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  • Writer's picturebrittanytblocker

Why isn’t all that cardio working for you?

Cardio has been the magic word for those looking to lose weight. I hear it all the time, “I need to do more cardio”.

Many people who struggle with weight loss often look to cardio as their saving grace. “THIS must be the reason why I’m still not where I want to be...I don’t do enough cardio!”

What if I told you that cardio is actually having the opposite effect on you and your weight loss journey. What if I told you that cardio has the chance of actually adding weight to you rather than losing?

Sounds crazy I know, we’ve been all taught over and over that cardio burns calories and burning calories is how you lose weight.

Where this is true in regards to the calorie expenditure, it is not true that cardio is the prime way to get your body shedding those extra pounds.

What I want to do here today is to give you some science for why cardio isn’t the best way to burn fat but also talk about how cardio can be a determinant to your success. I’ll give ideas on how to incorporate different styles of training so that you can maximize your weight loss results!

What do we define as cardio?

Cardio is short for cardio respiratory training. This can be any exercise that creates an energy demand on your body that elevates heart rate and gets your blood pumping. Usually cardio is seen as a form of steady-state exercise, keeping one singular pace and working more for time than intensity. Common forms of cardio are as follows:


The most popular form of cardio which most people will immediately associate with the word cardio - running at a steady pace for an extended period of time is a super popular way for people to work on their health and aim to lose weight. Running can be anywhere from a short mile run all the way up to a marathon and beyond.


A low-impact form of cardio - if you embrace our evolutionary roots you might be someone who loves going into a pool and doing a few laps. This is a great way for people to get their heart rate up without putting the undue stress that running puts on your body.


Although this is something that doesn’t immediately appear to be cardio because it’s slower paced - it absolutely works the heart in the same fashion that running would. You get the added bonus of being in nature which helps with emotional and mental health as well!


This one is a bit more fun and dynamic - a full body workout that has you twisting and turning in ways you didn’t think possible. Kickboxing is a heart pumping activity that is sure to get you pumped and ready to star in your own action film kicking and punching all around!


My favorite form of cardio (we’ll get to why later) , rowing is a low-impact form of cardio that also uses muscles in your arms creating a more full body experience. You have the ability to row for long distances (shout out to those who have done a 5k!)


Super popular style of cardio - spin bikes have been a huge weekly exercise routine for many people. This is also true for those who enjoy riding a bike outside and embarks on several mile journeys on their bikes. This is a low impact form of exercise which keeps the body safe and allows you to work your legs super hard.

Jump Rope

Less popular but super effective cardio workout is using a jump rope. This is not for those with joint issues as the continually jumping up and down can cause some havoc on your body. If you can manage this one - this is a great choice to throw into the mix.

Everyone has their favorite form of cardio and many people are huge fans of 1 or 2 styles. For me, I’m all about rowing and hiking. I love rowing because it’s low impact, provides a way to work your arms and back, and leaves you the ability to set up intervals to make it more into HIIT (High intensity interval training).

Hiking on the other hand is more for my emotional and mental health than anything with the bonus to that steady state cardio work. Walking 10k steps in an hour or two will definitely keep your heart rate elevated with low impact and burn plenty of calories.

Now there is nothing wrong with doing cardio - it’s necessary to have a well rounded health profile! Strengthening your heart by routinely going out and doing cardio work has profound benefits that I can’t deny.

What I want to hone in on - are for those that believe this is the end all, be all way to effectively lose weight and look better.

Energy expenditure with cardio

If you are an avid runner or enjoy doing hour long spin classes you might have recognized that after a workout you are ravenous. Putting the body through continuous stress and energy expenditure burns calories and has your body craving food.

Let’s just say that you took a spin class, went on a run, or did some biking for an hour. If you are working decently hard and have your heart rate at about 65% capacity you can burn anywhere from 200-500 calories during that hour long cardio session.

Afterwards, you will definitely want to eat something and for most people will eat a meal that is somewhere in the range of 250-400 calories.

Since you’ve worked out you will be in a calorie deficit for the day if you eat like you normally would on any other non-workout day. The deficit will probably be in the range of 300-500 calories total for your day. This is significant for sure and will show results at the start of including these cardio sessions into your weekly activities.

However as you get better at running or cycling - these benefits may start to wane. Let’s look at some long-term impacts of cardio based fitness.

