When someone gets their second wind, they get a return or boost of energy which enables them to achieve their goal, continue their activity, or start again. Getting a second wind is more commonly heard in social situations, specifically sports-related activities, rather than professional environments.
During my first marathon, I got extremely tired mid-way through. It was only when I got my second wind that I knew I’d be able to finish.
The man repetitively worked through the accounts and when his boss offered him some time off, he said: “I’m okay now, boss. I think I just got my second wind.”