In my 20s, sleep was my last priority; not only was I uninterested in it, but I honestly didn’t seem to need that much of it. Despite working seven days a week, I still had the energy to stay out most nights until well past midnight and wake up early to hit the gym before heading into the office. Sure, I woke up with makeup smeared all over my pillow and relied on coffee so heavily it was essentially my signature accessory, but somehow, I lived that way for the better part of a decade.

I look back now on these late nights and think, How? Now, despite being in bed most nights before 11 p.m., trying to squeeze a gym sesh in before work is a rarity; virtually every time my alarm goes off, that extra hour of sleep wins out. It’s not just a me thing, either: Now, when I text my friends to see if they want to meet up after work on Friday, the response I’m usually met with is, “Sure, but can it be around 6?” And the women I know who are older and going through perimenopause and menopause often complain about being tired all the time.

This raised all sorts of questions about the causes of low energy in women as they get older, so I turned to some experts to find out if energy depletion is inevitable with age. It turns out that feeling more tired as you get older isn’t inevitable—but there are some factors that can make it more likely.

According to women’s health physician and The Adrenal Thyroid Revolution author, Aviva Romm, MD, physiologically, there’s no reason why it should be harder to get up in the morning at 45 or 55 than it is at 25. When people feel more tired as they age, it generally has more to do with their habits and health—not their age alone. “Often, people do feel more tired as they get older, but it’s because they’re not getting enough sleep, eating right, or exercising regularly, not because they’re older,” she says. In other words, the culprit comes down to lifestyle, not age. The lifestyle reasons you might feel more tired are long and varied; everything from having kids to a more demanding job could impact your day-to-day energy levels.

It’s also important to note that there is a slight difference between tiredness and fatigue, and sleepiness. While tiredness and fatigue are interchangeable, they’re different from being sleepy, says sleep psychologist Jade Wu, PhD, author of Hello Sleep and sleep advisor for Mattress Firm. If you’re sleepy it means you’re able to fall asleep soon, while being tired or fatigued just refers to feeling worn out or out of energy.

Factors that can contribute to low energy in women

Not getting enough sleep

There’s no scientific evidence that your sleep needs change between your twenties and thirties. “The amount of sleep we need really doesn’t change until we’re over 65,” Dr. Romm says. She explains that adults need between seven and nine hours of sleep a night (it varies a little depending on the person), but older adults actually feel rested with a bit less¹—typically seven to eight hours. In fact, you likely needed more sleep in your twenties than in your thirties. “People in very early adulthood still have growing brains and possibly bodies, and often have higher physical activity levels and faster metabolism, all of which requires more sleep,” says Dr. Wu.

Even if you don’t necessarily need more sleep as you age, regularly slacking on getting enough is a habit that can make you more tired as you get older. Chronic sleep deprivation impedes the body’s ability to release growth hormones that help it repair itself during the night, says Dr. Wu. Remember that getting high quality sleep, meaning enough undisturbed sleep each night, is key in any age group. (If you’re not able to get enough sleep during the week, though, it might help to try to catch up on sleep by sleeping in for one or two hours on weekends.)

Still, I pressed Dr. Romm on another front: what about when women hit perimenopause and menopause? Even then was there no physiological reason to feel more tired? “Some of the symptoms of perimenopause and menopause can disrupt sleep, such as hot flashes, so that can lead to women feeling more tired, because their sleep is interrupted,” she says. Once again, the culprit was actually disrupted sleep, not age.

Not getting enough exercise

Lack of exercise can make you feel more tired, and it’s something Dr. Romm says she notices regularly in her patients in their thirties and forties because of life demands getting in the way. “Exercising regularly gives you more energy because the more muscle you maintain, the more mitochondria you produce², and the mitochondria affects how much energy you have,” she explains. “Exercising also helps with oxygen flow, getting more oxygen to your brain, which also helps with energy levels.”

A diet that doesn’t work for you

There isn’t one system of eating that works best for every person, but there are certain foods that may contribute to lower energy levels if they make up the majority of your diet. Because of their nutritional makeup and how the body absorbs and digests them, certain foods such as sugary treats and processed grains can cause your energy levels to crater after eating them over the course of the day.

“Everybody has the capacity to have a decent sense of what is their best diet, there are probably hundreds of diets and cultural ways of eating that are really good,” says Mikhail Kogan, MD, geriatrician and Medical Director of GW Center for Integrative Medicine. Even if what you eat is mostly nutritious, it could just be that your diet isn’t the right one for you; for example, he says some people might tolerate eating more carbs while someone else feels very tired if they eat even some carbs.

Surprising reasons for low energy in women

Menstrual periods

Lifestyle factors aside, Dr. Romm says there are a few factors affecting energy levels people may not be aware of. For women, she says it’s 100-percent normal to feel an energy drop in the days before getting your period, and in the first few days you have it. “This is a big recurring factor for why women can feel tired,” she says. “Some women especially have really heavy periods, which can lead to very low levels of iron and that’s definitely going to lead to feeling more tired.”

Stress

Stress has major effects on all aspects of your mental and physical health, and energy is no exception. It disrupts sleep, particularly the necessary and restorative REM variety; prolonged or chronic stress can lead to fatigue, which can majorly disrupt sleep and impact your energy levels. Fatigue and stress have a cyclical relationship, where they both feed each other and each makes the other’s effects more pronounced.

