The One Thing I Wish Everyone Understood About Energy

I’ve talked a lot about mitochondria, but I want to take a step back and give you a deeper understanding of energy itself.

Mitochondria enable the process in your cells that effectively uses electrons from the food you consume and oxygen from the air you breathe to generate adenosine triphosphate (ATP). ATP is essentially the energy source for everything that happens in your body. Moving your muscles, thinking, digesting food, repairing tissue, regulating your temperature, producing hormones—literally everything requires energy.

“Electrons from the food you consume” sounds a lot more complicated than it actually needs to. Think about where the energy in our food comes from in the first place. Everyone knows the sun is energy. You can feel it. Plants capture energy from sunlight through photosynthesis and store it. We eat the plants, or we eat foods that got their energy from plants. So, if you zoom way out, much of the energy your body is using right now can ultimately be traced back to the sun. I think that’s pretty amazing.

But here’s the part that is really important: energy is a finite resource.

You can never have more energy than what your metabolism is capable of producing. You can’t just eat unlimited food. First of all, you’re going to get full. And if you keep going up against your fullness, you’re eventually just going to gain weight. You’re not going to become more and more energetic. At a certain point, adding more fuel can actually make the system less efficient.

You also can’t breathe unlimited oxygen. You can, however, help your body become more efficient at delivering and using oxygen, and that’s one of the reasons exercise is so helpful. When you do cardio exercises, you’re supporting the systems responsible for getting oxygen where it needs to go.

It can feel like you have more energy, but it’s not necessarily that you suddenly have an unlimited supply of it. Your body has become more efficient with the resources it has available. It can deliver oxygen better. Your muscles can use it better. Your mitochondria can adapt to increased energy demands. The entire system can become better at doing its job.

That completely changed the way I think about energy.

Most of us think the solution to being tired is to somehow get more energy from caffeine or a supplement. Something that will give an extra boost so you can keep going. Caffeine can give you a temporary boost, but it doesn’t change the limits of your energy supply. It just makes those limits easier to push past for a while.

Since energy is finite, there’s another side to the equation we have to pay attention to: how we spend it.

I broke down energy in Chapter 4 of The Glow Effect in a way that’s easy to understand because I think understanding this changes how you take care of yourself. You don’t need to know every step of cellular respiration or memorize the electron transport chain. You just need to understand how to support the mechanisms in your body that create your usable energy, recognize that there is a limit to that energy, and be intentional about how you spend it.

So the goal isn’t to figure out how to endlessly create more. It’s to help your body become more efficient at using what’s available, and stop spending every bit of it just trying to keep up.