Cardio Vs Weight Lifting: What's Better for Weight Loss and Health?

Simplified:

Cardio is Better For Your Health Right?

• No. Weight Lifting lowers chronic inflammation and thus is protective against cancer, heart disease, and diabetes.

• Cardio is one of the most injurious physical activities there is. While weight lifting strengthens bones and joints.

Lift weights to bulk up, do cardio to lose weight.

• Losing weight is not the true goal. Losing body fat is the true goal.

• Lifting weights makes it easier to lose body fat, keep it away, and simultaneously allows you to eat more food while doing it.

Intro

There’s the never ending debate. Cardio vs weights. Let me settle the debate right off the bat. They both have their place. 

But we are going to compare the two training modalities on their most questioned aspects. Their overall health benefits, and their impact on weight loss. 

"Don’t you need to do cardio for your health?"

Always a question I get, and one that I appreciate. It’s generally good when a person is considering their longevity and not just how they look in regards to what they’re doing in the gym. 

However, there’s a general assumption that resistance training confers either very few, or no health benefits, and this simply isn’t true.

So let’s take a look at some of the most common diseases and how both cardio and resistance training improve them. 

“Heart Health. Cardio Wins Automatically… right?”

Based on the available research, both seem to do an equally good job of preventing or improving cardiovascular disease. People assume cardio will be superior for two key reasons. One, it’s called cardiovascular training. Name’s are important. Two, regularly elevating your heart rate should improve your heart’s function.

Now, both of these things are true. But it’s not the end of the story. Of course, cardio is great for your long term heart health. But resistance training is as well. 

There are a few things to consider here. We’ll start with the most simple point. 

The heart is not your brain, meaning, it’s not particularly intelligent. The heart is not conscious of the type of exercise you’re performing, nor does it care. If you’ve ever done a set of 15 squats, you know that your heart rate elevates. So the question then becomes, how much heart elevation does an individual need to see heart health benefits? We don’t have a hard line on this. Given the research that we’ll come to momentarily, resistance training seems to elevate the heart enough to confer the same heat health benefits. 

The second misinterpretation people make here is assuming that heart health is purely a matter of cardiovascular capacity. There’s another massive element at play here. Inflammation. 

Quickly, let’s define inflammation, acute inflammation, and chronic inflammation. 

• Inflammation- The body’s response to a foreign substance, or an injury. The immune system sends out cells to heal injured tissue or trap foreign agents. 

• Acute Inflammation - Inflammation happens in an acute manner, and begins the healing process. This is what happens when you cut your finger for example. By the way, this is also how muscle growth occurs. You damage a muscle. The damaged muscles get inflamed, and as the inflammation lessens, the muscle becomes stronger and larger. 

• This kind of inflammation is good and necessary. This is also the reason Non-Steroidal Anti-Inflammatory Drugs are NOT GOOD FOR YOU. But that’s beyond the scope of this article. 

• Chronic Inflammation - The body continues to send inflammatory cells even when there is no injury or foreign substance. One example of this is arthritis. Inflammatory cells continuously attack the joints, causing pain and damage. 

• Chronic inflammation ruins the muscle growth process. If you are in a constant state of inflammation, you won't get the adequate response to the acute inflammation seen after lifting weights. 

Chronic inflammation is extremely unhealthy, and will lead to all sorts of different health problems across the entire body. Including everything from cancer to diabetes. This is true of heart disease as well. 

Some of the things that can lead to chronic inflammation:

• Alcohol Consumption

• Sugar

• Obesity. Chronic inflammation is one of the things that makes being obese SO unhealthy. As well as having poor hormone production.

• Chronic Stress

• Smoking.

So now we come full circle. Improving heart health and preventing heart disease is both a matter of exercising your heart, as well as avoiding chronic inflammation like the plague. 

Which both resistance and aerobic exercise accomplish. And this isn’t theoretical, of course, I brought studies.

• One study from 2010 found that resistance training was effective at improving inflammation levels and lowering risk of cardiovascular disease and diabetes. (1)

• A meta-analysis from 2012 that included 21 studies found resistance training effective for lowering individuals’ age-related chronic low grade inflammatory. This lowered the incidence of heart disease as well as sarcopenia (age related muscle loss). (2)

• Another analysis of 78 studies found both aerobic and resistance training to be effective at reducing chronic inflammation and preventing all the diseases that come with chronic inflammation. Including cancer. 3

All the above also means resistance training is inherently protective against all diseases that are inflammation related. Including cancer, autoimmune diseases, metabolic diseases, gastrointestinal diseases, lung diseases, and even mental health conditions. 

But I want to emphasize diabetes specifically, as it is one of the leading causes of mortality globally. Having more muscle mass will improve your insulin sensitivity. Therefore, resistance training is massively protective against type 2 diabetes. Again, this isn’t theoretical. 

One study that assessed 1000s of healthy males from age 10 to 60. The researchers concluded, “The study finding suggests an inverse association of the skeletal muscle mass with blood glucose level which encourages the implication of muscle-building exercises as the preventive measure for T2DM (type 2 diabetes mellitus).” 4 

"What about joints? Surely Cardio is a safer method of exercise? All that weight lifting will ruin your joints right?"

