Podcast 6

What about Cardio? Part 2: Fat Loss vs. Weight Loss, and How to Stay Strong and Lean into Old Age

. . .

SHOW NOTES

In part 2 of this series with Dr. James Fisher, Brian and James discuss the downsides of cardio and why so many people can’t seem to resist binging after cardio exercise. Learn why cardio is important and useful when done right, and how it can lead to even worse health outcomes if not done properly.

• While improving heart health is great, it’s not everyone’s goal when exercising or doing cardio. Weight loss is another major focus and cardio can certainly help accomplish that.
• When doing cardio and exercising at a low enough intensity we are using our aerobic energy system, and that’s reliant on our fat stores as energy. So it’s easy to think that if you do cardio you will burn fat, but the reality is that anything that raises our energy expenditure and increases our metabolism is beneficial for fat loss.
• Building muscle is great for maintaining a higher metabolism and burning more fat.
• With a low-intensity exercise, we see an increase in our stress hormones, as well as a fluctuation in our leptin and ghrelin levels. These are the hormones responsible for hunger and they regulate how our body replenishes and restores calories. When we do higher resistance training we don’t get the same hunger response. The big problem is that going for a long run or bike ride may feel great, but the following hunger response may undo all the work you just did.
• More movement and more steps in a day is a good place to start, but if you go out and start running, cycling, or swimming you are going to swim against the tide and your body will start to resist your efforts.
• Increasing muscle mass is about increasing the quality of our body composition, and that itself is increasing our metabolism. If you look at the bigger picture, cardio alone doesn’t lay the foundation for long-term weight loss.
• Studies generally show that the weight loss that occurs from cardio and a caloric reduction is 50% muscle, which is probably the worst possible outcome, especially as we age. Whereas if we perform resistance training and pay attention to protein intake the weight loss is almost exclusively fat.
• When people say they want to lose weight, they mean they want to lose fat. We need to do something that allows us to hang on to the muscle we’ve got. Starting with resistance training, and then nutrition, with cardio as a tertiary thought is the best method to achieve fat loss and optimal long term health.
• If we do what it takes to protect our muscle with proper nutrition and strength training, the weight that we lose leads to a better body composition since fat takes up so much space on the body.
• Start with resistance training and nutrition, then add cardio if you feel like it.
• When we think of older adults we think of frailty, despite the fact that they are often lean. The reason they are frail is because they are not carrying a high proportion of muscle mass. If we do resistance training and focus on maintaining as much muscle mass as we can when we age, we are setting ourselves up to be lean and functional as we age instead of merely frail.
• An epoc is Excess Post-Exercise Oxygen Consumption, it’s also known as the afterburn effect. When performing high effort exercise our heart rate is elevated for a time after the exercise is complete but with low-intensity exercise, there is almost no after-effect. The energy expenditure from prolonged low effort exercise is about the same as interval training or resistance training a third of the duration. A 20-minute high-intensity workout has the same energy expenditure as a 1-hour run.

When we exercise at a low enough intensity, we’re using our aerobic energy system, and that’s reliant predominantly upon our fat stores as energy. So it’s easy to think that if you do cardio, then you will burn fat.

Welcome to the Strength Changes Everything podcast. I’m Aimee Hudson, and today’s episode will be part two of a series answering the question, what about cardio? This is a continuation of an interview between Brian Sagan, co -founder and CEO of The Exercise Coach, and Dr. James Fisher, a leading expert in exercise science and human health. If you’re just joining us, I encourage you to go back and listen to episode six of the podcast to get the foundation for this topic as Brian and James discussed what we mean by cardio and the connection between our heart health and the type of exercise we do. This portion of their interview covers the connection between cardio and weight loss. What impact does aerobic activity have when it comes to weight loss?

Is there a better way to exercise that could lead to this outcome in a lot less time? Let’s listen in and find out as Brian Sagan and Dr. James Fisher continue the conversation.

As you mentioned, getting healthy is great. Protecting our health and promoting longevity is great. And for some people though, we’re really after trimming down the waistline, as you said. So let’s transition to weight loss because this is another area where cardio is brought up, where we help people trim down and look great. And as we do that often, because we’re not presenting people with an approach that involves conventional cardio. Once again, we’re asked by people who say, wait a second, I want to lose weight.

What about cardio? And but I guess, James, that’s true. Everybody knows that you have to do cardio to burn fat and lose weight. Is that the case?

Yeah, cardio is good for weight loss, but you don’t have to do cardio for weight loss. So the reason that there’s been an attachment between cardio vascular exercise or cardio respiratory exercise, like running, cycling, swimming and weight loss is because As I said at the start, when we exercise for prolonged periods, we exercise at a lower intensity. And when we exercise at a low enough intensity, we’re using our aerobic energy system, and that’s reliant dominantly upon our fat stores as energy. So it’s easy to think that if you do cardio, then you will burn fat. And in black and white, that’s not far off. But the reality is, and in contrast, if we do higher intensity exercise, then we become more dependent upon carbohydrates, upon our glycogen stores within the muscle.

