Is fasted cardio just a fad? Or is it superior for fat loss?

The fitness industry is constantly jumping from trend to trend. As coaches we need to develop core values based upon scientific principles and stick to them. When new stuff comes up, we need to think about it, see where it can fit in with our clients, apply it, and collect data to see whether it is working or not.

One of the current trends is training in a fasted state for weight loss. To reemphasize that last part, this tactic is used only for weight loss. Those of you looking to increase performance are best served not applying this approach. For those of you looking to drop a few pounds, let us look at what the science says.

What the Science Says About Fasted Cardio

A study performed in 2010 compared fasted training to fed training over a six-week period. Researchers looked at some key areas and compared the two groups. Training was always performed in the morning and consisted of two sixty-minute sessions and two ninety-minute sessions. 

"Both the fasted and the fed groups increased their glucose tolerance, but the fasted group increased it substantially more."

The fed group was given a breakfast of 675 calories, made up of 70% carbohydrate, 15% protein, and 15% fat. On top of that, they were given 1g of maltodextrin per kg of bodyweight about ninety minutes before training. The fasted group received this exact same cocktail in the midafternoon. The areas the researchers compared were glucose tolerance, GLUT4, muscle glycogen, metabolic enzymes, body composition, and exercise capacity. The results of the study were quite interesting.

Both the fasted and the fed groups increased their glucose tolerance, but the fasted group increased it substantially more. GLUT4 is a glucose transporter that allows glucose to enter muscle cells. The more of these we have, the more glucose gets taken up into the muscles, as opposed to being stored as fat. GLUT4 transporters increased by 28% in the fasted group and only 2-3% in the fed group.

Glycogen stores increased more in the fasted group when compared to the fed group, but there was no significant difference between intramuscular lipid stores.Increased intramuscular lipid stores are seen in obesity and can lead to insulin resistance and mitochondrial dysfunction.¹ 

"Glycogen stores increased more in the fasted group when compared to the fed group, but there was no significant difference between intramuscular lipid stores."

The only differences in metabolic enzymes were seen in translocase/CD36 and carnitine palmitoyltransferase¹. These two enzymes play a role in our abilities to metabolize both fat and glucose. The fasted group saw an increase of approximately 30% and the fed group did not see an increase. All other metabolic enzymes tested remained the same.

As expected, the fed group had a greater increase in VO2max, but the fasted group showed a greater increase in fat oxidation. As I stated previously, fasted cardio is not a way to increase performance, but instead to lose weight. With less glucose present, it is no surprise that the fasted group showed greater fatty acid oxidation for energy.

The Practical Side of Fasted Cardio

There are other studies that show similar results as the one presented in this article. After reading that study and hearing that other studies back up these findings, you may be ready to jump right into a fasted cardio weight-loss routine - but it’s not for everyone.

"[K]ey areas to assess are sleep, vitamin D, stress levels, exercise routine, and diet. If all of these are squared away, then give fasted cardio a try."

I have messed around with the fasted cardio component with myself, as well as with clients, and I have experienced a mixed bag of results. For some it worked great, but for others it didn’t. This is something you may have to mess around with for a period to see if it helps. Before doing that, I encourage you to assess your lifestyle and improve upon areas that may be weak. Some key areas to assess are sleep, vitamin D, stress levels, exercise routine, and diet. If all of these are squared away, then give fasted cardio a try.

There are some key points to keep in mind if you do decide to try it:

• This study was performed in the morning, and I encourage you to do the same. Waiting until the afternoon or evening to work out while fasting all day may be too much of a stressor and could have the opposite of the desired effects. 
• I also encourage you not to make the fasted cardio something intense. Low-level aerobic activity between 70-80% of VO2max should suffice. Anything more intense may also become a stressor. 
• Make sure you take in carbohydrates with your first meal. I ran into this problem with quite a few clients. We use a paleo diet template, and I encourage my clients to get their carbs in the afternoon or evening. This created the habit of them having a large salad with meat and very little carbohydrates for lunch. This didn’t work well for coming off a fast. So, if this sounds like your current lunch make sure to add some fruit or sweet potatoes to it.

Those of you who have tinkered with fasted cardio I would like to hear from you. Let us know how you implemented it, for how long and how well it worked for you. Your experiences may be able to help someone else trying to lose a few extra pounds.

How do sleep and nutrition effect recovery?

