You won’t lose fat despite hours on the bike. Here’s why!

You’ll lose fat if you’re riding, right?

If you’re reading this article you already know the answer. Some of us are blessed with “wonderful” genes. Our bodies are ultra efficient. They manage to digest food very well, extract every single calorie from food and are very efficient in every type of movement. Therefore, we manage to gain and retain weight easily, especially in form of body fat. From evolutionary perspective this made total sense. Sadly, we live in times of abundance and our efficiency is hurting our W/kg and hiding our abs. I am sure that the millions of people take up sports each year in false belief that this will automatically lead to weight loss. After all, the best (tri)athletes look lean. To be honest, this is the reason I got seriously involved in triathlon myself.  I was chubby in my teenage years and I really struggled to loose fat. I began doing sports and I somehow did manage to get my body fat below 12%, which “confirmed” my false conclusion that doing sports leads to fat loss. But going below 12% was not enough for me. I wanted to go below 10% body fat and stay there. After training more and more for two years and not really accomplishing much in this regard (except getting more muscular and stronger) I decided to start experimenting with diet – with macros to be more precise. The low carb one seemed very popular, but it proved unsustainable for my active lifestyle. I’ve temporarily lost a kilogram or two, but I quickly regained every gram that I lost. In the meantime I also fell in love with the sport and was even more worried about my performance. Without carbs I simply couldn’t do high intensity trainings. As stubborn as I was, I reasoned that I’m not losing fat because I’m training too little and I have to increase my training load (especially duration of low intensity work). In 2014 (at the age of 23) I started preparing for the Ironman Klagenfurt and racked up my training to more than 20 hours per week. Again, prolonged hours did not result in fat loss, but at the most in overtraining (although I managed to finish in a very solid 9 hours and 45 minutes). During preparations for the Ironman I gained some more weight and went from 79 kg to 81.5 kg, albeit the weight increase was again attributed predominantly to muscle mass (fat percentage stayed roughly the same). Preparation for the Ironman Klagenfurt was a nail in the coffin for me. Obviously prolonged training hours weren’t working. I decreased my training load post race and to my surprise my fat percentage stayed the same. I was really confused but I just couldn’t find any plausible explanation. I kinda gave in to thinking that I am genetically programmed not to go below 10% of body fat for longer periods of time. After wandering in the dark for 3 years I slowly regained my enthusiasm and I finally decided to tackle fat percentage problem again. I got armed with many weight loss, endurance and strength training books and scientific articles. I was determined that this time it would work. And it did. Here’s how I did it and how you can do it too!

The basics

We, especially endurance athletes, are constantly bombarded with marketing messages about potential deficiencies. Eat enough protein to properly recover. Eat enough carbs so you can maintain high intensity. And don’t forget to eat enough fat for proper hormone profile. While the above claims are all true, you shouldn’t forget that surpluses are just as harmful as the deficiencies. Especially if your body is genetically inclined to store excess energy in form of body fat, the abundance may be doing the most damage to you. Which leads us to the first rule of any successful weight loss regime:
Prolonged caloric restriction is the only proven nutritional method of weight loss.
Unfortunatelly, all above (marketing) claims are causing us to forget this basic method. Instead on focusing on caloric restriction, we’re overwhelmed by deciding between things that don’t have any significant impact on weight loss. Deciding between a high and low carb diet, to give you one common example. Keeping in mind the only rule, every diet works, if it recommends or leads to caloric restriction. If you follow a calories restricted diet you will lose weight.
In other words, to lose weight (fat or muscle), you should consume less calories than you expend. And to gain weight (fat or muscle), you should consume more calories than you expend. From perspective of weight loss, calorie is a calorie. The distinction between macronutrients only becomes relevant in the second stage, once you’re already achieving caloric deficit. Only then should you consider playing with macronutrients to make sure it’s predominantly fat that you’re loosing and not muscle.
Our bodybuilding brothers know this for a long time: “Simply put, you can’t get fatter unless you feed your body more energy than it burns, and you can’t get leaner unless you feed it less energy than it burns. Contrary to (currently) popular belief, it doesn’t matter how many carbohydrates you eat or how high your insulin levels are throughout the day. Energy balance is the first law of thermodynamics at work: fat stores can’t be increased without the provision of excess energy, nor can they be reduced without the restriction of energy. That’s why research has shown that so long as they’re eating less energy than they’re burning, people lose fat equally well on high-carbohydrate or low-carbohydrate diets. The bottom line is that the types of foods you eat have little to do with losing or gaining weight. In this regard, a calorie is a calorie. That isn’t to say that you should eat nothing but junk food to lose weight, however. What you eat does matter when we’re talking about maintaining optimal body composition. If you want to lose fat and not muscle, a calorie is not a calorie.” “So, the bottom line is this: you will need to watch your calories to effectively lose weight. You’ll have to stay disciplined and forego the snacks and goodies not worked into your meal plans. You’ll probably have to deal with some hunger now and then.” (Matthews, Michael. Bigger Leaner Stronger: The Simple Science of Building the Ultimate Male Body (The Muscle for Life Series Book 1). Oculus Publishers. Kindle Edition, p. 37) So, you will lose weight only if you’ll establish a caloric deficit. And you will have to keep an eye on your macros if you want fat to lose predominantly fat and not muscle. In the next chapter I’ll briefly explain the basics that you need to understand to effectively loose weight.

