The acts of rebellion are small: turning off my phone or leaving it in another room, looking out the window while on the bus, or being fully immersed in a book. It’s tragic, really.
Most of the time, I am just as much a victim to the tantalising distraction of my phone as the next person. It’s rare to watch a TV show without also scrolling, then having to ask my partner what just happened.
Between 2004 (when Facebook launched and Wi-Fi became available on phones) and 2016, the average attention span dropped by nearly 70 per cent, from 2½ minutes to about 47 seconds.
This atrophy of attention has had an impact on our mental performance, stress levels and physical performance.
The antidote, in the age of distraction, may be to build our “cognitive endurance”.
What is cognitive endurance?
The ability to sustain mental effort over a continuous stretch of time is called cognitive endurance and, like physical fitness, it isn’t fixed.
“It can be built up through practice,” behavioural scientists Heather Schofield and Supreet Kaur wrote in a new feature for Scientific American.
In a 2025 study, they explored whether 20 minutes of training, up to three times a week for six months, could enhance the cognitive endurance of primary schoolchildren.
The duration wasn’t a magic number, Schofield says over email: “The kids weren’t able to focus more than 20 to 30 minutes.”
Sixteen hundred students were split into three groups: one group worked on maths problems; the second did non-academic but cognitively demanding games, such as mazes or tangrams; while the control group spent the time in a study hall where they could do whatever they liked.
After six months, only those in the cognitive endurance training groups improved their performance.
Building cognitive endurance also mitigated performance decline by 21.9 per cent, in the second half of the test periods when students typically become cognitively fatigued.
The children who did the games improved as much as those who did the maths, suggesting that training focused mental effort was what mattered – it didn’t need to be task-specific.
A new systematic review found that training cognitive endurance can improve our athletic performance too, consistently improving time to exhaustion, time trial speed, intermittent endurance and sustained muscular endurance.
It also led to faster reaction times and enhanced resistance to performance decrements under mentally fatiguing conditions.
The importance of cognitive endurance is now widely recognised in elite sport, says Dr Sumeyya Ozsoy, an applied sports scientist who works with Tennis Australia, premier soccer clubs and has worked across the F1, AFL and NRL.
“Once you’re at the top, the physical capabilities aren’t what’s comparing a winner to a loser,” says Ozsoy. “It’s the cognitive threshold or the cognitive resilience that an athlete has that can give them that special edge.”
The toll of poor cognitive endurance
When we can’t maintain focus on mentally demanding tasks, we make more mistakes.
On average, error rates among workers increase by roughly 12 per cent as the day goes on; doctors who switched their attention rapidly made errors in 208 out of 239 prescriptions they wrote; while paramedics are more likely to drop patients, drive carelessly and make treatment errors, stemming from problems in sustaining attention.
Tasks also take us longer (it takes about 23 minutes to resume an interrupted task) and it causes stress in the form of higher blood pressure, lower heart rate variability and perceived stress levels.
University of California psychologist Gloria Mark calls it a switch cost. “So every time you switch your attention, you have to reorient to that new activity … this creates more effort. It uses more of our very precious mental resources on top of the work that we actually need to do,” she says.
And, of course, it makes it difficult to enjoy a book or TV show, being with other people or performing well when we can’t maintain effortful attention.
Good sleep, nutrition, reasonable working hours, taking regular breaks and putting our phones away while completing tasks all help us to improve focus.
But training ourselves can also help.
How do we build it?
Like physical fitness, it is about training smart, building slowly and allowing recovery time.
Ozsoy likens it to a six- or eight-week training cycle where you develop strength and endurance. “That is the same way that brain endurance training works, but instead it’s your brain, and you’re really trying to grow the neurotransmitters and the neural pathways to try to enhance its resilience to fatigue.”
For a sports person, that might involve a 30-minute session training physically – on a treadmill, for example – while doing a cognitive task, such as a mathematical equation or having to make fast decisions based on colours that flash up on the screen.
For those of us who simply want to improve our focus in a world of distraction and enhance our cognitive stamina, the key is novelty and sustained time on mentally effortful activities.
“Novelty is really important to help us build that endurance,” says neurologist Emma Devenney, an associate professor at NeuRA and UNSW.
“You have to switch on these other mental abilities, but also you’re building new connections within your brain.”
It ought to be enjoyable too. “If the task is challenging but boring, it’s really difficult to maintain your attention on it, and it contradicts what you’re trying to do.”
Activities can be as diverse as challenging puzzles, learning a musical instrument or language, or playing mentally demanding video games.
Schofield says she builds her endurance by scheduling blocks of time for research design and focused writing.
If the activities sound similar to those recommended for dementia risk reduction, that’s because they are.
“It’s all about trying to train our brains in a way to make them more effective and make them less vulnerable to distractibility or vulnerable to pathological changes that happen as we age,” says Devenney.
“It’s all part of this move towards brain health.”
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Sarah Berry is a lifestyle and health writer at The Sydney Morning Herald and The Age.Connect via X or email.
