If you can’t decide if you should follow a low-carb or a high-carb diet, why not just combine the two diets in an effort to address all of your sports-performance and weight-loss concerns? Believe it or not, this is an actual dietary approach known as carb cycling, which involves alternating between high- and low-carbohydrate days for six days and including a reward or “cheat” day on the seventh.
The theory is that low-carbohydrate diets lead to more effective weight loss (both from fat and water loss), but that rotating carbohydrates into the diet plan provides more energy for high-intensity training days. Proponents also claim that the reintroduction of carbohydrate helps boost metabolism, which may become stagnant on a chronically low-carbohydrate diet. Carb cycling has its roots in bodybuilding, a sport in which competitors cut carbohydrate prior to a event in an effort to lean out (the lack of glycogen and water from the muscles provides a lean, cut look). Eventually, the community noticed that alternating high-carb and low-carb days provided the best of both worlds—enough energy for training, but lower body fat.
How It Works
You may have heard of “plateau-busting” or “muscle-confusion” workouts for continued strength gains. Could it be possible that, like the musculoskeletal system, the human digestive system requires controlled chaos? There may, in fact, be some truth to this concept—at least mentally, if not also physiologically. Strict diet plans take a toll on both focus and mental drive (which is why they only work temporarily). Thus, keeping the mind and body guessing could be an effective plan for relatively long-term weight loss. Having said that, a completely chaotic or haphazard diet plan is not intuitive or productive.
Depending on your goals, proponents of carb cycling offer advice for tweaking the schedule. For example, if you would like to lose weight, include five low-carb days intermixed with two high-carb days. If your goal is to gain muscle mass, try doing the opposite—four or five high-carb days with just a few low-carb days. No plan is perfect for everyone, so monitor your results (both subjective and objective) to create a program that facilitates fat loss without completely depleting your energy.
Like every other diet plan in the world, carb cycling comes with its own set of pros and cons. Overall, if you have the discipline to count your macros and restrict your intake every other day (or so), this diet plan can be a healthy option. Also, like every other plan, the choice to follow it will depend on your goals. Outside of bodybuilding, carb cycling seems best suited for individuals who would like to lose weight, but have been unsuccessful with other diet plans.
Some carb-cycling diets, however, are tied to supplements. While supplementation is not necessarily unhealthy or counterproductive to goals, always use caution when following diet plans that require supplements. For example, some plans and products will sling jargon such as, “Low-carb days enhance your body’s fat-burning potential, while high-carb days boost your body’s metabolism into high gear.” Or they may recommend substituting a product (a shake, for example) for one of the daily meals.
Further, for those with high-energy needs, such as endurance and collegiate athletes, too many “low” days are counterproductive to training and may potentially increase the risk of injury. Regardless of the diet plan you follow, consider your goals and what will work for you consistently.
Value What Matters
In terms of evaluating progress, subjective fitness gains are arguably more important that objective ones. Monitoring variables such as how you sleep, how you recover and your energy level during workouts, for example, is more imperative than the number on a scale.
The carb-cycling plan may be more sustainable than other diets, but can you endure the countless counting? Given your work, travel, vacation and holiday commitments, is it a plan you can follow indefinitely? For that matter, will any incredibly specific plan be sustainable for an entire year? If you are a competitive bodybuilder, the answer may very well be “yes” (and good for you, if that is the case). But if you are trying to lose a few pounds, just want to feel better or would like to shave some time off of your next triathlon, don’t follow a strict diet and don’t count calories (but keep reading).
Types of Carbohydrate Matter
High-carb days and cheat days can be easily misconstrued. Like the term “moderation,” everyone has his or her own definition. Regardless of whether or not you are carb cycling, added sugars and processed carbohydrates should comprise a minimal part of your diet. Processed carbohydrates can have a negative impact on blood-sugar regulation, which may alter hormone levels. When hormones (such as insulin and ghrelin) are out of balance, weight loss becomes more difficult. Any time you eat carbohydrates, focus on minimally processed, high-fiber foods and naturally occurring sugars.
Create a Plan That Works
Conceptually, carb cycling follows the principle of nutrition periodization, which means matching your energy intake with expenditure. High-intensity training days require more energy (calories) than rest days. On a broader scale, certain months of the year may require more energy than others; for example, you may require a higher caloric intake during in-season training versus what might be required while training during the off season.
Consider the following plan, which incorporates the ideas of carb cycling and nutrition periodization, but makes the day-day-day management easier:
Follow a moderate carbohydrate intake (roughly 50 percent of total caloric intake).
Fill half of your plate with vegetables, one-third with protein and healthy fats, and slightly less than one-quarter with starches, grains or fruit at each meal.
Include fiber, protein and healthy fats at each meal and snack.
Include one or two higher-carbohydrate meals or snacks on your workout days, or even on the days before or after a very intense workout. Examples include a fruit smoothie with protein, homemade energy bars, oatmeal with dried fruit and nuts, fresh fruit with nut butter, trail mix, chocolate milk, 100 percent fruit juice or an extra serving of starch vegetables (potatoes, corn, peas) or whole-grain starches.
Justin Robinson is a Registered Sports Dietitian and Strength and Conditioning Coach who has worked with athletes from youth to professional level. As the nutrition director and co-founder of Venn Performance Coaching, he specializes in practical sports nutrition recommendations and functional conditioning techniques. Over the past 15 years, he has worked with athletes from the youth to professional level, including runners and triathletes, MLB players and U.S. Military Special Operations soldiers. He graduated from Cal Poly, San Luis Obispo with a dual degree in Nutrition and Kinesiology, completed his dietetic internship at the University of Houston and earned his Master's Degree in Kinesiology at San Diego State University.