So here we are, part 5 and the final segment of the Recovery Series. Having already covered Ice Baths, Massage, Compression Clothing, and Active recovery, we are now left with two of the most important aspects of performance and recovery – Sleep and Nutrition.

Let’s get down to it.

To begin I’m going to talk about hydration. It’s often spoken about how important it is to stay well hydrated, yet people will often let this be the first thing to slip when they start to focus on other things. It often seems to drift into the back of their mind as soon as they have something else to think about.

 

Well hydration is damn important. So drink some water people! It can help aid you in fat loss, keeps performance high both mentally and physically¹, and when recovering it is essential to replace the fluids you lose when sweating – so try to make sure you get a good amount of water in as soon as you can. I know that after a good game of club rugby on a Saturday all you want to do is sink a pint of Irish black gold, and believe me that would be my first thought too, but before you get yours hands on that beautiful well deserved pint get some water in.

(Alcohol in general is obviously not good for performance, or for recovery, but I’m just being realistic here – especially now that “Dry January” is over.)

 

Nutritionally speaking the best way to explain it is through a very cliché quote;

“You wouldn’t put diesel in a petrol car”.

And it’s true, when practicing a sport or exercising, your body is the car. And for that engine of yours to work at its best it needs to be adequately fuelled.

 

Now there is a huge amount of information about nutrition out there on the Internet, and within that there is contrasting advice and endless different diets. Honestly, it’s a bit of a pain in the arse. Wouldn’t it just be amazing if there were one way that fits everyone? In my opinion it would. But that isn’t the case, and there is a reason. Different people react differently. For instance some people have food intolerances, some react better to carbohydrates, some better to fats, some can work well eating the majority of their carbs late at night, others would get fatter by doing the same thing.

 

So it can take a bit of time to find out what works for you. Trial and error, and not just trialing for something for one day and saying it doesn’t work. You have to try it, allow time for adaptation to occur, and then make a decision based upon results. This goes for weight gain, maintenance, and loss.

 

That being said – there is some basic information that can be very transferrable, and that should be put into place when trying to improve recovery.

First off – you need to eat! Even if you were lay in bed doing absolutely nothing but breathing and thinking all day your body would still burn calories. This is called your basal metabolic rate. The amount of calories you would burn doing the absolute minimum. So if you’re not eating, you will gradually lose weight and your everyday bodily functions will start to suffer if not properly fuelled.

What foods do we need? Well the obvious answer first up is to look at your macronutrients – Carbohydrates, Protein and Fats.

When you consume carbohydrates, the body can break it down into glycogen, which then is utilised for energy production (I’m putting it simply – its much more complicated than that in real life, but for that stuff go read a text book).

Protein is made up of amino acids, these are the building blocks for muscle repair. So to make sure you maintain muscle or build muscle, you need to get protein in from somewhere such as meats, eggs or supplements.

Fats – oh here we go! So fats get a lot of stick in the press. Low fat this, low fat that. That’s great, well done, but the body needs fat. Simple. Fat can also be used as fuel for the body, as well as insulation. Different fats that we get through food can also be used to help keep our joints healthy, and keep our brain functioning.

 

So how much of each should you be eating? Unfortunately it all depends on you. Protein should be a mainstay. If you are a sports person, or if you train regularly, you will need more than the average person as your muscles are being used on a regular basis. Carbohydrates can fluctuate, for me personally I feel like crap if I eat loads of carbohydrates, but equally if I eat a low amount I feel rubbish too. So I rotate them so I eat more on hard training days to fuel my workouts and replenish afterwards, but less on off days as I don’t need that fuel. I then rotate fat consumption to balance my carb intake.

 

If you feel like you are always tired, or you’re losing weight or strength, you probably need to eat more. If you’re gaining weight, but are having no performance improvements and just getting fat, you probably need to eat less. But finding something that works for you takes time. My advice would be find a balance, try it for 6-8 weeks, then change if necessary.  Eat more carbohydrates when you’re training hard, plenty of protein every single day no matter whether you’re training hard or resting, and get fats in through good sources such as nuts and fish.

 

One last thing on nutrition – eat your vegetables! ^{(Nutrition references 2-5)}

 

The final section of this article is my personal favourite, and the most important. Sleep. Everyone needs to sleep. It is absolutely fundamental to performance, and to general health. Lack of sleep not only leads to tiredness (obviously), but it can screw up your hormone balance, which will lead to performance changes.

