Fat Burning: how and why?

Fat burning is a very popular and often used term..

Fat Burning: how and why?

Fat burning is a very popular and often used term among endurance athletes.

There are fat burning workouts, fat burning nutrition supplements (fat burners), exercise machines in the gym have fat burning options and heart rate monitors tell you when you are in the fat burning zone.

The term fat burning refers to the ability to oxidize (or burn) fat and use fat as a fuel instead of carbohydrates. Often fat burning is associated with weight loss, decreases in body fat and increases in lean body mass.

However, it must be noted that such changes in body weight and composition can only be achieved with negative energy balance: you have to eat less calories that you expand, independent of the fuels you use!

Are you eating less calories you lose weight?

How are you finding it?

It is important to realize that increasing fat oxidation does not mean losing body fat or body weight!

Here we will discuss the importance of fat burning and the most important factors influencing it as well as nutrition supplements that claim to increase fat burning.

The importance of fat metabolism 

It is becoming increasingly clear that the ability to burn fat is important for both performance and health. it is also well established that well-trained endurance athletes have an increased capacity to burn fatty acids.

This enables them to use fat as a fuel when carbohydrate stores become limited. In contrast, patients with obesity, insulin resistance and type 2 diabetes may have an impaired capacity to burn fat.

As a result, fatty acids may be stored in the muscles and in other tissues. The accumulation of lipid in the muscle and its metabolites mat interfere with the regulation of metabolism. Although evidence for this is not available it is appealing to think that an increased capacity to burn fat may aid those who want to lose weight and, in particular, body fat if used in combination with a negative body energy.

How often do you workout and how many calories do you burn each workout?

Factors that affect fat burning

The factors that affect fat burning have been listed in the table below, and will be discussed below. Not all of these factors are equally important. They have, therefore, been ranked in order of importance based on the available evidence. Exercise intensity and diet are the most important factors and will be discussed first.


Fat Burning

Factors that affect substrate utilization

Exercise Intensity

One of the most important factors that determine that rate of fat burning during exercise is the intensity. Although several studies have described the relationship between exercise intensity and fat burning, it was not until recently that this relationship was studied over a wide range if intensities.

In absolute terms, findings showed that carbohydrate burning will increase proportionally with exercise intensity and that the rate of fat burning will initially increase but will decrease again at higher exercise intensities.

While it is often claimed that you have to exercise at low intensities to burn fat this is not always true….

Do you exercise at low or high intensity?

There are many recent studies that have defined the exercise intensity at which maximal fat burning is observed as “fatmax“. There was a group of trained individuals it was found that exercise at moderate intensity (62-63%vo2max or 70-75%HRmax) was the optimal intensity for fat burning, whereas it was around 50%vo2max for less trained individuals (achten et al. 2003b; jeukendrup et al.2005). It is important to note that the inter-individual variation is very large.

A trained person may have his maximal fat burning at 70%VO2max or 45%vo2max and the only way to rally find out is to perform one of these fatmax tests in the gym. However, in reality the exact exercise intensity at which fat burning peaks may not be that important because within 5-10% of this intensity (or 10-5 beats per min), fat burning will drop rapidly. This exercise intensity (fatmax) or “zone” may have importance for weight loss programs, health-related exercise programs, and endurance training. But very little research has been done to date.


Dietary effect


There are many factors in a persons diet, A diet high in carbohydrates will suppress fat burning and a diet low in carbohydrate will result in high fat burning rates.

Taking in carbohydrates in the hours before exercise will raise raise insulin production and subsequently suppress fat burning by up to about 35%. This effect of insulin on fat oxidation may last as long as 6-8 hours after a meal which means that the highest fat burning rates can be achieved after an overnight fast.

Do you exercise fasted? 

Many endurance training athletes will train fasted as a way to increase the fat burning capacity of the muscle. If you wish to increase your endurance then this is the way you will need to train. We prefer to train after a meal but it depends of the individuals goals.

Duration of Exercise

It has been long established that fat burning becomes an increasingly important fuel as exercise progresses. During ultra-endurance exercise fat burning can reach peaks of 1 g/min although fat burning may be reduced of carbohydrate is ingested before or during exercise. in terms of weight loss, the duration of exercise may be one of the key factors as it is also the most effective way to increase energy expenditure.




Will Caffeine Help you lose weight?

Yes but…

  • Only if you drink a caffeinated cup of coffee within a  hour before you workout so…
    • You can have more energy to workout harder and longer to burn more calories to lose weight faster and…
    • Caffeine helps your body use or burn mostly only fat for energy while you workout &…
    • As a Bonus: Caffeine increases your metabolism andsuppresses your appetite. See What is too much caffeinebut also…
  • Only if your coffee doesn’t have a whole lot of extra added calories from creams & sugars and…
  • Only if you drink about 1-to-2 cups of coffee per day so on the other hand…


Its not okay to drink more than 1-to-2 cups of coffee because when trying to lose weight because in the long run…

Too much coffee and caffeine will only make you gain weight mainly by making you eat too much because…

  • Caffeine increases the stress hormone cortisol and cortisol increase your cravings for sugary, salty & fatty foods that make you gain weight and…
  • The sugars and creams you put in your coffee will cause your blood sugar levels to rapidly go up and then right back down making you hungry for more food and…
  • The artificial sweeteners like Nutrasweet, Equal, & Sweet N Low that you use in your coffee will make you gain weight by also increasing your cravings (just like diet sodas do) and finally…
  • Too much caffeine will also make your blood sugar levels go up and down quickly increasing hunger and also…

When you drink too much coffee…

  • You’re going to end up drinking too many calories that does nothing to satisfy your appetite and…
  • When you’re on a basic 1200-to-2000 calorie weight loss dietyou don’t want a large part of your diet made up of liquid coffee, soda and/or tea calories so basically…
If you want to lose weight while drinking coffee & caffeine…
  • Drink no more than 1-to-2 cups of coffee per day and…
  • Drink those 1-to-2 cups within 1 hour of working out to lose weight faster and…
  • Limit the amount of sugar and creams you use or better yet…
  • Use natural sweeteners like Sweetleaf, Sun Crystals, Stevia,Truvia or PureVia and…
  • Avoid using the artificial sweeteners like Nutrasweet, Equal, Sweet N Low, Sweet Twin, Sugar Twin, Splenda, Sunett & Sweet One that make you gain weight but…


What is too much caffeine?


Well, that answer will vary from person-to-person but generally when it comes to burning fat faster…

  • All you need is about 50-to-300mg of caffeine within an hour of working out to get the energy boosting & accelerated fat burning benefits and…
  • More than 300-to-600mg of caffeine per day is too muchbecause it may lead to side effects like nausea, headaches, trouble sleeping, nervousness, irritability or fast heartbeat but…

When you’re trying to find out the right amount of caffeine for you…

  • Start off with only 50mg, 1 cup of coffee, ½ can of red bull or ½ the serving size of your fat burner and…
  • If that doesn’t give you the energy boost you need then get more caffeine but…
  • Once you get to a point where you need more than 300-to-600mg…
  • You’re going to have to bring your tolerance levels back down by not taking so much caffeine for next few days, weeks or months so you can continue to get an energy boost off the safer 50-to-300mg of caffeine because…

Your body gets used to caffeine very quickly &…

  • Usually (depending on which study you look at) within 2-to-12 days of taking 50-to-300mg of caffeine daily the fat burning & energy boosting effects will wear off because…
  • Your body has gotten used to or developed a tolerance to the 50-to-300mg of caffeine you’re taking and…
  • That’s why your fat burners, cups of coffee and energy drinks stop giving you an energy boost because you use them too much without giving yourself a break from caffeine so again…
  • Once you get to a point where you need more than 300-to-600mg…
  • You’re going to have to gradually stop using so much caffeine for a couple of days, weeks or months so you can reset or lower your tolerance to caffeine so that…
  • You can go back to increasing your metabolism, burning more fat and getting a energy boost off the much safer 50-to-300mg per day.
Green Tea Will It Help You Lose Weight?

Most of us enjoy a cup of tea, but could the nation’s favourite drink help us shift those excess pounds?

Forget the latest diet and exercise fads. According to recent hype, it seems losing those excess pounds could be as easy as sitting back and drinking tea all day. It sounds like the perfect solution for a nation that already has a healthy relationship with the teapot – in fact, on average, us Brits get through a huge 165 millions cups of tea day. There’s just one hiccup though – if drinking tea is all it takes to give us Hollywood bodies, why as a nation, are we getting fatter?

Sadly, that’s where there’s a catch. Because it’s not our humble cup of PG Tips or Tetley’s that reportedly has the power to melt away the pounds! Instead, we need to turn to more exotic leaves. And unsurprisingly, it’s A-listers that have led the way!

Burning More Calories

But whilst green tea and pu-erh tea have made headlines thanks to their celebrity followers, they aren’t the only brews that have been linked with shifting those pounds. A quick Internet search reveals there are literally hundreds of teas that claim to help us lose weight – and most of them are about as far away from a cup of Earl Grey as you can get when it comes to taste and expense!

Amongst one of the most popular is Wulong or oolong – a tea that falls somewhere between black and green tea and reportedly boosts metabolism.

Boost Energy Levels and Metabolism

Porangaba tea has received recent media interest following reports that Brazilian babes frequently drink it from beach stands in Rio. The brew, which is made from the leaves of a small tree found in the Amazon, apparently suppresses appetite, boosts metabolism and increases energy levels.

Weight Loss Benefits

Okinawan tea is another variety that frequently gets promoted for its weight loss benefits. But read beyond the hype and it’s simply a variety of green tea that’s frequently drunk by people living on the Japanese island of Okinawa. Granted, the people who live on this island are known for having one of the highest life expectancies in the world and, until recently, have had few problems with obesity.

But experts believe their good health is due to a number of factors including low levels of stress, regular activity into old age and a diet that includes plenty of fish, vegetables and soya – in other words, their longevity and slim figures aren’t just down to drinking green tea. As a more Western way of life is being adopted on the island, obesity is becoming an increasing problem, regardless of tea drinking habits!

Reduce Cholesterol, Detox and Suppress Appetite

Feiyan tea – a Chinese herbal tea that includes green tea, lotus leaves, cansia seeds and vegetable sponge – promises a huge number of health and slimming benefits.

As well as claiming to improve metabolism, marketing materials suggest it will also reduce blood fat and cholesterol, reduce bloatedness, detox the body and suppress your appetite. For a small cuppa, these are big promises that are largely based on unfounded science!

Herbal Tea Weight Loss

Adding to the confusion are the large number of herbal teas that sometimes link themselves with weight loss, thanks to specific herbs they contain. Herbal teas that include dandelion or nettle – two herbs that are considered to have diuretic properties – often claim to eliminate excess water and so reduce weight. Teas that contain fennel – an ingredient that reportedly suppresses appetite – sometimes make claims related to weight loss.

Slimming Claim

You don’t even need to surf the Net, take a trip to Chinatown or visit your local health food shop to get hold of slimming teas, many are now available in supermarkets. Birt & Tang’s Figuro Herbal Tea is available in Sainsbury’s and combines pu-erh tea with cassia tora, apple, water lily leaf, Oriental water plantain, Tianyeju, tangerine peel, notoginseng, Chinese cinnamon and cloves.

And whilst, the product doesn’t blatantly make a slimming claim on its packaging, it does infer weight loss by highlighting that it’s “for people who care about their figures”. Dr Stuart’s Slim Plus, also available from Sainsbury’s, combines fennel with linden leaves, dandelion root, corn silk, galangal root, green oat and natural orange flavour, and claims it’s “a really refreshing way to kick start your day and get into shape”.

But can having a brew really help you lose weight?

It sounds too good to be true – and according to most experts that really is the case. In fact, some herbal teas may actually do more harm than good if they include certain herbs that have potent diuretic or laxative effects. Excessive urination, diarrhoea and stomach cramps may be just some of the side effects associated with some of the more unusual ‘tea’ preparations that can be bought on the Net or from practitioners of traditional Chinese medicine.

Limited Scientific Evidence

There’s also limited scientific evidence to confirm that slimming teas actually work to shift those pounds. To date, most research has focussed on green tea. Both green and black teas come from the same plant – Camelia sinensis – but the leaves are processed differently.

As a result, both teas contain similar amounts of flavonoids, which act as powerful antioxidants in the body. However, because of the processing differences, they contain different types of flavonoids. As black tea is fermented, the flavonoids have a more complicated structure and consist of theaflavins and thearubigins.

In contrast, unfermented green tea contains flavonoids called catechins, which have a simpler structure. The most abundant of these catechins is epigallocatechin gallate or EGCG.

Together with caffeine – which is found in both green and black tea – it’s thought that catechins, and specifically EGCG, are responsible for the slimming effects of green tea. Consequently, research has focussed on these ingredients.

Fat Burning Properties

Sadly though, whilst studies have revealed that green tea may reduce fat and boost metabolism, most work has been carried out in test tubes or animals such as rats and mice. In fact, very few studies have looked at the fat-burning or weight loss potential of green tea in humans – and in many cases, although a positive link has been found between green tea consumption and weight loss, these studies have been poorly designed or included only a handful of subjects.

Calorie Counting

Bottom line: more well-designed clinical studies are needed to firmly confirm the weight loss benefits of green tea.

Cynics argue that any weight loss benefits are probably down to the calorie savings made by switching from a milky, sugary cup of black tea to a calorie-free cup of green or herbal tea. And in reality, this is a feasible argument. A standard mug of tea with semi-skimmed milk and 1tsp sugar contains 38 calories.

Four cups a day totals 152 calories, adding up to a massive 55,480 calories a year – ultimately, enough to help you lose 16lb in a year if you replaced those mugs with calorie-free green tea! Plus, chocolate digestives don’t taste as good with green tea!

Health Benefits Clear

Whilst the slimming benefits of green tea remains unclear, a large amount of robust research has focused on the overall health benefits of flavonoids in tea. As a result, many health experts now suggest that as part of a healthy lifestyle, four cups a day could help to protect our bodies from the effects of free radicals – potentially harmful molecules that can damage cells. In turn, this may help to lower our risk of many health problems including heart disease, cancer, strokes, Alzheimer’s disease and even cataracts.

Tea is a natural source of fluoride, a mineral that’s important for healthy teeth. And even though both green and black teas contain caffeine, health experts say there’s an insufficient amount in a cup of tea to cause a diuretic effect. As a result, both the Food Standards Agency and the British Dietetic Association say that tea counts towards our daily fluid requirement.

So even if a cuppa won’t make you slim overnight, chances are it’s not going to do you any harm. Our advice: put the kettle on, skip the sugar and biscuits and enjoy your favourite brew!


These are but a few things to help you kick start your weight loss campaign… Fat burning is all down to the individuals goal whether its weight loss or weight gain or even to maintain. But if you are going to exercise then we suggest that exercising at a high intensity for a short period of time will work and save you hours in the gym. 

If you have the time then a steady state workout will be just as effective so use them both in your workouts. Caffeine and green tea personally i’m not a fan of hot drinks, but there are cases that show green tea has helped weight loss and even helped the individual lose extra pounds but are they just losing water weight?

What intensity do you exercise at?


Daniel Messer, RNutr, CPT

We eat clean, are always motivated and helpout beginners in need. We sell guides on Cutting, Bulking and Muscle Building. Checkout our website!

Related articles