HIIT or Steady Cardio? For Fat Loss, the Difference Is Smaller Than You Think

Intervals are sold as the better way to burn fat. But studies tell a much different story.

HIIT or Steady Cardio? For Fat Loss, the Difference Is Smaller Than You Think

Intervals are sold as the better way to burn fat. But studies tell a much different story.

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Today’s Health Upgrade

  • Let’s talk cardio and fat loss

  • Does the “morning alkaline detox” work?

  • Adam’s Corner: The discipline deception

Fitness
Why Your Cardio Style Won't Make or Break Your Fat Loss

For years, interval training has been sold as the superior form of cardio for fat loss. That pitch has led many people to high-intensity workouts because they assumed it was more effective.

The research suggests that the cardio debates aren’t much of a competition.

When researchers reviewed multiple randomized trials comparing intervals with steady, moderate cardio, the difference in fat loss was essentially zero. The same was true for cardio’s influence on muscle mass.

The researchers also found no evidence of “interval responders” and “steady-cardio responders,” which is the idea that one method is uniquely suited to your body.

Now, that doesn’t mean cardio doesn’t support fat loss. Compared with doing no exercise, both approaches led to small reductions in body fat. And cardio also improves fitness, supports your health, and increases the amount of energy you burn.

It is true, however, that high-intensity sessions can be a more efficient approach because they require less time. But it doesn’t mean they are better. 

As we’ve stated before, the real key is finding the types of exercise you can do consistently. Because over weeks and months, your body responds primarily to the total work you perform, not whether you split it into intense bursts or complete it at a steady pace.

So you can stop searching for the cardio method that burns fat “best.” And instead choose based on your fitness, schedule, joint health, and workout preferences.

Nutrition
Use It Or Lose It: The Morning "Alkaline Detox" Drink

The claim: A morning glass of lemon water with a spoonful of baking soda alkalizes your body, melts fat, and flushes out toxins.

Let’s break it down: No matter what anyone tells you, your blood pH is tightly controlled. Your blood stays within a razor-thin pH range of 7.35 to 7.45, and your body works around the clock to keep it there. Built-in chemical buffers respond immediately, your lungs remove carbon dioxide within minutes, and your kidneys clear the remaining excess over time.

A morning drink isn’t powerful enough to override that system. And if it did, you would be rewarded with a trip to the hospital.

When researchers gave people an alkalizing mineral supplement, their blood pH barely moved (from 7.40 to 7.41). On the other hand, their urine pH rose much more, from 5.94 to 6.57.

That difference tells the whole story. A higher urine pH doesn’t mean your body has become “less acidic.” It means your kidneys are doing their job and removing what your body doesn’t need.

If your blood pH ever changed enough to matter, you wouldn’t feel cleansed or energized. You’d need urgent medical care.

The other promises don’t hold up, either. 

Lemon and baking soda don’t make your body burn more fat. Fat loss still requires using more energy than you consume. And you don’t need a morning drink to “flush out toxins.” Your liver and kidneys already handle that job continuously.

The baking soda may also add an unintended downside. One teaspoon contains more than half of the American Heart Association’s ideal daily sodium limit, which can matter if you have high blood pressure, kidney problems, or have been told to limit sodium.

This isn’t an argument against lemon water. If you enjoy the taste, or it helps you replace a sugary drink, then keep it. Just leave out the baking soda.

The verdict: This drink can change the pH of your urine, but it won’t alkalize your body, melt fat, or detox anything. Keep the lemon if you like it. Lose the unfounded health claims.

Adam’s Corner
Can You Be Too Stoic?

I recently read a story by Jon Goodman. And then, I did something I rarely do. I read it again. 

The second time, I was intentionally searching for something I hadn’t found the first time.

If you don't know Jon, he's one of the best writers in the fitness world, and one of the good ones as a person too. On the night of July 29th, his crypto wallet was emptied. Seven minutes later, $1.6 million was gone.

This didn't happen because he was careless. Jon did everything right, followed all the rules from cold storage to never sharing the keys with anyone. But it didn’t matter. He was robbed of more money than many people make in a lifetime.

So Jon did what writers do, and he wrote about it. He shared his experience, reactions, and lessons.

One of his big surprises was that he wasn’t angry. And, because I know Jon, I believe him.

But then I started to wonder, and even worry, about what people would take from Jon’s experience.

The Costume Stoicism Wears

Stoicism is having a moment. Or, maybe it’s a decade. If we’re being historical, it’s really been about two centuries. 

If you’re not familiar, Stoicism is the operating system for people who want to stay cool when the pressure spikes. But you’ll mostly hear it referenced when people talk about their morning routines or when podcasters discuss mental optimization.

To be clear, I'm not knocking it. I love Stoicism. The man primarily responsible for its recent surge, Ryan Holiday, is one of the most talented writers I know. I own all of his books. The philosophy has done a lot for me.

And yet, as I’ve watched Stoicism explode, I’ve seen a shift. 

The idea of "being stoic" is being used as a permission slip to feel nothing. Or maybe an expectation that we can’t feel. 

So, we bury the anger and try to be unbothered. We swallow the grief and call it strength. 

The narrative becomes, “I can't be mad about this.” 

But it could be building another type of problem. We label and pathologize more than ever. And while it’s not good for anger to consume or control us, it’s also not good to mute the very things that make us human.