Nope!

An analysis done by the good folks over at Bayesian Bodybuilding looked at four studies. Each study calculated the incidence of injury in four categories.

As you can see, the incidence of injury in running is nearly as high as that of team sports. Likely because all team sports also have some degree of running. Most team sports will also have some level of contact increasing the incidence of injury a little further. 

Powerlifitng, olympic lifting, and crossfit have a relatively low amount of injuries sustained. And bodybuilding has an extremely low amount of injuries sustained.

Why might this be the case? I don’t have a study for this so I can only make an educated guess. 

I suspect there are a couple of reasons. First, very few people assume they need to learn running technique when they decide to begin doing regular cardiovascular exercise. While most people will at least look up a video on how to perform a weight lifting exercise. People more often assume they need to learn technique out of fear they will get hurt with lifting. This inherent fear of sustaining injury from lifting weights ends up having a positive impact.

Second, lifting weights not only makes your muscles stronger, but also your bones and joints. So as you engage in resistance exercises, you make yourself more resistant to injury. It’s like a vicious cycle, but a good one. 

Third, when running, every time your foot hits the ground, your hips, knees, and ankles sustain a significant impact. A jolt of force shoots through your joints. Now consider that your foot will hit the ground dozens, if not hundreds, if not thousands of times over the course of one cardio session. Now consider doing that multiple times a week, for months, or years. Also, contemplate on the surface that your foot is striking. Running on hard concrete is very tough on joints. A track is better, because it is softer. 

Quick sidenote. This is why I always restricted my clients to doing cardio on the elliptical. Because the foot never leaves the surface, there is no impact on the joints. 

There is also a lack of impact when doing resistance training. Making it much better for the joints.  

“Cardio for losing weights. Lifting weights to bulk up.”

This is the big one. The most commonly held false assumption around cardio vs lifting. Maybe the most pervasive fitness myth. I only say maybe because I still hear ladies say they don’t want to lift because they might get too bulky, and these days, I hear people arguing that being obese is as healthy as being lean. 

So let’s dispel this with research.

Let’s start with the idea that you burn more calories and therefore fat doing cardio. This is usually assumed because your heart rate becomes more elevated for a longer period of time when doing cardio as opposed to lifting weights. 

This is actually true. You will burn more calories and fat WITHIN a session doing cardio over lifting. But, once again, it’s not the entire story. 

First off, the amount of fat burned is infinitesimally small. One review of 64 studies stated “The effect of regular aerobic exercise on body fat is negligible. 5” This same study also stated the amount of fat burned within a session was usually no more than 10 grams. There are roughly 454 grams in a pound by the way. 

I pulled some of the specific studies from the review. Specifically, the researchers found an improved amount of weight loss for those who did cardio and dieting as opposed to just dieting, but once again it was a relatively small amount. So, yes, cardio does burn fat, but it isn’t the furnace it’s made out to be. More like the flame of a lighter. (6, 7, 8, 9)

Yes, an hour of cardio will burn more calories than an hour of lifting weights. But here we arrive at another misconception. Burning calories, does not mean burning fat. It just means, well, burning calories. Calories aren’t fat. 

Obviously, the amount of fat burned within a session would be even lower with resistance training. But, what about after the session?

Quickly I need to explain how body fat loss happens. 

You have what’s called Total Daily Energy Expenditure (TDEE). Or the amount of calories your body will use in a given day for its functions. Organ function, blood circulation, etc… plus any physical activity you might do. Then we have energy consumption, or put more simply, eating. 

When the amount of calories consumed is greater than the amount expended, you gain weight. When you consume less calories than you expend, you lose weight. Things can get quite a bit more complicated from there. There are several if not dozens of factors that can affect this, but the primary detail we need to focus on is Resting Energy Expenditure (REE), sometimes also referred to as Resting Metabolic Rate (RMR).

REE is the amount of calories you burn when you’re doing nothing. The energy your body will be using while you’re watching a movie or playing video games. Since the amount of body fat we can burn within a workout is so minuscule, wouldn’t it be fantastic if we could increase the amount of calories our body is using when at rest? See where I’m going with this?

One study found that the more muscular subjects in their study had an average of 14% higher RMR than their less muscular counterparts (10). For context, let’s say hypothetically if the less muscular person had a RMR of 1500 calories, the more muscular person would have a RMR of 1710 calories. The muscular subjects could consume 210 more calories before hitting maintenance calories. Making it much easier for them to consume fewer calories and stay at caloric maintenance or even a deficit. 

And before you ask, no, you don’t need to get obscenely muscular for this to work. Another study done on men ages 50-65, found an increase in RMR of 7.7% (11). Two other interesting things present in this study. One, the subjects’ weight did not change. Their muscle and bone mass had increased at the same rate as their body fat decreased. 

The other interesting thing is this was an eight week long study. So, in 8 weeks, these 50-65 year old men increased their RMR by nearly 8%. I’m sure I don’t need to state this but, 50-65 year old men will not pack on slabs of muscle, especially in 8 weeks. 

