A new year routine that lasts past January.

Quick answer. A new year routine lasts when it is small, specific and tied to a cue you already have, such as putting the kettle on. In a study from University College London, people repeating a daily behaviour took 66 days on average for it to become automatic, with individuals ranging from 18 days to a forecast 254, so expect to still be working at it in March. Use the UK guidelines for the targets: at least 150 minutes of moderate activity a week, strength work on 2 days, and at least 5 portions of fruit and vegetables a day.

What makes a good new year routine?

A routine is a short list of things you do at the same point in every day. It is different from a resolution, which is usually an outcome, such as get fit or eat better, with no plan attached. The routines that last tend to share four things.

• They are small. Ten minutes of walking that happens every day beats an hour at the gym that happens twice in January.
• They are specific. Walk at lunchtime on weekdays can be done or not done. Move more cannot.
• They have a cue. Each new habit is attached to something that already happens every day: waking up, the first coffee, getting home, brushing your teeth.
• They survive a bad week. The plan says what you will do when you miss a day, which is to start again the next day.

The UK Chief Medical Officers make the same point about exercise. In their physical activity guidelines they write that "lasting change is most likely when activity is enjoyable, or useful, or part of everyday routines."

How long does it take for new year resolutions to stick?

Longer than the 21 days you often hear. A widely cited study is by Lally and colleagues at University College London, published in the European Journal of Social Psychology in 2010. Volunteers chose one healthy eating, drinking or activity behaviour, did it once a day in response to a daily cue (for example, after breakfast), and rated each day how automatic it felt. They were followed for 84 days.

The UCL researchers' own summary of the study says "it took, on average, 66 days for the habit to form", and adds that the first repetitions made the biggest difference, with progress slowing as the behaviour became automatic. They also found that simple behaviours, like drinking a glass of water, became habits faster than harder ones, like doing 50 sit-ups.

The authors are careful about the number. In their words, "it's unwise to attempt to assign a number to this process." The practical reading is this: a routine started on 1 January will probably still need effort in early March, and the simpler it is, the sooner it runs on its own.

How to make new year resolutions that stick.

1. Choose one or two changes, not ten.

Every new habit competes for the same attention. Start with one, add a second when the first no longer needs thinking about.

2. Write it as after X, I will Y.

After I make my morning tea, I will walk round the block. After I get home, I will put my running kit on. The first half is the cue, and the cue is what makes it automatic over time.

3. Make the first version easy.

The NHS notes on its walking for health page that "a brisk 10-minute daily walk has lots of health benefits" and counts towards the weekly total. Start there and lengthen it once it is fixed.

4. Plan for January's dark mornings.

The new year arrives at the darkest end of the morning. London's sun rises at about 08:06 on 1 January and sets at about 16:02, calculated for the city, and the latest sunrises of the year fall around New Year. A routine that needs daylight at 7am will fail on the first Monday. Put the outdoor part at lunchtime, or make the morning part indoor. Our guide to waking up on dark mornings covers the first hour of the day.

5. Keep score lightly.

A tick on a calendar is enough. The point is to see the run of days, not to grade yourself.

6. Restart the next day.

Missed days happen in every routine. The habit comes from repeating it in the same situation over weeks, so the important day is the one after the miss.

Realistic new year goals, based on UK guidelines.

If you want targets, use the official ones rather than inventing your own. These are the UK recommendations for adults, with a smaller version to start January with.

The activity and strength figures are from the NHS physical activity guidelines for adults, which also ask adults to "reduce time spent sitting or lying down". The fruit and vegetable portion is from the NHS 5 A Day portion guide. The alcohol figure is the NHS low-risk drinking advice, and the sleep point is the first tip in the NHS's advice on sleeping better: "Keep a regular sleep routine."

The Chief Medical Officers add a line worth keeping in mind in January: "if you do no physical activity do some, and if you do some do a bit more."

What should a new year morning routine include?

Keep it short enough to survive a late night. A morning routine that lasts usually has three or four fixed steps in the same order.

• The same wake-up time. Going to bed and getting up at similar times each day is the NHS's first sleep tip, and it makes every other habit easier to place.
• Water and breakfast. Set breakfast up the night before so it needs no thought.
• Light and movement. If it is dark, a few minutes of stretching indoors. If it is light, a short walk.
• One planned thing for later. Decide when today's walk or session will happen, and put it in the diary.

For how much movement adds up to enough, our guide to how much exercise you need a week sets out the numbers.

Where Immufix fits.

Immufix is one 25g scoop in around 200ml of water, once a day. It suits the after X, I will Y pattern well: most people take it with breakfast, so the kettle or the cereal bowl becomes the cue. It sits alongside a varied diet, not in place of one. B vitamins and magnesium contribute to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. Pantothenic acid contributes to normal mental performance. Every ingredient and amount is on the science page.

The short version.

• Pick one or two small, specific changes and attach each to something you already do every day.
• UCL research found a daily habit took 66 days on average to become automatic, with a range of 18 to 254 days.
• Use UK guidelines as targets: 150 minutes of moderate activity and 2 strength days a week, and at least 5 portions of fruit and veg a day.
• Plan around January's late sunrises, around 08:06 in London on New Year's Day.
• When you miss a day, start again the next day.

Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. If you have a medical condition, are pregnant, breastfeeding or taking medication, speak to your GP or pharmacist before taking any food supplement.