Caloric expenditure of human body

Here’s how the total daily caloric expenditure (TDEE) of human body is structured:
  • RMR or Restring Metabolic Rate,
  • PAL or Physical Activity Level,
  • DIT or Diet-Enduced Thermogenesis. Some use the term TEF  or Termic Effect of Food.).
The ratio of each component in energy expenditure of individuals varies greatly.


The RMR figure tells us how many calories our body expends irrespective of our physical activity or feeding. In other words, this figure represents the number of calories you would have burned even if you were laying in your bed a whole day and not eating anything. We won’t discuss RMR any further, because the RMR is predominantly affected by internal organ size (which increases/decreases linearly with body weight) that you can’t affect in the short term. You can’t affect it by physical activity or increased muscle mass (unless you increase total body weight; you gain muscle without losing fat). But, don’t cut out strength training just because muscle mass has a negligible effect on RMR. You should do strength training because it will help you retain muscles mass and predominantly lose fat instead of muscles when you’ll be losing weight. If you don’t use it, you lose it.


The PAL number tells us how many calories our body expended during any physical activity. Not only cycling, but also walking, dish-washing etc. You can affect PAL significantly. For serious endurance athlete, who trains 12 hours/week or almost 2 hours/day, PAL represents a considerable share in his TDEE. In concrete terms: I weigh 80kg and I can easily burn 1.500 calories/day from training. As such, PAL (net) in my total daily expenditure of 3.800 kcal (2.200 RMR + 1.500 PAL + DIT 100) represents around 40%. If you’re using activity trackers to estimate your caloric estimates you should be vary. Many if not all activity trackers (e.g. Garmin, Strava) that estimate calories burned from a heart rate monitor overestimate the calories burned, because they give you a total number of calories burnt during the activity, which also includes the calories that represent the RMR. Thus, the number includes the calories you would have burned even if you were watching TV. You should therefore substract appropriate calories from the caloric estimate given by activity tracker to get the PAL (or net expenditure). For example: if your RMR is 2.400 kcal/day, this means that your body is burning 100 kcal/hour even while sleeping. If you went cycling for two hours, you should deduct 200 kcal from the number that STRAVA/Polar/Garmin gives you, if it’s derived from a heart rate. If however you’re using the powermeter, mentioned activity trackers accurately estimate your PAL. As already noted, your ability to affect your PAL significantly doesn’t give you permission to eat as much junk as you like. Junk foods make it very easy to eat more than you’ve expended on even the longest of your rides. This is the reason you’re getting fat or at least is holding you back from losing that remaining fat mass. Also, it is a very bad idea to “abuse” exercise for the purposes of fat loss. This article explains very well, why you can’t outrun a bad diet. If you don’t bother reading it, here’s a brief summary. While physical activity should be an integral part of healthy lifestyle, it’s value is not in weight loss, but predominantly in agility and mental well-being. If you increase your physical activity, you will experience hunger and generally greater laziness, with which the body will try to force you to eat back what you lost or at least make you not expend the calories you would have otherwise expended throughout other parts of the day. In addition, I would add that PAL does help in fat loss, however to a lesser extent that many people attribute to it and in a different way. I would argue that it’s easier to maintain a caloric deficit if you’re doing sports because a planned caloric deficit (e.g. 500 kcal/day) represents a smaller share of TDEE and it’s hence psychologically easier to curb hunger.


DIT tells us how many calories our body expends for conversion of food to energy or storage. While we can affect DIT by eating fibrous and high protein foods, I would argue that it is much more complicated than affecting the PAL. Nowadays, it is very popular today to prescribe protein rich diets in loosing weight (fat) because of two reasons:
  • they supposedly help with recovery (increase/retain muscle mass),
  • they help to achieve caloric deficit (DIT of protein is 25% of their gross caloric value).
I would argue that both arguments are true, but they need to be viewed in perspective. Concerning the role protein play in recovery processes, you should note that as soon as minimum protein requirements are met, additional protein doesn’t result in faster recovery (more is better only until you meet the requirements). Consuming protein as a way to achieve caloric deficit is somehow futile. While it’s true that DIT of protein is 25% of their gross caloric value, this only means that you are going to become hungry, despite a greater gross caloric value consumed. Because of human body’s somewhat inefficient in digestion of protein it also means that the body has to “work harder” to digest protein so that they become suitable for our body. Hence, the energy that could have gone for recovery is now used for digestion.

