20% off £30


20% off £30



🏷️ Buy 1 Get 1 Free☀️ Summer ShopOffersOffers HubBuy one get one 1/2 priceSave up to 1/2 PriceBuy 1 Get 1 Free25% off Online Only OfferOutletFree gift with purchase1/2 Price2 for £50Short DatedVitamins & SupplementsVitamins & Supplements HubVitamins & Supplements Shop AllCBDShop all CBDCBD OilCBD CapsulesCBD SprayCBD GummiesCollagen & SilicaHair, Skin & NailsShop all Hair, Skin & NailsHair GrowthFunctional MushroomsVitaminsShop all VitaminsMultivitaminsVitamin AVitamin BVitamin CVitamin DVitamin EVitamin KVitamin DrinksMineralsShop all MineralsMagnesiumIronZincCalciumSeleniumChromiumSupplementsShop all SupplementsFibre SupplementsAcidophilus & Friendly BacteriaPeppermint OilGrapeseed ExtractLecithinCollagen & SilicaOmega & Fish OilsPlant Sourced SupplementsSuperfood SupplementsArnicaApple CiderRaspberry KetonesAloe VeraChondroitin & MSMCo Enzyme Q10Evening Primrose OilGarlicGinkgo BilobaGlucosamineGlucomannanSeaweed, Kelps and Aquaceuticals5 HTPSaw palmettoCharcoalWomen's HealthShop all Women's HealthMenopauseMenstrual SupportUrinary Tract HealthPregnancy & ConceptionMen's HealthShop all Men's HealthProstate HealthChildren's HealthConditionShop all ConditionWater RetentionAllergy & Hay Fever CareAnxiety SupportBone & Muscle HealthMuscle Support & Joint PainBrain & Memory SupportWomen's HealthMen's HealthChildren's HealthPain ReliefCold & Immune SupportFatigueDigestive HealthHair, Skin & NailsHeart & CirculationLiver CareMood SupportSexual HealthSleep & RelaxationStress ReliefVisionHerbal & Licensed RemediesShop all Herbal & Licensed RemediesValerianSt John's WortRescue RemedyAgnus CastusAshwagandhaEchinaceaMilk ThistleDevil's ClawGinseng & GuaranaBlack CohoshHomeopathic & Flower RemediesShop all Homeopathic & Flower RemediesRescue RemedyTissue SaltsFlower RemediesHomeopathic RemediesAt-Home TestsVegan Vitamins & SupplementsBuy one get one 1/2 priceBuy 1 Get 1 FreeSave up to 1/2 PriceHolland & BarrettVitabioticsSolgarWeledaNew NordicBioglanBetterYouNatures AidGrass & Co.Nature's WayDairy FreeGluten FreeSesame Seed FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeFish FreeKiwi FreeLupin FreeNew inFood & DrinkFood & Drink HubFood & Drink Shop AllVegan FoodHoney, Jams & SpreadsShop all Honey, Jams & SpreadsManuka HoneyHoneyJams & ChutneysNut ButtersSpreadsPateTeas, Coffee & Hot BeveragesShop all Teas, Coffee & Hot BeveragesCoffee & Coffee SubstitutesMushroom DrinksTeasSuperfood TeasMatcha & Green TeaSleep & Relaxation TeaDried Fruit, Nuts & SeedsShop all Dried Fruit, Nuts & SeedsNutsDried FruitSeedsMixesSuperfoodsShop all SuperfoodsSuperfood PowdersMaca PowderGoji BerriesBaobabMoringa PowderFlaxseedSpirulinaChia SeedsSnacksShop all SnacksProtein BarsLow Calorie SnacksChocolate, Cakes & BiscuitsSavoury SnacksSweet SnacksSnack BarsCrisps & ChipsFlapjacksPopcornFood CupboardShop all Food CupboardHoney, Jams & SpreadsBreakfast CerealsSuperfoodsApple Cider VinegarCondiments & SaucesTinned FoodsRice, Pasta, Pulses & GrainsBreakfast CerealsShop all Breakfast CerealsCereals, Bran & FlakesGranolaMuesliOats & PorridgeBreakfast BarsDrinks & JuicesShop all Drinks & JuicesKombuchaNatural Energy DrinksJuicesSoft DrinksWaterAlcohol Free DrinksCookingShop all CookingCooking IngredientsApple Cider VinegarCondiments & SaucesSoya & Meat AlternativeSoup & Ready MealsRice, Pasta, Pulses & GrainsHerbs, Spices & SeasoningGravy & StockHome BakingShop all Home BakingBaking MixesBreadFlourSweeteners & Sugar AlternativesEgg SubstitutesDairy AlternativesShop all Dairy AlternativesOat, Rice & Hemp DrinksSoya DrinksNut DrinksCoconut DrinksNutritionally Complete FoodBuy one get one 1/2 priceSave up to 1/2 Price25% off Online Only OfferHolland & BarrettNaturyaHeath & HeatherPukkaGrenadeMeridianTwiningsBionaNakdHuelGluten FreeDairy FreeEgg FreeWheat FreeMilk FreeMustard FreeCelery FreeFish FreeSulphites FreeCrustaceans FreeNew inSports NutritionSports Nutrition HubSports Nutrition Shop AllProteinShop all ProteinClear ProteinWhey