Fitness Rush Personal Training Blog

Cardio before or after weight training

Cardio before or after weight training

When is the best time to complete cardiovascular exercise for fat loss?


This is a well debated question in the fitness industry and like many talking points, there are numerous answers as it can all depend on the individual. I have tried many scenarios to configure the most beneficial times to use cardio for fat loss and here are my findings.

A lot can depend on calorie consumption throughout the day, training frequencies, and workout times, to name a few variants but firstly we should look at our bodies energy storage systems. If we look at how the human body uses calories, we will discover that glycogen is its primary energy source. Glycogen is a stored form of glucose (sugar) which has been consumed as food, then used as energy when the going gets tough.

We have learnt over time that our bodies utilise increased calories from glycogen through using weight training exercises rather than intense cardiovascular activities, meaning by completing resistance exercises before cardio sessions, we can reduce the amount of glycogen in the body and prepare for the next stage of energy consumption in the name of fat breakdown.

To put it simply, our bodies uses Glycogen, Fat, then Protein (muscle), in that order. So, to tap into our fat storage, we need to make our weight workouts heavy and intense but with good form (obviously) to deplete our glycogen as much as possible.

Once we have depleted our glycogen stores – within 30 – 45 minutes (depending on workout intensity), it is time to take advantage of our fat burning system but completing steady state cardio for a prolonged period of time. Since our bodies will be searching for its next hit of energy, it will start to breakdown fat to use as energy, so you can continue with your exercise.

There seems to be a common misconception that cardiovascular exercise needs to be intense enough to have you feeling out of breath and completely knackered, but this is not always the case, especially where fat breakdown is concerned.

Our bodies can burn up to 50% more fat at approximately 65% of your maximum heart compared to higher levels, like during a fast sprint.

Your maximum heart rate (MHR) calculated at 220 minus your age, is the upper limit of what your cardiovascular system can handle during physical activity. An example calculation for 65% of your maximum heart rate for a 35-year-old would be;

220 – 35 (age) = 185
185 / 100 x 65 (heart rate zone) = 120 BPM (beats per minute)


Just replace your age for the one above and calculate your fat burning heart rate which should be followed as close as possible throughout the workout.

Fat burning contains a fine between total fat burn and tapping into protein (muscle) stores and considering how hard you have worked to grow your hard-earned muscles, the last thing you want to do is break it down for energy. So, common sense will need to prevail here. If you reach the point of dizziness or feel you can no longer continue at your steady pace, it is time to cool down and grab some well-earned food.

Fasted Cardio

Another sure-fire way to breakdown fat, is to complete steady state cardio in the morning before you consume your first meal. The reason for this is due to the fact that your body has reduced glycogen levels after hours of being fasted during your sleep. So, there is no need to perform your normal weights session as your body is already in a prime position to start breaking down fat immediately. Again, this can be detrimental to our muscle mass, so be careful towards how long your cardio session lasts. 30 minutes maximum would be a safe bet to begin with.

As soon as your session is complete, it is important to fuel your body immediately to replenish your energy stores and crucial nutrients your body needs to function efficiently.


So, to cut a long story short;

Use more calories than you consume,
Complete weights to deplete glycogen stores,
Utilise Fat breakdown through cardiovascular exercise,
Cardio can be completed on a number of apparatus, as long as its steady,
Be careful not to tap into muscle stores,
Cardio can be completed before food is consumed but again be aware of muscle usage,
Intense exercise isn’t bad, just more useful in different scenarios.


Cardio doesn’t have to be intense for fat loss, just steady for longer!