I think endurance exercise is mostly great for increasing focus and concentration for me, with a few exceptions. Higher training volume sometimes leads to somewhat slower thinking. That could be an advantage in some situations where consideration is better than quickly reacting, but not always. Inadequate nutrition compounds the issue, so if I’ve been training a lot and not getting in enough good calories I might find myself underperforming.

There’s a reason pro athletes consider eating and resting adequately a significant part of their full-time job.