Nutrient timing is a critical element that many people are missing from their health-related goals. It could be why you see so many people plateau throughout their fitness journey. It’s the foundation for all things health-related, from trying to lose weight to maximize muscle growth. Once you understand nutrient timing in terms of when and what to consume, you’ll start to see results you’ve been trying to achieve. However, nutrient timing is only as effective as the appropriateness of the nutrients provided.
By Seante Collins
You’ve probably heard over time that breakfast is the most important meal of the day, but few have explained why. Breakfast is essential because it restores muscle and liver glycogen levels. It is also “breaking the overnight fast” period, so it is critical to fuel your body with the proper nutrients and make sure this meal is not skipped. A 2012 study was conducted by the Third National Health and Nutrition Examination Survey. The objective was to investigate the relationship between breakfast, total daily energy intake, and body mass index. The findings of this study were eye-opening. First, people who skipped breakfast had a higher BMI. Second, skipping breakfast was not shown to be an effective way to lose weight. Previously, breakfast consumption had been positively associated with weight management, appetite control, and feelings of hunger.
Consuming macronutrients at breakfast are essential. Protein intake (30-40g of high-quality protein) at breakfast tends to reduce appetite during the next meal and enhances satiety during calorie restriction. Carbohydrates in the morning are divided into fast or slow digesting. Slow-digesting carbs and fiber contribute to satiety over the day. A 2014 study suggested that 2-3x more fat burned during exercise (3hrs later) after consuming slow-digesting carbs compared to fast-digesting carbs. Higher fat breakfast (45%) has also been shown to burn more fat throughout the day. High carbohydrate breakfasts may predispose you to rely primarily on the carbs for energy the rest of the day. Whereas higher fat, low-carb breakfast programs derive fuel from fat. So, if you start your day with a well-balanced meal, it will jump-start your metabolism and help keep hunger cravings away until lunchtime.
Protein is a sequence of amino acids that serve as the building blocks for more complex tissues. Protein has many functional roles in nutrition, and the timing of protein consumption is more significant than was previously thought. A 2013 study consisted of three groups. Group 1 consumed 10g protein every 1.5 hours. Group 2 consumed 20g protein every 3 hours, and group 3 consumed 40g protein every 6 hours. Ultimately, Group 2 was superior to all the groups for increasing myofibrillar protein synthesis. The timing of protein intake does appear to matter for maximizing optimal muscle growth. If you haven’t been seeing the best results in the gym after putting in the work, consider changing your diet. Start eating minor protein-packed meals multiple times a day, rather than just eating three large meals. It is also essential to eat protein in the 3-hour gap window, post-resistive activity to enhance muscle growth. As demonstrated that resistance training does have a post activity anabolic window of time for nutritional benefits. The intake of protein is vital within this time frame to maximize protein synthesis. Delayed intake may be counterproductive. Consuming protein and carbohydrates post-exercise provide energy and restores glycogen. It also stimulates insulin secretion, which stimulates amino acid uptake in the muscle. Consuming protein, post-exercise provides the tools required to rebuild muscles. After exercise, the post-meal is critical. If the protein intake is low, the protein balance remains negative without the necessary amino acids. To optimize your muscle growth, dietitians recommend consuming 1.2-1.8grams of protein per 1 pound of body weight.
While nutrient timing is significant, there are certain things to eat before and after your workouts to optimize your health-related goals. The food to consume also depends on the type of aerobic or anaerobic training performed. Aerobic nutrient timing is different because aerobic and anaerobic training are entirely different. So, what to consume pre- and post-exercise are going to be different as well. A 1985 study found that nutrient timing for pre-aerobic activities should include foods that will help top off muscle glycogen storage, optimum blood glucose concentration, restore liver glycogen, and stay hydrated. For pre aerobic activities that are 90-minutes or longer, you should consume a high carbohydrate diet to super-compensate glycogen storage, 3 – 4 days before the event. Then, 24 hours before the event, continue to consume high carbohydrates. On the day of the event, keep consuming a carbohydrate-loaded diet. The carbs can then be stored as 1200-2000 kcal and used for fuel throughout the event.
For post-aerobic activities, immediate glycogen recovery is needed, according to a 1988 study. There is a specific metabolic window of opportunity to normalize muscle glycogen levels. Its timing is critical, and the window lasts for about 45minutes. If this process is delayed, a 50% reduction in synthesis occurs. A 2008 study suggested that the metabolic window of opportunity is the time after exercise in which muscle is highly capable of responding to anabolic effects of insulin in sufficient substrate made available without nutrient intervention. This metabolic window begins to close within 45 minutes following exercise.
There are many research studies involved with nutrient timing. Often, you will get different opinions on the idea of what to eat and when to eat it. But the critical elements are the kind of training and how intense the activity is. Then, you can narrow down some options to optimize your end goals related to health and fitness. Remember that post-workout nutrition is vital for muscle protein synthesis. Protein plus carbohydrates will stimulate synthesis and decrease breakdown. Multiple smaller meals that are protein-packed throughout the day seem to be more beneficial to reach protein goals and optimize muscle growth. For endurance activities, nutrient timing is critical for rapid and complete recovery. However, once the metabolic window of opportunity has closed, nutrient supplementation will not be nearly as effective. Nutrient timing is an essential aspect for either aerobic or anaerobic training. But, nutrient timing is only as effective as the quality of the nutrients provided.
Cermak NM, Res PT, De Groot LC, Saris WH, Van Loon LJ. Protein Supplementation Augments The Adaptive Response Of Skeletal Muscle To Resistance-Type Exercise Training: A Meta-Analysis. Am J Clin Nutr. 2012
Coyle EF, Coggan AR, Hemmert MK, Ivy JL. Muscle Glycogen Utilization During Prolonged Strenuous Exercise When Fed Carbohydrate. J Appl Physiol. 1986;61(1):165–72.
Dreyer HC, Drummond MJ, Pennings B, Fujita S, Glynn EL, Chinkes DL, Dhanani S, Volpi E, Rasmussen BB. Leucine-Enriched Essential Amino Acid And Carbohydrate Ingestion Following Resistance Exercise Enhances Motor Signaling And Protein Synthesis In Human Muscle. Am J Physiol Endocrinol Metab. 2008;294
Fujita S, Dreyer HC, Drummond MJ, Glynn EL, Volpi E, Rasmussen BB. Essential Amino Acid And Carbohydrate Ingestion Before Resistance Exercise Does Not Enhance Postexercise Muscle Protein Synthesis. J Appl Physiol (1985).
Galloway SD, Lott MJ, Toulouse LC. Pre-exercise Carbohydrate Feeding And High-Intensity Exercise Capacity: Effects Of Timing Of Intake And Carbohydrate Concentration. Int J Sport Nutr Exerc Metab. 2014;24(3):258–66
Ivy JL. Glycogen Resynthesis After Exercise: Effect Of Carbohydrate Intake. Int J Sports Med. 1998;19(Suppl 2): S142–5
Kerksick C, Harvey T, Stout J, Campbell B, Wilborn C, Kreider R, Kalman D, Ziegenfuss T, Lopez H, Landis J, et al. International Society Of Sports Nutrition Position Stand: Nutrient Timing. J Int Soc Sports Nutr. 2008;5:17.
José L. Areta Louise M. Burke Megan L. Ross Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. J. A. Hawley: School of Medical Sciences, RMIT University. March 2013.