Cardio is the sweaty messiah of fat loss.

You have to do cardio if you’re trying to get lean.

Lots of cardio.

So you climb onto the treadmill, crank the incline like you’re preparing for a NASA launch, and start rhythmically thudding forward. On the all-to-real hamster wheel. For thirty minutes. At least. Hoping that, if you repeat this on a daily basis, consistency will eventually sandblast you into a wet marble Adonis glistening under fluorescent gym lights.

Unfortunately, doing cardio to lose fat is like having a kid to save a marriage.

Rarely works the way people want it to. Truth is, you don’t need to do cardio to lose fat. And it seems like, more often than not, cardio ends up being counterproductive for reasons you wouldn’t expect.

I know the previous statement has the power to short-circuit a select few subreddits, but I’ll concede. Slightly.

Because the reason “cardio” became synonymous with “shredded” is actually pretty logical, which is exactly where we’ll start to better understand this booby trap.

Why does everyone think cardio is required to get six-pack pixelated?

Cardio is often recommended for fat loss because, a long time ago, some lab-coated sleuths discovered that triglycerides are the primary fuel source for aerobic respiration. (Hang in there.) Triglycerides are fatty packets of energy driving on the roadways inside you thanks to the food you eat. (Almost every food that passes through your throat can be transformed into triglycerides.) When traffic builds, your body clears the roads by shoving excess triglycerides into storage—specifically into adipose cells.

This is the villain origin story of body fat. Body fat is triglycerides parked in adipose. (And in case you’re new here, I’ll be calling “body fat” adipose from here on out. If this causes distress, please take it up with your frontal lobe.)

As for the machinery? Your muscles can run on different fuels depending on which energy system you’re using. One of the systems available is the aerobic system, and it tends—tends—to favor triglycerides for fuel. So when your aerobic system is active (when you’re undergoing aerobic respiration), your body is probably chewing through triglycerides to move you forward like a mammal late for something it regrets agreeing to. With enough aerobic respiration, your body will burn through the more readily available triglycerides and then be forced to take and use the ones stored in adipose cells. End result? Less squishy stuff crammed into those cells, which equates to less jiggly stuff hanging in your love handles.

Need a dumbed-down metaphor? I got you. Aerobic respiration targets triglycerides the same way arcades in the 1990s targeted quarters. You could walk into Funland with a credit card, a checkbook, maybe even a crisp twenty—perfectly valid forms of currency. But the machines didn’t care. No quarters, no Time Crisis. The system required one very specific input. Your body is similar. It has multiple energetic currencies available. But when you trigger aerobic respiration, you’re targeting a specific one. You’re grabbing the body by the ankles, flipping it upside down, and attempting to shake its adipose into the ether.

This is where cardio re-enters the chat.

Why is everyone cuckoo for cardio?

Cardio is a specific type of exercise that maximizes aerobic respiration, which maximizes triglyceride use, which maximizes the absolution of adipose. In theory. Unfortunately, most people use the word cardio the way toddlers use the word dog. Four legs? Dog. Pants? Dog. Emotional-support ottoman? Also dog. So people do four-minute HIIT meltdowns, wheeze through burpees, flirt with unconsciousness, and proudly announce they “did cardio,” convinced they’ve cracked the adipose vault when they barely brushed the energy system that was supposed to be doing the work.

But that’s a story for another day.

For now, let’s assume you’re actually doing cardio. Real cardio. Steady, rhythmic, aerobically-taxing cardio. Which brings us back to maximization of aerobic respiration, the obliteration of triglycerides, and—supposedly—the best possible setup for getting rid of the gelatinous goo stored inside adipose tissue.

Sounds great.

Case cracked.

Jog forever.

Or until you realize you’ve been undergoing aerobic respiration nonstop since the moment you’ve were born.

