When it comes to losing weight and body transformations, there’s a seemingly endless debate going on about cardio and strength-based exercises. I say this because it was frequently discussed in the gym I went to 10 years ago and those same conversations haven’t died down today.
So, what exactly is the best way to lose weight fast cardio or strength training?
Well, the straight up answer is cardio and there’s actual science that proves it.
According to a research from the Journal of Applied Physiology, aerobic training (i.e. cardio) burns fat and overall weight better than resistance training. That’s likely because a typical cardio session generally burns more calories than lifting weights.
However, that doesn’t mean cardio is the superior method overall (it’s not). Both have their pros and cons and, in reality, doing both instead of just one might be the optimal way to get fit. So, Let’s talk about both of them for a bit, starting with cardio.
What is cardiovascular exercise and why is it important?
Cardiovascular (cardio) exercise is basically any training that challenges your aerobic metabolism or endurance. Thus, why cardio is also called aerobic or endurance training.
Also, with aerobic metabolism, your body needs oxygen. Therefore, challenging it with exercises like running, jogging, swimming, dancing, rope skipping, or other exercises that get your heart racing also trains your body to use oxygen more efficiently.
It’s important to do cardio because when your body becomes better at utilizing oxygen, you don’t get tired as easily and your heart, lungs, and blood vessels get stronger.
On a real-life scale, this could mean you eventually climbing a few flights of stairs without feeling so out of breath, or having the energy to play with your kids or pets, or basically any activity that you normally would feel too tired of doing.
Out of all the ways you could do endurance exercises, however, fasted cardio is one that’s supposedly the best for weight loss. But, what is it?
What is fasted cardio?
Basically, it’s cardio hours after you’ve had any food in your belly.
This is easiest done in the morning right after you wake up and before you eat breakfast because sleep does all the fasting for you. However, fasted cardio can also be done at later times of the day given that you wait for your body to digest all your food.
The latter option is a much, much harder option since most experts say that a “true” fasted state can only be achieved after 8-12 hours since you last consumed any food. This is when both your glycogen stores and insulin levels are at a low baseline.
Though, some do say that about 3-4 hours is enough for your digestive system to clear out everything you ate. In any case, people who’re into intermittent fasting are who I usually see do this.
Per research, the advantage of fasted cardio over fed cardio is that the former essentially forces your body to be better at using fat for fuel because it’s other energy source, glycogen, isn’t readily available.
So, is fasted cardio better for fat loss than fed cardio?
Ironically, not really.
While fasted cardio makes your body more efficient at using multiple energy sources (fat included, of course), it does not make it better for reducing body fat.
In fact, a recent review (published this year, 2020) from the Open Access Journal of Sports Medicine notes no significant difference between fasted and fed cardio. A relatively more dated research (2014) from the Journal of the International Society of Sports Nutrition supports this notion, too.
So, in the end, it’s really up to you whether you want to do cardio with or without food in your belly. Both are equally just as good for weight and fat loss.
That being said, let’s move on to strength training.
Can I lose weight by lifting weights only?
Good question — and, yes! Absolutely!
Losing weight, or gaining weight for that matter, is all about energy balance — or how many calories you put inside your body versus how many calories you burn.
For weight loss, specifically, you want to consume less calories than your body uses. So, you’re going to want to move more and eat less. Treat this as an unyielding law to any body transformation you want to achieve.
Now, when you lift weights, you’re exerting effort which means you’re burning more calories. This, by itself can help you lose weight.
However, while a bout of strength training generally burns less calories than an equal time with cardio, it brings a lot of other things to the table. This brings us to…
How lifting weights affects the body
The metabolic effects of strength training extends after your session
In typical gym bro terms, this is called the afterburn effect but scientifically, we call this excess post-exercise oxygen consumption (or just EPOC for short).
What this is, basically, is the amount of oxygen needed to get your body back to its pre-exercise state. According to an article from The University of New Mexico, this includes:
- Replenishing your energy sources (i.e. creatine phosphate, ATP, glycogen, pyruvate)
- Putting oxygen back into your bloodstream
- Leveling your hormones back to normal
- Reducing your body temperature
- Normalizing your breathing and heart rate
The more oxygen your body needs to do these things, the more calories you burn post-workout.
