Cardio vs Weights: Which Training is Better?

Fitness and Workouts

I get asked this question a LOT! I’m not sure if I’ve ever met a new client who did not ask me this question at some point early on in their training. At my studio I use a heart rate monitoring system to track each client’s workout. The program also estimates their calorie burn during the session. People are often surprised at how few calories they burn during a weight training session, and bring up the fact that their FitBit or Myfitnesspal app tells them they burn WAY more when they go for a run of the same length of time. They’re worried that they could be doing MORE to get better results. But there’s actually more to it than just the number of calories burned during a workout…

More is NOT Always Better

It’s easy to slide into the trap of believing that because cardio burns more calories, it’s better for weight loss than strength training. It’s true that going for an hour long run will use more energy during that hour than spending an hour at the gym lifting weights. Your heart rate is more consistently elevated during a cardio workout than during a weight training one, where you are intermittently exerting yourself, then resting. Especially if you are strength training properly with muscle building in mind, those rest breaks are really important! But when it comes to long term body composition changes (ie., fat loss and muscle gain), strength training is critical.

Here’s why…

The Afterburn effect (EPOC)

Ever heard of it? It’s the elevation in metabolic rate (aka calories burned) after you complete you workout. It’s also commonly known as “Post Exercise Oxygen Consumption”, or EPOC. After a workout your body has to restore homeostasis (balance), which takes more energy than if you were resting. The afterburn from a typical cardio workout is about 3 hours (depending on the intensity), so you continue to experience a bump in your metabolism for a few hours after you complete your run. Doesn’t sound too bad does it?

But a good weight training workout? That afterburn, or EPOC is estimated to be up to 48 hours. That’s right for up to two days after finishing that workout your body is still working a little harder than usual to restore balance.

Why? Because when we strength train we are causing damage to our muscle cells. We’re creating tiny tears in our muscle fibres that our bodies have to repair in order for us to get stronger.  This takes time and energy! Learn more about the science behind EPOC, here.

So, What Now?

So, if you were to do a good quality strength training workout 3-4 times per week, you would be experiencing a higher metabolic rate almost all the time.  Add this up over weeks and months and you’ll see why strength training is so strongly encouraged by fitness pros.

The other benefit of regular strength training is that when you have more muscle mass on your body (vs more fat), you experience a higher metabolic rate all the time just to keep that muscle alive. Muscle is a high maintenance tissue, which means it needs more calories per day to keep it functioning vs fat tissue. This increase in metabolism may be small, only a few hundred calories per day even with a large amount of muscle, but it can make all the difference as we age in preventing unwanted weight gain.

Don’t get caught in the cardio training trap!

Let’s say you want to start getting in shape.  So you decide to start running. Great! You start running and build up to 30 minutes 5 days per week. Because this is a big change for your body, it is very likely you’ll experience some weight loss in the first few months. But, after awhile we adapt to the workout and get more efficient at completing the task. So at first you might have burned 700 or 800 calories during that run, but as you lose weight, your heart gets stronger, and you keep doing the same workout, that calorie burn decreases. Your weight loss hits a plateau. So what do you do?

Most people will choose to run for longer in order to burn more calories and continue to lose weight. But eventually, inevitably they will teach a point where they can no longer dedicate such a huge amount of time to cardio (who honestly has two hours a day to work out?!) They’re frustrated from working SO HARD without seeing changes in their physique, and at higher risk of injury from the constant repetitive motion (if there’s an imbalance in your running stride you’re definitely going to know it after that much running!). And lets’s face it, doing the same workout the same way for months or years on end gets boring. 

Eventually it gets harder and harder to get yourself out the door or onto that treadmill. I’ve seen it time and time again. People are doing really good for awhile…then a combination of a lack of results (or an injury), and getting tired of the same old workout causes them to just quit.

Change It Up and Challenge Yourself

But don’t get me wrong, I’m not hating on cardio! I’ve even done a few half marathons myself.  I love running, and I love helping others become better runners.  The benefits of regular cardio are HUGE for disease prevention, mental health, and healthy aging. Setting goals like training for a race can be great motivation as well. However, doing more cardio will not necessarily lead to more weight loss. We need to change it up and challenge our bodies to keep seeing changes!

Strength training is really the key for getting the most out of the time you spend being active. And, If you want to be a better runner then doing some running-specific strength workouts is critical to get a stronger more efficient stride (Click here for some running-specific exercises!) You don’t need to continuously increase your time spent running to see results. Read here for more information on how much cardio you should be doing. If your goal is to complete an endurance race like a marathon or half marathon, then yes doing a lot of running is critical for a successful race. But for everyone else, doing hours and hours of cardio every day isn’t a great way to use their precious time.

* It’s also important to remember that each of us has unique genetics that dictate how we respond to different types of exercise. Some people take up running and lose huge amounts of weight, others lose none at all. Some people gain muscle readily when they start strength training, others struggle to put on any muscle size. We’re all different so it is important to find a balance of physical activity that you enjoy and is right for you!*

Will lifting weights make me bulky?

No! Absolutely not.  In order to look like a body builder you would need to train in a very specific way for YEARS and probably take some questionable substances.  Most people do not have the genetics to grow huge muscles naturally.

How do I get started?

The good news is, a great strength training workout can be done with zero equipment, right from home! There are plenty of free workout plans available online (I’d only advise paying for a plan if someone is making it specific for you) To begin, start with a full body circuit training workout 2-3 times per week. Choose exercises that target all of the major muscle groups. Remember- you should be exercising at level you’re at, not the level you want to be at!


Need help getting started? Contact me for a personalized fitness plan!