I’m not a scholar, but I’m pretty sure the Stoics never said that we can’t feel a wide range of emotions, nor was it their intention.

Seneca wrote a whole book about anger. He considered it one of the most dangerous things in the world. However, being aware of the dangers of anger is not the same as suppressing or ignoring it. 

He said the first jolt is involuntary. The flush in your face, the heat that climbs before you've decided anything. He explained that everyone feels it, even the wise ones. 

You’re not supposed to skip it, fight it, or ignore it. We are humans. We have emotions. It’s data and information that helps us understand the world and grow from the experience. 

If you ban anger, you can’t learn how to manage it or learn from it. And if you bury anger, it can easily sit, swell, and become something else underneath the surface. Or infect your heart and mind, creating an invisible poison that’s hard to fight because you didn’t even realize it existed. 

Stoicism isn't about not feeling. It's about not letting disruptive emotions take hold, and then deciding what happens next after the emotion has hit and settled.

Marcus Aurelius ran an empire and still sat down at night to write notes to himself, talking himself down, reminding himself not to be ruled by frustration or grief. We hand his journal to people as the gold standard of Stoic calm. 

It's a man wrestling his own feelings onto the page so they wouldn't run his morning.

We forget that part, and it’s part of what makes the philosophy so powerful. 

We tend to look at the outcome — I’m not going to stay mad — rather than the process that allowed us to get to that point. 

Stoicism was never about feeling less. It was about making sure the feeling didn't get to control your decisions.

Burying your feelings isn't discipline. It can also be a dangerous lie.

Psychologists call it avoidance or suppression. The emotion you refuse to look at doesn't disappear. It goes underground and starts charging rent.

It’s OK To Be Angry. But Then Be Useful.

The key to all of this is that we can't lose what makes us human.

Emotions, mistakes, processing, pain, frustration. There's a place for all of this.

We try to hack and optimize so much that, in the quest to reach the end result, we forget that it's the journey that not only clarifies where we want to go but also how we learn and grow.

We don't just skip the reps and show up stronger, more muscular, smarter, or more appreciative. We suffer, and learn, and stumble, fall, and pick ourselves up again.

Death is what makes life valuable. Disconnection gives meaning to love. Anger allows you to appreciate joy.

Let's not skip to the end and call it wisdom. Let's make sure we live, make sense of the lessons, and then pay them forward in a useful way, whether it's a stoic response or not.

Maybe Jon's calm is the real thing. Some people genuinely take a gut punch and metabolize it faster than the rest of us. 

But if you read what happened to him and wondered if you're not allowed to be upset, that a stronger person would just breathe and move on, tell that voice to go to hell. 

You can be angry, as long as you don’t stay angry or let it control you. 

Instead of fighting heavy and hard emotions, make sense of them, listen to them, and learn from them.

Remember, it’s the resistance that causes tension that leads to growth. Don’t run from that discomfort. And once you look it in the eye, do the hardest thing and be useful with it. 

That's what I was really hunting for when I read Jon's post the second time. Not the anger. The proof that he let himself feel before he set a path forward.

The courage to say “this hurt, and I'm angry, and it isn't okay” is worth more than any amount of looking like nothing touched you. It's how the lesson gets in. It's how you turn into someone worth learning from.

So feel it. All of it. Then go find the fulfillment anger was never going to give you. -AB

-Adam Bornstein is the co-founder and co-editor-in-chief of Arnold’s Pump Club

Better Today

Take any of these tips from today’s email and put them into action:

1. You Don't Have to Suffer Through Intervals to Lose Fat

For fat loss, which cardio style you choose barely matters. Randomized-trial evidence shows intervals and steady, moderate cardio produce essentially the same fat loss, and the same holds for muscle mass.

2. Your Morning "Alkaline" Drink Isn't Doing What You Think

A lemon-and-baking-soda drink can raise your urine pH but cannot alkalize your blood, melt fat, or detox anything, because blood pH is held in a tight range by your lungs and kidneys.

3. Can You Be Too Stoic? Why Suppressing Emotion Isn't Discipline

Stoicism was never about feeling less; it's about not letting a disruptive emotion control your decisions, and burying the feeling entirely often backfires.

The Positive Corner of The Internet
About Arnold’s Pump Club Editorial Standards

We do things a bit differently here, starting with transparency.

  1. The Content: All APC emails are researched, written, and fact-checked by the APC editors (see bottom of the email), with written contributions from Arnold (noted with “Arnold’s Corner”). Links take you to original studies (not second-hand sources).

  2. Does AI play a role? Not for the primary content, but it is used in two ways. The main items are original content written by the APC team. The summaries at the end are AI-generated based on the human-written content above. We also use an AI tool to edit and review our interpretations of the research, ensuring scientific accuracy. We don’t assume AI is right, but we use technology to hold ourselves accountable.

  3. Yes, we have partners (all clearly noted by “Together With”). Why? Because it allows us to keep the APC emails free. We first test products, and then reach out to potential partners who offer ways to help you improve every day. The bar is set high, and to date, we have turned down millions in ad deals. (Example: we will not partner with any non-certified supplements or those without evidence in human trials). If we won’t buy the product, we won’t recommend it to you. And if there’s no evidence it works, then there’s no place for it here.

Publisher: Arnold Schwarzenegger

Editors-in-chief: Adam Bornstein and Daniel Ketchell


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