What you’ll learn here
If you’re trying to lose weight, you may be grappling with a tricky question – to get the most bang for your buck, which should it be: strength training vs. cardio?
On the one hand, cardio helps you torch calories when your heart rate is elevated.
But on the other, strength training increases your muscle mass, which then causes you to burn more calories throughout the day.
Strength training vs. cardio: it seems like an awfully close fight, doesn’t it? What a dilemma.
So, how do you choose between treadmill workouts and dumbbell sessions? Fret not. You’ll get answers soon.
Here’s an evidence-based deep-dive into everything you need to know about strength training vs. cardio for weight loss.
What determines weight loss?
Contrary to popular belief, the key to losing weight isn’t jumping into whatever fad diet is popular at the moment. Ahem, keto diet, ahem.
You don’t need to – and shouldn’t – eat only one kind of food (we’re looking at you, grapefruit diet).
For all interested to know, the grapefruit diet generally consists of eating one grapefruit, amongst other foods, at each meal.
Don’t blindly follow the fitness influencers on your Instagram feed, either. You don’t need to go on a juice cleanse to ‘give your digestive system a break.’ Why does your digestive system need a break, anyway?
Instead, the mechanics of weight-loss boils down to your calorie balance (1, 2, 3, 4, 5, 6).
If you consume fewer calories than your body uses to perform its daily functions, you’ll lose weight. It’s as simple as that.
Don’t believe anyone who tells you otherwise – they probably have a diet book (or bottles of juices) they want you to buy.
If you’re interested, learn more about how many calories you need for your fitness goals.
You need to be in a calorie deficit (eating fewer calories than you burn) to lose weight.
Which is better: Steady-state cardio or HIIT?
Alright, now that we’ve covered the underlying mechanics of weight loss, let’s move on. As you probably know by now, many different activities can be considered as cardio.
Running, for example. Also, interval training. Given how different their programming can be, can they bring about different results? Is there one that’s better than the other?
To find out, we need to study the differences between the two main types of cardio (7, 8, 9):
- Steady-state training (LISS): LISS cardio workouts are as simple as they come. All you need to do is maintain a consistent speed, level of intensity, and heart rate (120 to 150 beats per minute) during an exercise session.
- High-intensity interval training (HIIT): With HIIT, you’re expected to work at about 80%–95% of your maximum heart rate for anywhere from 5 seconds to 8 minutes. Each work set is followed by a predetermined rest interval (usually 3 minutes or less). You then alternate the intervals for 20 to 60 minutes, depending on your fitness level, time constraints, and goals.
Now, if you’ve read anything related to cardio training, you’ve likely been led to a single, solid conclusion: HIIT is better than steady-state cardio.
As many articles on Google would have you know, not only does HIIT burn more calories than low-intensity cardio, it also takes less time.
Choosing between the two seems like a no-brainer, right?
But is HIIT genuinely better than steady-state cardio? What does science say?
For some evidence-based answers, we need to look at HIIT’s supposed benefits over steady-state cardio in two parts:
First, does HIIT burn more calories than steady-state cardio?
An alleged benefit of HIIT is that it allows your body to stay in fat-burning mode long after your workout is finished.
This can be attributed to the afterburn effect: EPOC (Excess Post-exercise Oxygen Consumption).
EPOC is the amount of oxygen your body needs to return to its normal, resting metabolic state (10, 11, 12, 13). The more intense your workout, the more oxygen needed, and, therefore, the more calories you burn.
Now, since HIIT produces more afterburn, HIIT is definitely better – right (14)?
In a 2015 study, researchers compared the afterburn of cardio, HIIT, and strength training workouts (15).
They concluded that both HIIT and strength training led to more afterburn than cardio for up to 21 hours post-exercise.
But they also noted that their study is the only one which shows HIIT has a higher afterburn than cardio (7% difference) – provided both workouts burn the same number of calories.
Read that again: it’s only when both workouts burn the same number of calories does HIIT offer a higher afterburn than cardio.
What’s more, let’s see what a 7% advantage in afterburn between a 30-minute HIIT workout and 30 minutes of cardio translates into.
According to fitness author Lyle McDonald, that’s just 14-21 calories. You can burn that (and more) by just adding another 5 to 10 minutes to a treadmill jog (16)!
So – HIIT has almost no advantage over steady-state cardio. What about its other claimed benefit then?
