Ever find yourself bragging about working a 60, 80 or even 100 hour work week or publicly complaining on social media about that incessantly heavy workload of yours? This is not a badge of honor. It is generally a sign that something is wrong, and it could be the way you go about your work.
When it comes to any generalizations, take it with a grain of salt. The takeaway is valid though - working long hours does not linearly (or exponentially) translate to increased throughput. In fact, humbly, in my own experience, it deteriorates.
That said, bragging or complaining is not a solution. What worked for me was logging my activities and understanding the throughput religiously. And personally, my throughput did not justify beyond the continuous 8 hour mark and the phased 10-hour mark.
Additionally, 6 hours of sleep was proven to be a requirement for average throughput and 7 hours made a significant difference in increased throughput.
Try, measure, and you can optimize.