ProteinMass GainersVegan ProteinDiet ProteinCaseinSports SupplementsShop all Sports SupplementsTestosteroneSports CollagenBars, Drinks & SnacksShop all Bars, Drinks & SnacksEnergy BarsEnergy DrinksProtein BarsProtein ShakesProtein SnacksNutritionally Complete FoodMeal Replacement ShakesPre Workout & EnergyShop all Pre Workout & EnergyPre WorkoutAmino Energy DrinksAmino Energy PowdersIntra WorkoutKetoPost WorkoutAmino AcidsShop all Amino AcidsAmino Energy PowdersAmino Energy DrinksBCAAL-LysineGlutamineCarnitineArginineCreatineShop all CreatineCreatine PowderCreatine CapsulesRehydrationShop all RehydrationElectrolytesEnergy GelsVegan Sports NutritionShop all Vegan Sports NutritionVegan ProteinVegan Protein BarsVegan Pre Workout & EnergyVegan Amino AcidsVegan CreatineSports AccessoriesShop all Sports AccessoriesBottles & ShakersFitness EquipmentFitness GoalShop all Fitness GoalRecoveryMuscle & StrengthLean MuscleEnergy & EnduranceDiet & Weight LossSave up to 1/2 PriceBuy one get one 1/2 price2 for £50Optimum NutritionPE NutritionUSNApplied NutritionGrenadePhDSiSFoodspringHuelYfoodDairy FreeGluten FreeSugar FreeSoya FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeFish FreeKiwi FreeNew inBeautyBeauty HubNatural Beauty Shop AllAromatherapy & HomeShop all Aromatherapy & HomePure Essential OilsBlended Essential OilsBase & Carrier OilsHolisticSkincareShop all SkincarePremium SkincareFace CareBody CareSun CareTanning & BronzingEye CareLip CareFoot CareHand & Nail CareSkin AilmentsSkin OilsCBD BeautyHair Skin & NailsWashing & BathingShop all Washing & BathingShampoo & ConditionerBathing AccessoriesShower Gel & Body WashDeodorantDentalHand WashSoapBath Soak & OilBody ScrubBath Bombs & SaltsFeminine CareIncontinence SupportHair CareShop all Hair CareShampoo & ConditionerHair ColouringHair MasksHair Oil & SerumHair Spray, Gel & MousseHair AccessoriesMother & BabyShop all Mother & BabyBaby Skincare & ToiletriesElectrical WellnessSexual WellnessSave up to 1/2 PriceBuy 1 Get 1 FreeBuy one get one 1/2 priceDr OrganicFaith in NatureWeledaNaturtintTisserandSukinMiaromaQ+AEthiqueSo EcoAlcohol FreeParfum FreeParaben FreeSLS FreePalm Oil FreeGluten FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeNew inCBDWeight ManagementWeight Management HubWeight Management Shop AllFat Burners, Binders & Appetite SuppressantsShop all Fat Burners, Binders & Appetite SuppressantsFat BurnersFat BindersAppetite SuppressantsSlimming TabletsShakes & Weight Management ShotsShop all Shakes & Weight Management ShotsMeal Replacement ShakesDiet ProteinDiet Food & DrinkShop all Diet Food & DrinkDiet FoodLow Calorie SnacksSlimming TeaExercise SupportShop all Exercise SupportFitness EquipmentMeal Replacement ShakesDiet ProteinProtein BarsSave up to 1/2 PriceBuy one get one 1/2 price2 for £50Optimum NutritionGrenadeHolland & BarrettUSNPhDPulsinEat WaterNatures AidNew NordicSlimExpertDairy FreeSugar FreeGluten FreeWheat FreeNew inVeganHealth & WellnessShop all Health & WellnessJoints Bones & MusclesGut HealthHair Skin & NailsStress AnxietySleep & RelaxationBuy one get one 1/2 priceBuy 1 Get 1 FreeSave up to 1/2 PriceHolland & BarrettWeledaVitabioticsDr OrganicSolgarNaturtintOptimum NutritionNew NordicHeath & HeatherBioglanDairy FreeGluten FreeParaben FreeSLS FreeAlcohol FreeParfum FreeSugar FreeWheat FreeSoya FreeEgg FreeNew inShop for your WellnessWomen's HealthMenstrual HealthMenopauseJoints, Bones & MusclesGut HealthHair, Skin & NailsImmunitySleep & RelaxationFood & DietChildren's HealthStress ReliefHealthy HeartEnergyLow Mood & DepressionConcentration & AlertnessEye HealthSexual HealthLearn about WellnessWomen's HealthPeriods & Cycle HealthMenopauseJoints, Bones & MusclesImmunityGut HealthFood & DietSports & FitnessSleep & RelaxationHair Skin & NailsAll articlesHealthFood & nutritionGut healthImmunityJoints, bones & musclesWomen's healthWellnessHair & skinMental wellbeingSeasonalSleep & relaxationSports nutritionRecipesAll recipesGluten freeLow sugarVeganDairy freePodcast