But the reality is that anything that raises our energy expenditure, which can be resistance training or cardio, and then ideally increases our metabolism beyond exercise cessation, so beyond the finishing point of exercise, which really is only achieved by higher intensity exercise like resistance training or building muscle. Anything that does that is great for fat loss, so energy expenditure and increased metabolism. But it’s also a bit more complicated. And if we stop there, that’s a nice picture for people to take away that actually building muscle is great for maintaining higher metabolism and burning more fat. But actually there’s a hormonal response to exercise as well. So prolonged low intensity exercise such as swimming, cycling or running causes an increase in our stress hormones and ultimately it causes an increase in a hormone called ghrelin.

and another one called leptin, which goes down. Now, when ghrelin goes up and leptin goes down, basically, it tells our body to replenish and to store calories. And it’s a completely hormonal response. It’s not something that we can resist particularly easily. But when we do shorter duration, higher intensity exercise in the form of interval training or resistance training, we also raise our stress hormones, but we also raise our growth hormones. So, leptin and ghrelin go down and we don’t get the same hunger response.

So, our big problem in layman’s terms, our big problem is going for a long run, a long swim or a long bike ride is great, but you will probably feel hungry after it and undo all the good you just did.

Wow, that I think is a bit of a paradigm shift. and a very important area for people to even be aware of, just the hormonal impact of exercise, for better or worse, different modalities of exercise. It seems like for so many years, and even to this day, the average person looks at weight loss very mechanically as if they can just Uh, go out and move to burn enough calories to balance the scales of energy balance and just be shedding all kinds of body fat. Is that, would you say at this point that is, would you say that’s misguided? Would you say that’s just an incomplete understanding?

I think that’s an incomplete understanding. And I think that’s not a bad thing for people to think. If that’s what they think, then that will probably encourage more movement. It will probably encourage more physical activity, more steps in the day and so forth. And that’s a good place to start for some people. But I think that from there,

if they transition into typical cardio exercise, going for a run, cycling, swimming, and so forth, they’re going to start to swim against the tide a little bit, because their body is going to resist what they’re doing by elevating certain hormones and sending a stimulus to replenish and store calories. And that’s something that they can’t fight against. And it’s something that most people don’t know. And beyond that, of course, we’ve talked about building muscle. We’ve already talked about the importance of muscle, but increasing muscle mass is about increasing the quality of what our body of our body composition and that itself is about increasing our metabolism. So our body is now working more efficiently based on the food that we consume anyway.

So it’s going to use the protein from muscle. It’s going to burn the fat or the muscle itself is going to burn the fat just by being muscle. If we look at the bigger picture, and it’s not much bigger, it’s just the details that I mentioned there, we can start to see, actually, it’s not as simple as if I go for a run, I burn 400 calories, and that allows me to eat this donut, because if all you eat is the donut, then that’s probably not the end of the world, but you haven’t built any muscle as a product of it. As we move If I continue, Brian, if you don’t mind, as we move on, looking at weight loss within exercise, the other thing that we move into generally is diet. So diet changes really have to contribute to weight loss, for substantial weight loss anyway. And the big problem with doing cardio exercise and reducing our diet is the studies generally show that the weight that we lose, and people always say weight loss, they don’t say fat loss, they say weight loss.

And people get on the scales because that’s what they have and they say I lost two pounds, I lost three pounds, I lost nine pounds. But if they’ve reduced their calories, and they’re doing cardio, then about 50 % of the weight that they’ve lost is muscle.

And that’s awful.

That’s tragic. It’s absolutely tragic. It doesn’t get much worse than that we should be hanging on to every bit of muscle that we can, especially as we age. Whereas if we perform resistance training, and if we control our protein intake. So I’m not suggesting that we need to start counting all our micronutrients or even our macronutrients to any extent. We might count our calories, but we might look at the protein intake.

And if we do that and we perform resistance training as well, then the studies show that all the weight that’s lost is fat. It’s almost exclusively body fat, which is exactly what we want to achieve to begin with. When people say they want to lose weight, they don’t mean they want to lose weight. They mean they want to lose fat. And that’s the big picture in all of this. So we need to do something to hang on to the muscle that we’ve got.

And we need to create a state where we can maintain muscle protein synthesis by our protein intake and by performing resistance training. Now, we can add cardio to that. Absolutely. But we should start with resistance training. then nutrition, and then cardio becomes a tertiary thought in my mind.

