Nutrient Timing for Optimal Performance

Some say that timing is everything. That’s certainly true in relation to nutrition and athletic performance.


Some say that timing is everything. That’s certainly true in relation to nutrition and athletic performance. We now know that it isn’t simply what foods or, more specifically, key nutrients you consume but also when you consume them that will determine their impact on optimal CrossFit performance and fitness. 

Here’s why: Strenuous training challenges muscles and the cardiovascular system; a challenge that one must be properly prepared to initiate, fueled to endure, and nourished to recover from and adapt to. Improvements in one’s performance and physique are based on adaptations that occur at the cellular level over a minimum of several hours. Nutritional intake is one of the most potent factors in determining the degree of positive adaptation. Knowing this, your diet must transcend simply Paleo, Primal or Zone to become much more tactical in order to optimize performance and adaptation. 

Pre-WOD Nutrition

As your workout draws near, your thoughts should turn toward effective hydration and maximizing carbohydrate stores in muscle. Strive for at least 50 grams of carbohydrates a couple of hours before an upcoming WOD to help maximize muscle glycogen stores to power through those muscle-ups and Olympic lifts and consume ample fluid to avoid even mild levels of dehydration. Meanwhile, taking at least 15 to 20 grams of whey protein a couple of hours before workouts can help maintain muscle amino-acid levels during training. However, be careful with what you consume in the hour prior because gastric content and bloating can reduce performance. Usually, this is the time when some will use a preworkout supplement including caffeine. 

During WOD Nutrition

If your training period is relatively short, lasting only 15 to 30 minutes, then the need for “intraworkout” nutrition is reduced. However, for those training for longer periods, maintaining hydration and providing some fast-acting/high-glycemic carbohydrates and even some branched-chain amino acids can aid performance. The best way to estimate fluid-replacement needs during training is to check your weight right before and right after training. The weight that you lose during training is by and large sweat; 1 pound of weight loss is the equivalent of about ½ liter of water. 

Post-WOD Nutrition

The stimulus on muscle to grow is strongest in the first couple of hours after training and slowly abates thereafter. It is important to understand that exercise increases muscle protein synthesis and muscle protein breakdown, two counterbalancing yet distinct processes. Simply put, the most potent way to maximize the former is by consuming high-quality protein and to minimize the latter is with higher-glycemic carbohydrates. Strive for at least ¼ gram of protein and ½ gram of carbohydrates per kilogram of bodyweight as soon as possible after completing training, following that up with a protein and carbohydrate meal two to three hours later.

Daily and Nocturnal Nutrition

Combined, pre-, intra- and post-WOD nutrition only cover a quarter or third of a total day, but optimizing performance requires planning nutrient timing over a 24-hour period, including sleep. That’s because muscle recovery and adaptation can endure over a full day’s time, from the close of one WOD to the onset of the next. Carbohydrates and protein should be portioned throughout the day, and protein should even be consumed closer to bedtime to offer fuel to the body during the eight-plus hours you go without eating. At that time, a “slow protein” such as casein protein powder is ideal. For the same reason, carbohydrates and protein should be allocated for the morning meal, but a “fast” protein like whey is ideal after rising. CrossFit athletes who train strenuously and frequently should aim to eat 1.5 to 2 grams of protein per kilogram of bodyweight daily, a target easily hit for those following the Zone, Paleo or Primal diets. 

The proper nutrient timing for optimized CrossFit performance is simple to achieve, with nothing more than a little awareness and preparation. The easiest way to assess your success is to keep a food journal and see how your intake aligns against recommendations.