The circadian rhythm – everything you need to know

Your circadian rhythm is your internal body clock. How much do you know about yours and could it help you get a better night’s sleep?

Are you a natural ‘morning person’, or do you love a lie-in? Do you thrive on six hours’ sleep, or are you a nine-hours-a-night type?

Have you noticed this changing over the years, or have you had a similar sleep pattern for as long as you can remember?

The answers may lie in more than just your lifestyle habits. Meet your circadian rhythm.

What is the circadian rhythm?

Humans, like all living things, have a circadian rhythm. The circadian rhythm is the brain’s way of aligning the body with the environment.

It’s a set of physiological changes over a 24-hour-or-so period of time that is set by your internal body clock (we have a big one in our brains and mini ones in every cell of our bodies).

They tend to run no matter what, but our environment does have an influence on them -  most specifically light is very influential. This is why we sleep when it’s dark and we are awake when it's light.

Our sleep/wake cycle follows this circadian rhythm, as does our mood-regulating hormones, our appetite-regulating hormones, and our temperature.

Our ancestors once lived by their circadian rhythm – getting up with the sun and going to sleep when darkness fell.

In modern times, however, electric lighting, technology, alarms and commuting times mean that many of us are keeping hours which might be at odds with our natural body clocks.

What controls the circadian rhythm?

Your circadian rhythm is controlled by a small area within the section at the base of your brain called the hypothalamus.1

The hypothalamus instructs the body to release certain chemicals and hormones during each 24-hour period. The timing of these releases is in-built into our body clocks - but they’re also partly influenced by external factors.

These external factors include whether it’s light or dark. The hypothalamus receives signals from the eyes when it’s dark, causing it to release melatonin – the sleep hormone – which makes you feel tired.

Light stimulates the production of cortisol – which wakes your body up and energises you for the day ahead.2

Why is the circadian rhythm important?

The circadian rhythm sets the pace for the body’s rest and repair.

Deep sleep is vital for cell regeneration. So, whenever you’re catching good quality sleep, your body is using that time to restore itself.3

Your immune system, cardiovascular system and muscles are all areas which undergo this restorative process as you sleep.

How do circadian rhythms differ?

Just like people, no two circadian rhythms are exactly the same. Circadian rhythms can also change throughout our lives.

  • After birth, babies typically take a little time to adjust to the light/ dark circadian rhythm. At first, babies sleep between 12 – 16 hours of sleep in a 24-hour period, including naps. This reflects the huge amount of growth that is occurring in their bodies. Young children up to age five are beginning to synchronise with the light/ dark circadian rhythm, and should get between 10 – 14 hours, including naps.
  • Teenagers need around between 8 – 10 hours of sleep.4 Teens have a developing circadian system, so they can find early starts challenging. (This isn’t just a myth!).5
  • Adults over 60 can find themselves tired earlier in the evening than when they were younger. Older adults also wake up more during the night and tend to wake up early in the morning.6

What can disrupt the circadian rhythm?