Not enough evidence for you yet? Wait, I’ve got one more. A massive study with 10,500 subjects that took place over 12 years (96-08) compared waist circumference and body weight for those who did weight training and those who did cardio (12). The researchers found a greater diminishment in waist circumference for those who performed resistance training over the cardio group. However, they did find that those who did the moderate to vigorous aerobic activity lost more weight than the weight training group. 

How does it make sense that the resistance group had a larger decrease in waist circumference, while the cardio group had a larger decrease in weight? If you recall, the study on the 50-65 year olds had a similar finding. Where the subjects lost more fat, but not more weight. 

This makes total sense if we stop conflating the words “weight,” and “body fat.” I often caution people against using weight as a measure of their diet success. You don’t want to lose “weight,” per say. Your weight is made up of several different things including digested food, bone, muscle, fat, and water. What you are really concerned with is body fat. 

This is also why Body Mass Index is not a good measure for people who lift weights. I, for example, would be considered overweight by the BMI standard, even though I am 10-12% body fat year round. 

The question is not of weight, but what the weight is made up of. So it makes complete sense that these studies would find a greater decrease of body fat and waist circumference for lifters, and a greater decrease in weight for runners. The lifters are gaining muscle and losing fat simultaneously, meaning their weight is hovering around the same amount. 

You may have heard the old phrase “eat less, move more.” It’s the ever present answer to “how do I lose weight?”   

It’s definitely worth checking out Menno Henselman’s article “Why Eat Less, Move More Is Bad Advice.” 

And I arrived at Menno’s same conclusion. It is bad advice.

On the surface, it seems like a totally reasonable assertion to make. Decreasing your caloric intake and increasing your activity will put you in a caloric deficit and thus make you lose body fat. 

However, the move more eat less advice ceases to be valuable when you look a bit deeper. 

Consider this, the number one predictor of diet success is not the kind of diet. So you can throw out all the paleo vs keto vs if it fits your macros debates, at least in the context of weight loss. The number one predictor of diet success is adherence. Or does the person follow the diet consistently over a significant period of time. This has been found by a multitude of studies (13, 14, 15, 16, 17, 18).

And the number one predictor of adherence to a diet is hunger. If you can avoid being hungry, you’re far more likely to succeed. Hunger is one of the human body’s most intense motivators. One could argue that, along with reproduction, hunger is the primary driver of human behavior. We don’t identify with that in these modern times of abundance. But our hunter gatherer ancestors intimately understood this. 

People on Instagram and Youtube will drone on and on about it just being a matter of discipline and mind over matter. And I’m all for those things. But I also think it’s myopic to put it kindly. Again, based on the potency of hunger. 

There’s also an issue of efficacy long term with the eat less advice. As you lose weight, the metabolism slows, and then you need to eat even less to continue losing weight. If cardio is your sole method of exercise, you will either need to keep doing longer bouts of cardio, or keep eating less and less food. Neither of which are feasible for extended amounts of time.

But what if we could eat more, and not less, and still see the body fat loss we want?

Lifting weights makes it easier to lose body fat, and keep off body fat, while concurrently allowing you to eat more food and not less. 

“Surely there’s some good reason to do cardio”

Of course there is. I think it’s unfortunate that in these modern times we hold such a black and white view of absolutely everything. That if I or another exercise scientist makes the case that weight lifting is a better method of exercise than cardio, then we are also saying cardio is useless. Of course it’s useful in certain contexts. As are most things. And this brings me to the title of this article. “Is Cardio Worth It?”

I’m going to quote my favorite writer here. C.S. Lewis. 

“It is hard because so many people cannot be brought to realize that when B is better than C, A may be even better than A. They like thinking in terms of good and bad, not of good, better, best, or bad, worse, and worst.

I’m going to adjust Lewis’ next sentence to fit in the realm of this article. You want to know if I think cardio is a good form of exercise. I would reply, lifting weights is the superior method of exercise for all the reasons I articulated, but cardio is, of course, far better than doing nothing!

I would ask you, do you like doing cardio? Is it an enjoyable form of exercise for you? Then do it! 

Cardio is great for your heart. It can help you increase your energy expenditure and therefore help you lose body fat. And carries with it all kinds of beneficial mental and emotional effects.

I would call resistance training a borderline necessary part of your physical training regimen. While I have many views on the optimal and suboptimal methods of resistance training, so long as you’re doing some kind and degree of resistance training, you’re good. You don’t need to lift daily like I do. You don’t need to select exercises with the perfect resistance curves. Just lift something with good technique, and you will receive all the above benefits.

I would call cardio optional. Cardio is certainly better than doing no exercise at all. It also carries with it several great health benefits. There’s also what I’ll refer to as the adherence factor. We can wax poetic over the benefits of weight lifting over cardio all day. But if you hate lifting, and love cardio, it frankly doesn’t matter, because you won’t adhere to the program anyway. Put more simply, if you enjoy cardio, go for a run.