# I measured my brain during one of the hardest business trips of my year. Here’s what I learned about performance > Source: > Published: 2026-08-17 10:45:00+00:00 Last month, I traveled through three countries and multiple time zones, packing investor meetings, customer dinners, panels, and leadership sessions into just 10 days. Like many founders, I wore the schedule as a badge of honor. If I could keep up, I assumed I was performing at my best. Then I looked at my brain. Throughout the trip, I’d been wearing Neurable’s EEG-powered headphones, giving me an objective view of how my brain responded to everything from travel and sleep to stress and recovery. Rather than relying only on how I felt, I could compare my subjective experience with objective measures of neural activity. I expected to see increased stress levels in my brain data during a work trip. What I didn’t expect was how often the data contradicted my intuition, and it made me wonder how often I was pushing through cognitive fatigue without even realizing it. As a neuroscientist, I’ve spent my career studying the gap between how our brains function and how we perceive them to function. This trip reminded me that we’re all prone to judging our cognitive performance by how we feel rather than what the brain is actually experiencing. It’s easy to see how so many business leaders can fall into this trap, particularly because today’s work culture makes this blind spot difficult to recognize. We’ve created a world that never switches off. Our offices live in our pockets, our days are filled with endless decisions, and true downtime has become a rarity. We accept that pace as the cost of doing business, yet we rarely stop to ask how it’s affecting the quality of our thinking. Instead, most of us judge our ability to perform in the workplace by a simple question: Do I feel ready to tackle my work today? The first morning after arriving in Germany, I felt like many travelers do after a long international flight. Mentally, I was eager to get to work. Physically, I wanted to crawl back into bed. I assumed it was ordinary jet lag, but my brain data suggested something more nuanced. My sleep debt had largely been repaid during the flight, but my circadian rhythm hadn’t caught up. My body was in Germany while my internal clock was still somewhere over the Atlantic. I expected the effects to linger much longer, but within about three days, my cognitive measurements had largely returned to baseline. It was my first reminder that feeling ready and being cognitively ready aren’t always the same thing. As it turns out, my experience wasn’t unique. [Research](https://urldefense.proofpoint.com/v2/url?u=https-3A__pubmed.ncbi.nlm.nih.gov_12683469_&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=xHenyQfyc6YcuCNMBsOvfYGQILM1d1ruredVZikn4HE&m=TMWib44enkJI7227Boi1qLJXhc56UoCvN44vzQSDGOh5ui5SQciqbYwkQIrHICmY&s=9PgM0zfdagq7242Z0hbIxYkV-RwUPEh9rmnT_OBJHpo&e=) has consistently shown that after insufficient sleep, objective cognitive performance can continue to decline even after people’s subjective sense of impairment has plateaued. Looking back, I wondered how many strategy meetings, business decisions, or difficult conversations I’d entered simply because I felt sharp, even when my brain data was telling a different story. A few days later, I noticed something else unexpected. My brain had largely recovered from jet lag. I was surprised by how quickly it bounced back, which made me appreciate just how central recovery is to sustained performance. Professional athletes understand this instinctively. They don’t train at maximum intensity every day because they know recovery is essential to peak performance. Business leaders often do the opposite. We celebrate pushing through and treat recovery as something we’ll get to later, if at all. The biggest lesson from the trip, however, came from something entirely within my control. Like many people, I assumed jet lag would be the biggest challenge. Instead, the greater cognitive cost came from a series of ordinary decisions. One evening in Vienna, I attended a networking dinner, enjoyed a couple of glasses of wine, and stayed up until nearly 2:30 a.m. taking work calls back to Boston. The next morning, my cognitive measurements looked remarkably similar to what I’d seen after crossing the Atlantic. The combination of wine, a late night, and about five and a half hours of sleep had produced a cognitive cost comparable to jet lag. It made me realize how often we misdiagnose our own performance. We prepare meticulously for investor meetings, board presentations, and international travel, yet we rarely prepare for the cumulative impact of another drink at dinner, another hour spent answering emails, or another morning convincing ourselves that six hours of sleep is enough. None of those choices seems consequential on its own, but together, they shape the quality of our judgment, the very thing we depend on most and measure the least. The irony is that modern companies already measure almost everything, from revenue and margins to customer acquisition costs and burn rates. On a personal level, many of us now also track our sleep, heart rate, and physical activity. Yet the organ responsible for every negotiation, [hiring](https://www.fastcompany.com/section/hiring) decision, strategic pivot, and creative breakthrough has remained largely invisible and rarely optimized for peak performance. Before diving into yet another work task, I used to ask myself a simple question: Can I push through this? Now, I ask a different one: Is this the version of my brain I want making this decision? That question doesn’t always change my schedule. Sometimes the meeting still happens, and the flight still takes off. But it changes how I prepare, which decisions I tackle first, and when I remind myself that recovery isn’t a luxury, but rather a necessity. Every important business decision begins in the mind of the person making it. Every leader should spend a little less time asking whether they can push through their packed schedules and a little more time making sure they’re setting themselves up to think at their best. After all, every important business decision deserves the clearest thinking we can bring to it.