Your aerobic system is working right now as you read this sentence in your underwear. (Yes, I see you.) Cardio increases the activation of the aerobic system, but the system itself never fully powers down. It’s always on. Which means your body is constantly chewing through triglycerides to recycle its energy supply and keep the machine known as “Donald” (or whatever your name is) humming along. Put in terms even Shemps can understand: you “burn” fat simply by existing.

You can get a decent estimation of how much energy your body uses on a daily basis by multiplying your bodyweight (in pounds) by thirteen. So if you weigh 180 pounds, your body probably chews through about 2340 calories worth of energetic material every day. (By the way, “calories” aren’t real. They are simply unit of measurement for heat energy, just like “degrees” are a unit of measurement for temperature. Confused? Me too.)

Now, it would be wrong to say triglycerides are the only type of energetic material your body uses under that calorie umbrella. But they’re used far more than most people would guess. Which raises the obvious question:

If you’re burning fat all day long… why don’t you look like it?

Because there’s another variable in the physiological financial equation often ignored: income.

Yes, you’re using triglycerides. Damn near constantly. But you’re also earning them through the food you eat, because food is energetic material your body loves turning into triglycerides whenever the opportunity presents itself. And, much like with real money, the opportunity presents itself when income exceeds expenses. The balance determines how much ends up parked in adipose at the end of the day.

Most people aren’t ripped despite being natural fat-burning machines because they earn more than they spend over time. Your body’s survival expenses are already high. And fairly fixed. Simply existing costs a lot. Which is why fat loss doesn’t require heroic cardio or metabolic theatrics. It just requires a fixed income below regular expenses. Under this condition, your body has no choice but to dip into its savings to pay the bills.

Make no mistake: You don’t need to do cardio to lose fat… but you should still do cardio.

Cardio is great. Not necessarily for fat loss, but for almost everything else. Health. Longevity. Blood pressure. Insulin sensitivity. Not dying early. You know. Trivial stuff. Stuff that clearly matters less than visible abdominal muscles.

Cardio is strength training for your heart. Just like squats make your leg muscles stronger, cardio makes your heart stronger. You should do some kind of cardio. Joint-friendly cardio. If you’re an overweight, middle-aged man who’s been sedentary for the past nine years, pause for a moment before resurrecting your high-school running program. Consider the preparedness of your feet, knees, and hips before you repeatedly bash your bones into concrete. I wince when I see people affluent with adipose jogging on the sidewalk.

Beyond health, cardio does increase your overall expenses. It nudges the equation in favor of fat loss. It helps you shrink adipose tissue more than would otherwise occur. Just not by as much as it feels like it does.

When you finish a cardio session and feel your heartbeat behind your eyes, it’s natural to assume you just chewed through a massive wad of fat.

As if whatever crumb was clinging to your abs surely melted, and a six-pack is now seconds away.

Eh. Not quite.

Professor Google will tell you jogging burns about 100 calories per mile. (For the record, you’ll also burn about 100 calories walking a mile. From a fat-loss standpoint, jogging’s main advantage is finishing faster—which is always a good thing unless you’re in the bedroom. So let’s say you lace up, put on your Sunday best, and jog for 30 minutes at a 10-minute-mile pace. You used to run in high school, right? You can cough up a 10-minute mile, right? Thought so. That’s three miles. Roughly 300 calories burned.

In theory.

Thanks to exercise efficiency, metabolic adaptation, and human biology being quietly vindictive, you probably didn’t burn 300 calories. Some research suggests you only burn 50–75% of the calories you think you do after accounting for exercise-related metabolic adaptations, but I’ll give you the benefit of the doubt and say your bout with breathing difficulties deleted all 300 calories worth of energetic material trapped inside of you. Otherwise you might feel too defeated and never try.

What does 300 calories actually buy you?

Well, one pound of adipose (body fat) is commonly said to “contain” 3500 calories worth of energetic material. Under generous assumptions, pretending every calorie burned came directly from adipose, it would take more than ten 30-minute jogging sessions to lose a single pound of fat.

