9 reasons you’re always tired

Written by Martin Ebner
Updated Sept 2026

Feeling tired after a late night, a difficult week or an unusually hard training block isn’t mysterious. You’ve asked more of yourself than usual and your energy has taken the hit.

Feeling tired most days, even when life looks fairly normal, is different. It may still come down to sleep, food, stress or training, but persistent fatigue can also have a medical cause. If it’s been going on for several weeks, is getting worse or is interfering with ordinary life, speak to your GP rather than trying to diagnose yourself from a list on the internet. The NHS guidance on tiredness and fatigue is a useful starting point.

That said, there are some common patterns worth checking. Here are nine places I’d look.

1. YOU’RE NOT SLEEPING ENOUGH

Obvious, yes. Properly addressed, surprisingly often not.

Many people judge their sleep by the time they get into bed, rather than the time they actually spend asleep. An eight-hour window can quickly become six and a half once you include scrolling, waking during the night and lying there thinking about something that could absolutely have waited until morning.

Don’t obsess over one imperfect night. Look at the pattern across a couple of weeks. If you regularly need an alarm, struggle to get going and sleep far longer whenever you get the chance, you may simply need more sleep than you’re allowing yourself.

If last night was the exception, my guide to feeling better after a bad night’s sleep covers how to manage the day sensibly and decide whether training still earns its place.

2. THE SLEEP YOU GET ISN’T RESTORATIVE

Time in bed and good sleep aren’t the same thing. You can spend eight hours under the duvet and still wake exhausted if your sleep is repeatedly interrupted.

Loud snoring, gasping or choking during sleep, morning headaches and heavy daytime sleepiness can be signs of sleep apnoea. Restless legs, pain, reflux, hot flushes and frequent trips to the bathroom can also keep breaking the night up. You may not remember waking, but your body still knows it happened.

If somebody regularly complains about your snoring, don’t dismiss them as an enemy of joy. The NHS sleep apnoea guidance explains the signs and when to speak to a GP.

3. STRESS IS USING MORE ENERGY THAN YOU REALISE

Stress doesn’t need to look dramatic. Sometimes it’s a major event. Sometimes it’s twenty small things sitting open in your head all day, none of them catastrophic and none of them ever quite finished.

That can make it harder to fall asleep, easier to wake during the night and more difficult to switch off even when you technically have time to rest. Low mood and anxiety can also show up as low energy, poor concentration and a loss of interest in things you’d normally enjoy.

Exercise, daylight, time with people you like and a more realistic diary may all help, but they’re not substitutes for proper support. If your mood has been low for weeks or you’re struggling to cope, speak to your GP or a qualified mental-health professional.

4. YOU’RE NOT EATING ENOUGH FOR THE LIFE YOU’RE LIVING

The original version of this article blamed large meals, sugar and fast-digesting carbohydrates. That was far too simplistic. Feeling sleepy after an enormous lunch is one thing, but cutting out rice and potatoes isn’t a serious answer to persistent fatigue.

What matters more is whether you’re eating enough overall, whether your meals contain useful amounts of protein and carbohydrate, and whether the pattern fits your day. Someone training hard, trying to lose weight quickly and surviving on coffee until mid-afternoon has created a fairly convincing explanation for feeling flat.

For active people, prolonged under-fuelling can affect health, recovery and performance. The IOC consensus on low energy availability makes it clear that this can affect men as well as women. Fatigue alongside declining performance, repeated injuries, frequent illness, menstrual changes or a loss of libido deserves proper attention, not another reduction in calories.

5. YOUR TRAINING IS OUTRUNNING YOUR RECOVERY

Exercise creates fatigue. The plan works when you recover from it and come back capable of doing a little more. If hard sessions keep piling up while sleep, food and life stress are moving in the opposite direction, the balance eventually stops making sense.

One tired day doesn’t mean you’re overtrained. A run of falling performance, persistent soreness, poor sleep, irritability and disappearing enthusiasm is more useful information. My guide to deciding whether you need a rest day explains how I separate ordinary reluctance from a genuine need to pull back.