There are plenty of people who aren’t getting where they want to be in sport or business, and they will give an extra 2 hours a day training or working in the office at the expense of sleep, and this will then just pile on top itself to manifest into something bad. If they had an extra hour or two each day, their concentration throughout the day would actually increase, and likely their productivity.

For those of you wanting sporting gains, our muscles repair when they are resting. And we get a boost of naturally occurring growth hormone when we sleep. Combine those two statements and you should realise that you need sleep.

 

So there we go. A little bit longer than my usual articles, but we have covered a lot in this one. I’ve put a few references together at the bottom, including a couple of podcast episodes which are fantastic for understanding the importance of sleep, so have a flick through them if you want.

 

As I mentioned at the start, this was the final part of the Recovery Series. I hope you have enjoyed reading them, and please share them around as much as you can. It would be great if these could reach more people, as a lot of athletes don’t understand the importance of recovery to their performance.

 

Next week we will be looking into something new, so I’ll leave you hanging on to find out.

 

Thanks again for reading, and feel free to get in contact.

 

Rob Nitman. BSc. ASCC.

 

References:

 

1.      Gibson-Moore, H. (2014) Hydration and Health. Nutrition Bulletin, 39 (1).

2.      Dr. Israetel, M. (2014). The Renaissance Diet. E-Book.

3.      Bean, A. (2013). The Complete Guide to Sports Nutrition. Bloomsbury Publishing PLC, London UK. 7^th Edition.

4.      American College of Sports Medicine. (2009). Nutrition and Athletic Performance. Medicine & Science in Sport & Exercise, 49 (3).

5.      McLaren, D. (2008). Protein, Carbohydrates and Muscle Recovery. The Journal of the UK Strength & Conditioning Association, 10.

6.      Barbell Shrugged. 158 - The 1 Thing That Will Make You Better at Everything. 07 January 2015.

7.      Barbell Shrugged. 113 - 1 Quick Way To Naturally Increase Testosterone: Sleep. 16 April 2014.

Basic Principles of Sports Nutrition to follow

When preparing to train and compete in a sport, athletes need to build a foundation from which they can develop and progress. In my opinion diet and nutrition should provide a consistent underlying fundamental from which all the training and performing. Assessing your diet from its present state until where it is where you want it to be is a process, a journey.

When taking on an assessment of your nutritional intake, in terms of the demands of your sport, you should always consider a few fundamental notions to follow to help you progress:

1.    Saturated fats and salt levels should be avoided or kept to a minimum wherever possible

2.    Seasoning can be a great way to enhance the flavour of foods without resorting to high sugar sauces – things like herbs, spices (chilli can be a great addition to spend up the metabolism, due to its capsicum content) and black pepper– use as much as you wish to enhance taste

3.    Be careful of low fat substitutes – although they may provide a low fat alternative to your choice, it may be counteracted by high levels of sugar or additives as a result, so always check and use with caution

4.    Consider GI when consuming carbohydrates – try to predominantly use low GI carbs as sources of fuel from carbohydrates, wholegrain and whole wheat are best. These give you a more gradual release of energy at a more consistent level

5.    Proteins in their original form should be eaten regularly - Each meal to contain some bio-available protein in low fat form – e.g. chicken breast, turkey breast, and very lean beef, and include oily fish as a choice at least twice a week.

6.    Fats have benefits – especially during the recovery process, unprocessed fats sourced from both animals and vegetables will be beneficial to your recovery. Try food sources such as salmon, mackerel and herring alongside vegetables such as avocado will benefit you immensely. Cooking your food using coconut oil will only boost these benefits further, and provide natural aids that cooking with normal oil cannot provide

7.    Deep fried foods should be a no-go area – using different variations of cooking to keep things fresh and remove tedium. Techniques include dry roasting, baking steaming and grilling

8.    Salads and vegetables with at least two meals of the day.

9.    Still mineral should be served with all meals

10. Keep it simple - Good simple foods with plenty of taste/flavour works best - there is no need for adding lots of extras just for an extravagant presentation or serving of food.

11. Plan ahead – this should go alongside the above point, in order to maximise the benefits you can reap.

The right choices in the kitchen make your choices in the gym worthwhile!

This article was expertly written by Morgan Price-King BSc.