Waking up early: the first hour sets your day.

The alarm goes at half six. You hit snooze twice, then reach for your phone: three emails, a message from your accountant, the headlines. Before your feet touch the floor, you're in a meeting with half the world.

Then coffee standing up, toast and jam, the car. By ten you're running on empty. Many decide the answer is a 5am start, like the founders in the biographies. It rarely is. What counts is the first hour. It's one of the first things I look at with clients.

A morning that starts badly

It shows more in how you feel mid-morning than in how you get up.

• You hit snooze. Twice, three times, and you get up already rushing.
• Phone before feet on the floor. Other people start your day for you.
• Coffee instead of breakfast. Or coffee and something sweet, standing up.
• The mid-morning dip. Hunger, a short temper, another coffee.

What happens in that first hour

Grogginess is chemistry. While you're awake, your brain builds up a molecule that makes you feel tired. If the alarm catches you in deep sleep, it's probably still working, so some mornings you're slow even after a long night. Meanwhile cortisol, the hormone that gets you going, is rising. It peaks about half an hour after you wake. The fog lifts by itself.

Indoor light is weak. Your body clock is set mainly by the light reaching your eyes. Outside, even under cloud, there's at least twenty times more than in your kitchen. Between house, car and office, the morning signal reaches it faintly.

Your phone puts you on alert. Morning is a delicate time for your nervous system. Start with emails and news and you're on the back foot for hours. Leave them until after breakfast and read them awake.

The first hour, in order

No heroics, no hours stolen from sleep. A few things, in the right order.

A large glass of water. As soon as you're up. You've gone all night without a drink, and part of that morning tiredness is thirst. You feel thirst less with age, so drink anyway.

Ten minutes of light, on the move. Within an hour of waking, get outside, no sunglasses: the garden or the street. Move gently as you go: neck, shoulders, torso, hips, or just walk. Light and movement are two of the strongest signals for your body clock. If you're up before dawn, go out as soon as it's light.

A savoury breakfast, sitting down. After the night your stomach is empty and sugar hits your bloodstream fast, so it's the worst time for cereal and pastries. A breakfast that spikes your blood sugar throws it off at lunch and dinner too. Eggs, Greek yoghurt, nuts. Get it ready the night before.

First coffee with breakfast. After the water and the light. In the morning it works with your cortisol, which is already high, and peaks in about forty minutes. But it masks tiredness without creating energy. Drink it the moment you wake and you feel fine, so you skip light and breakfast.

Half an hour at a time. To get up earlier, bring the alarm forward half an hour, hold it a few days, then another half-hour. Keep it away from the bed, and the same seven days a week. Five o'clock isn't for everyone. About six people in ten sit between lark and owl, and an owl forced onto a lark's hours pays in stress, hunger and tiredness.

Start with one thing, whichever costs you least. The first hour is the only one in your day nobody has filled yet. Keep it for yourself.