How Do I Get More Energy and Stop Feeling Tired

Persistent tiredness almost never has a single cause, and “just sleep more” rarely fixes it. For most people, low energy is the combined result of several overlapping factors: how well you sleep (not just how long), how much daylight your eyes get, how often you move, what and when you eat, and how you manage stress. Addressing even two or three of these usually produces a noticeable difference. Sometimes, though, fatigue is a signal that something medical is going on, from iron depletion to an underactive thyroid, and no amount of lifestyle tuning will help until that root cause is treated.

Your Morning Light Habit Matters More Than You Think

One of the fastest levers you can pull is getting bright light into your eyes within the first hour of waking. Light does two things at once: it helps shake off the grogginess that follows sleep (called sleep inertia), and it anchors your circadian clock so you feel alert during the day and sleepy at the right time later. A study testing a light source used upon waking found that participants rated themselves significantly more alert and energetic under the light condition compared to a dim control condition, regardless of what sleep stage they woke from.¹ Morning light also appears to sharpen the natural cortisol rise that is supposed to accompany waking. Research on dawn simulation found that simulated dawn light led to significantly higher cortisol production during the first 45 minutes after waking and greater self-reported arousal compared to waking in darkness.²

If you live somewhere cloudy or wake before sunrise, a bright artificial light (sometimes marketed as a “light therapy lamp” or “SAD lamp”) placed at eye level during breakfast can serve a similar function. The key is brightness and timing: dim indoor lighting does far less for your clock than even a few minutes of real outdoor light.

Cut the Blue Light at Night

The flip side of seeking light in the morning is limiting it in the evening. Your circadian system is especially sensitive to short-wavelength light, the blue-enriched kind emitted by phone screens, tablets, and LED monitors. Evening exposure to these devices can suppress and delay melatonin secretion, decrease sleepiness, prolong the time it takes to fall asleep, and worsen sleep quality.³ You do not necessarily have to abandon screens altogether. Blue-blocking glasses have been shown to significantly reduce LED-induced melatonin suppression in the evening and to lower alertness before bedtime, at least in younger users.⁴ Dimming screens, using a warm-tone night mode, or simply switching to a book or podcast in the last hour before bed can all move the needle.

Move a Little, More Often

You do not need a gym session to fight fatigue. Some of the best evidence points to brief, frequent movement breaks throughout the day, especially if you spend long hours sitting. A pilot study comparing a day of uninterrupted sitting to one interrupted by light walking breaks found that fatigue levels were significantly lower at both the four-hour and seven-hour marks in the active condition.⁵ That was light walking, not vigorous exercise. Even shorter micro-exercise breaks, done once an hour at a desk, have been linked to meaningfully higher self-reported energy and productivity.⁶ A separate trial on active breaks in office workers found that post-lunch sleepiness dropped from about 30% to 17% after introducing the intervention, alongside significant reductions in perceived stress.⁷

Longer-term, regular exercise also changes the cellular machinery that produces your energy. Exercise triggers the creation of new mitochondria in muscle cells and improves how efficiently existing ones work, which has direct consequences not just for physical performance but for whole-body well-being.⁸ The paradox of exercise and fatigue is real: spending energy on movement actually creates more available energy over time.

Drink More Water Than You Think You Need

Dehydration drains energy in a way that is easy to miss because you may not feel particularly thirsty. Even mild water loss, in the range of one to two percent of body weight, can impair cognitive performance.⁹ For an average adult, that is roughly the water lost from a few hours of desk work in a warm office without drinking. A controlled trial in college-aged men measured the effects directly: dehydrated participants had significantly lower vigor scores and worse short-term memory, while rehydration brought significant improvements in fatigue, mood, memory, and attention.¹⁰

The practical upshot: keep water accessible and sip throughout the day. If you rely on thirst as your cue, you are probably already mildly dehydrated by the time you notice. Coffee and tea count toward fluid intake but carry their own timing considerations, covered below.

What You Eat and When You Eat It

The classic afternoon energy crash after a large meal is not just in your head. When your body processes a big hit of rapidly absorbed carbohydrates, insulin spikes, blood sugar drops, and drowsiness follows. In people with undiagnosed insulin resistance, this pattern can be extreme enough to qualify as a medical complaint. Case reports have documented excessive post-meal sleepiness severe enough to interfere with daily life, which resolved after insulin resistance was identified through glucose-tolerance testing and treated with standard diabetes medications.¹¹ Most people will not need medication, but the lesson stands: meals that combine protein, fat, and fiber slow glucose absorption and tend to produce steadier energy through the afternoon compared to refined carbohydrates eaten alone.

