4 Reasons Why Too Much Cardio Is Bad For You and What to Do instead

4 Reasons Why Too Much Cardio Is Bad For You and What to Do instead

By Mackennon Klink, CSCS, PN1

I have a confession: back when I was a runner I used to hate resistance training.

Yup.  I hated it with passion.

Allow me to rewind a bit to explain why.

It’s my junior year of high school. It’s winter break and I’m with my family at Sun Peaks Resort in Canada.  My brother and I were learning how to snowboard. I don’t know if you ever tried to snowboard, but you fall down.  A lot. For the week we were there, I remember my brother and I spending more time on the snow rather than on our board.

On our third day on the slopes, we were slowly making our way down the mountain.  I think it would be more accurate to say we were falling our way down the mountain.  Anyways, I was starting to make some progress. I’m doing it! I thought. I’m actually staying up.  Boom! The edge of board caught on the snow and throw me down onto the ground. Except this time instead of snow, both my knees directly landed on a rock.  OUCH!

After that incident, I couldn’t snowboard pain-free.  I couldn’t even walk without pain. I spend the rest of the week icing my knees while my family enjoyed the little remaining time we had at the resort.

Flash forward to my Sophomore year of college, and I’ve finally recovered from my injuries.  My snowboard incident caused me to undergo dual parallel surgery to remove the scar tissue and repair the tissue. It took a full three years to recover.   It wasn’t a pretty easy recovery as i could barely move. I was 17 and I had the mobility of a 91 year of man. If I did any sort resistance training it caused my knees to ache for days.  I struggled to regain my athletic ability, but I just couldn’t.

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A young Mack, super excited on finishing his first Marathon

Missoula, Marathon 2011. Full Marathon time 4:12:19

However, the only thing I could do was run.  I went to the University of Montana where endurance running was popular and I caught the running bug.  I was hooked and I transformed myself into a marathon runner. During my 5 year “running career”, I’ve completed 13 half marathons and three full marathons.  

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Hindsight is always 20/20 and knowing what I know now I wish I didn’t become a marathon runner.  

You might be wondering, “Mack! As a former runner what do you against running??!”

First, allow me set the record straight:  Cardio does have benefits. It’s great for your heart health. And it can help with fat loss. But you shouldn’t think of it as the main driver of fat loss. Also, if its something you enjoy doing, then by all means continue doing it!! My only issue is when it’s the only thing you do.

In fact, doing too much cardio can slow down your metabolism, fat loss progress, and do more harm than good for your body.  

I know from first hand experience.

Here four reasons why too cardio is bad and a simple solution that will get you back on the right track:

  1. Your Body Increasingly Resists and Holds Onto Fat:

    When it comes to weight lost, many people’s first thought is to start by increasing their cardiovascular exercises (running, swimming, biking, etc).  This makes sense as long duration cardio exercises are one of the best bang for your buck exercises in terms of total calorie expenditures.

    Yet, the positive fat-burning effects of cardio exercises have a short half-life.  Once you stop exercising, your body’s metabolism quickly return to homeostasis - back to its normal state.  Cardio training is the “manual” way of burning calories and as you get better (i.e. running faster and longer), your body adapts to make the exercise less effective at burning body fat.

  2. Your Body Remains “Soft” and Fragile:

    If weight loss is your goal, then it’s exciting to see the scale numbers start to drop and for good reason.  Your hard work is paying off!However, is that your true goal?  If your only goal is to see a number on a scale, then congrats.

    But what about developing yourself?  What about improving your self confidence, discipline and self-worth? I know from my experience, I suffered in all three areas and I did so just to see that scale number say 170.  While reducing your bodyweight is an alright goal, your true goal should be in improving your body composition.  

    Your body composition (i.e. the ratio of lean body mass to body fat) helps determines the overall shape of your body.  Unfortunately, long duration cardio exercises (ex. half and full marathon running) is actually reducing your body fat while simultaneously reducing your lean body mass.  

    The end result?  All your hard work is actually preventing any positive body composition from occurring!

  3. Constantly hurt all the time:

    Due to it nature, cardiovascular exercises often cause the individual to suffer both minor and major overuse injuries.  Marathon runners takes a serious pounding through their ankles, knees, hips, and lower back with every run. Cyclists suffer from poor posture in their shoulders and back from hunching over.  Even swimming can cause shoulder issues over time.

    Can I ask you a question?  How do you joints feel on a day-to-day basis?

    If you are constantly dealing with chronically achy or creaky joints, that’s your body telling you to stop! You need to listen to your body.  It’s trying to tell you something is wrong.

    You might not immediately notice a change in how your body feels but chronic soreness develops gradually.  It’s very easy to overlook, but there’s no question about it - Excessive cardio will eventfully take a toll on your joints.

  4. You Always Feel Like You’re Running On Empty:

    Exercise is supposed to be a natural energy-booster, and it certainly can be, but overloading on cardio training can have the opposite effect.

    Exercise is also a form of physical stress.  It stresses your body which leads to physical improvement over time.  Your body adapts to this stress by developing endurance and aerobic capacity so you can run faster and/or further.  

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That’s Good!

However, just like any system, your body only has a finite capacity to deal with cumulative stress. Pushing and challenging your body while dealing with other stressers (work, relationships,etc.) will overload your body and you won’t be able to cope.  As a result, you’ll eventfully burn yourself out and feel tired and worn out throughout the day.

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That’s Bad!

Your Solution to Cardio Overload: Strength Training

If you’re experiencing any or all of these four symptoms, it’s time to change your routine.  I don’t want you stop exercising altogether, or even exercise less. Rather I want you to modify your program by incorporating more mobility and strength training in your training.  

Again, let me be crystal clear:   In NO WAY I am even remotely suggesting you stop exercising altogether, or even exercise less frequently.  

Instead, modify your training by incorporating more mobility and strength training in your program.

Strength training has a host of benefits that endurance athletes need to improve their performance.  First, strength training will help maintain muscle mass and improve your running.  By increasing your leg muscles this will allow you to run faster, become less injury prone, and will help you develop a more aesthetically appealing physique.

Second, strength training will provide the necessary variety to avoid overuse injuries commonly associated with cardio-only training.  Developing your strength will also support your ligament and joints making them more resistant so you are even less likely to suffer from chronic soreness or injuries.  

Cardio training is an excellent tool for your overall health, but moderation is key.  Aim to balance your cardio training with strength training. Replacing even two cardio-focus days with strength training can reduce the physical toll your body undertakes and restore your energy levels.  

Resistance vs. Cardio Training - Which is better?

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