Feeling Low on Energy? 8 Reasons Why (According to Science)

Jul 12, 2023 | Health

Do you spring out of bed in the morning, ready to face the day? If the answer is no, then you may be struggling with a lack of energy. 

We all have experienced days where we don’t have our usual enthusiasm. From feeling drained after a long workday to skipping a workout, it’s normal to need some downtime. However, if you’re frequently feeling low on energy, it’s essential to investigate the cause.

To get to the bottom of it, we need to understand what ‘energy’ really is and why it’s crucial for our wellbeing. In this article, I’ll also explore 8 ‘energy thieves’ that can make you feel run down. 

When we understand the sources of energy, we can make conscious steps to boost our energy levels and get the most out of life. Let’s get started!

What is Energy? Why Is It Important?

Energy is essential to a healthy life – it’s the fuel we need for all our physical and mental activities. Even simple daily tasks can feel overwhelming when we’re low on energy.

On a physical level, our bodies need three main things to create metabolic energy: oxygen, food, and water. These elements are turned into energy through the biochemical process of metabolism.

When we talk about ‘energy’, though, it’s more about how we feel – encompassing a range of physical, mental and emotional factors. We can eat all the right foods but still feel like we’re on ‘low battery’ if we’re stressed or don’t get enough sleep.

There isn’t a perfect model for this concept of ‘energy’ in Western medicine, but it’s long since been recognised in Eastern philosophies. Examples include Qi (Chi) in Traditional Chinese Medicine or Prana in Ayurveda, an ancient Indian practice. Both terms refer to a ‘vital life force’ which must be balanced and flow freely for optimal health and wellbeing. 

To maintain our energy levels, we must understand the sources that fuel us. If you’re feeling drained, you’ll want to learn more about the top ‘energy thieves’ holding us back. More on that below – keep reading!

8 Reasons You’re Low On Energy (According to Science)

Is your tank running low on fuel? Here are eight potential reasons you may be feeling weary:

1. Nutritional Deficiencies

Diet significantly impacts our energy levels since food is fuel for our bodies. Eating the right foods can be a complex balancing act. For optimal energy, we need enough:

  • Carbohydrates to power our muscles
  • Protein for growth and muscle recovery
  • Good fats to fuel our brain, heart and lungs
  • Essential vitamins and minerals

Fatigue culprits include iron deficiency (especially in menstruating women) and magnesium. 

When our energy levels are low, we’re more likely to crave unhealthy foods, which can worsen the problem. Rich foods make you feel ‘heavy’, and sugary snacks can give us a temporary energy spike, soon followed by the inevitable crash.

The best diet also varies according to your body’s metabolic type. The wrong foods will make your digestive system work harder, making you sleepy. When you understand your metabolic type, you’re empowered to eat accordingly.

2. Toxins 

There is mounting evidence of the link between toxins and fatigue. Over time, the accumulation of toxins can drain our energy and lead to illness. Common contributors include environmental pollutants, alcohol, smoking and processed foods. 

Toxins like smoking and alcohol also cause inflammation and hinder our circulation, leading to fatigue. Binge drinking is especially hazardous – a single night of excess alcohol (more than four drinks) can cause a leaky gut, releasing bacteria and toxins into the bloodstream. 

Alcohol also compromises your sleep quality, leaving you tired even if you get the recommended 7 to 8 hours.

The body expends energy when eliminating toxins, so if your body is working overtime, it can quickly deplete its reserves. Detox programs are popular for fatigue because they help reduce the strain on our body’s resources, which can boost energy levels.

3. Lack of Exercise 

Exercise is essential for optimum energy production. Feeling energised is directly connected to circulation – so we want to maximise our heart’s ability to pump blood around our body. 

When we’re sedentary, circulation slows down, and vital nutrients are less efficiently delivered to our cells. By increasing your cardiovascular fitness, your body will find the same day-to-day activities easier. Exercise also supports mental health and mood, as it releases natural endorphins, which can give us a boost.

Running, spinning classes, walking, and jogging are great for cardio fitness. Any activity where you huff and puff is a good pick! Be careful not to overtrain, though, as this will have the opposite effect.