Practical guide to caloric deficit, macros and training

What should my daily caloric deficit be?

Let’s assume that I managed to convince you that caloric restriction is a way to to loose weight. But, how big should you daily caloric deficit be? Based on research, you can only lose 96 kcal from each kg of body fat that you carry per day. If your caloric deficit is larger than that, the wight loss will inevitably come from muscle, even if you eat enormous amounts of protein and do a lot of strength training. To figure out the exact number, you should establish your fat mass % and thus the absolute fat amount you’re carrying. Use this picture to estimate your fat %. Then multiply that percentage with your weight (e.g. 0,12 (12%) x 80 (kg) = 9,6kg) to establish your fat mass. Then multiply fat mass (in kg) with 96 and you get the maximum number of calories your body can loose from fat within a day.

What should be my macros?

Michael Matthews put it nicely in Bigger Leaner Stronger (p. 45): “If you eat too little protein while restricting calories for weight loss, you’ll lose more muscle than you would if you had eaten an adequate amount. If you eat too few carbohydrates while in a calorie deficit, your training will suffer, your muscle repair will be impaired, and your hormone profile will become more catabolic. If you eat too little dietary fat, you can experience a significant drop-off in testosterone levels and other undesirable effects. As you can see, if you want your weight-loss regimen to be maximally effective, you want to restrict your calories but also eat enough protein and carbohydrate to preserve muscle mass and performance and enough dietary fat to maintain healthy hormone levels as well as general health. Adequate dietary fats are necessary to maintain healthy skin and hair, insulate body organs against shock, regulate body temperature, and promote healthy cell function. While that sounds complicated, it’s not.” Nowadays it is very simple (but not easy – it requires willpower) to calculate caloric intake with the help of numerous weight loss apps (more on that below). And luckily, so is calculating the macros. Actually, you shouldn’t really concern yourself with the macros. You should only make sure that you consume enough protein. If you do that, you can eat any ratio of carbs/fat as you wish, as long as you maintain the desired caloric deficit. Contrary to outrageous claims that body of an athlete needs 2.2-3 g/protein/kg of body mass/ day, the McMaster research recommends 1.3-1.8 g/protein/kg of body mass/ day and the WHO paper on protein and amino acid requirements found no difference in muscle mass gain (when strength training) between individuals, who consumed 1.3 and those who consumed 2.2 g/protein/kg of body mass/ day. So, I would argue that 1.3 g/protein/kg of body mass/ day is all you need. Note that recommendations are based on the protein with highest biological value (amino profile that ensures the best facilitation by the human body), which are animal protein. If you’re a vegan, keep in mind that your protein intake should be higher, because it should account for a lesser biological value of plant based protein. You can greatly reduce this need by combining protein from different plant sources. At this point I should note that you shouldn’t strive to eat only animal sources of protein. Why? Numerous studies have indicated numerous health risks associated with (excessive) animal protein consumption (read Proteinaholic, The China Study or many other books and articles on this matter). 

How should I train?

The popular belief is that you should train low intensity to burn most fat. While it is true that human body expends a higher % of calories from fat, you should also note that the absolute amount of fat your body burns during any physical activity remains constant up until about 80% of VO2 max (approx. 98-102% FTP) (more on that in Eat Stop Eat). That being said, you shouldn’t make any changes to your training just because you’re trying to lose fat. As endurance athlete you are already doing most of your training below this intensity. The only thing you should keep in mind is that your absolute metrics and recovery will almost certainly be compromised. Caloric deficit is a form of stress on your body and you should act accordingly. Even if you eat enough protein your body will simply need more time to compensate for induced stresses. Keep that in mind, don’t push that often or that hard and don’t stress about it. You cannot expect your body to loose fat and simultaneously increase lactate threshold (FTP) values. Keep in mind that your victory is lost fat and not absolute FTP number! But, you should see improvements in your relative metrics (e.g. W/kg). So, I would recommend you to do a relative power test (e.g. W/kg or % of body-weight for strength training) before you start with fat loss program. You should see gradual improvement in relative metrics. Actually, from pure performance perspective, you should stop losing fat once your relative metrics start to stagnate or even decrease. Of course, even with constant measurements establishing this will be more art than science, because you should expect some trainings to go bad no due to real decrease in relative power but due to insufficient rest and/or depleted energy stores. Therefore, before doing measurements of relative power, consume a carbohydrate rich meal to at least partially fill up your glycogen stores.

