There once was a time when you woke up each morning raring to goeager to seize the day. You were able to get through a 9 to 5 schedule with energy left over to meet friends for happy hour, go out to dinner, and maybe even enjoy a nightcap. You were tireless. Nothing could stop you. You were a machine! But now… something’s changed.

You’re exhausted by the time you get home. Sometimes it’s hard for you to get out of bed in the morning. Your workouts aren’t what they used to be. and the most appealing thing in the world to you is your bed—or your couch, when you can’t even make it to your bedroom to conk out.

What happened? How come you’re so tired all the time?

Here are 11 reasons you have no energy—and what to do to get it back.

1. Too Much Stress

Chronically feeling overwhelm. can be a huge culprit in constant fatigue, explains Steven Lamm, M.D., Medical Director of NYU Langone’s Men’s Health Center. Too many demands at work or home can sap your vitality, especially if you don’t have an opportunity to decompress — either by discussing your feelings with a trusted friend or mental health professional or having regular opportunities to unplug and get away from it all.

Luckily, there are proven ways to manage stress so it doesn’t get the better of you. Dr. Lamm points towards healthy habits like mindfulness, yoga and meditation., as well as seeking the counsel of a therapist. It’s also not out of the question to consider whether the current job you hold or the current relationship you’re in is something you may want to transition out of in order to improve your health. Dr. Lamm also recommends getting a pet, for those of us who need some extra TLC.

How can you tell if stress is getting the better of you? One surefire way to check is keeping tabs on your morning erections, says Dr. Lamm. Their occurrence is actually a marker of health, he explains. If they disappear for a while, that’s a sign something’s amiss.

2. Depression

Another factor that’s as much mental as it is physical? Depression. Dr. Lamm says that many men may not realize a mood issue lies at the root of their fatigue, but it’s a serious factor that shouldn’t be ignored.

In addition to feeling like you have no energy, Dr. Lamm says that other signs of depression include decreased libido, slower cognitive function, and feeling sad, hopeless, or helpless. “In some men, depression manifests as irritability and aggressiveness,” he says, “as well as physical complaints like chronic pain and headaches.”

If you think you’re suffering from depression, reach out to a clinician who can assess you and suggest a treatment program to get you back up to speed.

3. OD’ing on Caffeine

In the short term a small dose of caffeine—like 20 to 200 milligrams max—will give you a burst of energy, says New York City based dietician Jessica Cording, MS, RD. “But chronic consumption exceeding 300 or 400 milligrams on a daily basis can disrupt your sleep cycle and interfere with your ability to fall into and stay in deep sleep.” End result: You wake up feeling exhausted.

Caffeine can be a hard drug to quit, Cording acknowledges. But if you feel like you have to consume more than three or four cups to get you through the day, it may be time to force yourself to scale back. Sure, it may suck for a few days as your body recalibrates. But with the more restful nights you’ll ultimately gain as a result—and the potential reduction in agitation you’ll feel from not being so overly caffeinated all the time—your body will eventually thank you.

As an alternative — or adjunct — to coffee, Dr. Lamm recommends trying the supplement French Oak Extract (a.k.a. Robuvit) to keep fatigue at bay. Several clinical trials have found this compound improves energy levels in adults and athletes.

4. One Too Many Happy Hours

After a stressful day, many of us are tempted to take the edge off by enjoying a few adult beverages. with our buds. According to the Centers for Disease Control and Prevention, two servings of wine, liquor, or beer are considered “moderate” for an American male. Any more than that and you’re likely kissing your optimal energy levels goodbye.

While alcohol may help you fall asleep initially, excessive amounts of it disrupt your sleep cycle, screwing with the time you spend in deep, restorative sleep and interrupting REM sleep, which some researchers believe plays a crucial role in memory consolidation.

Alcohol (like caffeine) also acts as a diuretic, says Cording, which can dehydrate you and, as a result, contribute even further to fatigue.

5. Not Enough Recovery Time

Not including a rest day in your exercise regimen or working the same muscle group multiple days in a row prevents your body from repairing itself and making gains in strength and endurance, says Dr. Lamm.

As you age, you’re not going to be able to recover as quickly as you did when you were in your early twenties, says Dr. Lamm. He says that after 35 years of age the swiftness with which your muscle and cartilage cells bounce back into action following a heavy workout starts to slow—and you need to honor that. Sure, guys still run marathons well into their seventies, he concedes, but not everyone shares those go-getters’ genetic profiles.

You’ve probably already heard that it’s smart to take at least one day off a week. But if you feel like you’re dragging yourself through most of your workouts, you may need to tack on another day of rest to your regimen or dial back some of your exercise sessions—say, by scheduling shorter workouts or swapping in lighter routines like yoga, Pilates, or a brisk walk.

6. You’re Not Eating Enough Carbs

Cording sees a lot of clients who make the mistake of drastically cutting carbs while continuing to do tough workouts. This is a recipe for exhaustion, she says. “When you work out, your body derives energy from glycogen stores, an energy surplus located in muscle and liver cells that shores up the sugar we consume from food,” she says. “You need to replenish those stores post-workout by eating enough of the right kind of carbohydrates.”

