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Why am I so tired?

by Lumen Editorial Desk · June 19, 2024 · 8 minute read
Why am I constantly tired?

Do you ever find yourself wondering, "Why am I constantly tired?" 

If you feel like you’re getting the recommended hours of sleep each night but still waking up feeling sluggish and drained—you’re not alone. 

Why do I constantly feel tired?

Many experience this frustrating phenomenon, where even a seemingly perfect night of sleep doesn’t shake off those feelings of exhaustion and fatigue as you go about your day. Luckily, the fascinating world of sleep science can help you figure out what might be causing your chronic fatigue even when you’re getting plenty of rest.

Read on to learn more about the link between metabolism and sleep, how to improve your sleep habits, and boost your energy levels.

The connection between sleep and metabolism

Sleep is not just a time for rest—it’s a cornerstone of your overall health and well-being. Getting quality sleep can impact everything from cognitive function to immune health to metabolism. 

Sleep is regulated by the circadian rhythm, your body’s 24-hour internal clock, which is naturally aligned with the day-night cycle. While you sleep, your mitochondria, the powerhouses of your cells, have time for maintenance, repair, and reproduction, so they can continue to produce the energy you need. However, when the circadian rhythm is disrupted due to inadequate, irregular, or low-quality sleep, mitochondrial repair and function may be compromised [1], impacting your metabolic health.

Sleep plays a crucial role in balancing your metabolism not just because of mitochondrial rest and repair, but also by influencing hormones involved in energy balance [2]. According to Mia Dige, a metabolic health coach at Lumen, “sleep deprivation can actually cause changes in your glucose levels, metabolism, and hormonal function.” Poor sleep quality can affect leptin levels, a hormone responsible for appetite regulation, contributing to weight gain and other adverse health effects.  

Disrupted sleep patterns can also impair insulin sensitivity, potentially increasing the risk of metabolic disorders such as type 2 diabetes [3]. High insulin sensitivity means your body needs only a small amount of insulin to help glucose enter the cells. This efficient glucose uptake supports your cells’ metabolic functions, ensuring they have enough energy for daily activities.

Not giving your mitochondria adequate rest to produce energy effectively and fuel your metabolism can often contribute to the fatigue or sluggishness that might have you asking that pesky question, “Why am I constantly tired?” despite seemingly getting enough sleep. 

Because of this, creating and maintaining healthy sleep habits is essential for supporting your metabolic health and energy levels.

How to feel more rested: 9 tips to consider

Reclaiming your energy and combating feelings of chronic fatigue begins with recognizing that your sleep quality is influenced by various factors. Things like what you eat, when you eat, and even your nighttime routine can all impact how well you rest.

Beginner tips for when you’re feeling tired

Here are nine tips from Lumen’s metabolic coaches to help you feel more rested if you constantly feel tired or have low energy.

Eat dinner earlier

One strategy to enhance your sleep quality is to adjust your meal time before bed. Consuming a heavy or rich dinner too close to bedtime can disrupt digestion and interfere with sleep. Sleep expert Dr. Michal Breus explains, “There’s a very strong connection between food, digestion, and sleep. Eating at the right time can facilitate a good and restorative sleep.”

Opting for lighter, easily digestible dinners that are lower in carbs, and allowing plenty of time for digestion before hitting the hay can promote better sleep. It also helps you wake up in fat burn, indicating your mitochondria are efficient since fat is the ideal fuel during rest and fasting. 

Limit caffeine intake

While caffeine can provide a short-term boost in alertness in the morning, limiting caffeine intake, especially in the afternoon and evening, is crucial for uninterrupted sleep. Caffeine’s stimulatory effects can linger in your system for hours, disrupting your internal sleep-wake clock and sleep quality. 

Aim to stop consuming caffeine at least six hours before bedtime [4] and opt for caffeine-free alternatives like herbal tea later in the day.

Why am I constantly tired all the time?

Get the right amount of sleep

Ensure you’re getting the right amount of sleep for your individual needs. While the recommendation for adults is typically seven to nine hours per night, this can depend on factors such as activity level and age [5].

Listen to your body’s signals and adjust your sleep patterns accordingly to find the optimal balance to feel rested and rejuvenated.