Now, according to the same article, strength training has a more distinct effect on your EPOC than does cardio. Meaning, you burn more calories after a typical weight lifting session than you would running on a treadmill given the same amount of time and effort.
Furthermore, there’s evidence that shows how ramping up the intensity of weight training further amplifies the effect it has on EPOC.
In theory, the way strength training forces your body to use more energy after your time at the gym should balance, if not edge out cardio — fasted or not — in terms of total calories burned.
If that’s so, why is cardio better than weight training for weight loss?
Strength training also builds muscle
So, while you do lose fat with strength training, some of that weight can be gained back with muscle.
If all you’re after is reducing the number on the weighing scale, you might think that this is one of the disadvantages of weight training. However, solely relying on your weight can be misleading because muscle is denser than fat. Meaning, it occupies less space despite having the same weight.
To give you a clearer picture, let’s imagine a pair of identical twins. They’re both the same height and weight but:
- Twin A lifts weights, has 12% body fat, and has built more muscle
- Twin B is more sedentary, has 25% body fat, and less muscle mass
Despite showing the same exact number when they step on the weighing scale, Twin A is going to look slimmer than Twin B because he has less fat (which is less dense and occupies more space) and more muscle (which is denser and occupies less space).
Speaking of more muscle…
Strength training might be better for long-term weight loss
I say this with a hint of caution because it’s never the same for everyone. I mean, I’m sure you’ve come across people who’ve successfully maintained their weight through cardio alone, right?
That being said, the increased muscle mass that inherently comes with strength training can raise your resting metabolism. Per research, increasing your muscle mass by about 2 kg also lets you burn about 50 more calories per day.
Granted, 50 calories isn’t a lot but it does add up over time. In a week, that’s about 350 calories — about the size of 2 servings of Cheetos. In a month, that’s 1400 calories — or about 4 and a half slices of Domino’s pepperoni pizza.
Now, imagine you didn’t eat those foods despite knowing you can. That’s faster weight loss right there!
Plus, there are definitely better food options that you can eat everyday to lose weight instead of junk food and take out.
Cardio vs weight training for belly fat
Now that we’ve established how fasted cardio and strength training are both effective for weight loss, which of them is specifically better for belly fat?
Straight up: neither.
You may have heard otherwise — like training your abs can help you burn more belly fat or how cardio helps you shed stubborn weight — but the truth is that there’s no such thing as spot reduction. When you burn fat, you burn fat systematically.
That’s why people who lose weight on their bellies are likely also going to notice weight loss on their faces and other parts of their body.
That being said, what I recommend you do is…
Incorporate both cardio and strength training to your routine
When you lift weights and do cardio, you get the advantages of both workouts. You get to burn calories during and after your workouts and you also get to lose weight while keeping some of your muscle. This leads to a more toned physique.
There are a few things you might want to remember before you do this though.
If you do them on the same day, give your body at least 6 hours of rest
Endurance (or cardiovascular) exercise affects you differently than strength exercise. So, doing both in close succession is only going to confuse your body about which type of exercise it’s going to adapt to.
This is called the interference effect and research has proven that it’s a real thing.
One such study says that simultaneously doing resistance and endurance training derails your strength and mass gains.
The good news is that another study, while also describing concurrent or simultaneous training as “not optimal”, says that you can wait at least 6 hours for your body to recover so you can get the full adaptive response to both training types.
The way I see it, working out twice a day is certainly going to accelerate your weight loss journey because you will be burning more calories.
But, let’s be real here: you probably don’t have the luxury to spend that much time in the gym.
So, in case you can’t workout at this frequency, you can always do the next best thing which is…
Split your cardio and strength training routines
To me, this is a lot more doable.
For a sample weekly split, the CDC recommends the following:
- 150 total minutes of moderate-intensity cardio with 2 or more days of strength training
- 75 total minutes of high-intensity cardio with 2 or more days of strength training
- The equivalent of mix of high- and moderate-intensity cardio for at least 2 days with 2 or more days of strength training
For the first option, that’s about 30 minutes of brisk walking for 5 days.
For the second option, that’s about 25 minutes of running for 3 days, or 15 minutes per day for 5 days.
Mix strength training in between those cardio workouts, and you should be good to go.
