What we mean when we ask you to 'Use caffeine'

You benefit from using caffeine “little and often”. A cup of tea or coffee, or a caffeinated soda, every other hour should help you stay awake. More than that will not be helpful and will just reduce your ability to sleep later.

Do I have to use caffeine?  

No! You don’t have to use caffeine to make the plan work. If you are already using caffeine, the advice is designed to help you use it in the most effective way possible to support the plan. If you don’t already use caffeine, you shouldn’t start using it now!

What will happen to my jet lag if I don’t use caffeine?   

You may find it harder to stay awake at the recommended times. It should not affect the overall plan, however.

What does “use caffeine little and often” mean?

“Little and often” mean one cup of tea or coffee, or one caffeinated soda (equivalent to about 50mg of caffeine) every two hours. Using more than that will not make you more alert but may increase the risk of sleep disruption or caffeine side effects.

What contains caffeine? 

Caffeine is present in tea, coffee, caffeinated sodas, chocolate, and in some pain medications. Brewed ‘drip’ coffee and energy drinks tend to have very high amounts of caffeine so only half a cup of these is needed every two hours. Work out the caffeine content of your typical drink so you can plan how much to have.

The Science

When we are awake, our cells use energy. A by-product of this energy use is an increase in the amount of adenosine in our bodies. Adenosine is part of the sleep regulation system, and is associated with increased sleepiness.

Caffeine is an adenosine-receptor antagonist and therefore blocks the sleepiness-inducing effects of adenosine. As a result, caffeine is a highly effective stimulant.

Caffeine stays in our system for a long time. It typically has a half-life of three to five hours so if you take 100mg of caffeine at 10am, you will still have 12.5mg of caffeine in your system at bedtime 12 hours later. Having caffeine in your body at bedtime will have a negative effect on your sleep that night. 

Using caffeine “little and often”, and then stopping it as long as possible before bed, will optimize the benefits of caffeine and minimize the negative effects on sleep.

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