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The 411 on Cardio


When to do cardio? This is an age-old question that we will turn to in this week’s blog post. In at nutshell, and to set the record straight, the short answer is “ it depends.” Not so helpful, I know…

In general, there are three main times when people do cardio training; post workout, pre workout and in the morning (usually fasted). Now, let’s look at the reasons why the timing is important and how it relates to each person’s own fitness goals.

Post workout – If your goals are to increase lean mass and decrease body fat, doing cardio post workout is a good option. After weight training, you have depleted the stored energy in your muscles called glycogen. With glycogen level low, this puts you in an ideal state for burning fat. Therefore, if you did 20 – 30 minutes of post workout cardio, then you would be burning pure body fat because in order to burn fat, your glycogen supplies must be depleted.

Pre workout – If you’re not concerned about lean mass to body fat ratios, and you simply want to shrink yourself, then doing pre workout cardio is an option. In this situation, you are depleting your glycogen levels before doing weights, so when you start your weight training, you will be burning muscle as well as fat. Also, keep in mind that you will have much less strength and energy when you go to hit the weights. Essentially, you will become a smaller version of your unaesthetic self. You will simply occupy less space, weigh less, but in reality, you wont be looking any better…. which kind of defeats the purpose of being in the gym!

Did you know that cardio doesn’t actually burn fat, muscle does! So the number one priority when attempting to loose fat is to keep the muscle you have. Muscle tissue is metabolically responsible for most of the fat you’ll loose. Ten pounds of muscle burns 50 calories per day, even at rest.... so if you loose muscle it will be even harder to burn fat.

Morning cardio – Fasting throughout the night leaves us with very low glycogen levels when we wake up. If you go to do cardio with an empty stomach, and preferably with a cup of coffee to boost your adrenal glands, you will start burning fat within the first few minutes. If you did half an hour, you’d be burning adipose tissue practically the whole time. BUT hold up… I have to add in a warning here… doing fasted morning cardio is generally more for the advanced athlete, or when someone is cutting for a fitness competition. It does not protect muscle from being eaten up and this is due to high cortisol levels. Our cortisol levels are the highest in the morning; this cortisol spike is the natural energy boost that allows up to wake up. If you d