
This is important, because if the only way to maintain youthful cognitive skills is to expose ourselves regularly to pain and frustration, it doesn't make old age look particularly inviting.
The same argument has been put forward with regard to physical ageing. Not long ago, many advocated HIIT – High Intensity Interval Training, exerting yourself to your maximum capacity, interspersing your effort with short periods of rest – as a way to improve cardiovascular function and lose weight.
HIIT does appear to help in this way, as David Swain and Barry Franklin at Old Dominion University in Virginia found. However, many of us find such intense workouts demotivating and, for a few, they may even be dangerous.
Now research is emerging – for example, Dr Jean-Philippe Walhin's study at the University of Bath – to suggest that LISS, or Low Intensity Steady State (working out within your aerobic zone) may be just as effective as HIIT for weight loss. Certainly, it's more enjoyable.
And "enjoyable" is the key. If what you're doing is enjoyable, you're more likely to keep working hard at it – probably without even noticing any discomfort.
This is a double win, because research such as Ed Diener and Micaela Chan's study at the University of Illinois shows that subjective wellbeing – feeling satisfied with your life and experiencing few if any negative emotions – is associated with better health and a longer life.
Making yourself work until you're exhausted and frustrated holds little appeal. On the other hand, finding an activity you love so much that you don't even notice when you're pushing yourself hard seems a far more attractive way to keep your brain active as you grow older.
Linda Blair is a clinical psychologist, author of The Key To Calm.