I’m willing to bet 9 out of 10 people would assume they’d lose more than one pound of fat after two weeks of jogging for 30 minutes every day, which is unfortunate because it’s optimistic.

Most Shemps wouldn’t lose weight after adding casual cardio to their lives because most adults gain weight every year. Not because they’re broken, but because they eat more and move less as life piles on. They discover the wonders of beer in college. The need for sugar-crusted Starbucks to help them cram for final exams. They hang up their cleats and stop playing their favorite sports. They rely on packaged food when their daughter is born because nobody has time to wash dishes anymore. The number on the scale rises in a slow, depressing, linear fashion. In other words, most Shemps live in a moderate energy surplus over time.

(I know I’ve been using a money metaphor throughout this and here’s where it gets a little weird because in real life, most people work themselves into debt. But at the dinner table, most people do the opposite.)

Adding casual cardio to this surplus system can certainly help the upward climb. Cancel out the keg stands and kielbasa. Slow annual upward creep toward metabolic syndrome. But the overall impact of this addition depends on *drumroll* how much energetic material you’re eating. (If you’re surprised, you’re not a great reader.)

The odds of casual cardio producing meaningful fat loss in a timely manner are low when the diet isn’t doing its job. Even though cardio tips the scale in the right direction by increasing expenses, the increase simply isn’t Super Effective! enough to make income a non-factor.

I wish this weren’t true. I wish cardio burned an unfathomable amount of energetic material—an amount physically impossible to ingest. But it doesn’t. When you break it down, casual cardio barely negates the calories inside one of those insect-sized boxes of raisins. Never mind the cupcakes, chips, and “reward food” Shemps start morally bargaining for the moment they begin exercising.

“I ran today. I can have that cupcake.”

You can’t.

Cardio is not powerful enough to ensure fat loss without nutritional awareness, which is somewhat ironic because nutritional awareness is powerful enough to ensure fat loss without cardio.

This doesn’t mean cardio is bad. Or useless. It’s just been wildly miscast. Cardio doesn’t fail fat loss. It just can’t combat the energetic toll of twelve quarter-pounders with cheese. You can run around Funland all day blowing quarters, but if you earn a handsome paycheck at the dinner table, you’re never going to end up in debt.

That’s the mistake.

Cardio is a tool, not a throne.

It can assist fat loss.

But it will never rule it.

Do cardio anyway.

Do it so your blood pressure doesn’t resemble a phone number. Do it so walking up stairs in your 50s doesn’t feel like a medical emergency.

Just don’t ask it to wear a crown it can’t carry.

If you want six-pack abs, you should wear a waist-trimmer belt when you do cardio.

After a thirty-minute jog, the neoprene corset suffocating your stomach will be soaked with sweat infused with the salami you ate yesterday — a surefire sign you’ve melted a significant amount of fat covering your abs…

or so the story goes.

Unfortunately, if sweating was a sign of spot reduction, then everyone who gets swamp ass would have rock-hard rumps. 

I’ll be honest. I haven’t investigated a scientifically acceptable number of humid human holes to definitively conclude the swamp-assed don’t have six-pack-shredded sphincters, but my intuition says I should be confident with my initial conclusion.

Waist-trimmer belts won’t spot reduce body fat, but they aren’t totally useless. You can use them to suffocate yourself in shame on account of believing sweating was the secret to fat loss. (Don’t suffocate yourself, but feel free to imagine that lady with the bell from Game of Thrones following you around all day.)

You can burn fat from specific places on your body by exercising the muscles beneath the area you want to tighten.

Want to lose your belly fat? Do crunches. Want to lose your bat wings? Do triceps extensions. Want to get rid of your sausage fingers? Become a typist…

or so the story goes.

Unfortunately, if using a muscle triggered fat loss directly atop said muscle, then fat people wouldn’t have fat faces.

