In my previous post, How to Exercise on a Keto Diet, I outlined the some of the basic facts about exercise and the most common myths. In this and future posts, I'd like to focus on nutrition aspects of exercise. Foods containing carbs are not all evil and I'll explain when clean paleo-friendly carbs can be used even on a keto diet. Let's start by busting some of the most common myths...
Carbs and Performance
Do we need carbs for better performance? One of the most common myths is that low-carb eating will negatively affect your performance. This is down to studies that ignore keto-adaptation and only focus on the immediate effects of carb restriction. There is, indeed, a transitional period in which performance drop occurs but it only lasts for a few weeks.
Once you get keto-adapted (usually 3-4 weeks), your body will switch from using glucose to using ketones and fatty acids as the main source of energy. This study performed on elite athletes shows that a keto diet does not affect strength performance. Eight athletes over a period of 30 days were fed virtually a zero carb diet and didn't experience any drop in performance. In fact, more and more studies are showing the beneficial effects of keto-adaptation.
Even athletes that are doing very long cardio training or marathons can follow a keto diet. Timothy Allen Olson is just one of the many super athletes who have proven to be thriving almost purely on a diet that is best described as low-carb, keto and paleo. However, Timothy doesn't follow a standard ketogenic diet - he eats carbs strategically. Before or after his workouts he eats clean carbs such as sweet potatoes and fruits. He also uses glucose gels on training runs. Everyone is different and although some may thrive on a Standard Ketogenic Diet, others may benefit from adding some carbs. On his website, Timothy says: "I believe each person/body is very unique and you need to find the best way of eating for yourself, each body accepts or rejects foods differently."
Some people can tolerate more carbs than others. Those who are insulin sensitive will, in general, do better with carbs-ups compared to those who are carbohydrate intolerant and insulin resistant. Carbohydrate intolerant individuals should, in general, avoid carb-ups.
Carbs and Muscle Growth
Another common myth is that you won't be able to gain muscle mass or even that you will lose muscles on a keto diet. The assumption is that you will not be able to gain muscles without the carbs to trigger an insulin response.
Ketogenic diets have shown muscle-sparing effects. Jeff Volek and Stephen Phinney have published several studies on both performance and muscle-sparing effects which they also analysed in their best-selling books (The Art and Science of Low Carbohydrate Living and The Art and Science of Low Carbohydrate Performance).
Muscle gain on a keto diet is slow but definitely pays off (less chances of gaining body fat). So unless you want to achieve maximum anabolic effects (bodybuilders), you won't need to add carbs to build muscles.
So if carbs are not vital for muscle growth, what are the main factors?
- Adequate protein intake. This depends on your lean mass and activity level and is 0.6 - 1 grams per a pound (1.3 to 2.2 grams per a kilogram) of lean mass. The more you exercise, the more protein you will need. Too little protein will lead to muscle loss. You can learn what your ideal level is by using our keto calculator.
- Calorie surplus. If you want to gain muscles, you have to eat more. About 10-15% over your maintenance level is ideal. When you follow a ketogenic diet, calorie surplus will translate into increased fat intake (carbs and protein are the same).
- Proper training. You have to do the right type of exercise to promote hypertrophy (the process of individual muscles increasing in diameter). The right type of resistance training is crucial for muscle gain.
- Don't overtrain. Your body needs time to recover, otherwise it would be counterproductive and you may actually lose muscle mass. This doesn't mean your "resting" days have to be inactive - you can do light cardio instead.
- Sleep. Just like weight loss, muscle growth won't happen without proper sleep. This review article lists several negative effects of sleep deprivation. Sleep deprived individuals produce less growth hormone, have impaired glucose metabolism and show a decreased level of leptin - the hormone that signals satiety. On the other hand, they show an increased level of ghrelin - the hormone that tells the brain when we are hungry. People who are sleep deprived are likely to store more body fat: try to get at least 7-9 hours of sleep every day.
Want to know how to gain muscles, lose body fat or maintain a healthy weight on a keto diet? Discover your ideal macronutrients using our keto calculator.
When Do I Need to Carb-Up on Keto?
Carb backloading, carb nite, carb day,... all these are different names for carb-up techniques. There is no approach that universally works for everyone and we simply need to embrace personalised nutrition in order to determine the best method for everyone.
Fat Loss and Weight Maintenance: No Need to Carb-Up
Will I need extra carbs? Most likely, no you won't. If you want to lose body fat, you should avoid large amounts of carbs. You probably have enough body fat that can be used for energy. If you want to avoid carbs but still need more energy, you can add some MCT oil or coconut oil to boost your energy levels. Again, you'll have to try this yourself. Some people tolerate MCTs well while others may experience stomach distress.
If you want to maintain your weight, you won't need large amounts of carbs unless you're doing an intense exercise for extended periods of time and experience issues with muscle recovery.
Muscle Gain: It Depends
Will I need extra carbs to gain muscles? Maybe, it depends on what you want to achieve. Apart from the Standard Ketogenic Diet, there are variations which allow extra carbs. On the Targeted Ketogenic Diet (TKD), you eat carbs strategically round your workouts to maintain performance without interrupting ketosis for too long. The Cyclic Ketogenic Diet (CKD) is used by advanced individuals, mostly bodybuilders, for maximum muscle growth and sustained performance. CKD and TKD are not suitable or advisable for the vast majority of people. Be aware that it's easy to consume excessive carbs and gain body fat if you use the CKD approach.
If you want to try TKD or CKD, you should already be quite lean. For a TKD, avoid fructose based foods and go for glucose or dextrose based foods instead. Unlike fructose which will interrupt ketosis (replenishes liver glycogen), glucose will be used as an immediate source of energy (replenishes muscle glycogen). This is a great resource for both CKD and TKD approach - check it out if you are interested in this type of ketogenic diets.
You should never use the Targeted or Cyclic Ketogenic Diet as an excuse to eat extra carbs. These diets are only suitable for advanced athletes and bodybuilders who want to enhance their performance and maximise muscle growth.
Explosive Exercise Actions (HIIT): Yes You May Need To Carb-Up
What is explosive exercise? Explosive exercise builds power, strength and fitness faster and can be defined as movements in which the rate of force development is maximum or near maximum.
Whether you'll need carbs or not also depends on the type of exercise. For the vast majority of people, extra pre or post workout carbs are not needed. However, if you do CrossFit, sprinting and other high-intensity activities which require explosive actions, extra carbs can be beneficial for sustaining strength.
To Sum Up...
Studies show that a the ketogenic diet does not negatively affect performance in athletes. Studies also show that the ketogenic diet will help you preserve and build muscle mass.
We need to embrace personalised nutrition. Those who are insulin sensitive will, in general, do better with carbs-ups compared to those who are carbohydrate intolerant and insulin resistant. Keep in mind that carbs are not responsible for the obesity epidemic. It is the overconsumption of carbs, processed foods and changes in life style.
When considering carb-ups, type of exercise matters: Those who do high intensity exercise and need to be able to perform explosive actions will benefit from carb-ups. Extra carbs may be beneficial for activities like CrossFit, sprinting, etc.
Carbs-up are not an excuse for binging: adding carbs is not an excuse for eating sugary foods, pizza or chips!
You can read even more about protein and exercise nutrition in this post: Ketogenic Nutrition and Exercise: Protein and Ketogenic Nutrition and Exercise: Carbs
Have you tried carb-ups? Let me know your thoughts!
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