Rehabilitation & Recovery

7 Reasons Too Much Cardio Is Killing Your Strength

too much cardio

The Hidden Downside Of Too Much Cardio

We’re sure you’ve heard of the saying ‘too much of a good thing’ and that relates to anything; food, technology, exercise, and so on.  

When it comes to working out, we’re told that regular strength training and cardio exercise is good for our overall health and immune system, and we’re not going to dispute that.  

After all, resistance training helps to increase muscle mass while a regular cardio session keeps our hearts healthy and helps to prevent excess body fat.  

But, how much is too much cardio?  

In this article, we’ll be delving into the pitfalls of overtraining and excessive cardiovascular exercises and their potential impacts on your body.

​What Can Happen If You Do Too Much Cardio

Whatever your fitness goals are, more isn’t always better.  It doesn’t matter what type of exercise you do, training to extreme levels can result in certain negative effects and is counterproductive to good health.  

Too much cardio can result in loss of muscle, premature aging, reduced metabolic rate, weak joints, and poor bone health.  

woman on cardio bike

Let’s look at these affects and more in further detail. 

Muscle loss is one of the more noticeable effects of too much cardio.  

Not only will this make you weaker it will also impact the health of your joints and tendons.  

This is because muscles are responsible for supporting your joints and when muscle atrophy occurs this could affect joint stability leading to a great chance of injury.  

What’s more, as lean tissue breaks down, there’s a decline in overall strength which can it more difficult to perform everyday activities.  

If your goal is to maximize strength and increase muscle mass, your focus should be on weight lifting and not excessive amounts of cardio.  

Studies have shown that the more days per week you perform cardio and for long durations, the more it interferes with building muscle.  

Prolonged and intense cardio, such as long-distance running, can disrupt hormonal balance, especially for women, resulting in disruptions to menstrual cycles which can negatively impact bone health.  

Stress hormones (cortisol) tend to rise during any form of cardio whether it’s hiit workouts or steady state cardio.  

This is normal and happens so that your body can metabolize energy and allow you to perform your exercise routine.  

However, this is a temporary effect and typically lasts anywhere from 30 to 90 minutes post-exercise.  

Too much cardio can cause cortisol levels to remain elevated which can lead to high blood sugar due to temporary insulin resistance, muscle weakness, and weight gain affecting your overall body composition.  

Studies have shown that too much aerobic exercise can increase levels of oxidative stress, which can be damaging to bodily cells and your DNA resulting in premature aging.  

Other symptoms of oxidative stress include graying hair, tiredness, and an increase in wrinkles which all contribute to an aging effect on the body.  

What’s more, too much cardio can impact your body’s ability to produce collagen which is a vital building block responsible for supporting skin and connective tissues.  

Without proper nutrition and inadequate recovery time, collagen can break down causing the skin to lose its elasticity.  

Too much cardio, especially when it results in overtraining and placing significant stress on your body, can suppress your immune system.  

Various factors contribute to this including increased cortisol levels and the build-up of chronic inflammation.  

This can interfere with the function of things like T cells which are important in helping your body’s defence against illnesses and infections.  

If you’re a marathon runner or you just like to partake in regular long-distance running or cycling, you’ll increase your risk of overuse injuries.  

This is because too much exercise puts more physical stress on your joints and tendons due to repetitive movements over a long period.  

These injuries can range from tendinitis, shin splints, and stress fractures and they become more likely if you don’t allow for plenty of rest days between your workouts.  

Overtraining happens when the intensity and volume of your workout routines exceed your body’s ability to recover. 

Too much cardio, without sufficient rest and recovery, can lead to overtraining.

This condition is characterized by persistent fatigue, decreased performance, irritability, poor quality sleep, and an increased risk of injury.

In short, your body feels tired, you’ll probably notice more aches and pains in your joints and normal everyday tasks feel that much harder to do.   

If you perform too much cardio, you may notice you feel hungry more often.  

This is because there can be a rise in the hunger hormone known as ghrelin which is produced by your stomach.  

When you constantly feel hungry, you’re much more likely to indulge in unhealthy snacks which can be counterproductive to your weight loss goals.  

The Benefits Of Cardio

People who regularly perform any form of physical activity are typically much healthier when compared to those who perform no exercise at all.  

Let’s look at some of the main reasons why regular, moderate exercise is important.

cardio agility ladder footwork

Numerous studies have been undertaken and all of them show that regular exercise, whether that’s weight training or aerobic training, can add several years to your life expectancy.

This is because working out reduces the likelihood of becoming overweight and strengthens your heart helping to prevent conditions such as heart disease.  

When you exercise this increases blood flow and oxygen to your muscles and when your circulation improves this can improve the efficiency of your cardiovascular system which in turn can support energy production.  

Steady-state cardio that’s performed over an extended period can help to increase your stamina and endurance.

Regular physical activity can help your body to adapt to stress more efficiently.

Over time, when you undertake consistent moderate exercise, this can lead to a blunted cortisol response meaning that the body becomes more adept at regulating cortisol levels.

Moderate exercise helps your body to utilize stored fat as a source of energy.

This process is known as fat oxidation and helps contribute to a reduction in body fat.  

What’s more, you’ll burn more calories helping you to get into a calorie deficit which further helps with your weight loss goals.

Good heart health is important for pumping blood around your body and when it can do this efficiently this can help to lower your blood pressure.

What Type Of Cardio Is Best

The best type of cardio really depends on your goals and, interestingly, the type of cardio you choose to perform can have different results depending on your objective.  

High intensity interval training (HIIT) involves short bursts of intense exercise followed by longer rest periods.  

This can be something like cycling, running, or rowing.  

If you want a form of hiit that’s going to be easier on your body with a faster recovery time, then cycling has been shown to be the best method when compared to running.  


The great thing about this form of exercise is that you only need to do it for around 15 to 20 minutes to get the most benefit.  

It’s also been shown to be far less muscle-sparing when compared to other forms of cardio.  

So, if muscle growth is your primary goal but you want to perform regular cardio to keep yourself healthy, hiit could be the best choice for you.  

When it comes to the best time to perform your hiit workouts, this ideally would be on rest days or post weight lifting.  

If you carry out hiit training prior to a resistance workout, you’ll likely find that you can’t do as many reps or lift as much weight due to fatigue setting in which could have a negative impact on those all-important muscle gains.  

Hiit training can be demanding both physically and mentally with the main disadvantage being that you won’t be able to perform too many of these workouts.  

Stick to around two hiit workouts per week and combine with some steady state cardio.  

Low intensity steady state cardio (LISS) is performed for longer durations and can be anything from swimming, jogging, and brisk walking.  

As you’ll want to sustain this type of cardio for longer periods you’ll want to keep your heart rate steady.  

When steady state cardio is performed to moderate levels, you’re much less likely to suffer from overuse injuries with far less impact on your joints making it a great option for seniors and beginners.  


In terms of frequency, aim for around two liss sessions per week for around 25 to 30 minutes.  

You can increase the duration or frequency as you see fit but make sure you avoid overtraining and don’t do too much.  

Wrapping Up

A moderate amount of exercise has many health benefits and one of the best ways of reaping all of these benefits is to keep things varied.  

By incorporating a range of cardiovascular training, a couple of times per week along with lifting weights and even a brisk walk every now and then, you’ll help to keep your body in tip-top condition.  

Always listen to your body and if you’re ever unsure consult with a personal trainer to discuss a suitable workout plan to best suit your goals and ability.  

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