Where do you think your chewing muscles are?

There’s only one scientifically proven way to spot reduce body fat. It’s not FDA-approved.

It’s dangerous.

But it works.

Ready for it?

Are you sure?

Takes a little grit.

(And bloodshed.)

Because you have to use a knife.

You’re not dumb enough to use this unorthodox “cutting” strategy to spot reduce body fat (even though it’s the only scientifically-proven way to get the job done). To lose fat from specific areas of your body, you have to create an energy deficit and cross your fingers. Your body will burn fat from areas deemed less important first. Could be the fat in your neck. Could be the fat between your toes. Could be the fat between your eyebrows.

No way to know.

No way to nudge.

Like trying to pour out a crumb stuck in a cup of water. You tip the cup, hoping the water-logged carbohydrate flops out first. But it never does. It sinks to the bottom of the cup because it’s obeying the laws of physics, not your fickle feelings.

The physics of fat loss bends the knee to survival, not six-pack abs.

And for whatever survival-based reason, you should expect to lose fat around your lower abdomen and love-handle region last. You may not enjoy how your stomach looks like a series of hot dogs rotating on one of those roller machines when you sit down, but your body sure does.

If you’re losing fat everywhere except the one place you want to lose fat most, there’s only one thing you can do: keep going. Your body will eventually zap fat from your troublesome areas (unless you tried to spot reduce body fat with science and now you’re dead).

You can make specific areas of your body toned and defined as opposed to big and bulky by lifting a light weight for high reps.

Want sculpted shoulders that look like scalloped seashells? Pick up a pastel-colored plastic-coated dumbbell and do lateral raises until your delts burn like you’ve angered a minor deity. Make your muscles burn so hard chlamydia seems like child’s play.

Do this for every major muscle group and you’ll look like Brad Pitt in Fight Club before next Tuesday… or so the story goes.

Unfortunately, if lifting a light weight for high reps was an effective way to increase muscle tone and definition, then childcare workers would have amazing bodies.

Because they’re constantly lifting babies. And bottles of wine. Light weights, you know?

Alas, childcare workers don’t have shrink-wrapped stomachs or biceps that resemble veiny baguettes. Unless being toned and defined is like time travel, where going forward at a suicide speed takes you backward in time. Maybe childcare workers are soft and squishy because they’re knock-dead toned and defined?

Until someone from the future tells me otherwise, I’m going with my gut on this: Lifting a light weight for high reps is dumber than daytime television for the same reason picking up babies doesn’t carve you into a Greek god (and just gives you Cheerios in your cleavage).

The best way to become more toned and defined?

Stop training for tone and definition.

Slap someone’s arm on a table and saw their biceps in half and you’ll see a big bone surrounded by muscle mass (steak) surrounded by body fat (mashed potatoes) surrounded by skin (plastic wrap). Your body composition is primarily a byproduct of these four variables. To change your appearance, you have to modify at least one of them.

Let’s knock out the obvious ones: bone and skin. Unless your master plan involves early-onset osteoporosis or skinning yourself alive, those are off the table. Which leaves us with the only two variables you can actually manipulate: The two remaining variables are muscle mass (steak) and body fat (mashed potatoes), and here’s where things get trickier than rocking a rhyme:

You can’t “tone” or “define” either of these attributes.

Muscles can either grow and get bigger, or they can shrink and get smaller. Nothing will make your muscles grow (or shrink) more toned and defined as opposed to less toned and defined. (Not even sarcoplasmic hypertrophy—story for another day.) In other words, you can’t tenderize your meat. Beating your meat a certain way won’t make it firmer. There are bigger muscles. There are smaller muscles. There are no lean, toned, or defined muscles.

Same goes for body fat, which is more accurately know as adipose. You can either accumulate more adipose and get squishier, or you can dissolve the adipose you have and get harder. That’s all you can do. There isn’t a special kind of adipose that will make you appear more or less toned and defined; any kind of adipose (visceral, subcutaneous, brown, whatever) will make you less toned and defined.

