Calculate Your Biological Prime Time  During the day, your energy fluctuates. This fluctuation is impacted by what you eat and when, how much caffeine or sugar you consume, how tired you are, how hard you work, what type of work you’re doing, how much you’re using your physical body, and a whole lot more. Sam Carpenter, in his book Work the System, coined the phrase “biological prime time.” He suggests charting our energy during the day for a few weeks. And not just noting your energy highs and lows between six a.m. and nine p.m. You want to jot down your peak times of focus and lack thereof as well as those bursts of motivation. You’d want to note when you exercise and for how long, what times you wake up and go to sleep. Basically you keep a journal with the emphasis on energy and concentration. Think about trying this.