Personally, I suggest doing your strength workouts every other day because there’s research showing how you need at least 48 hours to recover. Your muscles need that recovery period to grow or, at the very least, maintain their strength and size.
Here’s a sample split you can use as a guide:
|Monday||Cardio. 25 minutes of running or jogging.|
|Tuesday||Strength training. Work on your upper body.|
|Wednesday||Cardio. 25 minutes of jump roping.|
|Friday||Strength training. Work on your lower body.|
|Sunday||Cardio. 25 minutes of climbing hills or stairs.|
This split gets you 75 total minutes of vigorous cardio and 2 days of strength training that works out your entire body which follows CDC’s recommendations. The rest days are also there to give your legs time to recover, giving you a better chance of maintaining muscle mass.
Another thing you can do is High-Intensity Interval Training (HIIT)
HIIT has been buzzing around the fitness community for quite a few years now. And, from where I’m standing, the noise around it hasn’t died down one bit — and for good reason!
It’s mind-blowingly effective for weight loss and it has the benefits of both cardio (fasted and fed) and strength training. It’s almost literally like hitting 2 birds with 1 stone.
You catapult your heart rate like you would with cardio but the intervals help you maintain muscle mass like you would with strength training. Oh, and did I mention it takes a fraction of the time to do both?
In fact, one study compared how many calories you can burn with resistance training, steady state cardio, and HIIT. To no one’s surprise, HIIT burned more calories and had a higher heart rate than the other 2 types of exercises. This leads to faster weight loss.
Furthermore, another study says that HIIT has a more pronounced EPOC over 24 hours than does continuous cardio.
So, how do you do a HIIT session, you ask?
A basic HIIT workout looks like this:
- Sprint as hard as you can for 15 seconds. This is the “high intensity” part of the workout.
- Next, you walk or jog slowly for a minute. Consider this the “interval” or rest portion of your routine.
- Repeat until you reach your target time. If it’s 15 minutes, then you do this cycle 12 times.
For beginners, even 10 minutes of this cycle is going to take your heart rate through the roof. Once you get better conditioned though, you can manipulate the ratios to make it harder and burn even more calories.
For example, instead of 15 seconds sprint and 1 minute walk (1:4 ratio), you can either bump up your sprinting to 30 seconds and maintain your rest for a 1:2 ratio or you can maintain your sprint time and trim down the rest to 30 seconds (also a 1:2 ratio).
Of course, HIIT isn’t just limited to sprints and jogging/walking. You can do battle ropes for your “high intensity” portion, for example, and move to the stationary bike for your “rest.
The ratios aren’t limited to time either. You can use reps and distance as well.
Bottom line is be creative. I personally like the sprint/walk routine on my cardio days and pair that with weight training on another day.
Having said that, it’s almost time to end this. But, before I do, let me ask you this:
Do you have to do cardio to lose weight?
Short answer: No.
But, if you haven’t figured that out by now, here’s a recap:
- A typical cardio session, fasted or not, generally burns more calories than strength training. Session for session, this makes cardio superior to resistance training for weight loss.
- Strength training has a more intense effect on EPOC which supposedly balances out the total number of calories burned between cardio and strength training. However, the latter also builds muscle. You’ll still look slimmer but the higher density of muscle may slow down your short-term weight loss.
- A better weight loss method is to use both. If you do them on the same day (not recommended), wait at least 6 hours between each session. If you don’t, wait 48 hours before you train the same muscle group to ensure recovery. Alternating between cardio and strength training is a good idea.
- Also a good idea is using HIIT. It burns more calories during and after a session compared to both cardio and strength-building routines.
So, in conclusion, I think that if you want to lose weight, you want to examine yourself to figure out what type of training suits your goals.
Do you want to lose weight overall? Cardio.
Do you want to teach your body how to use fat as fuel? Fasted cardio.
Do you want to burn fat but maintain strength and muscle? Cardio + weight training.
Do you just want to build strength and muscle? Weight training.
Are you short on time but want to burn as many calories as you can? High-intensity interval training (HIIT).
You get the point, right? There’s a training type out there for whatever goals you set out for yourself. All you have to do is pick the right one.
Aaand, that’s it for me. Share this with a friend before you leave, will ‘ya? Thanks!