This begs the question:

If muscle mass and body fat can’t be toned or defined, how does one become toned and defined?

Appearing toned and defined is like Golden Corral’s business model: Quantity matters more than quality. You need a mediocre amount of muscle and a low amount of body fat. Miss the mark in either direction and your chances of looking toned and defined will sink faster than Squints in The Sandlot. (If you don’t appreciate that reference, we probably weren’t meant to be friends.)

Look at super-skinny runway models. They don’t have much adipose, which is good for tone and definition. Adipose is mushy, like mashed potatoes. If you lather a steak with mashed potatoes, you won’t be able to see the steak’s striations. Unfortunately, super-skinny runway models don’t have much muscle mass; they don’t have steaks. They have a few tissue-thin slices of salami stuck to their bones. There are no striations to see, so they look like conscious coat hangers. They’d look more toned and defined if they gained muscle.

On the other end of the spectrum, there are heavyweight powerlifters and off-season bodybuilders. (The legendary Doug Hepburn comes to mind.) They have a bunch of muscle mass, which is good for tone and definition. Big steaks are dense and detailed.

Unfortunately, heavyweight powerlifters and off-season bodybuilders also have a bunch of adipose; their muscles are covered in mountains of mashed potatoes. This suffocates the subtleties of the steak, so they look like swollen sausages. They’d look more toned and defined if they eliminated some adipose.

Between both extremes exists toned and defined bodies, like that of Brad Pitt in Fight Club and Brie Larson (who I only look at for research purposes). Their muscles are big enough to display detail, and their body fat levels are low enough to put the details on display.

Appearing toned and defined is a game of quantity more than quality: You need a big (enough) muscle and a low (enough) body fat percentage.

So if you aren’t as toned and defined as you like to be? You have two options. Lose fat. Or build muscle. Odds say you need to do both. For whatever reason, skinny-fat guys tend to overestimate how much muscle they have and underestimate how much fat they have. (I have something known as “personal experience” with this delusion.)

Of course, I could be wrong.

You might already have sizable steaks, which means you should focus more on fat loss. Or you might already have minimal mashed taters, which means you should focus on more muscle growth.

I don’t know.

But I do know this:

There are dead wasps inside of figs. (Seriously, look it up.)

I also know this:

Training for tone and definition won’t help you lose fat or build muscle.

When knuckleheads train for tone and definition they usually lift a light weight for high reps, trying to make their working muscles burn. In order for this kind of training to have an impact on tone and definition, it’d either have to contribute to fat loss or contribute to muscle growth.

It does neither.

I don’t care what the lady wearing yoga pants told you, lifting a light weight won’t trigger muscle growth no matter how many reps you do for the same reason tickling your skin with a feather won’t create a callus. The stress isn’t large enough to warrant adaptation. You need to put down your sister’s plastic-coated dumbbells and lift heavier things. The resistance you’re opposing should make you more “sticky” than “springy.”

Traditional “toning” training won’t really help with fat loss, either. Muscle burn is a byproduct of the lactic-anaerobic energy system, which uses glycogen within working muscle(s) to replenish energy. Glycogen is stored carbohydrates, not stored fat. In other words, when you feel the burn, you aren’t burning fat. Spot reduction isn’t real, in case you didn’t know.

And so, lifting a light weight for high reps is less effective than Goldeen in Super Smash Bros. 

Increasing the size of a muscle and decreasing the amount of fat surrounding the same muscle (to a significant degree) with one single exercise of training technique is impossible. Becoming (more) toned and defined has been and always will be a two-part process. You have to grow your muscles with “sticky” resistance training. You have to decrease your body fat levels with an energy deficit. If you aren’t doing either of these things, then you aren’t gonna be tightening or firming or toning or defining much of anything (except your hatred for your body).