• kasper verschaeve

Intermittent Fasting for Fighters

Bijgewerkt: 12 nov 2019


Even if you are only slightly interested in nutrition and health, you’ve probably heard about intermittent fasting (IF). Intermittent fasting is the idea of cycling between periods in which you consume food and periods in which you don’t consume food to optimize health. In a way, everybody adheres to such cycles because we sleep, a period when we can’t eat. That’s why the first meal of the day is called break-fast. Intermittent fasting is not a diet, it’s an eating pattern. It doesn’t dictate what to eat, but rather when to eat.

Obviously, when someone talks about IF, he talks about some more unconventional way of cycling between eating and not eating than just between day and night. The fasting (not eating) period should be longer than usual.

You can approach IF in various ways. Some people fast for an uninterrupted 24 hours or more, every week or month. But most cycle between eating and fasting within one day, also called time-restricted feeding (TRF).

The most popular way of doing IF, is TRF. TRF is the way Tom DeBlass, BJJ ace and motivational figure, and George Saint Pierre, all time MMA great, approach intermittent fasting. In the clip below Tom DeBlass explains the rationale behind the practice:


Health Benefits

It doesn’t happen very often that I get excited about a new diet, eating pattern in this case, or training method, but the more I read about IF, the more it fascinates me. Fasting has many claimed benefits and it seems that most of them have been proven by solid scientific studies. Below I list some of the most promising benefits that could enhance your life in the long run:

Me personally, I’ve been implementing IF in my own life for about half a year now. The two biggest benefits that I experienced actually weren’t directly connected to my health, but rather to convenience and budget:

  • It’s very simple! Let’s say you decide that Monday-Friday you only eat between 12 and 8 PM, then that’s the only thing you have to think about. You don’t have to count calories (e.g. weight watchers). You don’t have to autisticly adhere to a certain composition of your macros (e.g. the ketogenic diet).

  • It saves you a lot of money! Well, for me at least, it does. I’m an above par consumer, I like consuming, especially food. For example, before I implemented IF in my life, I had a lot more snacks on the road. Every time of the day was a good time to buy a snack. When practicing IF, snacking in the morning and late in the evening is taboo, because those periods aren’t in your feeding window. Also the number of times IN my feeding window that I eat out are reduced, the reason being that I want to have control over the few meals I have. I want them to be nutritious and fulfilling.

In combat sports

This has been a nice introduction to convince you that IF is nice way to optimize health for people in general. But of course, this is a blog about healthy habits of competitive fighters (MMA, Muay Thai, boxing,…). So, let’s zoom in on this specific category of people.

Let’s first look at the benefits that would be particularly beneficial to fighters:

Body composition (muscle/fat ratio)

Fighters fight in weight classes. It’s important to be in the best shape possible for the particular weight class in which they fight. This means among other things, that you don’t have any excess body fat. IF can help immensely here.

Weight loss

You could argue that when you diminish your eating window, the chances are high that you’ll also reduce total caloric intake, and so lose weight. This effect is also scientifically supported. This study found an average drop of 350 calories daily among the participants of the study. But the reduced caloric intake isn’t the only mechanism at play. If it would, IF wouldn’t be more helpful for weight loss than a normal diet which works with ‘portion control’ (reducing calories without diminishing your eating window). How many people do you know that are or have been practicing portion control? Many, right? And how many have significantly lost weight and kept the weight off? Very few, right? Dr Zoe Harcombe even claims there is a failure rate of 98%. So what is the reason for this high failure rate and why should it be any different with IF. I see three main reasons.

  1. High dropout rate. Portion control demands a lot of discipline: ever meal and snack you eat, you should calculate the calories. Moreover every meal you have, you have to eat less than you want. In comparison IF is extremely easy, as I stated earlier. After a while you get used to not eating before 12 and after 8pm. And in your eating window you can feast like a king.

  2. Drop in metabolism rate. More than 70 years ago, Dr. Ancel carried out the famous Minnesota Starvation Study. In this study volunteers are placed on a diet which reduces their intake to 1500 calories a day, which on average was a drop of 30% of daily caloric intake. Dr. Ancel discovered that after a certain period of portion control, the metabolic rate dropped linear with the reduction in calories. From here on the subject would not lose weight anymore. So we could conclude that portion control can only work in the short term. However, this drop in metabolic rate is not harmless. IF on the other hand does not lower metabolic rate, IF even increases the rate slightly.

  3. There is no period where body fat is the only fuel source for the body. When you eat less, but eat the entirety of the day, your body will use the food you consume as your main source of fuel. This isn’t the case with IF. Roughly the first 12 hours after your last meal your body will operate on this meal and on stored sugars. After these 12 hours your body will use your stored fat as fuel. You could say your body becomes a fat burning machine until your next meal.

Preserve muscle while losing weight

If you are overweight, losing weight is great. But not all weight losses are equal. A fighter will want to keep or even build muscle as much as possible, while at the same time losing fat. For this purpose IF is by far superior to portion control, a review from 2011 revealed. Reason being that, in contrast with portion control, IF drastically stimulates growth hormones in the body. Growth hormones stimulate muscle growth.

Reducing inflammation

Contrary to popular thought, inflammation isn’t necessarily a bad thing. It’s, among other functions, a natural response to an injury. This response helps speeding up recovery. So, you could even argue, that inflammation is crucial for an athlete. The problem arises when inflammation becomes chronic. Chronic inflammation wreaks havoc on the body and is the cause of a wide arrange of problems: Fatigue, joint pain, dementia, gut problems, skin rashes and even cancer.

The training of athletes in combat sports is very hard on the body. On top of that most athletes will train as much as possible to become the best version of themselves. It’s very likely that they would fare well with strategies that can keep inflammation in check.

IF has been shown to have anti-inflammatory effects.

Negative: less flexibility

Incorporating IF in your life, limits your flexibility in regards to your training schedule. There is no way around it: without any carbohydrates you can still train, but you won’t be able to physically perform at your highest level. For the regular person this is no problem, for competitive fighters however, this is a potential issue. It’s not optimal to do hard sparring or hard drilling while fasting. You don’t want to be hit repeatedly in the face or not be aware of your full capacities.

That’s why the harder training should happen in the afternoon, after you have broken your fast. Unless you are George Saint Pierre or Conor McGregor, you probably have to stick to the schedule of your gym. If the hard sparring in your gym happens in the morning, you’ll probably have to adjust or drop your fasting schedule. If you are GSP or Conor McGregor, it’s likely that you can determine the gym schedule yourself.


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