Intermediate tips for boosting your rest

Take a magnesium supplement

Supplementing with magnesium is another effective way to improve your sleep. This essential mineral promotes muscle relaxation and facilitates sleep cycle regulation [6]

Incorporating magnesium-rich foods into your diet, such as leafy greens or nuts or taking a magnesium supplement, may encourage more restful sleep.

Create a nighttime routine

Going to bed and waking up at the same time each day helps regulate your body’s internal clock, promoting a more consistent sleep-wake cycle. 

Changing your sleep times too often can confuse the body and disrupt your sleep hormones. Try creating a calming pre-sleep routine and limiting screen time at night to signal to your body that it’s time to wind down.

Supplement with melatonin

Melatonin is a hormone naturally produced by the pineal gland in the brain, which plays a key role in regulating the sleep-wake cycle [7]. It’s often referred to as the "hormone of darkness," as it is triggered by darkness and suppressed by light. 

Taking a melatonin supplement about 30 minutes to an hour before bedtime can signal to your body that it’s time to sleep, potentially reducing the time it takes to fall asleep and improving overall sleep duration. However, using melatonin supplements responsibly and in moderation is important, as excessive use can disrupt your body’s natural production of this hormone.

Advanced tips for improving your energy levels

Why am I constantly tired and fatigued?

Try red light therapy

Red light therapy, also known as photobiomodulation, has gained popularity for its potential benefits in improving skin health, sleep quality, and overall well-being. This therapy involves exposing your body to red or near-infrared light, which can penetrate the skin and stimulate cellular repair and regeneration.

Research shows that red light therapy can increase the number of mitochondria [8] and boost mitochondrial function by exciting electrons with photons from red and near-infrared light [9]. This process enhances ATP production, powering your cells and giving you more energy.

Studies suggest that red light therapy may regulate circadian rhythm [10]. As we mentioned earlier, the circadian rhythm is essential for supporting healthy mitochondrial function and keeping energy levels high.

Why am I constantly fatigued?

Start meditating before bed

High stress levels negatively affect the body’s ability to rest and recover [11], hindering cellular energy production, sleep quality, and insulin sensitivity [9]. While short-term spikes in the stress hormone cortisol are normal and healthy, chronically high cortisol overworks the mitochondria, damages their membranes, and reduces their lifespan. Chronic stress also causes your mitochondria to become overreliant on carbs to produce energy compared to using fat for fuel.

If stress is impacting your sleep, here’s some good news: implementing a mindfulness routine may benefit adults with sleep disturbances [12]. Mindfulness practices like meditation and yoga are proven to promote relaxation, reduce stress, and enhance overall well-being. Try incorporating meditation into your daily routine to regulate your blood sugar, calm your central nervous system, and wake up feeling more rested.

Practice mouth taping

Mouth taping may sound unconventional, but it’s gaining recognition as a simple yet effective way to improve breathing patterns, especially in people with sleep apnea. This practice involves applying a small piece of tape over your mouth before bed to encourage nasal breathing during sleep.

Breathing through your nose is important, as it allows you to access nitric oxide, which the body produces in the sinuses. Nitric oxide helps your body regulate blood pressure and can improve sleep quality. Studies suggest that adults and children who primarily mouth breathe are deprived of nitric acid [13].

Nasal breathing has also been shown to have other benefits for sleep in some people, including improved oxygen uptake, reduced snoring, and improved energy levels. In one study, 78% of subjects who practiced mouth taping reported higher daytime energy levels  [14]

Boost your sleep quality by understanding your unique metabolism

So, the next time you ask yourself, "Why do I constantly feel fatigued?" remember that sleep is not just about resting—it’s crucial for mitochondrial repair and reproduction, metabolic health, leptin regulation, insulin sensitivity, mood balance, and cognitive function.

By tracking your metabolism with a tool like Lumen, you can see in real-time how your metabolism is doing upon waking.  If you've been feeling sluggish, you may find that your mitochondria are burning carbs, a sign they are not well-rested. 

With the right lifestyle modifications,  including eating earlier in the day, limiting your caffeine intake, and managing your stress to balance your cortisol levels, you can boost your metabolism, improve your sleep quality, and wake up energized.


