Cardio Fitness Not Improving? 6 Reasons Why You’re Failing

by Josh | Last Updated:  September 1, 2020
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Cardio is not a comfortable exercise to do; one has to push himself very hard if he wants to achieve results. Cardiovascular sessions are very crucial if one wants to remain in good health. However, what if you work hard during your cardio and still don’t get the expected results?

Why is my cardio fitness not improving? In many cases this will be due to lacking of overall cardio training at a proper level using a more casual walk or jog. Additionally this can be caused by being stuck training on a gym machine and not performing cardio outdoors. The final piece may be a lack of nutrition and not giving your body proper fuel.

Many people complain about their endurance not increasing, no matter how much they perform well at cardio. It can result from a plethora of causes, and throughout the article, all possible causes will be discussed in detail. Make sure to stay with the article until the very end.

What Are You Doing Wrong During Your Cardio?

Cardiovascular endurance means the heart’s ability to provide your muscles oxygen during extended amounts of time; your muscles require energy in the form of ATP (Adenosine Triphosphate). All living cells require ATP to function adequately.

Just like other materials, it reaches your living cells through the circulation of blood; hence the stronger your heart is, the stronger your endurance will become. Keeping these in mind, let’s alone move along to the common mistakes people do during their cardio, which hinders their progress.

Exercise treadmill cardio running workout at fitness gym of woman - Why is my Cardio Fitness Not Improving
Exercise treadmill cardio running workout at fitness gym of woman

Not Focusing On Aerobic Exercises

Cardiovascular exercises are at their core, aerobic exercises i.e., they are designed so you can enhance your stamina, be able to run greater distances without getting tired, and improve your breathing.

Aerobic means with oxygen, during an aerobic exercise, you are maximizing the amount of oxygen intake through respiration that your heart is using as fuel.

When you do aerobic exercise, the goal is to strengthen your heart, so it develops for functioning during prolonged periods of high-intensity exercises such as marathon running.

Anaerobic means without oxygen and this respiration occur in your muscle tissues when you perform immediate high-intensity workouts which require quick bursts of energy such as sprinting or heavy lifting.

During this scenario your body has to rely upon the stored sources of energy in your body such as glucose instead of oxygen in the air, as a consequence lactic acid is then produced and deposited in the muscles.

So, where does this fit into the picture of cardio? Well, as it’s a case with many people, they don’t realize that they are doing anaerobic exercises such as sprinting rather than aerobic exercises such as running over long distances. 

Sprinting while it is a great exercise, doesn’t at all benefit someone who is hoping to build endurance since during sprinting your body switches into anaerobic respiration mode, the running you do doesn’t contribute to the strength of your heart.

This is one of the key factors as to why so many people complain about not improving their cardio training.

If you are also asking “why my cardio is so bad” then you should consider taking rests in between to catch your breath and allow your body to switch back into the default mode of aerobic respiration and start running again at a slow pace for extended duration such as for 30 to 60 minutes.

Slow and steady wins the race. Don’t worry about the pace; what matters is whether or not you can reach the desired goal of running for at least 40 minutes.

Within a few weeks, you will experience better endurance and improved speed. Prolonged periods of running are a great way to improve your stamina.

Some other aerobic exercises which you can do to improve the heart rate are swimming, skiing, and cycling. However, swimming and running are the best options to go for.

Also, be sure to check for the safety precautions first. Consult your doctor if you have a heart or a breathing problem and pay attention to injury risks.

male using air bike for cardio workout at Functional training gym - Why is my Cardio Fitness Not Improving
Male using air bike for cardio workout at Functional training gym

Your Mode of Exercise Is Probably Steady State

Steady State cardio exercises are a type of cardio where your heart remains consistent throughout the session. But if you want to challenge yourself and improve your cardio, then you don’t want that.

Steady-state cardio doesn’t offer much challenge or room for your heart to develop and build the endurance you desire, rather you remain at the same place as you were before.

To challenge the heart rate, you need variations in the workout intensity.

High-Intensity Interval Training (HIIT)

HIIT (High-Intensity Interval Training) is a form of cardiovascular exercise that combines high-intensity workouts and short periods of intervals in between until the person is exhausted to continue.

HIIT exercises are a great way to maximize the effort you put into your cardio. In the above we spoke about not going for short, immediate exercises such as sprinting.