How should I measure my caloric intake?

For me the easiest way was tracking my caloric intake with a smartphone app. I’ve tried many (including MyFitnessPal), but I opted for Lifesum. It’s very user friendly, it only has the functions you need and it doesn’t bother you with annoying adds. Using a calorie tracking app (for at least first month) has two big advantages. First, it’s eye opening to SEE for yourself, how easy it is to eat 1.000 calories or more! Second, it is much easier to restrict calories and stop eating if the app tells you to do so. After you get the feeling of portion sizes, calories and protein amounts, you can stop using the app. As you’ll quickly find out, you should only eat proper meals and hold back, when it comes to snacking. It’s nothing wrong if you feel some hunger now and then. After all it’s a natural feeling that we’ve almost forgot how it feels and which is the primary reason that you’re reading this article. When you experience hunger you simply have to use some willpower to come through.

Try Intermittent fasting (IF)

I believe that IF is not something necessary if you want to loose fat. You should try it and see how you body responds. According to Eat Stop Eat (I seriously recommend reading it) there are many health benefits to various forms of IF.  From better insulin sensitivity to better muscle mass retention. I found that my body responds well to IF, that’s why I’m incorporating it in my daily life. I found it especially helpful, because it helps me curb hunger. It’s much easier for me not to eat at all than to eat, but eat the right amount and avoid snacking. That being said, there are various forms of IF and you should choose the one which suits your needs the best. It’s best to follow a sub-optimal plan than not to follow a perfect plan. If you’re endurance athlete, you might find the 16/8 method the most suitable for your needs (it is for me). It means that every day you try to be fasted for 16 hours and eat only in the 8 hour window. I do it like that:
  • I fast (don’t eat) between 20 in the evening and 12 in the afternoon (16 hours)
  • The exception to this rule is, if I do a training in the morning. In this case I do a training fasted at least first 30 minutes. I figured out I eat much less during a ride if I do that. There is no study to prove it (yet), but I believe that the body goes into “fat-burning” mode for the rest of the workout, sparing precious glycogen and burning fat 🙂

Do strength training (even if your endurance athlete)

Strength training is proven to help with retention of muscle mass, especially in phases of caloric deficit. I always knew that, but I made one big mistake; I tried to make a strength training and endurance training. I did high rep training with no or very brief rests between sets. Unfortunatelly, the body is “primed” for muscle loss when in a calorie deficit or when doing endurance training, and by focusing exclusively on muscle endurance (higher-rep ranges), I set myself up for rapid strength and muscle mass loss. It is only this time that I learned that the key to preserving strength and muscle while losing weight is to lift heavy weights. The goal is to continue progressively overloading your muscles, which ensures protein synthesis rates remain elevated enough to prevent muscle loss. So, to reap the benefits of strength training, you should do a proper strength training; low rep work and long rests between sets.

Concentrate on the big 5 compound movements!

Below, I am giving you a brief outline of a proper strength training. If you want to learn more, you can read my excerpts on strength training or hit me up and I might write an article dedicated to strength training. If you don’t bother reading the whole excerpt or can’t make any sense out of it, here are the basics:
  • focus exclusively on the big 5 compound movements (squat, deadlift, pull-up, bench-press, military press) and disregard all other movements, including core work. There’s plenty of core work in squat and deadlift;
  • do strength training 2 times/week at most (otherwise you’ll overtrain!);
  • do only 2-4 movements in each training;
  • for each movement do 3 sets of 4-8 reps (same weight in all sets);
  • rest 3-4 minutes between sets;
  • each set is AMRAP (as many reps as possible);
  • aim for progressive overload. Once you achieve more than 8 reps in first set, increase weight (for 2.5-5%) in next training.
That’s it. If you follow the above guidelines you will surely lose weight and not just any weight but predominantly fat. You might be wondering what effect this diet and training regime had on me. Well, from February to June 2018 (4 months) during a period of strenuous endurance training I went from 86 kg (13% body fat) to 79,5 kg (10% body fat), thereby losing 3,2 kg of pure fat. In June and July I rested a bit and kept the weight constant. In August 2018 I started doing strength training more seriously and I tried to have a minimum caloric surplus not to add too much fat to my frame. By October 2018 my weight rose to 81,5 kg while. I managed to keep the same fat %, thereby gaining only 0,2 kg of fat and 1,8 kg of muscle. My goal is to be in the 6-8% body fat range at sub 80 kg. I still have some work to do, but now that I know the described method is working, it’s much easier to apply willpower when necessary. If you like this post, please share it with people, who might benefit from it.

Written by marko