Not all hours are created equal. Therefore, the key to increasing productivity is to spend the right time, on the right things, the right way, and with the right energy.

We all have power hours or peak performance periods where we’re in “the zone”, ploughing through tasks with maximum efficiency and ease. Some of these periods are quite obvious, but many are camouflaged by daily activities that could be executed during less efficient parts of the day.

Identifying and utilising our power hours in the best way is one of the most powerful, and least used time management techniques that can be used to cut down on study time without negatively impacting results.

Our most productive times follow a cycle that repeats every 24 hours and is referred to as a circadian rhythm.

The typical circadian graph describing the alertness level in an adult (20+ years) or child (< 12 years) is shown below and arises as the result of our relative need for sleep as opposed to our urge to stay awake. Note that:

  • Sleep urge is greatest at night with a small increase at midday.
  • Sleep need increases throughout the waking hours and is replenished during sleep.
  • Peak performance occurs after 8am and in the evenings.
  • The lowest levels of alertness occur before sunrise and mildly after lunch.

Adolescent Circadian Rhythms

The biological clock of children (< 12 years) shifts by two hours during adolescence (ages 12 to 19), leading to a later bed time (11:30 pm or later) and a natural tendency to wake up later in the morning. Because of this shift, teenagers lose two to three hours sleep every school day. They often come to school sleep deprived and without eating breakfast, both which have a significant impact on memory and learning.

Concentration and Focus

The psychological-cognitive cycle plays a significant role in memory and learning and is heavily influenced by the sleep-wake cycle. The psychological-cognitive cycle regulates our ability to focus on incoming information, which means that our concentration levels fluctuate throughout the day.

In general:

Research has shown that although the psychological-cognitive cycle is very similar for preadolescents and adults, it is quite different during adolescence.

If the wake-up time occurs at 6am:

  • Teenage concentration levels are at their lowest in the morning, with peak alertness occurring between 8am to 1pm. Students undertaking very early morning studies report being less alert, wearier, and having to expend greater effort whilst studying.
  • Concentration levels begin to decrease from about 1pm, reaching half of the maximum value by 3pm. During this period, learning can still occur, but it does require more effort.
  • Most teenagers experience a drop in energy and feel drowsy somewhere between 2pm and 4pm. This is a great time to take a 15 to 30-minute nap – not only will you feel more alert and focused on waking, you’ll be replenishing your levels of brain chemicals (neurotransmitters) that play a critical role in memory and learning.

  • Following the mid-day slump, concentration levels quickly rebound to about 80-90% of the maximum value and remain at these high levels until around10pm.
  • The drive for sleep becomes very strong between 11pm and midnight. This means that the majority of teenagers do not fall asleep until at least 11.30pm.


  • People can be loosely categorised as early risers (larks) or late risers (owls).
    Morning people tend to wake up and go to sleep earlier and are most productive early in the day. Evening people tend to wake up later, start more slowly and peak in the evening.
    If you’re an “owl”, each stage described in this tip will roughly occur between 1 and 4 hours later.
  • If you’re a morning lark, your peak productivity times will occur in the morning. Night owls are more productive and concentrate better in the evenings.
  • Alertness tends to slump after eating a meal.

Using Your Circadian Rhythm to Improve Productivity

As there are individual variations in daily rhythms, it’s a good idea to chart your energy, concentration and motivation levels across the day. Once you determine your internal biological clock’s daily schedule, you can then plan your study sessions around those times of day when you’re most alert and motivated.

Working with your circadian rhythm will not only increase your daily efficiency and productivity, it will also help maintain a healthy body and mind. Your confidence levels will also improve, and you’ll be less likely to procrastinate future studies!


Don’t be concerned if your study regime differs from other students – it’s not uncommon to see large variations in alertness, as shown below.

Identifying Your Most Productive Hours

Step 1: Record focus, energy and motivation levels out of 10, across a 1 to 3-week period. Use the definitions and rating     scales detailed on the back page.

Note: Take measurements at the same times every day so the data isn’t skewed.  Although you may see trends within the first week, the longer you collect data, the more reliable your graphs  will be. 

Step 2: Enter your data into the ‘Productivity Spreadsheet’ that has been supplied with this study tip.

This spreadsheet will automatically calculate averages and produce your personalised productivity graphs. Examples of such graphs include:

Step 3: Use the “Notes” column to document what motivated or demotivated you and whether you did something that could have affected your energy levels. For example, sleep duration, exercise, the number of cups of coffee, diet, exposure to light etc).

In Summary

The graphs will show you WHEN you’re most productive

The NOTES may give you the reasons as to WHY



Step 4: Every time you record your levels, ask yourself the following questions:

What makes me more productive?

What activities, foods, conditions, times etc drain my energy?

Where possible, apply your findings so you can increase the number of power hours in each day.

Additional Suggestions:

  • Identify which of your regular tasks require high levels of focus and concentration and which ones do not.
  • Make a list first thing each morning and designate time frames for each of the tasks you need to accomplish that day, arranging lunch and fresh air breaks for the times when your focus is low (and hunger is high!).
  • Each evening, spend a few minutes optimising your timetable for the following day.
  • Each Sunday, put together a rough schedule for the upcoming week. Make a list of the major tasks you want/need to complete and assign them to the most ideal days.

Leveraging Your Concentration Cycle

  • Numerous studies have shown that when we operate at our optimal times of day, our ability to filter out the various distractions around us greatly improve, which is why we’re capable of focusing more intensely on the tasks to complete.
  • Large efficiency gains can be obtained by rearranging the order in which tasks are performed i.e. according to the level of focus and concentration that will be required for their completion.

For example: Difficult or high value tasks should be addressed when concentration levels are high.

  • Do not work on concentration intensive tasks when your alertness and energy levels are low. Not only will you make avoidable mistakes, tasks will require more time and effort to complete, increasing the likelihood of you becoming overwhelmed or demotivated. Use these times to eat, relax, clean, sort, research or answer emails.
  • Most people are more easily distracted from noon to 4 pm.
  • Do not fight your natural biological clock. For example:
    Do not force yourself to work through an energy slump, particularly if you’re in the middle of a high-concentration task.
    You’ll waste more time plodding through that task than if you were to stop for a while and pick up a low concentration activity.
  • After identifying your power hours, protect them so that you can spend them where you need it most.  Don’t use these periods to attend appointments, play sport, socialise, clean or sleep in. These hours should be used for tasks that require high levels of concentration or motivation. You can also create additional power periods using the techniques discussed in the next study tip.