But, HIIT synthesizes those exercises to integrate them into your cardio sessions. During HIIT, your heart rate spikes and oxygen intake is maximized; hence you burn way more calories than your usual cardio exercises.

Why HIIT Is Recommended?

What’s good about HIIT is that it doesn’t always have a specific workout, rather you can convert any exercise into HIIT by taking it to another level by incrementing its intensity by adding ropes, weights into the equation.

Always remember that taking rests in between is the defining feature of HIIT workouts. Allowing yourself to take rests makes your body switch between the two modes of respiration i.e., from High intensity (Anaerobic mode) to lower intensity (Aerobic mode).

This prepares your body for quick adaptation to both modes and results in a more significant fat loss and maximum heart rate. Once HIIT sessions start your metabolic process, it continues to burn calories even after the workout by EPOC (Excess Post Exercise Oxygen Consumption).

To prevent you from overdoing it, you can combine this with moderate cardio and make sure to take tons of rest to balance everything out.

Your Cardio Lacks Diversity

Another common mistake people tend to do is that they do the same cardio exercises every day and stunt the growth of their endurance by putting their hearts to the same intensity every day and do not experience new exercises in their workout schedule.

Human bodies are very great at adapting to any condition when you do the same exercises in your routine. Your body adapts to those exercises, and those exercises gradually become comfortable for you to perform.

Thus the body refuses to grow any further than that until you add more diverse exercises in your routine. To level up, you should also level up your workout routine.

It’s common to get comfortable in a position. When you try to do new exercises, you experience a kind of anxiety and unwillingness to leave the place where you experience comfort.

That’s the same unwillingness your body expresses when you do workout for the first time; naturally, our body wants to feel comfortable, so it first tries it’s best to not engage in high-intensity activities.

But, when you force yourself to do it, it quickly adapts to that activity and hence doesn’t grow beyond that. Therefore, you must add more diversity to your workout routine.


You Might Be Relying Too Much on Gym Equipment

If you aren’t making the above mistakes, then it’s still possible that you are making your body rusty by relying too much on gym equipment such as treadmills.

While it’s great to use a treadmill, solely running on a treadmill limits the growth you will experience in cardio. It’s recommended that you take your time to do cardio outside along with running on treadmills.

You Might Not Be Complimenting Your Cardio with Weight Training

Many people make the mistake of not supplementing their cardio with weight training. If you want a better physique, then cardio alone won’t do the trick in itself.

You need to make a plan for your workout routine where you balance out usual weight training with an adequate amount of cardio.

You Might Not Be Supplementing Your Body with Energetic Diet

A factor that must not be looked down upon is diet. What you ingest plays a significant role in what you will become. Cardio workouts require a rich amount of nutrients to be able to perform those intense activities.

Both carbohydrates and fats are a great source of energy for cardiovascular exercises.

You should always take care of your diet and pay attention to the intake of fats and carbohydrates to provide energy doses to your body when you subject it to high-intensity cardio.

Some good sources for carbohydrates are whole grains, legumes, fruits, vegetables, beans, dairy milk, and yogurt. Some good sources for fats are avocados, salmon and other fishes, nuts, seeds, peanut butter, eggs, and cheese. Arranging a good time when to eat is also very critical.

Foods that take longer time to digest, such as fiber-rich foods, proteins, and fats should not be taken directly before a workout. Focus on the carbohydrate-rich diet before a workout after workout remembers to award yourself with lots of protein to aid in muscle growth.

Final Thoughts on Why My Cardio Fitness Is Not Improving

Cardio is a very useful type of workout to do that when done correctly, yields excellent results. You should always pay attention to the execution of the exercises to make sure that you are not making those mistakes that hinder your growth.

Building up your cardio system and endurance is sometimes forgotten and instead all focus is on muscle building, this is not very good for your overall health and you should strike a balance.

I actually love getting out and running when the weather here isn’t exceptionally hot and humid, when it is I focus on the treadmill and bike to get in a good workout for my cardiovascular health, it is a core component to health, treat it like it is!

Want To Build Your Home Gym? Get Premium Cardio Machines Now

If you are looking for some good options for at home based workouts for your cardio then I can provide some of the best options I have found:

I grew up in a home where most our days were spent inside, and sports were not a family priority. I did play soccer and baseball as a kid, but the older I got, the more I lost interest. To regain my health, I decided to adhere to the three tenets of health and longevity. I hope you will join me, by making it your purpose to live as long and well as possible.