By doing so you’ll be able to keep your mental sharpness and energy up for the whole day and workweek. I do this by setting my timer for 45 minutes. During those minutes I only focus on the task at hand and it becomes easier to do so because I know that I only have to do it for this limited time period.
When the time is up I set it for 15 minutes. During those minutes I focus fully on just resting by drinking coffee, having a snack, taking a short walk or resting with closed eyes on my chair.
This will keep your focus sharp and you feel you have plenty of energy throughout the day.