If stress were a muscle, the presence of stress should mean you're able to handle more of it over time. It would be more like inching your way into the pool rather than cannonballing into the deep end. Except stress is definitely not a muscle — and too much of it wears down our ability to predict future dangers.
New research from New York University suggests that stress does not make us more alert, more vigilant, or more reactive. The study involved physical stress like electric shocks or immersing your hand in ice, but the principle translates. Lead author Candace Raio found that "when we are under stress, we pay less attention to changes in the environment, potentially putting us at increased risk for ignoring new sources of threat," she said in a press release. "As a result, stress can reduce the flexibility of our responses to threats by impairing how well we track and update predictions of potentially dangerous circumstances."
It's true that short-term stress can make you sharper under certain circumstances. Maybe that's why all-nighters worked in school (unless they didn't). In acutely stressful situations, fight-or-flight mode is supposed to help you escape danger and survive. But long-term, too much stress diminishes your ability to respond quickly to threats. It's one reason why you might start missing deadlines or getting reprimanded at work.
All this further proves the necessity of taking breaks, big or small. Schedule them into your day if you have to, whether for longer doses of relief or shorter ones. Don't be afraid to take a walk around the block, go be near greenery for 10 minutes, or put on some white noise with headphones and sit quietly. Stress is your body's way of telling you to slow down and reevaluate your conditions. When you're able to manage it effectively, your job and your holistic, non-work self have everything to gain.