A major factor which disrupts the circadian rhythm is unnatural light and the timing of our activities.

This could be electric lights in the house, a streetlight outside your bedroom window, or the glare of a TV, mobile phone or other electronic device.

The blue light which comes from electronic devices can suppress melatonin production, which can stop you feeling tired and making it more difficult to drop off to sleep at night.7 

Shift work is another significant disruptor of the circadian rhythm. Irregular work schedules which include night shifts (such as those undertaken by healthcare workers) can lead to insomnia and/or excessive sleepiness.

This phenomenon has even been called shift work disorder (SWD) by scientists.8

How can I improve my circadian rhythm?

The best thing you can do for your circadian rhythm is to give it routine and predictability.

It's common for many people to believe that their early or late preferences are genetically set in stone.

This is true to a degree, but more often it is our behaviours that ‘set’ our preferences. We have more control than we think!

  1. Get up at the same time every day

See waking up as a type of reset button.

If you hit it at different times each day, your body cannot regulate itself.

You can find yourself feeling groggy in the mornings when you want to feel awake, feeling low energy when you want to exercise, and having not much control over your mood or your appetite.

By contrast, do not force yourself to go to bed at the same time each day.

Every day is different and you cannot possibly control all the variables that affect how sleepy you feel.

But by waking at the same time every day you are controlling the amount of sleepiness you will have built up by the end of the day (sleep is a drive state; the longer you are awake the greater the need to sleep!).

By going to bed when you are sleepy tired, and waking up at the same time no matter what, you will start to notice that your body starts to make you sleepy around the same time each night anyway.

Dictating it whilst still lying in, snoozing etc, will only lead to anxiety and ‘wired but tired’ minds when the sleepiness does not come.

  1. Exercise during the day

Physical activity can help improve sleep quality, helping you feel less drowsy in the day and drop off easier at night.9 

Also, the natural daylight you get by being outside helps synchronise your circadian rhythm to the light/ dark pattern.

If you can exercise first thing as part of a morning routine with a consistent wake time and plenty of light, you are really setting your body up as best as you can for the day and night ahead.

You should notice from this consistent behaviour that your mood improves, your appetite is regulated and predictable and your sleep quality is improved.

  1. No phones in the bedroom! 

Or any tech or daytime activities for that matter. The bed is for sleeping.

Encouraging your brain to do daytime activities in the night will make it think you don’t want to sleep, and it will try to make you more awake so you can perform that activity better.

Also, the light levels of these activities are not helpful - especially if you have spent the evening in low levels of light, and then expose yourself to something much brighter and more concentrated in bed. 

Not only are you delaying your sleep onset, but you are potentially going to disrupt the quality of your sleep to come by not allowing your brain to switch off.

  1. Do you often find yourself working late?

Firstly, if you choose to do this and don’t have a natural separation between work and sleep where you can wind down, eat well and process your day, you will always be compromising on your sleep.

By consistently working late you will notice your behaviour shift your sleeping pattern to a later time period anyway.

There are blue light blocking technologies out there, but make sure to give yourself time to wind down too. Stimulating your brain with daytime activities is just as influential on your nighttime sleep as the light can be.

How to develop healthy habits with Madeleine Shaw

How to develop healthy habits with Madeleine Shaw

In this episode, we explore Madeleine's morning and evening routines, her favourite healthy snack ideas for on the go, how to meditate and why it provides so many people with comfort, plus tips on instilling healthy habits in the generation to come. 

Last updated: 9 June 2022

Related Articles

  • Visa
  • MasterCard
  • PayPal
  • AmericanExpress
  • ApplePay
  • ClearPay
  • AliPay
  • Instagram
  • Pinterest
  • Facebook
  • Twitter
Copyright © Holland & Barrett Retail Limited, 2024. All rights reserved. hollandandbarrett.com is a trading name of Holland & Barrett Retail Limited,. Registered office: Samuel Ryder House, Barling Way, Nuneaton, Warwickshire CV10 7RH. Registered in England: company no. 2758955. Registered VAT no. 211727395.