Dr. Romm adds that there are some societal factors that can disproportionately affect the energy levels of those who identify as women. “Researchers have studied this, and the emotional work of being a woman is greater than it is for a man,” she says. Carrying this load can be exhausting both mentally and physically. “For example, in a work meeting, women [often] exert energy managing others’ emotions, something the men in the room aren’t likely doing.” She also points out that in heterosexual couples, many women who work outside the home still take on the majority of the responsibilities when it comes to parenting and managing the household, which can, of course, be exhausting. If you hold several marginalized identities, the stress can be even greater. But again, these factors aren’t technically tied to the aging process.

Besides the psychological factors that can lead to fatigue, Dr. Romm says there’s a wide range of physiological reasons for fatigue, too. Experiencing digestive problems, being low in certain vitamins and nutrients (especially iron and protein), and hormonal imbalances can all lead to energy depletion, she says. If you think a physical reason is the culprit, Dr. Romm recommends working with an MD to get to the bottom of it, so they can run tests to see if you are low in any critical nutrients.

What to do about low energy levels and when to see a doctor

If you find yourself feeling more exhausted than you used to, the reason isn’t just because you’re a few years older. Adjusting some lifestyle habits, like prioritizing sleep and nutrition, can be helpful, but there may come a point when at home fixes or habit changes aren’t enough to get your energy back. “If you’ve tried all this and nothing is changing, you should see someone,” adds Dr. Kogan.

There are so many possible causes of low energy and fatigue that finding the exact culprit may be time consuming because it requires a process of elimination. According to Dr. Kogan “you can’t take any case of fatigue at face value because you have to investigate all of [the symptoms], and ask specific questions and do work ups.” He recommends starting by adjusting your sleep, movement, and eating habits and taking note of what happens.

If you find that your lack of energy is impeding your ability to live your life—for example, if you’re not able to socialize, parent, or work without feeling exhausted—Dr. Wu says it’s a sign to contact your physician for help. It’s worth it to work with a physician who can run tests to rule out medical issues, like thyroid issues, and to advise on other lifestyle changes you might make. If you need further help, Dr. Kogan particularly recommends working with a doctor or team that specializes in whole system care, which pulls in treatments and healing methods from a variety of medical and holistic disciplines.

If you find that your fatigue doesn’t improve with rest and that nothing seems to be helping, it’s worth talking with your doctor about myalgic encephalomyelitis, or chronic fatigue syndrome (ME/CFS). According to the Centers for Disease Control and Prevention, people who have this complex, serious condition may be confined to their beds for a period of time, and “are often not able to do their usual activities…ME/CFS may get worse after any activity, whether it’s physical or mental.” Diagnosing ME/CFS involves a combination of looking at a patient’s medical history, running tests, and examining lifestyle habits; managing this condition shouldn’t be done on your own.

Dr. Kogan recommends not waiting too long before speaking to a doctor about any energy issues. “I say you go [see a doctor] at the point where you’ve tried some of these basic methods and they haven’t worked because the reality is you either haven’t done enough of those things and you need professional guidance or there’s something else going on that’s a bigger problem and in both cases you will need professional help.” If you’re in your twenties or thirties and having issues with your energy levels, he highly recommends seeking help sooner rather than later because “anything that becomes chronic gets a lot harder to fix,” he says.

FAQs about low energy in women

What are some signs of low energy in women?

According to Dr. Wu and Dr. Kogan, there are plenty of signs of low energy to look out for. If you’re experiencing any of these, you might have low energy:

• Feeling stressed or burnout
• Hormone issues
• Medication side effects
• Boredom or not being mentally stimulated
• Being overstimulated
• Eating foods that don’t give you energy
• Dehydration
• Loneliness
• Physical or mental health conditions, such as depression or anxiety

What lack of hormones causes tiredness?

Remember that there are a host of reasons for feeling low energy, and that hormonal imbalances are only one reason. However, Dr. Wu says hypothyroidism, which is a disruption of thyroid-stimulating hormone, TSH, is often associated with fatigue. “Changes in progesterone levels, either rapid increases or decreases, can also be associated with fatigue,” she adds. If you have consistently low energy, it might be worth chatting with your physician to be tested for this condition.

How can I increase my energy levels?

If you need a temporary energy boost, you can turn to an energy drink, have a little coffee pick-me-up, or try out some herbal teas for energy. Remember that caffeine has an adverse effect on your (all-important) sleep, so limit your caffeine intake to earlier in the day. You might also try eating fatigue-fighting foods, such as whole grains, leafy greens and walnuts—these foods contain vitamins and minerals that can help you feel more energized.

Naps can’t make up for not getting enough sleep in the long term, but they can provide a helpful boost to your energy level. As for the ideal nap length? Aim for 20 or 30 minutes, which is enough time to reap the restorative benefits of rejuvenating slow-wave sleep without progressing into all the sleep cycles and tossing off your nighttime sleep schedule. Just be sure to limit napping to the early afternoon so as not to interfere with your nighttime shut-eye.

Need more strategies for coping with tiredness? Grab a jump rope or do some jumping jacks. Getting in a quick HIIT workout can help boost blood flow and clear away brain fog, giving you a welcome hit of energy. Dr. Wu also recommends making sure your day-to-day is full of activities that are good for your body and mind, such as: going outside and getting exposure to sunlight; socializing; doing meaningful and fun activities; eating nutritious foods; working in movement in your day; reducing stress; and mindfully breathing for energy.

Check out this video for tips on what to eat before and during your period to help get your energy levels back up: