EPOC – Urban Myth or Fat Burning Miracle?

EPOC stands for “Excess Post-exercise Oxygen Consumption” and works a bit like my log burner – takes a bit of time to get going but once it is fired up the heat it produces is massive and it keeps warm even when the fire has gone out. Keep that image in your head.

Another phrase you may have heard in relation to this is “Metabolic Training” and these are both basically the same thing.  Our metabolic rate tends to be fairly steady – it increases when we have done exercise or when we have eaten food, it can also decrease in times of “starvation” -which is a good thing if you are starving – but not if your calorie controlled diet is the reason. These increases and decreases are temporary so we need to keep priming our metabolism to keep burning calories at a higher rate.

Each day we need a basic number of calories to keep our body ticking over. This is called your “Basal Metabolic Rate” or BMR.  This calorie intake is based on your weight and your activity level. For a rough calculation times your body weight (kg) by 25 cals e.g. 70Kg x 25 = 1,875 calories.  Now you can add a bit more – so 20% extra calories if you lead a “sedentary” lifestyle (this means that you do less than 30 minutes of activity a day), add 50% extra calories if you are active (more than 30 mins continuous exercise that gets you out of breath) on 3 days a week and a whopping 100% more calories if you are active 5-7 days per week.  The things that can affect your BMR are – age – the older you are the less muscle mass you have and therefore your BMR drops (get to the gym!!), Body Temp – BMR increases with body temp (see above comment in relation to the fire and your hot burning face when exercising) , being “stressed” – and not just your everyday stress but also that bit of stress you feel when you are pushing yourself in exercise or even “exercise excitement” (yes, this is true and it is when you are looking forward to training..!)   - and finally, hormones with adrenaline (which is released when you exercise or are stressed) and thyroxine can increase BMR.

So, can you now begin to see a link between increasing your BMR and how exercise can help you?  When we start to exercise our demand for oxygen increases – you know this to be true as you will start to get breathless as the body increases its demand! 80% of your blood in your body is held in the central core, but when we exercise 80% then is circulating in the legs and arms – which is why we need to “warm up” and move the blood around the body. This can take about 5 minutes but is much quicker as you get fitter. You know this is happening as you can have red blotchy legs or arms and definitely a red or hot face

So, EPOC stands for our increased demand for oxygen AFTER our workout which then continues to keep our metabolic rate burning at the higher level – much like my log burner heating the room even after the fire has gone out.  Some research indicates that your metabolic rate can stay high for up to 2 hours following exercise. Here is how to maximise this. First, a look at fat burning...

FFA stands for “free fatty acids” and these are released into the blood stream when we are exercising to produce energy. This is Fat Metabolism – and by now I am sure I have your attention! Yes, to increase your fat burning you need to remember all the above things. 1. You have to get warm and slightly out of breath 2. You need to do this on a regular basis. BUT there is one thing that stimulates fat released and that is low blood glucose (sugar). We have already talked about this in a previous post and the necessity to eat well before a workout (inc the day before) and not to eat sugar during the workout, or before the workout (unless you haven’t eaten all day otherwise you may faint!) or immediately following your workout. This means when you are exercising (and starting to increase your oxygen demand) you will begin to burn fat as part of your demand for energy.  This fat burning CONTINUES after you have exercises as you return the body to its normal state. This happens following weight training as well as endurance work – recovery is fat burning.

When you train on a regular basis the body gets used to storing more carbs and fat - and trained muscles access your fat stores QUICKER and more efficiently than untrained muscles. There can be up to a 30% increase in fat burning properties in trained people than beginners – so yes, they burn more calories doing the same workout...And this happens when you train at least 3 times a week – and can result in significant weight loss. Consistency is the key here and the exercise can be of your choice but at least 20 mins continuous.

So in order to maximise EPOC please follow these guidelines:

1.       Metabolic Rate is affected by food and exercise

2.       Make sure that you have sound nutrition before training

3.       High use of sugar in the day will stop you fat burning effectively

4.       Try not to eat an hour before training

5.       Exercise can raise BMR and keep it elevated for around 30 mins post exercise – this increases fat burning

6.       Try not to eat sugar immediately after training – wait at least 30 mins and then, if possible, eat protein

7.       Your body needs to be well hydrated for these to work effectively – so keep up your water intake.

8.       Exercise on a regular basis to maximise