Your gut bacteria also play a role in how your body handles the food you eat. Research using genetic analysis to tease apart cause and effect found that higher gut production of the short-chain fatty acid butyrate was causally associated with improved insulin response, while abnormalities in another short-chain fatty acid, propionate, were linked to increased diabetes risk.¹² Butyrate-producing bacteria thrive on fiber from vegetables, legumes, and whole grains, which is one more reason those foods tend to leave you feeling more stable than processed alternatives.

Iron Deficiency Without Anemia

One of the most commonly overlooked causes of fatigue, especially in menstruating women, is low iron stores that have not yet progressed to full-blown anemia. Your blood count looks normal, so doctors may not flag it, but your ferritin (a marker of stored iron) is low, and you feel exhausted. A randomized controlled trial enrolled 198 women aged 18 to 53 who had fatigue and ferritin below 50 µg/L but normal hemoglobin and gave half of them iron supplements for 12 weeks.¹³ The iron group showed meaningful improvement in fatigue compared to placebo. If you are a menstruating woman with persistent tiredness and no clear explanation, asking your doctor to check ferritin specifically (not just a standard blood count) is a worthwhile step.

How to Use Caffeine Without Making Things Worse

Caffeine works by blocking adenosine receptors in the brain. Adenosine is a molecule that builds up during waking hours and gradually makes you feel sleepy; caffeine fits into the same receptors without activating them, so the sleepiness signal gets muffled.¹⁴ The problem is that blocking the signal does not erase the underlying adenosine. Once the caffeine wears off, all that accumulated adenosine hits at once, which is the “caffeine crash.”

Timing matters more than amount. Caffeine’s half-life in most adults is roughly five to six hours, meaning that a coffee at 3 p.m. still has half its punch at 8 or 9 p.m. Even if you fall asleep fine, that residual caffeine can fragment your deeper sleep stages, leaving you more tired the next morning and reaching for more caffeine, a cycle that feeds itself. The research on caffeine’s ergogenic and alerting effects increasingly emphasizes that time of day modulates how well it works.¹⁵ A reasonable rule is to keep caffeine to the first half of your waking day and treat it as a tool rather than a crutch.

One counterintuitive finding from the sleep-inertia literature: caffeine administered before a short nap (a “nap-a-latte” or “coffee nap”) can be among the most effective ways to combat grogginess upon waking, because the caffeine kicks in right as you come out of sleep. A structured review of countermeasures to sleep inertia found that caffeine was the strongest option available, though it works best when given before sleep rather than after.¹⁶

Naps and Non-Sleep Deep Rest

A well-timed nap can genuinely restore energy, but duration and timing are everything. Naps of around 30 to 60 minutes, taken in the early afternoon when circadian drive for sleep naturally dips, appear to boost alertness, strengthen memory, and support emotional resilience without the heavy grogginess that comes from longer sleep bouts.¹⁷ Napping too late in the day or for too long can interfere with nighttime sleep and make the overall problem worse.

For people who cannot nap at work or struggle to fall asleep during the day, non-sleep deep rest (NSDR), a guided relaxation protocol that does not require actual sleep, has shown promising results. A study in physically active young adults found that a single NSDR session produced significant reductions in sleepiness, fatigue, and stress, along with improved mental performance capacity and overall recovery compared to a passive control condition.¹⁸ Separate research confirmed that NSDR was associated with benefits to physical readiness, emotional balance, and overall stress reduction.¹⁹ NSDR sessions are freely available online and typically run 10 to 20 minutes, making them a practical option for a lunch break or a mid-afternoon slump.

When Stress Itself Becomes the Energy Drain

Short bursts of stress can actually boost alertness, but chronic stress changes the game. Prolonged psychological stress, poor sleep, and dietary imbalances can dysregulate the body’s main stress-response system, the hypothalamic-pituitary-adrenal (HPA) axis, which governs cortisol and related hormones.²⁰ The result is not always what you would expect. Rather than staying in a permanently revved-up state, people who reach full burnout often show a blunted cortisol response: their stress system becomes under-reactive rather than over-reactive. Research on burnout patients found reduced cortisol reactivity to an acute stressor alongside an overactive sympathetic (“fight or flight”) nervous system, a combination that favors immune dysfunction and cardiovascular risk.²¹

This is the kind of fatigue that no amount of coffee or sleep hygiene can fully address. If you recognize yourself in it, the intervention is upstream: reduce the source of chronic stress, or build in genuine recovery practices (not just “relaxation” scrolling on your phone, but activities that actually downshift the nervous system, like the NSDR protocols described earlier, extended time in nature, or structured decompression).

