What's the key to better sex, weight loss and increased productivity? Timing.

That's according to clinical psychologist Michael Breus and his new book The Power of When.

Breus, who specialises in sleep disorders, believes the problems encountered in these areas of life may not be down to how you're working, exercising or having sex, but simply that you're doing these things at the wrong time.

"When is the ultimate life hack. It's so much easier than trying to overcome an obstacle or changing the way you do something," he told The New York Post.


The concept of focusing on "when" came to Breus when one of his patients spoke to him about her constant fatigue.

Breus says she told him her issue wasn't with falling or staying asleep, rather that she was falling asleep at the wrong time.

He arranged for the woman to start and finish work two house later each day, so her office hours would mesh better with her sleep schedule.

After two weeks, his patient reported that not only did her sleep improve, but she was far more productive at work and got along with her family better too.

The results led Breus to consider what else the concept could be effective for. Pretty much everything, as Breus discovered.

The Power of When dissects 75 activities, from drinking coffee to exercising, and tells you the best time to do each of them, depending on your biological clock, or your "chronotype."

Breus has identified four different chronotypes based on people's sleep requirements and personalities. The chronotypes are:

Photos / Getty Images
Photos / Getty Images

• Dolphin


: Intelligent, neurotic, light sleepers.

• Lion

: Morning-oriented, driven, optimistic, need a medium amount of sleep

• Wolf

: Night-oriented, creative, extroverted, need a medium

amount of sleep

• Bear

: is fun-loving, outgoing, like the sunlight, need to sleep a lot.

According to Breus, "There are certain times when our body is burning calories or producing more oestrogen, so it's all about using that knowledge" in order to operate at your optimum.

The best time to go to bed

Breus says the eight-hour rule is a myth. He says most people can function well on seven hours, while those befitting the "dolphin" chronotype can function with six.

When it comes to sleep, Breus says the most important thing is consistancy and making sure you're mentally prepared for bed (by turning off screens and allowing wind-down time) a full hour before getting into bed.

Breus also says: "You shouldn't get into bed for any reason except for sleep and sex." This will help you associate the idea of "bed" with "sleep".

• Dolphin: As close to 11:30pm as possible
• Lion: As close to 10pm as possible
• Wolf: As close to midnight as possible
• Bear: As close to 11pm as possible

The best time to go for a run

Dolphin types should run in the morning whilst bears should try running in the evening. Photo / Getty Images
Dolphin types should run in the morning whilst bears should try running in the evening. Photo / Getty Images

This depends on what you want to achieve: Fat burning, reducing anxiety or training for a race. But your chronotype can also suggest the best time for you. For example, Breus recommends dolphins get in an early morning run because it will curb their issues around relaxing and set them up for a good day.

• Dolphin: 7:30am.
• Lion: 5:30pm.
• Wolf: 7:30am or 12pm.
• Bear: 6pm.

The best time to wake up

Depending on your chronotype, waking up at a certain time will help curb sleep inertia: that groggy feeling many of us experience upon waking.

• Dolphin: 6:30am.
• Lion: 5:30am to 6am.
• Wolf: 7am.
• Bear: 7:30am.

The best time for drinking coffee

Most coffee should be drunk at least two hours after you wake. Photo / Getty Images
Most coffee should be drunk at least two hours after you wake. Photo / Getty Images

In general, sipping on coffee within two hours of waking should be avoided. This is because while you are sleeping, you exhale about a litre of water. So topping yourself up with a diuretic like coffee will increase your dehydration.

• Dolphin: 8:30am to 11am; 1pm to 2pm.
• Lion: 8am to 10am; 2pm to 4pm.
• Bear: 9:30am to 11:30am; 1:30pm to 3:30pm.
• Wolf: 12pm to 2pm.

The best time to have sex

For seventy per cent of people, the time they have sex is based on convenience. This tends to be when you're already in bed for the night, says Breus.

"But you want to have sex when your testosterone levels are high, and that happens to be earlier in the evening or in the morning."

If your partner has a different chronotype to you, Breus advises finding a time between both your peaks.

• Dolphin: 8pm.
• Lion: 6am to 7am.
• Bear: 7am or 9pm.
• Wolf: 10am or 10:30pm.