[1] Richardson, R. B., & Mailloux, R. J. (2023). Mitochondria need their sleep: Redox, bioenergetics, and temperature regulation of circadian rhythms and the role of cysteine-mediated redox signaling, uncoupling proteins, and substrate cycles. Antioxidants, 12(3), 674. https://doi.org/10.3390/antiox12030674 

[2]  Sharma, S., & Kavuru, M. (2010). Sleep and metabolism: An overview. International Journal of Endocrinology, 2010, 1–12. https://doi.org/10.1155/2010/270832 

[3] Morselli, L., Leproult, R., Balbo, M., & Spiegel, K. (2010). Role of sleep duration in the regulation of glucose metabolism and appetite. Best Practice & Research Clinical Endocrinology & Metabolism, 24(5), 687–702. https://doi.org/10.1016/j.beem.2010.07.005 

[4] Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine, 09(11), 1195–1200. https://doi.org/10.5664/jcsm.3170 

[5] Watson, N. F., Badr, M. S., Belenky, G., Bliwise, D. L., Buxton, O. M., Buysse, D., Dinges, D. F., Gangwisch, J., Grandner, M. A., Kushida, C., Malhotra, R. K., Martin, J. L., Patel, S. R., Quan, S. F., & Tasali, E. (2015). Recommended amount of sleep for a healthy adult: A joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Journal of Clinical Sleep Medicine, 11(06), 591–592. https://doi.org/10.5664/jcsm.4758 

[6] Arab, A., Rafie, N., Amani, R., & Shirani, F. (2022). The role of magnesium in sleep health: A systematic review of available literature. Biological Trace Element Research, 201(1), 121–128. https://doi.org/10.1007/s12011-022-03162-1 

[7] Pevet, P., Challet, E., & Felder-Schmittbuhl, M.-P. (2021). Melatonin and the circadian system: Keys for Health with a focus on sleep. Handbook of Clinical Neurology, 331–343. https://doi.org/10.1016/b978-0-12-819975-6.00021-2 

[8] Karu, T. (1999). Primary and secondary mechanisms of action of visible to near-IR radiation on cells. Journal of Photochemistry and Photobiology B: Biology, 49(1), 1–17. https://doi.org/10.1016/s1011-1344(98)00219-x 

[9] Ferraresi, C., Kaippert, B., Avci, P., Huang, Y., de Sousa, M. V., Bagnato, V. S., Parizotto, N. A., & Hamblin, M. R. (2014). Low‐level laser (light) therapy increases mitochondrial membrane potential and atp synthesis in C2C12 Myotubes with a peak response at 3–6 h. Photochemistry and Photobiology, 91(2), 411–416. https://doi.org/10.1111/php.12397 

[10] Zhao, J., Tian, Y., Nie, J., Xu, J., & Liu, D. (2012). Red Light and the sleep quality and endurance performance of Chinese female basketball players. Journal of Athletic Training, 47(6), 673–678. https://doi.org/10.4085/1062-6050-47.6.08 

[11] Picard, M., & McEwen, B. S. (2018). Psychological stress and mitochondria: A systematic review. Psychosomatic Medicine, 80(2), 141–153. https://doi.org/10.1097/psy.0000000000000545 

[12] Black, D. S., O’Reilly, G. A., Olmstead, R., Breen, E. C., & Irwin, M. R. (2015). Mindfulness meditation and improvement in sleep quality and daytime impairment among older adults with sleep disturbances. JAMA Internal Medicine, 175(4), 494. https://doi.org/10.1001/jamainternmed.2014.8081 

[13] Noda, A., Nakata, S., Koike, Y., Miyata, S., Kitaichi, K., Nishizawa, T., Nagata, K., Yasuma, F., Murohara, T., & Yokota, M. (2007). Continuous positive airway pressure improves daytime baroreflex sensitivity and nitric oxide production in patients with moderate to severe obstructive sleep apnea syndrome. Hypertension Research, 30(8), 669–676. https://doi.org/10.1291/hypres.30.669 

[14] Friedman, M., Tanyeri, H., Lim, J. W., Landsberg, R., Vaidyanathan, K., & Caldarelli, D. (2000). Effect of improved nasal breathing on obstructive sleep apnea. Otolaryngology–Head and Neck Surgery, 122(1), 71–74. https://doi.org/10.1016/s0194-5998(00)70147-1 

Our contributing team of in-house registered and certified nutritionists, dietitians, scientists, and researchers helping people become metabolically healthier

Lumen Editorial Desk

Our Lumen editorial desk includes an in-house team of certified and registered nutritionists and dietitians, scientists, researchers, and writers.