Will Doing Cardio Ruin My Gains?

Man running

Look. We all want to look good and feel healthy don’t we? Whilst some of us spend hours in the gym pumping weights whilst others are cardio monkeys and don’t really lift, the big question is will doing cardio ruin my gains?

The concerns about doing cardio playing havoc with strength and muscle growth are not new. Exercise junkies have studied doing aerobic and strength training at the same time, also known as “concurrent” training, for decades.

When too much aerobic work is added on top of a strength or hypertrophy (muscle growth) programme, there is indeed a detrimental effect.

If we do more than 30 minutes cardio, muscular power, strength and size can all be compromised.

But don’t forget doing cardio can promise many benefits and do good things for your body, such as stripping body fat, improve aerobic capacity, boosting metabolism and adding years onto your little ticker.

However, in order to maintain muscle mass during a hypertrophy phase we just have to get the right balance of cardio and think about doing quality not quantity.

How Much Is Enough?

As our metabolism declines after age 25, the average persons’ metabolism declines between 5 and 10% per decade.

This is why it is essential to add lean muscle tissue to help keep muscle metabolism high. Essentially this means meaning you do not get a drop in metabolism as you age – making it easier to lose and maintain weight.

It is because of this I will listen to my body each week and I will increase the intensity – only if I can cope with that intensity. So remember listen to your body though and back off if you don’t feel great.

I have the saying if you cant gain don’t train! So if you aren’t giving 100% take your foot off the gas.

Furthermore we are designed to move and do endurance training. After all we didn’t just sit there many moons ago and wait for our prey to turn up in a delivery van- we ran, chased, jumped and ran for hours trying to catch our next meal.

Estimates suggest that our recent hunter gathers expended as about 5 x more energy per day as the modern Westernised Man.

So, doing 3 x 30 minute cardio sessions on a bike reading a magazine will not make an ounce of difference to your fat loss goals.

Remember, we are genetically programmed to be much more active than what we are today. This is why I tend to tell my clients we are meant to move everyday and doing two sessions two days in a row wont kill you.

How Do I Make The Most Of It?

When doing cardio think about quality and think about work capacity.

Call it what you want, HIIT, cardio, intervals, you need to be giving 110% and emptying the tank and give no more if you want to strip body fat, get fitter and leaner.


Therefore, when doing cardio you need to combine it with smart training.

You will usually find the more fast twitch fibres the person has, the less they benefit from endurance and the more slow twitch fibres a person has the more likely they will adapt to and thrive with the endurance part of a conditioning program for fat loss.



What Does A Decent Cardio Session Look Like?

Well, as you probably know it’s better to do cardio in a fasted state during the morning to encourage fat burning.

This means as we go through the day you get more of a favourable cortisol to testosterone ratio, meaning you are more anabolic at around late afternoon say between 4-6pm and you are stronger – that’s why it’s best to get your cardio done in the morning if possible.

For example, a quality cardio session might look like…

  • HIIT session 10 minutes
  • XTrainer then 30 seconds
  • All out on the Rower/running sprints with 90 seconds rest.
  • Ratio is 1:3. Repeat 8-10 sets.

Done correctly, this is brutal and extremely effective at dropping body fat. So go on… experiment with HIIT in the morning and weights in the afternoon and make sure you are warmed up properly.

What Are The Benefits?

One of the benefits of doing HIIT and endurance is the increase in mitochondria.

The main signal necessary to promote mitochondrial adaptations is the reduction in adenosine triphosphate (ATP) and phosphocreatine, which occurs massively post HIIT training than the steady state boring endurance training.

As you are probably aware, doing HIIT properly increases your VO2 max over doing long steady state endurance.

According to Gary Dudley at State University of New York, training beyond 60 minutes per workout doesn’t have much value when it comes to the mitochondria.

So the bottom line is, think about an increase in intensity to bring the greatest adaptive response in the mitochondria.

This means if you are a runner, 10-15 minutes of running at 5km race pace can bring far more bang for your buck than running for 60-90 minutes at a slower intensities.

Finally, when you think of doing a cardio session the next time you are in the gym – consider intensity and quality, and make sure you recover enough to hit your next weights session by getting some good quality protein from Muscle Food to refuel!