Do you endorphins from either exercise or other stimulants such as caffeine help you engage fully when you need to do deep work?

Endorphins from exercise help me focus on deep work. When I have been at my best I would take a couple minutes to do high intensity interval training on my under-the-desk elliptical trainer. I’d do 10 second and 30 second intervals. Another thing that makes a big difference for me is staying well hydrated. Lastly, it helps if I can do something with the anxious thoughts that jump into my head. Preferably, I can solve them beforehand. If not, writing them down to consider later helps me to focus on whatever I’m trying to accomplish.

I do a little of exercise only to get enough energy, and also I set little spaces of relaxation during the day in the way I do not feel extremely busy

I find that my engagement is related to my mood. Anything that makes me feel anxious usually distracts me. Caffeine sometimes causes anxiety.

Depends on the person. Definitely not for me, since caffeine triggers anxiety attacks. Exercise helps me get focused on tasks that don't involve much thought, such as laundry and cleaning around, but I tend to get extremely "fuzzy" headed after exercise to the point where even if I do it first thing in the morning, I can count my day's deep work productivity destroyed. I can only do deep work if I haven't eaten, so skipping breakfast and fasting is the only way I can trigger productivity for my engineering work

I must say that make my mind much clearer but the effect that’s not last long so I need to find a more assist think of a way to generate this kind of energy and self-confidence. Sleeping is quite crucial and I must be with all my habits around a good healthy amount of sleep.