Not all carbohydrates are created equal in terms of how great they are for your energy levels. Steer clear of simple carbs like processed sugars and white flour while adding in complex carbs, such as whole grains, beans, lentils, sweet potatoes, peas, and fruits, suggests Cording.

Complex carbs help you feel fuller longer, and they often take longer to break down in your digestive system, so they offer a lasting level of energy to fuel not just your workouts but also the rest of your day, says Cording. Plus, you won’t have to worry about your blood sugar tanking when you consume complex carbohydrates, since they don’t court the same rapid rise and fall of that crucial energy currency as simpler carbs do.

Bonus points if you consume them with protein, since this, “gives you an even slower, more stable energy burn so you stay energized and satisfied for longer,” says Cording.

7. Your Diet is Lacking Fat

Another dietary faux pas that can lead to low energy is not eating enough fat, says Cording. Though many of us have been enlightened to the fact that not all fat is evil, folks who are eager to drop weight may still opt for low- or non-fat diets to cut calories — but that only serves to deplete your energy stores and prevents you from feeling satiated.

“Research over the past decade has found that even some saturated fats, especially those derived from dairy, coconut, and eggs, might not be as detrimental as previously thought,” says Cording, though she advises steering your palate towards unsaturated sources of the stuff, like fish, nuts, oils, and avocados. “Fat is an important and rich source of energy for the body. It helps to maintain efficient cell function and structure and, because it slows digestion, it helps you to feel fuller longer.”

8. You’re Deficient in D

With winter plowing through, many people’s exposure to sunlight will bottom out until spring. When you’re not exposed to adequate sunlight, Cording explains, the body doesn’t generate as much Vitamin D, which can leave you feeling sluggish no matter how much nightly rest you get.

Since booking a getaway to the Caribbean isn’t feasible for everyone, Cording recommends taking a vitamin D3 supplement or making an effort to consume foods high in the stuff. To help you in the process of choosing the right supplement, keep in mind that the daily recommended intake. for males under 70 is 600-800 IUs.

9. Your Diet is Low In Iron

Inadequate intake of iron can also result in fatigue because iron’s main role is to help your red blood cells transport oxygen throughout the body, says Cording. To bypass the energy-draining effects of not getting enough of the element, make sure you consume food sources known to be high in it. Meat, poultry, and fish are great sources. But if you’re a vegetarian, make a point to add more beans, lentils, leafy greens, and whole grains to your plate.

“Consuming iron rich foods with vitamin C rich foods can further help absorption,” Cording says. “A great example would be vegetarian chili with black beans, brown rice, chopped kale, and tomatoes—the vitamin C in the tomatoes will help the body absorb the iron in the rest of the ingredients.”

10. You Have Hormonal Issues

Though less common a cause than lifestyle issues, diseases or disruptions of your hormonal system. could be underlying the fatigue you feel on a regular basis, says Dr. Sarah Rettinger, M.D., endocrinologist at Providence Saint John’s Health Center in Santa Monica, Calif.

Hypothyroidism, whose symptoms include not just fatigue but also cold intolerance, weight gain, dry skin, or an enlarged thyroid gland, is one potential culprit. Low testosterone., characterized by loss of muscle mass., decreased body hair, and decreased libido, may also be at play. And, though not as common, if you’re experiencing intense cravings for salt, weight loss, nausea, vomiting, or dizziness when you stand coupled with an increased pigmentation on your hands, face, elbows, and knees, you could be suffering from adrenal insufficiency, says Dr. Rettinger.

It’s critical to consult with an endocrinologist or your primary care physician if you notice any of the above as only they can determine whether you’re actually struggling with such afflictions.

11. Your Sleep Routine is Poor

Getting seven to eight hours of sleep each night is just as important for your wellbeing as a healthy diet and a regular exercise regimen, says Dr. Lamm. Unfortunately, according to a 2013 Gallup Poll, 40 percent of Americans get less than seven hours. While this may have to do with an early alarm clock set to eke in a morning workout before you get to the office or thanks to a job that requires you to work crazy hours, a huge factor in less time spent sleeping is our nightly routines.

What you do in the hours before you hit the sack can make a world of difference for how rested you feel when you wake up. Keeping gadgets that emit blue light out of your bedroom, avoiding your phone for at least an hour prior to getting into bed, and staying away from caffeine in the evening and even the late afternoon can help you fall and stay asleep more soundly, suggests Robert S. Rosenberg, M.D., Board Certified Sleep Medicine Physician and author of The Doctor’s Guide to Sleep Solutions for Stress & Anxiety.

If you can, try to expose yourself to early morning sunlight—or invest in a light box. This helps calibrate your brain’s circadian rhythm to be alert sooner and to feel sleepier earlier in the evening so that you’re galvanized to get in to bed at a reasonable hour and wake up feeling more rested.

Dr. Rosenberg also recommends keeping your bedroom at a cooler temperature (ideally 65 to 68 degrees) so that you’re not left tossing and turning due to physical discomfort from being too hot.

And if your workouts are interfering with the hours of sleep you’re able to log, you may need to seek a more feasible exercise plan, suggests Dr. Lamm. Sacrificing your sleep on a regular basis to lift, run, or ride isn’t only unsustainable; it can interfere with any performance gains you’re gunning for.