I have been reading a lot recently about endurance athletes using a low carbohydrate high fat (LCHF) diet. One form of this type of diet is known as a ketogenic diet. According to various studies, nutritionists, and physicians, the diet has a number of health benefits including treating obesity, type 2 diabetes, high cholesterol, epilepsy, Alzheimer’s and Parkinson’s Disease. In some cases it has been linked to improved mood, sleep, mental focus, blood sugar regulation and reduction of general inflammation. Of great interest to me is the ability to use fat as an energy source rather than carbs during endurance training and racing.
There are a number of very good resources available about the theory and science behind the ketogenic diet so I won’t go into detail here. The short of it is that by reducing carbohydrates and increasing fat intake will shift your body to an alternate metabolic process known as ketosis. Once converted, your body becomes much more efficient at burning fat for energy. It takes a few weeks to fully engage ketosis as your body shifts the metabolic process.
Since it is the off-season for me, I decided to experiment with the LCHF concept to see if it would offer me any benefits without adversely affecting my training and racing. I’ll post weekly updates here. It may be a short-lived experiment if things don’t go well after about a month.
The first step is shifting your diet to minimize carbs and increase fat, keeping a moderate protein intake. No easy task for someone like me that lives on carbs. I went into the new diet without a plan, so the first day was quite a challenge. I was searching the fridge and the pantry for anything edible that was high in fat and low in carbs. There was not much there. With much help from Beth, the Crew Chief, we were able to cobble together a few meals, although, my carb intake was a little too high during the first week.
We loaded up on high-fat foods at the grocery store. Ingredients included lots of avocados, eggs, cheeses, something called coconut manna, nuts, and a variety of meats. The Crew Chief likes to experiment in the kitchen, so over the first several days she created a variety of meals and snacks that met my caloric intake targets. I have to admit I’m a big dessert guy, typically desiring just “a little something sweet” after my evening meal. To satisfy this urge, Beth created some “fat bombs” from cream cheese, coconut manna, and various other ingredients. I’ll have to admit that they were pretty good, providing me with additional fat and very few carbs.
In counting carbs, fiber content should be factored in. Fiber is a form of carbohydrate that is not used as an energy source by the body. Therefore, fiber is usually subtracted from the total carb intake to provide “net carb” intake. Net carbs is the important number when considering carb reduction.
For my first seven days on the program, I was able to keep my ratios pretty close to targets, and lower my carb intake. However, in my research I found several references that said I needed to get my net carb intake down to about 50 grams/day or lower to really get converted to ketosis. More work needed on lower carb intake.
For the most part during the first week of the diet, I did not notice any major adverse effects. Since going into the off-season, my body weight had shifted from my typical “race weight” of 165 lbs. to my typical “off season” weight of 170 lbs. The first noticeable effect of the diet is that I immediately lost 5 pounds without any increase in my offseason weekly exercise routine.
Another physical change was that I required less between-meal snacks. In my usual high-carb diet, I would typically have: breakfast, a mid-morning snack, lunch, a mid-afternoon snack, a snack before exercise, dinner, and then maybe something before bed. With the keto diet, I did not feel hungry between meals and I eliminated most of my snacking.
One adverse effect was that my body had an adjustment to make. (Sorry to have to go here, but I am reporting all results). I’m typically a very “regular” guy. I can almost set a clock to my bowel movements. Almost immediately after starting the diet, my system was out of whack and I was not so regular. My guess is that I was not taking in enough fiber. More experimenting to be done here.
I’m not sure if it was a placebo effect or if it was real, but after a couple of days on the diet, I seemed to have more energy. I often have an after-lunch dip in energy and feel like I need a nap. I noticed that after starting the diet, I did not have that same afternoon “crash.” Overall, I seemed to feel a little more mentally sharp.
Effects on Exercise
During my offseason, I have very little structure to my workout routine. During the first week of the diet, I did some relatively easy workouts including short runs and easy spins on the bicycle trainer. In general, I felt reasonably well during the exercise, keeping in mind that it was very low intensity.
On the second day of the diet, I did a 30 mile road bike ride that included one significant climb. I was pretty slow on the climb but I attributed that to off-season lack of fitness more so than the diet. My nutrition during the ride included only water and Base Salts. I would normally fuel with a carb drink for rides of this duration. I had no loss of energy throughout the ride. I attribute that more to the duration of the ride and not the diet since it would have been too early to see any benefits from the diet. It will be interesting to see the effect as I go out a little longer where, in the past, I would typically fuel with carb drinks and gels.
With one week of the ketogenic diet under my belt, I’m still a little leery and skeptical of the entire approach. It just seems so foreign to me to not take in a bunch of carbs every day. The biggest challenge is finding things to eat that meet the nutrition requirements. It takes a lot of planning to get it right. It also takes some researching to create enough variety in the diet. I will march on as I have committed to a minimum of one month for the experiment. Week 2 will be interesting since there are a lot of reports of getting the “keto flu.” This is a side-effect when your body is shifting to the alternate metabolic pathway in which people report feeling poorly and sluggish. Stay tuned.