You may need a day off, a lighter week or simply fewer hard sets. Recovery is part of the program, not an interruption to it.

6. YOU’RE NOT MOVING ENOUGH

This sounds unfair when you already feel tired, but doing very little can make you feel flatter rather than fresher. You don’t need to answer that with a brutal workout. A walk, a short strength session or twenty minutes outside is enough to change the direction of the day.

A systematic review of randomised trials found that regular exercise produced small to moderate improvements in fatigue, energy and vitality on average. That doesn’t mean exercise treats every cause of fatigue, and it certainly doesn’t mean you should train through illness. It means that when inactivity is part of the problem, sensible movement is usually more useful than waiting to feel energetic first.

Start below the level that wipes you out, then build. The goal is to create energy you can use, not spend everything in one heroic Monday session.

7. CAFFEINE IS BORROWING FROM TONIGHT

I love coffee. My family seems to regard it as a basic utility, and I once watched my uncle drink roughly twelve cups over a buffet breakfast. When I asked my aunt how he slept, she said, “He doesn’t.” Fair enough.

Caffeine can improve alertness, but it can also keep the cycle going. You sleep badly, drink more caffeine to function, then carry enough of it into the evening to interfere with the next night.

A systematic review and meta-analysis found that caffeine reduced total sleep time and sleep efficiency on average, although sensitivity varies enormously. There isn’t one perfect cut-off for everyone. If you’re tired every morning, however, moving your last coffee earlier is a cheap experiment.

8. ALCOHOL OR MEDICATION IS MAKING YOU DROWSY

Alcohol can make you sleepy without giving you especially restorative sleep. A few drinks in the evening may help you drop off, then leave the second half of the night more broken and the following day far less impressive.

Medication can matter too. Some antihistamines, sleeping tablets, anxiety medicines and other treatments can cause drowsiness, while other drugs make sleep more difficult. If the fatigue began after starting a medicine or changing the dose, speak to your pharmacist or doctor. Don’t stop prescribed medication on the strength of an article.

This is also worth checking with supplements. “Natural” doesn’t mean incapable of affecting sleep, alertness or another medicine you take.

9. SOMETHING MEDICAL NEEDS CHECKING

Persistent fatigue can be associated with iron-deficiency anaemia, thyroid problems, diabetes, infection, hormonal changes and several other conditions. The useful response isn’t to buy a drawer full of supplements and hope one of them wins. It’s to get the right assessment.

Speak to your GP if the tiredness has lasted several weeks, has no obvious explanation or is affecting your daily life. Make the appointment sooner if it comes with symptoms such as unexplained weight change, shortness of breath, palpitations, unusual thirst, frequent urination, fever, persistent low mood or heavy daytime sleepiness.

And if you’re struggling to stay awake while driving, don’t drive. That isn’t a motivation problem.

WHAT I’D DO THIS WEEK

Before changing everything, keep a simple note for seven days. Record when you go to bed, when you wake, roughly how often you wake during the night, your caffeine and alcohol, what you eat, how you train and when the fatigue feels worst. Also note any recent change in medication, work pressure or health.

You’re not trying to turn yourself into a research project. You’re looking for an obvious pattern. Four coffees after lunch, a six-hour sleep window and a hard calorie deficit don’t require a blood panel to become suspicious.

Fix the clearest issue first and give it enough time to matter. If there isn’t a clear issue, or the fatigue continues despite the obvious changes, take that information to your GP. A useful week of notes is far better than saying, “I’m tired all the time,” then trying to remember the previous month in the room.

TIREDNESS IS INFORMATION

Some tiredness is simply the bill for a busy life. Some is a sign that your routine needs adjusting, and some needs medical attention. The mistake is assuming every version has the same cause.

Start with sleep, food, stress, movement and recovery. Be honest about the pattern, but don’t turn fatigue into a character flaw. If your body keeps asking the same question, it’s worth giving it a proper answer.

If you enjoy fitness advice that remembers you have a job, a social life and absolutely no desire to optimise your bedtime like an Olympic final, Check It Oot is my newsletter. One or two emails a month, written by me, with the useful bits left in and the theatre taken out.