Second, is HIIT more time-efficient when it comes to burning calories?
Let’s take a look at the 2015 study again. Guess what?
Both the HIIT protocol and steady-state cardio workout took about 40 to 45 minutes to burn an equivalent number of calories!
Granted, the HIIT session included relatively long recovery intervals (2 to 3 minutes).
But that’s just how HIIT is designed to be: high-intensity intervals alternated with low-intensity recovery intervals.
And that means that HIIT may not be vastly superior to steady-state cardio after all.
To wrap this up, there’s perhaps nothing better than the conclusion from a 2015 meta-analysis: HIIT has a ‘possibly small beneficial effect’ over steady-state cardio (17).
- The afterburn effect (EPOC) is the amount of oxygen your body needs to return to its normal, resting metabolic rate. The more oxygen needed, the more calories burned.
- Increased workout intensity leads to higher EPOC.
- Only one study showed that HIIT had a higher afterburn effect compared to steady-state cardio. Even then, the difference is small (14 to 21 calories).
- HIIT also doesn’t seem to be more time-efficient than steady-state cardio when it comes to burning calories.
- HIIT only has a ‘possibly small beneficial effect’ over steady-state cardio.
Choosing between HIIT and steady-state cardio
Ultimately, whether or not you deem the grueling intensity of HIIT to be worth the minimal gains depends on you.
If you do have limited time to train and would like to get the most ‘bang for your buck,’ the intensity of HIIT would be best.
But if you’re not bothered by spending more time on the treadmill or rowing machine, steady-state cardio might be a great option that burns equivalent calories, while being easier.
Is fasted cardio better than fed cardio?
In the fitness world, there’s probably nothing more people like to share about on their social platforms than fasted cardio workouts.
But it makes for an interesting question: is all that hunger throughout the session worth it?
What is fasted cardio?
First, let’s define what fasted cardio is.
At the most basic level, it involves increasing your heart rate (cardio) on an empty stomach (18).
Typically, for your workout to be considered ‘fasted,’ you’d need to go without food for 8 to 12 hours. That’s the reason why most people opt to do fasted cardio right out of bed.
Does fasted cardio help you burn more fat?
Supporters of fasted cardio believe that because you haven’t eaten anything, your body is forced to use its stored reservoir of fat to fuel to work out – thus enabling you to burn more fat.
Now, at first glance, research appears to support this belief.
For example, a study found that when people ran on a treadmill in a fasted state, they burned 20% more fat compared to those who had eaten breakfast (19).
So – case closed, right?
Well, not so fast.
The truth is that just because you burn more fat during the cardio session itself doesn’t mean that you will lose more fat overall!
In fact, there’s increasing evidence that fasted, compared to fed, exercise does not increase the amount of weight and fat mass loss (20, 21, 22, 23, 24).
Ultimately, remember that weight loss and fat loss resulting from exercise is more likely to be enhanced through creating a calorie deficit – rather than fussing over fasted or fed states during cardio.
If you’re interested, here’s an article exploring science-based weight loss tips that actually work.
There’s no difference in overall fat-burning between fed-state exercise and fasted exercise.
Strength training vs. cardio: Which burns more calories per session?
Now that we’ve determined that HIIT, fasted, and steady-state cardio types are all pretty much comparable, you can just think of cardio as whichever you’re most inclined towards.
So, onto the central issue. Strength training vs. cardio: which burns more calories?
To answer that question, we can simply look at the Compendium of Physical Activities, in which researchers examine how many calories individuals burn during various activities (25).
According to the numbers provided:
If you were to run at a pace of 6 miles per hour, you’d burn around 365 calories in 30 minutes. On the other hand, if you lifted weights for the same amount of time, you might only burn around 130 to 220 calories.
In general, each cardio session will burn more calories than strength training for similar levels of effort.
If you’re keen, here’s an article on how much cardio you need to lose weight.
Cardio burns more calories than strength training in a single session.
Strength training offers unique long-term benefits
Before you hop onto the treadmill and stay there forever – do note that picking that dumbbell up can offer you other significant benefits that definitely shouldn’t be overlooked.
Increases long-term calorie burn
Perhaps the most crucial one to consider is that strength training is more effective than cardio at building lean muscle mass, which then basically serves as a calorie-burning powerhouse in the body.
That’s because muscle – a significant contributor to your lean body mass – burns more calories at rest than fat mass (26, 27, 28).
