The Hidden Cost of AI: Are We Losing Our “Time Under Tension”?

Walk into any gym, and you’ll hear the phrase: time under tension. It’s the measure of how long your muscles strain during an exercise. A slow, grinding squat that lasts thirty seconds pushes muscles far harder than a quick up-and-down rep. More strain, more growth.

Now swap the gym for the workplace or classroom, and the muscles for the brain. The same principle applies: the longer we wrestle with a problem, the more our minds grow. Struggle builds resilience, memory, and creativity. Psychologists call it “productive struggle.” Neuroscientists call it “plasticity.” Most of us just know it as the frustration of banging our heads against a problem until—finally—the solution clicks.

But what happens when that struggle disappears?

With the rise of Artificial Intelligence, many of those moments of friction—debugging code, drafting essays, analyzing data—can now be outsourced to machines. In seconds, AI can generate a solution that would have taken us hours. The time under tension vanishes. And with it, perhaps, a hidden ingredient in how our brains develop.

The Early Warnings

Several studies are already flashing red.

At MIT’s Media Lab, researchers tracked brain activity while participants wrote essays with and without AI. The results were stark: those using ChatGPT showed the lowest brain engagement, producing what teachers later described as “soulless” and formulaic work. Over time, these participants became passive, simply copying AI output with little editing. The term the researchers coined? “Cognitive debt.” Like financial debt, it buys short-term convenience at the expense of long-term growth.

In another study, more than 600 people were tested on critical thinking skills. Those who used AI most frequently scored significantly lower. The researchers found that heavy users tended to offload effort whenever possible, weakening their ability to reason independently. Younger, tech-native participants scored lowest of all. 

https://www.media.mit.edu/projects/your-brain-on-chatgpt/overview/

And it’s not just academia. A Harvard Business Review experiment found that while AI tools made workers more productive, they also left them less motivated. People accustomed to AI assistance felt bored and disengaged when later asked to complete tasks on their own.

https://hbr.org/2025/05/research-gen-ai-makes-people-more-productive-and-less-motivated

Taken together, the message is clear: if AI removes the struggle, it also removes the growth.

Use It or Lose It

Neuroscience has long shown that the brain works on a “use it or lose it” principle. Taxi drivers in London, for instance, famously developed enlarged hippocampi—the brain region for navigation—because they memorized the city’s labyrinthine streets. By contrast, GPS-reliant drivers show weaker spatial memory.

The same rule applies to other skills. Stop solving problems, and problem-solving pathways weaken. Stop persisting through frustration, and resilience fades. Now imagine a society where most people lean on AI for reasoning, writing, and decision-making. Over time, the collective capacity for deep thinking could erode.

It’s not an apocalyptic scenario—people won’t suddenly become incapable of thought. But the edge dulls. The mental muscle atrophies. And in a world already flooded with misinformation, declining critical thinking is the last thing society needs.

The Broader Risks

The implications stretch beyond individuals.

• Education: If students habitually rely on AI for answers, they may graduate without the grit or cognitive flexibility needed in the real world.

• Workplace: If employees stop wrestling with complex problems, companies risk building a workforce skilled at prompt-writing but weak in independent analysis.

• Culture: AI tends to generate average, homogenized outputs. If we lean too heavily on it, creativity could flatten, innovation could slow, and originality could fade.

• Democracy: Over-trusting AI outputs without skepticism risks making us more vulnerable to bias, error, or manipulation.
  
  

This isn’t a science fiction concern—it’s a subtle cultural shift already underway.

A Path Forward: Making AI a Sparring Partner

So what do we do? Do we ditch AI to save our brains? Hardly. The genie is out of the bottle, and the benefits are real. The challenge is to use AI without losing ourselves.

That means reframing AI as a sparring partner, not an autopilot. The healthiest use cases are ones where humans remain engaged—critiquing, editing, questioning. In the MIT experiment, participants who wrote first on their own and then used AI as a supplement showed increased brain activity. They treated the machine’s output as raw material to refine, not a finished product.

For educators, that might mean AI tools that guide students step by step instead of handing over complete answers. For workplaces, it might mean setting norms that encourage employees to attempt solutions before leaning on AI. For developers, it means designing AI systems that explain reasoning, prompt reflection, and keep humans in the cognitive loop.

And for individuals? It may be as simple as choosing to struggle sometimes. Write that first draft yourself. Debug the code before pasting it into an AI. Take the intellectual stairs instead of the cognitive elevator.

Conclusion

Every technological leap comes with unintended consequences. The Industrial Revolution automated physical labor, and only later did we realize we needed gyms and exercise to stay healthy. The AI revolution automates mental labor. Its hidden cost may be the erosion of our “time under tension”—those moments of productive struggle that make our minds sharper.

If we want a society that is not only more efficient but also more resilient, creative, and thoughtful, we must guard against the temptation of total ease. Convenience is good. Growth is better. And sometimes, growth only comes when the weight is heavy, the reps are slow, and the brain is forced to strain.

In short: let AI assist you, but don’t let it rob you of the struggle. Your mind still needs the workout.