I've noticed that there are a lot of martial artists and combat athletes who are jumping on the bandwagon too. Some of these guys swear by it. But is a ketogenic diet really the best dietary approach for fighters?
What is a Ketogenic Diet?For those of you who don't know what a ketogenic diet is, it's a dietary protocol in which you consume less than 50g per day of carbohydrates. Doing this quickly depletes your body's glucose stores and forces it into a state known as ketosis where your liver begins producing fatty acids and ketone bodies to be used as the body's primary fuel source. It's an extreme version of typical low-carb diets.
A ketogenic (or keto for short) diet is a popular method to medically control epilepsy. It's also very popular among folks who are looking to seriously reduce their bodyfat levels - bodybuilders, fitness models, and even athletes.
On a practical level, being on a keto diet limits your food choices to those that provide significant amounts of protein and fats to be used as fuel. Meats, eggs, some dairy (like hard cheeses, cottage cheese, various creams, & greek yogurt), oils, and certain dressings (like blue cheese, ranch, & mayonnaise) make up the bulk of a typical ketogenic diet. You're also allowed some very complex carbohydrates in the form of non-starchy vegetables.
I've used a keto diet several times in the past to quickly drop body fat and it has worked incredibly well for me in that capacity.
However, when it comes to recommending the diet to fighters, my suggestions are a much more nuanced. I think all athletes, but combat athletes in particular, should always take a look at the available evidence before to adopt any training or dietary protocol.
So, let's take a look at the evidence.
Evidence Based Pros and Cons for Fighters -Before we get into the specific pros and cons of a low-carb/keto diet, I want to point out that to date there has been very little clinical research into how these types of diets affect athletes. I've been unable to find any that dealt with combat athletes. So, please keep that in mind as your reading through these pros and cons. I've provided my sources at the bottom of this post.
- Improved Body Composition - No real surprise here. We've known for years that a keto diet can easily cause a significant drop in bodyfat levels because of the increased reliance on fat as a fuel source. A keto diet also has the tendency to maintain and even help build lean muscle. For fighters, having that extra leanness improves performance due to an increase in relative strength (lighter weight + unchanged or improved strength levels = greater relative strength).
- No Loss of Strength - Keto diets have been shown to be useful in maintaining strength levels in athletes who are losing weight. This is great news because a common issue among folks who are losing weight is a corresponding loss of strength. This isn't such a big deal for a bodybuilder or fitness enthusiast, but it's a huge deal for a fighter.
- Improved VO2 Max - I debated whether or not I should include this here because a high VO2 Max does not necessarily mean a higher level of athletic performance. However, it is widely known that a high VO2 Max does correlate strongly with improved ability to quickly recover from intermittent bouts of high intensity activity - which is exactly what fighters need. It isn't clearly understood why a ketogenic diet seems to have an effect on one's VO2 max, but it's been suggested that it may be due to a significant loss of bodyfat levels.
- Decreased Work Capacity - One of the main draw backs of a keto diet is that it causes a marked decrease in overall work capacity. This is most likely due to the decreased levels of glycogen in the muscles. Decreased work capacity is a huge issues for fighters who must be able to sustain high levels of "work" (aka: punching, kicking, throwing, and chocking your opponent) during a fight.
- Increased perceived level of effort - In addition to a very real drop in work capacity, ketogenic diets have also been shown cause in trainees an increase in perceived level of effort. This means that a three minute round on the heavy bag will feel much more difficult when you're on a keto diet than when you're on a higher carbohydrate diet. This perception can have an obvious detrimental impact to your performance during a fight. Not only do you have to overcome your opponent, but you have to overcome increased levels of "head trash" telling you everything you're doing is more difficult.
- Decreased motivation to train - Related to the previous con, keto diets can cause trainees to lose the motivation to train. It can be quite disheartening to have everything you do during a training session feel more difficult. Fight training is incredibly difficult as is and it takes an individual with a high level of self efficacy and motivation to both begin it in the first place and stick with it till the end under normal situations. Throwing in extra factors that decrease that motivation can be the straw that breaks the camel's back for many fighters, causing them to not put in the effort required to be successful.
What Should You Do?Personally, I feel fighters can use a ketogenic diet if they're smart about it - you just have to understand when is the best time to utilize a keto diet.
Well, when is that?
It certainly isn't right before a fight. You need solid glycogen stores in your bloodstream, muscles, and liver to perform at optimal levels during a fight and a ketogenic diet is not how you're going to achieve that. Also, you're going to need all the motivation you can get in the last few weeks leading up to a fight so you can train hard and keep your spirit up. During the final few weeks before a fight your training will be hard - really hard. And if you perceive it to be even more difficult then you're just setting yourself up for failure.
To ensure that you're in proper form for a fight you should be consuming normal amounts of "good" carbs (brown rice, sweet & regular potatoes, and whole grains) for, at least, the final 4 weeks of training prior to a fight. Don't over do it, however, because you don't want to come in overweight for your fight.
So, the best time to use a ketogenic diet, then, is in the very early stages of your preparation for a fight. During this phase you'll typically be working on building a base level of general strength and moderate conditioning. At this point the negative effects of a ketogenic diet won't be much of an issue because you've still got some time before you're doing more specific work. This will also be the phase were you'll want to drop the vast majority of weight. Trying to focus on the intense skill work in preparation for a fight and trying to drop weight at the same time is a bad idea.
You can effectively utilize a ketogenic diet any time prior to 4-6 weeks out from a fight. However, I'd start at least upping your carb intake immediately before, during, and immediately after workout times as early as 8 weeks prior to a fight.
Keto Bursts -Obviously, these recommendations are for ideal situations where you know well in advance when and where you'll be fighting. Most amateurs and even many pros don't often have the luxury of knowing that in 12+ weeks they'll be having a fight. Often, guys will take fights with as little as 2-3 weeks notice. So, for the majority of guys I like to suggest "keto bursts".
A keto burst is simply adhering to a ketogenic diet for a fairly short period of time. Typically, I recommend about a 4-8 week burst. These keto bursts allow you to enjoy the benefits of ketogenic diet (like keeping you closer to your fighting weight without the need for super intense training) without leaving you with your "pants down" should you decide to take a fight on very short notice. All you have to do is up your "good carb" intake and get ready to fight (again this has to be done smartly so you don't end up like a bloated fat-ass and miss your weight).
Conclusion -A very low-carb, ketogenic diet isn't for everyone. But, properly utilized and managed, a keto diet can be an effective tool for fighters during the right phase of their yearly training cycles. They key is to be smart about it and know when it's time to replenish your glycogen stores with adequate carbohydrates.
For those of you that are interested, I've included links to some studies and abstracts related to ketogenic diets for athletes and active individuals.