How Your Body Really Makes Energy
Let's talk about the power cycle of the body:
Let’s talk about energy — not the kind that powers your phone or car, but the kind that fuels you.
Ever heard of the Krebs cycle?— discovered by Hans Krebs in 1937 and expertly designed to confuse and haunt generations of medical students.
But here’s why it matters — even if you’re not a science geek: The Krebs cycle is at the heart of how your body makes energy. Understanding it (in simple terms) can help you live a healthier, more energetic life.
“Why Do I Have More Energy After I Work Out?”
A friend of mine recently said something interesting:
“On days I exercise in the morning, I feel energetic till evening. But when I skip it, I’m already drained by midday.”
Sound familiar?
It’s not magic — it’s biology.
The Body’s Energy Currency: ATP
Just like we use money to buy things, the body uses ATP (Adenosine Triphosphate) to pay for everything it does.
• Moving your muscles? That’s ATP.
• Thinking hard at work? That’s ATP.
• Pumping your heart and digesting lunch? ATP again.
Your body uses about your entire body weight in ATP every day — it just keeps recycling it. According to the Journal of Physiology, a single cell uses millions of ATP molecules per second to stay alive!
Where Does ATP Come From?
Unlike solar panels or windmills, which need to be powered up with energy from external sources, your body generates its energy from within. And to make ATP, the body has to break things down. This is where your metabolism and the Krebs cycle come in.
In simple terms:
You eat food »»» Your body breaks it down »»» The Krebs cycle (also called the citric acid cycle) takes over in your cells »»» You get ATP
The process is powered by:
• Glucose (from carbs)
• Fatty acids (from fat)
• Ketone bodies (during fasting or low-carb diets)
Each complete cycle generates about 32 ATP molecules — pretty efficient.
According to a study in Biochemistry (Berg, Tymoczko & Stryer, 2015), ATP production is tightly linked to how well your mitochondria function — these are the “power plants” in each of your cells.
Why Whole Foods and Exercise Give You More Energy
Here’s where it gets practical.
Whole Foods Requires More Work — That’s a Good Thing
When you eat whole grains (like cornmeal or wheatmeal), your body has to work harder to break them down, which fuels a more robust ATP production process.
Compare that to something like cornflakes , which are highly processed. They digest quickly, but don’t provide sustained energy because they bypass many of your body’s natural “energy-building” steps.
So: More chewing, more digesting = more energy building blocks.
2. Exercise Fuels the Cycle
When you exercise, you:
• Break down stored fat
• Boost cellular respiration
• Increase the demand for ATP
This encourages your body to ramp up energy production. That’s why you feel more energized after moving, not less.
And yes, it’s true — you’re burning fat and stimulating your mitochondria to work better. Research in the Journal of Applied Physiology shows that regular exercise increases mitochondrial density — meaning your body builds more little energy factories to keep up with your needs.
What Drains Your Energy?
Knowing how energy is made also shows us what drains it.
1. Mental Work:
The brain is a significant energy hog — it uses about 20–25% of your total energy even though it makes up only 2% of your body weight (Mink et al., 1981, Journal of Clinical Investigation). So yes, all that thinking at your desk is draining you.
2. Lack of Sleep:
Sleep is when the body recharges and repairs. Poor sleep equals poor mitochondrial function and low ATP. One study in Sleep Health (2017) showed that even partial sleep deprivation significantly reduced physical and cognitive performance the next day.
3. Alcohol:
Alcohol interferes with the Krebs cycle. It takes a metabolic shortcut (via alcohol dehydrogenase), meaning your body produces less ATP and stores more fat instead. Less energy, more fatigue.
So, How Do You Make More Energy Naturally?
If you want to improve your energy levels without caffeine or energy drinks, here are the core lifestyle pillars:
Sleep Well
Aim for 7 — 9 hours per night. Sleep is when your brain clears toxins, balances hormones, and resets your system.
2. Move Your Body
Even a brisk 20-minute walk can increase mitochondrial activity. Start small and stay consistent.
3. Eat Whole Foods
Think brown rice over white, oats over cereal, sweet potatoes over chips. Whole foods take longer to digest, leading to longer-lasting energy.
Your Body Is a Generator, Not a Battery
You don’t just use energy — you make it. The quality of your lifestyle — what you eat, how much you sleep, how often you move — directly determines how much energy you’ll have today and 10 years from now.
So next time you’re dragging by 2 PM, remember: You’re not “low energy” by default.
You might need to tune up your power cycle.
Cited Sources:
• Berg, J.M., Tymoczko, J.L., & Stryer, L. (2015). Biochemistry. 8th Edition.
• Hargreaves, M., & Spriet, L. (2006). Exercise metabolism. Human Kinetics.
• Mink, J.W., Blumenschine, R.J., & Adams, D.B. (1981). Energy consumption by the central nervous system. Journal of Clinical Investigation.
• Sleep Health Journal (2017). Sleep deprivation and its effects on cognitive performance.
• Journal of Applied Physiology (2003). Mitochondrial adaptations to endurance training.