Nutrition Periodization: How Carbohydrate and Energy availability are intimately linked

Caroline Kavanagh | Dec 21, 2020

Most athletes are familiar with the concept of training periodization. It refers broadly to training that is structured around periods of progressively-loaded training stress followed by rest. Most periodized training plans are organized by macro, meso and micro cycles. The macro cycle refers to over three months to one year (or season) of training and competition, and is made up of meso cycles consisting of week to month blocks. Each meso cycle is typically focused on a specific fitness goal, like endurance, sprinting or neuromuscular power, etc. A week of training makes up a micro cycle, and it will usually include three to five key workouts, a couple of lighter active-recovery style workouts, and/or a day off. Micro cycles are progressively loaded within the meso cycle; that is, each microcycle will build (in duration and/or intensity) on the last, until you get a recovery week. Nutrition periodization works in conjunction with the associated macro, meso and micro training model. It is a purposeful nutrition intervention that supports the athletes periodized training and recovery plan.

From a nutritional standpoint, the focus is on carbohydrate availability (CA) and energy availability (EA). Carbohydrate and energy availability are intimately linked. In the vast majority of scientific studies, or "in the field" when exercise is significantly increased, such as training overload or over-training syndrome, or where energy availability is decreased, either strategically or inadvertently, it generally coincides with low or lower carbohydrate availability. Generally speaking, as energy availability increases and decreases in athletes, carbohydrate availability is the major macronutrient involved in those energy changes and it tends to move in those same directions and magnitudes.

The chart below shows Macro, Meso and Micro training cycles with nutritional focus examples of how carbohydrate and energy availability are applied strategically within each of these phases.

Nutrition Periodization Risks and Rewards Strategic carbohydrate manipulations are applied depending on an athletes goals as well as individual moderating factors, for example, co-existing medical issues, injury history or previous nutritional deficiencies, etc. These issues are unique to each athlete and should be taken into consideration. Nutritional periodization is a balancing act and the word "strategic" is important here! If nutrition periodization is not implemented appropriately there are potential pitfalls. Remember, rewards are fleeting if long term health doesn't remain the top priority!

So..... what are some of the risks?

• Chronic Low Energy Availability (LEA): Increase in injuries (bone health), reduction of training adaptations, decreased sex hormones, risk for Relative Energy Deficiency in Sport - (RED-S). • Acute Low Energy Availability (LEA): Poor within day, over long period, resulting in markers of RED-S. • Acute/Chronic Low Carbohydrate Availability (LCA): potential impact on bone markers/bone health. • Chronic Low Carbohydrate Availability (LCA) (i.e. keto): negative impact on training adaptation, economy and performance (decreased CHO metabolism - metabolic flexibility).

And... what are the potential rewards?

• Low Energy Availability (LEA): Periodized optimization of body composition to enhance performance (i.e. increase power to weight ratio). • Acute Low Carbohydrate Availability (LCA): Appropriately periodization has the potential to enhance endurance training adaptations and by extension performance. • Acute Low Carbohydrate (LCA) and Low Energy (LEA) Availability: Mimic the physiological and psychological demands of late race endurance events.

Summary Models of carbohydrate and energy availability (nutrition periodization) are highly specific to the training structure of specific sports, as well as the athlete’s goals. What I have outlined here is a framework of fueling or adaptation for the work required to show how training models are potentially coupled with nutrition to optimize health and/or performance. The main goal here isn't to super-compensate glycogen stores as is the common practice with carb-loading, but to get just the right amount of carbohydrates to maintain training intensity while also creating a consistent metabolic environment that best facilitates training adaptations.

InsideOut Human Performance - nutrition:, #metabolicefficiency