Cardio vs. Strength Training: Which is better for weight loss?

Cardio vs. Strength Training: Which is better for weight loss?

I get this question a lot. “If I’m looking to lose weight, should I do cardio or strength training?” Well, let’s remove the suspense, the answer is both. But it also made me realize that many people are confused about what cardio and strength training actually is because they are not mutually exclusive. Let’s break down what cardio and strength training actually are along with their benefits. After that I’ll expand on my original answer.

What is cardio?

Cardio exercise is any exercise that keeps your heartrate up for more than 10 minutes. Cardio for most is synonymous with aerobic exercise.  This is movement that relies mainly on oxygen to help power you through the movement. Through your breath, you are able to take in oxygen and the blood is able to pump it to your muscles and fuel the movement consistently by breaking down carbohydrates and fats. In aerobic exercise, you are maintaining a heartrate that is below 80% of your maximum heartrate. True aerobic-only exercises get your heart pumping but you’re able to still say a few sentences as you move. Some cardio exercises can be brisk walking, running, cycling, jumping rope, elliptical machines, and dancing for more that 10 minutes.

What are the benefits of cardio?

Because of the heart and lungs work in cardio exercise, it improves cardiovascular health and condition as well as lung function and capacity. The metabolizing of the carbs and fats can lead to reduced bad cholesterol and blood sugar levels and also assist with fat loss.

What is strength training?

Strength training (or resistance training) is any exercise that focuses on building up muscular strength. Strength training for most is synonymous with weight lifting, but it’s really exercise that has resistance. It is considered strength training when your body is tapping into the anaerobic system where instead of using oxygen for fuel, your body is tapping into glycogen stored in the muscles. Glycogen comes from the carbs you eat. It will store what it can in the muscles for energy and send what it can to the liver for brain and spinal column use. Depending on how much “active” muscle you have, the more you can store in the muscles. Anything in excess will be stored as fat. True anaerobic-only exercise is anything that goes above 80% of your maximum heartrate or anything that requires quick contraction and release of muscles. Because of the speed at which glycogen can deplete, you can usually only perform these movements for a short period of time. Some strength training exercises includes weight lifting, pilates, barre fitness, and yoga.

What are the benefits of strength training?

Strength training is great for building muscle, but that muscle helps with increasing your metabolism. This is a result of increasing muscle mass, the more muscle you have, the more your Basal metabolic rate increases, and the more calories you’ll burn while just going about your day. It also increases joint and bone density and strength. Consistent strength training increases your glycogen storage capacity providing more energy for the next workout and less carbs store as fat. It will also increase your lactic acid threshold building up your muscle endurance.

Is cardio or strength training better for weight loss?

Now going back to the question on which one will impact fat loss more. This is layered for a number of reasons. Because of how cardio uses energy, in the moment, cardio workouts will burn more carbs and fat while strength training workouts will keep you burning calories carbs and fat after your workout is done.


But there is rarely an exercise you can do that doesn’t incorporate both aerobic and anaerobic energy systems at the same time. For example, if you’ve taken a STRONG class at The Fit In where resistance is used regularly, you’ll be challenged to end the class without gasping for oxygen. This is because you are moving weights around with limited breaks. Whether it's circuits, AMRAPS, or EMOMS, for most exercises you are performing at a rate that you can maintain for lengthy periods of time and those 15 second rests only bring your heartrate down a few beats before its back up again. Your body will use both systems to get the job done the entire 45 minutes.


Same thing happens when you’re running or cycling up hill. It will be hard for you to end your session without feeling like your muscles are on fire or your legs are fatigued. Both systems are at play and our body will lean more into one system vs. the other depending on what’s happening.


The right answer is to do it all but most importantly just do something you enjoy. Our STRONG classes are a great way to tap into both systems, but if you’re just doing pilates where you may not get your heart rate up, maybe incorporate a more cardio heavy modality. If you’re just running flat on the treadmill, then maybe incorporate some sprints or traditional weightlifting to build up your strength.

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