Wow, I love how you just put that. And in terms of the change in body shape that occurs when someone loses body fat, when we focus on doing what’s going to optimize fat loss, versus just bringing about weight loss, the change in body shape is significantly more, isn’t that right? Because of the space that body fat takes up. It’s so much less dense than muscle. So if we do what it takes to protect our muscle through strength training, you said, and through adequate protein intake, which we can do, then the weight that we lose leads to a greater change in body shape, a greater reduction in inches, because we’re losing fat tissue, which is more voluminous, takes up much more space.

Is that right?

Yeah, it’s absolutely right. And without applying a stereotype here, typically from women we hear the word toning. And what they mean by toning is greater muscle tone. What they generally mean is to reduce fat. But if they reduce fat and they shape their muscle or they build some degree of muscle, then they’re changing the shape of their body quite drastically in very favorable ways. Yeah, I completely agree with what you just said.

The amount and the volume of fat to muscle is key.

That’s great. So just to summarize, what I heard was, I love it, start with resistance training and nutrition and then Add cardio if you feel so great about the way your body’s working and you’ve got so much more energy and you’re motivated to be more active and get out and do something recreational, then add the cardio by all means, but start with resistance training and I would say whole food nutrition.

Yeah. A great example for this is if we think about older adults in maybe a nursing home or in a retirement village, we often see a degree of frailty, but we also see these older adults that are relatively lean. They’re not carrying a high proportion of body fat. But the reason that they’re frail is because they’re also not carrying a high proportion of muscle mass. So this is the important part about building as much muscle while we can and then sustaining it. So if we don’t do the resistance training, we’re really setting ourself up for a future of being lean, which these older adults are, but being frail.

If we build or retain the muscle mass, then we can still be lean, but we’re probably gonna be a lot more functional as we age. That’s that is the hope and the goal for sure. That’s what we want to help people do. Before we transition Dr. Fisher to talking about fitness, which we’ve touched on a little bit early, but maybe even sports performance a little bit. One more question in this area, because it certainly is purported to be important for fat burning. And it’s a term that’s been pretty prevalent.

It’s one that you learn about in an exercise physiology course. But in recent years, it’s been used a lot in the presentation of various fitness programs. And that is EPOC. I wanted to ask you while we had you, what the heck is this EPOC that people talk about?

And how important is it to consider in analyzing the effectiveness of a fitness program, especially for fat loss in particular? Yeah, that’s a great point. And EPOC is something that I constantly tell my students about, mostly because I’m running from one lecture hall to the next. So EPOC means excess post -exercise oxygen consumption. Okay, so in layman’s terms, what that is, if I go for a walk and then I stop and sit down, then I’ve burned calories while I was walking, but when I stop and sit down, my body’s back at rest and it’s reached that level of homeostasis quite quickly. If I sprint, for whatever reason that might be, whether I’m chasing the ice cream van or chasing after my son or my wife, and then I stop, then my body doesn’t recover as quickly.

It’s in a state of what’s called an oxygen debt. and my body’s having to work harder to recover that homeostasis. So I’m going to carry on in the long and short. I’m gonna carry on burning calories for a lot longer after the exercise has stopped. And that’s what EPOC is. It’s often referred to as the afterburn effect as well, that after we finished exercise, we carry on burning calories.

And the reality is that if we do, again, this is built around intensity of exercise. So if we do low intensity, long duration exercise, then there is almost no EPOC. It’s very minimal. If we do high effort, short duration exercise, then the EPOC And the energy expenditure from EPOC is very high. So whether that’s interval training on a spin bike or sprints or resistance training, so much so the energy expenditure from prolonged low effort exercise is about the same as interval training or resistance training of about a third of the duration. So a 20 minute workout or interval session effectively, when we include the afterburn, the excess post -exercise calorie expenditure is about the same as going for a one -hour run or a one -hour cycle or a swim and so forth.

Swimming’s a bit different because the energy expenditure is a bit different because of being in a pool or being in a lake, but certainly running and cycling. That’s pretty mind -blowing, actually, to think you’re saying that a brief, high -effort bout of exercise will about one -third the duration of long duration, low intensity activity will end up burning the same number of calories.

Is that what you’re saying?

Wow. Yeah, exactly.

That is incredible. That is incredible. So that wraps it up for part two of our What About Cardio series. Next week’s episode will conclude this conversation by delving into the type of exercise that leads to the most significant fitness and sports performance outcomes. And Brian and James will answer the most important question, does strength training improve cardiovascular fitness?

I know I’m looking forward to that. As always, thank you for listening. If you would like to try the world’s smartest 20 -minute workout in a studio near you, visit exercisecoach . com to register for two free sessions. We’ll see you next time. And remember, strength changes everything.