If you step foot into pretty much any gym, you’ll undoubtedly see a whole bunch of people slaving away on the cardio machines.

And for most of the people, the reason they are spending their time grinding it out on a glorified hamster wheel instead of doing something more fun is quite simple:

They want to lose some weight!

Let me say that this is an admirable goal, and I am certainly not taking away from people that are working hard to achieve it.

But the truth is that cardio is absolutely not necessary for weight loss.

If that caused you to spit out your coffee in disgust, I really do apologize, but it had to be said…

In reality, you can lose lots of weight, and get yourself down to very low levels of body fat, without doing any cardio whatsoever.

But rather then just leaving it at that, you’re probably wondering where I am getting this from.

I mean, everyone knows that cardio is great for fat loss, right?

Well, in this article, my hope is to provide a more measured understanding of how cardio impacts fat loss, and why you simply don’t need to do it if you don’t want to.

Let’s begin.

Cardio 101

First, let’s take a look at what cardio exercise actually is.

Cardio is short for cardiovascular – so it follows that cardiovascular exercise helps condition your cardiovascular system.

That is, the system in your body (also known as your circulatory system), that is involved in transporting oxygen and nutrients around your body, to fuel your cells and keep you alive.

More commonly, however, cardio is synonymous with aerobic exercise.

Aerobic exercise can be defined as a type of exercise that uses oxygen to meet the body’s energy demands.

Examples of this include running, biking, and swimming.

This differs from anaerobic exercise, such as weight training, which uses different energy systems that meet shorter-term demands.

But before I go off on too much of a tangent here, what you really need to know is that doing cardiovascular (aerobic) exercise will help condition your cardiovascular system, and better prepare you for endurance related activities.

You won’t get as out of breath walking up the stairs or running to catch the bus, as your body will get better and better at efficiently meeting your oxygen demands.

All of this is great, and there are certainly a vast number of health benefits to regularly doing cardio – ranging from a decreased risk of heart disease, strokes, lower blood pressure, and just feeling better overall.

OK, so now that we’ve defined what cardio is, and some of the broader health benefits that you can expect from doing it, let’s get back to the topic at hand here, which is how useful cardio is for weight loss specifically.

Cardio For Burning Calories

When it comes down to it, losing weight is all about energy.

That is, how much energy you are taking in vs how much energy you are burning.

Yup, that’s it.

It’s a deceptively simple concept that people often don’t want to believe…

They want to think that there is something more to it – that there is some awesome ‘trick’ or ‘hack’ to get your body to lose weight without complying with the basic rules of thermodynamics.

Sadly, there is no way to cheat the laws of thermodynamics. Your body is a closed system – and any energy you take in must be either burned or stored.

Now, the amount of energy that you take in is entirely controlled by what you eat. I won’t be going over that in this particular article, but really your diet is the only variable as far as ‘energy in’ is concerned.

On the other side of the equation, however, there are lots of different ways that you can burn energy.

For one, you are constantly burning energy just to maintain your basic functions (breathing and staying alive). This is known as your Basal metabolic rate.

In addition, whenever you move or do anything above that, you are burning additional energy to meet those demands.

…And this is where cardio comes in.

You see, whenever you do some form of exercise – be it aerobic or anaerobic – your body requires energy to meet these demands.

And whether that energy comes from glucose, fat, or even protein, the fact remains your body will be burning energy that you consumed at some point for fuel.

It follows, then, that cardio is simply a tool to help increase your body’s energy demands, thus burning more calories.

At this point you may be thinking that it sounds like I’m advocating doing lots of cardio for weight loss.

I mean, in theory, if you just keep increasing the amount of cardio you do, you’ll keep burning more and more calories, ultimately causing you to lose weight.

However, that is not how it all plays out in the real world…

You see, while cardio will indeed reliably help you burn calories, it is a small part of the equation.

Another way of saying this is that the number of calories that you can realistically burn through cardio exercise is actually fairly small.

Let’s look at an example to help illustrate this point.

From my experience, the average person will not have the time or inclination to do more than about 30 minutes of cardio several times per week.

In that 30 minutes, you could realistically expect to burn 300 or so calories. Maybe 400-500 if you are really going at very high intensity.

So for that half an hour you slaved away on the treadmill, let’s say for arguments sake that you burned 300-400 calories.

After you’re done, you leave the gym, and since you’re feeling hungry, you decide to get something to eat. You opt to indulge with a small muffin – after all, you deserve it after spending those grueling 30 minutes on the treadmill, right?

Well, unfortunately, that little muffin you shoved down in 30 seconds flat contains 400 calories.

So the net result is that you ended up roughly breaking even in terms of your body’s energy balance.

You burned 400 calories in 30 minutes of hard work, and then consumed 400 calories in 30 seconds on the way home.

Sadly, this means that you wouldn’t lose any weight at all.

Yes, you would have reaped the other health-related benefits from the aerobic exercise, but your weight will remain unchanged.

It All Comes Down To Diet

As the above example illustrates, you can do a lot more damage with your diet than you can ever possibly hope to fix through cardio exercise.

There is an old adage that you “can’t outrun a bad diet”, and it is 100% true as far as weight loss is concerned.

And while the concept of burning off your calories through cardio is alluring, it is a fool’s errand if you choose to rely on it as the lynchpin of your weight loss strategy (believe me, I’ve fallen victim to this type of thinking too.)

At the end of the day, the amount of food that you consume is the single biggest determinant of how much weight you’ll gain or lose.

Yes, there are examples of people whose extreme cardio exercise habits allow them to eat appreciably more. Think marathon runners, or people that choose to spend hours each day on a treadmill.

But if you’re like most guys who read this, you probably aren’t actively training for a marathon, and don’t have hours and hours each day to spend in the gym.

So, if you’re a normal guy, who can realistically make it to the gym a few times per week, then your diet will be what controls your weight loss, not the relatively insignificant amount of calories that you are able to burn through moderate cardio.

In Summary

Now I know that I may have ruffled a few feathers with this one, but I promise that it is for your own good.

Pinning your weight loss hopes and dreams on endless sessions of (unappealing) indoor cardio will inevitably lead to disappointment.

Whereas if you get your diet in order, adopting an approach to nutrition that works with your lifestyle while still putting you at the appropriate caloric deficit, you’ll be able to lose the weight without the unnecessary aggravation (and a lot less sweat).

So, to summarize:

1) Cardio has numerous health benefits, but unless you do hours of it you aren’t going to burn very many calories.

2) Weight loss is far easier to achieve through controlling the other side of the equation, which means focusing on your diet.

At the end of the day, I find it helpful to think of yourself as having a certain calorie allowance for the day.

Once you’ve spent your allowance, any further calorie spending will cause you to gain weight – just as spending money that you don’t have causes you to go into debt.

Cardio simply allows you to have a slight increase in your allowance, but won’t make much of a dent if you tend to have expensive tastes…

Do you use cardio for weight loss? Has it worked for you? Let us know in the comments.