Surprisingly, this topic about our bodies feeling heavy and tired was assigned around the same time that I was personally experiencing feelings of “sluggishness.” In my situation, it’s a combination of not exercising as much as I did a year ago and being busier at work.
I’m just getting back into a workout regimen after moving and having to build up my home gym at my new location.
When it comes to feeling heavy and tired, it all boils down to bioenergetics. Bioenergetics is a branch of biochemistry and cell biology concerned with the movement of energy in living systems. 
Bioenergetics aims to explain how living creatures get and transform energy in order to execute biological tasks. Whether we feel heavy or weary is closely related to how we obtain, store, and use the energy inside the body.
While bioenergetics is primarily concerned with the energy of the body, one’s overall energy bandwidth is heavily influenced by one’s mental state. Here are seven reasons why you feel heavy and exhausted in your body.
1. Lack of Sleep
This is most likely one of the primary causes of people feeling heavy and/or weary. I frequently feel like a broken record when it comes to emphasizing the benefits of good sleep, particularly REM sleep.
Energy is neither generated nor destroyed, according to the concept of energy conservation. It has the ability to change from one kind to another.
We require sleep to save energy, according to the energy conservation hypothesis. When we obtain enough sleep, we minimize our calorie demands by operating on a slower metabolism for a portion of the time. This theory is supported by the fact that our metabolic rate decreases as we sleep.
According to studies, eight hours of sleep can save humans 35 percent of their daily energy compared to total awake.
According to the energy conservation hypothesis of sleep, the primary goal of sleep is to minimize a person’s energy use throughout the day and night. 
2. Lack of Exercise
Exercise is an intriguing topic since it may be tough to find the desire to work out when you are not feeling motivated. If you do find it in you to exercise, you’ll be amazed at how much it improves your energy levels.
In theory, any type of exercise or physical activity will raise the heart rate and increase blood flow. It will also cause the release of endorphins, which will increase your energy levels.
Cardiovascular activities that require effort will generally strengthen your heart and increase your stamina.
After relocating to a new house, I’m in the midst of having my home gym rebuilt. I’ve been slacking on my workout and training for the past year. I can personally tell that I have had less physical energy in the last year than I had when I was training frequently.
I’ve been a Lifehack author for a few years, and virtually all of my prior posts were written while I was routinely exercising. I’m writing this as someone who hasn’t exercised enough and can attest firsthand to the fact that exercise produces greater energy.
3. Poor Nutrition and Hydration
Because water makes up the majority of the human body (up to 60%), a lack of hydration will drain energy. The brain and heart are made up of 73 percent water, while the lungs are made up of 83 percent water, according to research.
Water makes up 64 percent of the skin, 79 percent of the muscles and kidneys, and even 31 percent of the bones.  If you don’t drink enough water (I recommend natural spring water or alkaline water), you’ll probably have more problems than just a lack of energy.
When it comes to nutrition, it’s a good idea to stay away from too much sugar.
Sugar consumption is harmful to the body and brain, generating brief bursts of energy (highs) followed by mental fogginess, physical weariness, and crashes.
Sugary beverages, sweets, and pastries, in general, inject too much sugar (fuel) into your bloodstream too rapidly.
For a rapid source of energy, I’ve used these sorts of foods right before exercise. However, there is almost little value outside of that use. When you consume sugar in this manner, the crash that follows makes you exhausted and hungry.
Complex carbohydrates, healthy fats, and protein take longer to digest, which means they satisfy your appetite and offer a continuous stream of energy.
Stress is surprisingly underappreciated in our fast-paced world, despite the fact that it is the leading cause of a variety of ailments. One of the signs of stress is a heavy and weary feeling.
The musculoskeletal, respiratory, cardiovascular, endocrine, gastrointestinal, neurological, and reproductive systems have all been proven to be affected by stress.  Stress induces the adrenal glands to generate the hormone cortisol, which leads the body to release it.
Adrenal fatigue is a condition that causes weariness, cognitive fog, occasional “crashes” throughout the day and other symptoms. 
It’s critical to examine stress in your life completely and take steps to reduce it as much as feasible. Monday through Friday, I’m in front of dozens of devices and displays, supervising huge teams of individuals (15 to 30).
On weekends, I take long walks in nature (known in Japan as shinrin-yoku), utilize sensory deprivation chambers, and try out new supplements (being a biohacker).
5. Depression or Anxiety
These two frequently coexist with stress. It’s also often ignored in our society, despite the fact that millions upon millions of people suffer from depression and anxiety at work.
Many people who are depressed complain of a loss of energy, excitement, and a general unwillingness to get out of bed in the morning.
These are also conditions that should be thoroughly addressed inside oneself before taking steps to ameliorate. I’m a huge supporter of therapeutic psychedelics like Psilocybin and MDMA.
I’ve tried a number of mushrooms, both psychedelic, and non-psychedelic, and have a lot of experience with them. In reality, I utilize several strains of Psilocybin mushrooms in the bulk of my sensory deprivation tank sessions.
Much study has been done on the advantages of such drugs in treating depression, anxiety, PTSD, and other mental illnesses. 
Hypothyroidism, also known as underactive thyroid disease, is a disorder in which the thyroid gland does not generate enough hormones.
The metabolism slows down as a result of this disease.  Hypothyroidism, commonly known as an underactive thyroid, causes you to feel fatigued and gain weight. Hormone replacement therapy is a popular treatment for hypothyroidism.
7. Caffeine Overload
As someone who went from five cups of coffee per day to three cups per week, I’m writing this. I’m nearly completely decaf now.
I cut down on my coffee consumption since it was hurting my mood and energy levels. Excessive coffee use can have a negative influence on the adrenal gland, which, as I said before, can lead to poor energy and unpredictable energy dumps.
The most essential thing is to recognize when you’re feeling heavy or fatigued, and then take steps to better your condition.
Never accept feeling tired or low-energy as usual, since humans have a tendency to accept such situations as the norm pretty fast. You’re on the right track if you’ve made it this far!
Examine several parts of your life to see where you might improve in order to prioritize your mental, emotional, and physical well-being.
I really hope that these seven causes for feeling heavy, weary, or short on energy may assist you in your quest for a healthier and more vibrant self.