Long term impact of high impact cardio

What happens to the body when it gets more familiar doing an activity such as running? Your body adapts to the energy demands and will more effectively use energy to sustain your bouts of exercise. What this means for your calorie that it will decline.

Just like with any exercise demand on the body you will improve over time and become more efficient. This goes true for weights, swimming, rowing...everything!

For example, if you were to go run 2 miles every 3 days for the next 2 months you will start to notice a change in how it feels to run those 2 miles. You might do that run faster or feel less fatigued after the 2 miles are done. If you don’t change the volume or intensity you will actually be working your body to stay the same rather than improve. The body needs increasingly difficult demands on it to grow and change. This goes true with muscle gain as well as weight loss.

Another impact with cardio is the chance of injury. If you know a runner - you probably know that they have some type of lingering injury. Now this might be specific to running but keep in mind that doing any repetitive motion over and over can result in injuries.

Hips, Knees, Ankles...all are sore spots for avid runners.

What happens when you get injured? ...Well you stop working out as hard or as often as you previously had.

This results in doing less work and therefore makes less changes in body composition.

The cycle is a brutal one, a painful one at that.

There are cardio exercises that are better on your joints such as Rowing, and swimming (another reason why rowing is awesome!).

If you can’t effectively move on a consistent basis you will continue to hit walls and feel the need to “start over” and promise to yourself that this time you will do more cardio! This is a recipe for disaster.

What you should be doing instead

There are 2 methods of training that can result in far greater calorie burn as well as built in progression to keep the body challenged and adapting to new stimulus. Thus, promoting weight loss and body change.

High Intensity Interval Training (HIIT)

You might be familiar with this style of training - it’s structured in such a way where you do very tough work followed by short periods of rest.

Take a look at the famous “tabata”, a 4 minute interval circuit that has you doing 20 seconds of hard work followed by 10 seconds of rest.

The magic of this for fat burning is you are able to get your heart rate really high (80-90%) while allowing for a brief recovery. You can continually work hard to get a set number of reps in, which over time can show you the progress you are making.

For example a very simple one that anyone can do is the following:

4 minutes - 20 seconds Work : 10 seconds of Rest (8 rounds)

  • Air Squats

The goal here is to try and get 20 Air Squats in 20 seconds for the full 4 minutes.

This type of workout checks many boxes in the weight loss/ body composition category. By pushing yourself to get 20 squats each round you will be working at a much higher heart rate value.

You will also be testing yourself and therefore attempting to progress each and every time you do this workout. This allows for progression which allows for change.

Lastly you will be working a movement pattern that has many muscles working together, which helps to burn more calories during the short 4 minute time frame. Not only do you allow your heart rate to get high but you also get those muscles working in a more strength oriented way.

This brings us to my favorite way to burn calories and make body changes…

Strength Training

Let’s cut right to the chase here : building muscle requires more energy, which requires more calories to sustain that muscle.

When you develop lean muscle you are turning your body into a furnace that burns more calories even at rest!

The true beauty of it all happens when you are following a program that has you progressing weights each and every week. The heavier you can lift, the more muscle that is required. By doing this in a progressive overload you are enabling your muscles to adapt to the changes, grow, and require more energy to sustain.

There is a reason why bodybuilders need to eat so much food just to SUSTAIN their body. Not even to grow but to just keep them at their current size.

Think about it for a second: if we take 2 people...person A and person B.

Person A runs 3 times a week and does 2 days of dumbbell strength training.

Person B strength trains 3 times a week with barbells and does 2 days of HIIT style training.

Let’s think about a rest day in which no working out is taking place. With all other things being equal (food intake,portion size, temperature, movement) Person B will have a higher energy requirement because they are actively strength training. If both people were sitting in a chair just having a casual conversation, Person B will be burning more calories during their sedentary time than Person A.

IF you want to “get a faster metabolism” start adding heavier weights to your workout routine.

Cardio isn’t bad , it’s just not the whole picture

If there’s anything I want you to leave this article knowing today is this:

  • Cardio is important in building up a strong heart and creating an environment that is conducive to overall fitness and weight loss.

  • Cardio is NOT the main reason why people lose weight and it’s not the center piece that many think that it is.

  • A reliance on Cardio can have long term impacts that actually set you back rather than push you forward in your fitness journey.

  • Lack of cardio is not holding you back from making changes, it is not the cure for your weight gain issues!

Finally...a piece of advice for those hitting walls in their fitness even when they feel they are doing everything they can with exercise….You can't out exercise a bad diet.

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