Disclaimer: Our field is extremely competitive (deep learning) and other labs may have better working styles depending on their lab size and member composition. My lab's workload on average is 8 - 12 hours a day for 6-7 days a week, ramping up even more closer to deadlines. That being said, a lot of this time (50% or more) is for thinking and discussing. This schedule, while hard, seems to be effective for publishing…
If half of the time is thinking, why do you need to be on the spot? Seems really counterproductive to me.
Never understood what the purpose is to fill half the day with meetings. Beside the illusion of productivity.