Medical Causes Worth Ruling Out

If you have tried optimizing the lifestyle factors above and still feel drained, it is worth getting checked for a few common medical conditions that present primarily as fatigue.

Sleep apnea: You can have sleep apnea without knowing it, especially if you sleep alone and nobody hears you snore. The condition causes repeated partial arousals throughout the night, and the resulting chronic intermittent oxygen drops and sleep fragmentation lead to oxidative injury in the brain’s wake-promoting regions.²² Even mild apnea can leave you feeling inexplicably tired despite spending eight or nine hours in bed. Treatment with a CPAP device has been shown to improve objective daytime sleepiness, with the degree of improvement linked to the severity of nighttime arousals.²³
Thyroid problems: An underactive thyroid (hypothyroidism) is a classic cause of fatigue, and it can exist in a mild “subclinical” form that standard screening sometimes misses. A JAMA review noted that middle-aged patients with subclinical hypothyroidism may experience cognitive impairment, fatigue, and altered mood.²⁴ When overt hypothyroidism is treated with thyroid hormone replacement, fatigue severity tracks with thyroid hormone levels: higher TSH (indicating the thyroid is not keeping up) correlates with worse fatigue, and this relationship persists even after treatment begins.²⁵
Iron deficiency: Already discussed above, but worth reiterating here alongside the other medical causes. Low ferritin with normal hemoglobin is easy to miss on routine bloodwork.
Diabetes and pre-diabetes: Insulin resistance can produce profound post-meal fatigue long before blood sugar is high enough for a diabetes diagnosis. If afternoon crashes are a persistent feature of your life, a glucose tolerance test can reveal patterns that a fasting blood sugar might not.

This is not an exhaustive list. Depression, vitamin B12 deficiency, chronic infections, autoimmune conditions, and medications (especially antihistamines, blood pressure drugs, and some antidepressants) can all cause fatigue. But the four above are common, frequently underdiagnosed, and treatable once identified.

The Mental Side of Tiredness

Not all fatigue originates in the body. Extended periods of demanding cognitive work produce a form of mental fatigue that feels physically draining even when you have not moved from your chair. Research on this phenomenon suggests that sustained mental effort increases the accumulation of adenosine in the brain, the same molecule that caffeine blocks, which then heightens the perception of effort required for any subsequent task.²⁶ In other words, a mentally exhausting day at work can make a run or a gym session feel harder than it should, not because your muscles are tired but because your brain has already spent its adenosine budget.

This is useful to understand because it reframes some of the advice above. Movement breaks during the workday are not just fighting sitting-related fatigue. They are interrupting the accumulation of cognitive load. A five-minute walk after a 90-minute focus block is not wasted time; it is clearing some of the mental fog before it builds to the point where the whole afternoon is a slog. Similarly, NSDR and even brief naps appear to reset subjective fatigue in ways that suggest they are partly draining that adenosine backlog. If you routinely finish your workday feeling like you ran a marathon, the fix is probably not more sleep the night before. It is more breaks and genuine rest periods during the day itself.

Why Fatigue Feels Like It Protects Itself

One frustrating feature of chronic tiredness is that it resists your attempts to fix it. You know you should exercise, but you are too tired. You know you should cook a proper dinner, but takeout requires less energy. You know you should go to bed earlier, but scrolling is the only “me time” you have left. This is not weakness. From an evolutionary standpoint, fatigue appears to function as a conserved signal designed to reduce activity and protect your body’s homeostasis when resources are low or physiological stress is high.²⁷ Your brain is doing exactly what it evolved to do: pulling you toward inactivity when it judges your system to be overtaxed.

Knowing this does not make the problem disappear, but it can shift how you approach it. Instead of trying to override the fatigue signal with willpower (which eventually fails), work with it. Make the energy-positive behaviors as easy as possible. Fill a water bottle the night before. Put walking shoes by the door. Use a light alarm that turns on automatically. Prep meals on the weekend so you do not have to decide anything on a Tuesday night. Each small reduction in friction means one less moment where your brain’s built-in conservation program can talk you out of the thing that would actually help.