Because of this, building muscle is the key to increasing your basal metabolic rate – that is, how many calories you burn at rest.
According to a study that measured participants’ resting metabolisms over 24 weeks, it was found that strength training led to (29):
- An increase of about 140 calories burned per day for men
- An increase of about 50 calories burned per day for women (typically unable to build as much muscle mass as men because of lower testosterone levels)
Now, the above figures may not sound like much, but their effects do compound over months. Let’s take an increase of 140 calories per day for men, for example.
Over a month, that’s 4,200 extra calories burned – all because of muscle mass!
Who’d say no to that?
Helps with total body reshaping
I’d say this is one of the biggest (if not the biggest) benefits that strength training has over cardio. Lifting heavy things – repeatedly – in the gym allows you to reshape your body.
You can target specific muscles with weights because muscles are found in fixed positions on your body.
Don’t like how your butt looks in jeans? You can throw in a few sets of hip thrusts to target those glutes and get them growing. Want sexy arms? Well, you can target your biceps and triceps with various arm-focused exercises!
Also, with time, you’re able to progressively increase your weight and build more muscle – adding more curves to your body!
Now, cardio will generally help you shed the pounds.
But you’ll find that this weight loss is typically a combination of fat and muscle. So, what you’re left with is a smaller version of yourself.
On the other hand, when you’re performing strength training while following a calorie-restricted diet, you stand a better chance of losing more body fat in comparison to lean muscle tissue.
What this does is to help prevent you from losing lean muscle mass that gives you the highly sought after ‘toned’ look.
Strength training will give you a more aesthetically pleasing body transformation than if you just lost weight doing cardio.
Just think about it: if you want a bigger butt, running isn’t going to be enough. You’d need to focus on strength training exercises for your glutes.
If you’ve ever noticed someone who’s lost a considerable amount of weight but still looks somewhat ‘soft,’ that’s usually why – they have indeed lost significant fat, but their muscles aren’t ‘toned’. Worse still, they’ve also lost precious muscle mass.
Provides health benefits
Strength training’s benefits are not just limited to aesthetic ones, either. Research suggests that the health benefits of strength training are numerous and, often, unique to this specific type of exercise.
The following are just a few examples of how regular weightlifting can help with your health:
- Prevents osteoporosis: When you have a low bone mineral density (osteoporosis), your bones are incredibly weak and prone to fractures. On the positive side, many studies agree that regular strength training can help prevent osteoporosis through increasing bone mineral density (30, 31, 32).
- Enhances mental health: Don’t you just feel like a badass when you’re smashing out rep after rep in the gym? You’re not the only one! Positive changes in self-esteem due to strength training have been reported in numerous studies over the years (33, 34, 35, 36). Also, strength training has consistently shown beneficial improvements in depression and anxiety levels (37, 38, 39).
- Helps manage chronic pain: If you’re one of the unfortunate few suffering from chronic pain (pain that lasts over 12 weeks), you’d be pleased to hear that strength training can help. Multiple studies have shown that strength training can treat several types of chronic pain, including osteoarthritis, lower back pain, and fibromyalgia pain (40, 41, 42, 43, 44).
- While cardio burns more calories per session, strength training can boost your metabolic rate in the long-run by increasing your muscle mass.
- Strength training also offers many unique benefits, like total body reshaping, osteoporosis-prevention, and chronic pain management.
It shouldn’t be ‘strength training vs. cardio’
In fear of this article sounding as though I’m recommending strength training over cardio – here’s a disclaimer. You shouldn’t think of ‘strength training vs cardio’ as a strict either or. You shouldn’t give up on one for the other.
Ultimately, there isn’t one ‘right’ exercise.
You should include both of them in your fitness regimen for the best fat loss results.
With sufficient protein in your diet, doing a combination of strength training and cardio can help you maintain your lean muscle mass while losing fat at a much faster rate.
That’s the best of both worlds.
That said, though, keep in mind that whatever works for you and your life should never be ignored.
Weight loss for most people is simply the compounding of your efforts. The best exercise you ever do for fat loss will always be the one you’re most consistent with.
Don’t set yourself up to fail by doing something you hate. If you hate going to the gym, strength training might not be a great option. Finding a program you can stick to is the most important.
That’s because it’s one you would feel more motivated to workout with even on your laziest day.
Even though an ideal blend of cardio and strength training is always optimal – yep, just had to get that in as the conclusive statement.