If your fitness and/or strength has decreased in the last few years this will have a direct correlation to energy. People often don’t draw that connection as decline usually happens slowly. If you can’t spring up the stairs like you used to, it starts to take its toll energetically! Fitness improvements are one of the fastest ways to feel more energetic!

4. Inadequate Sleep 

We know we’ll feel tired if we don’t get enough sleep, but sleep quality is also critical to feeling energised. Disrupted sleep can lead to higher levels of stress hormones in the body, making us tired and sluggish.

Aim for 7 to 9 hours of quality sleep each night, or adjust your bedtime according to your body’s needs. There are many tips and tricks to help you get better quality sleep, so be persistent in figuring out what works for you.

If you feel like you never get enough sleep, a condition such as sleep apnea may be responsible. Sleep apnea symptoms include snoring and waking up with a headache, so speak to your doctor if they sound familiar.

5. Dehydration

Water is essential for physical energy production, so even mild dehydration can drain your energy. When you don’t consume enough fluid, blood pressure drops, slowing oxygen delivery to the brain, leaving you feeling flat.

How much water you should drink will vary from person to person. A good indicator is that you should aim to go to the toilet at least three times a day. Between six and eight glasses of water-based drinks a day is generally recommended.  However, if you’re consuming caffeine or alcohol, exercising, or sweating a lot, you’ll need to drink more water than usual. 

If you don’t like the taste of plain water, try adding fruit for flavour. You can also eat water-rich foods such as fruits and vegetables to help you stay hydrated.

6. Hormonal Imbalance

Hormonal imbalances can cause fatigue, and it’s something that can gradually creep up on us. This is particularly common in women as they reach perimenopause or menopause and during pregnancy. 

Hormonal conditions such as thyroid issues or adrenal fatigue can also be a factor. Thyroid hormones are critical in energy production, so a sluggish thyroid can fatigue you.

Stress is often a factor when it comes to hormonal imbalance. Our adrenal glands secrete cortisol, the ‘stress hormone’, vital in regulating metabolism and energy production.

If your fatigue seems out of character for you or other physical symptoms (for example, weight changes, hair loss, hot flashes etc.), it may be worth checking your hormone levels.

Hormone imbalances can be caused or worsened by endocrine disruptors in our environment.

7. Stress & Anxiety

Stress and anxiety can be a giant energy zapper. Constant mental chatter, fear and worry can take up a huge amount of energy as our mind struggles to deal with the perceived threat. 

A state of stress causes the body to release cortisol, which increases heart rate and blood pressure, burning up our energy. When stress persists for long periods, cortisol levels become chronically elevated, known as ‘adrenal fatigue’. This can lead to feelings of exhaustion, lack of motivation and burnout.

Regular time out and engaging in activities that help you relax are essential for managing stress levels. If stress becomes too overwhelming or starts impacting your day-to-day life, don’t be afraid to ask for help.

8. Negative Mood & Mindset 

If you were asked, “Are you happy most of the time?” what would your answer be? If the answer is no, you’ve got some work to do. 

Chronic low mood and lack of energy can be symptoms of depression. Mental health issues can also disrupt sleep and make getting up in the morning hard. If you’re lacking motivation to face the day ahead, it’s worth speaking to your GP.

However, a mind cleanse is a great way to renew your zest for life if you’re just in a slump. If you’re feeling flat, try to expand your horizons! Read books, journal, speak to people, and most importantly, work out your life’s goals and desires. 

When life has a purpose, is balanced, and you are growing, it’s amazing how your energy grows too.

Next Steps

Overall, having plenty of energy is essential to living a healthy and productive life. By understanding and nurturing our body’s energy sources, we can tackle each day with enthusiasm.

If you’re feeling sluggish and run down, it’s worth booking an appointment with your doctor. Getting a health check-up is crucial if you have other symptoms, like weight changes or hair loss.

A simple blood test can detect many causes of low energy, including hormonal issues or nutrient deficiencies. Biomarker testing is also helpful in understanding what might be happening in our bodies.

Not sure why you’re low on energy? Start by taking my quiz: Which of the 5 Energy Thieves is Holding You Back?


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