Total protein intake is more important than nutrient timing for muscle growth. There are no downsides to consuming a protein shake immediately after post-exercise. Nutrient timing, once considered a window of opportunity, is now recognized as a garage door (i.e., a much larger time frame than previously thought).
Bodybuilding nutrient timing for muscle growth is not necessary, but there is no harm in consuming protein and carbs post-exercise. The total protein is more important than the timing of meals.
Current nutrient timing books advocate that it is more like a garage door than a window.
There are no drawbacks of nutrient timing for using nutrient timing for peak performance.
The latest research suggests that nutrient timing for fat loss may be a possibility.
HOW IMPORTANT IS NUTRIENT TIMING?
The four R’s of recovery are Rehydration, Refuel, Repair, and Rest. The amount, composition, and timing of nutrients for optimal recovery depend on the type of sport, the time between sessions, etc.(1) For years, it was told that there was an “anabolic window” in which a protein shake after exercise must be consumed within 45 minutes, or gains would be lost. Nutrient timing books flooded the market, suggesting protein after a workout was the best time to eat for muscle growth.
This led to bodybuilders rushing home to get their protein after workout meal for muscle gain, or some started bringing a protein shake to the gym so they could consume it directly after exercise. Macros before and after workout were deemed the most important meal of the day.
Does protein timing matter for optimal gains in muscle mass? Some suggest that during the post-exercise window, a catabolic state exists, cortisol and catecholamine (i.e., adrenaline) are elevated, glycogen and insulin are lower, and increased protein breakdown occurs.
DOES NUTRIENT TIMING MATTER?
Nutritionists have suggested that bodybuilding nutrient timing for peak performance should contain rich sources of complete protein and complex carbohydrates (i.e., macros before and after exercise). A combination of carbohydrates and protein, or protein alone, can reverse all the effects leading to an anabolic state.(2)
Eating carbs after a workout can replenish glycogen and enhance post-exercise recuperation resulting in enhanced carbohydrate anabolism. If you train early in the morning and are competing in an all-day event, it may be beneficial to eat carbs the night before your workout.
It was said that nutrient timing was the most important anabolic meal of the day after training; some even claimed it was more important than the total protein consumed daily. Protein intake after exercise, but the million-dollar question is: Does protein timing (i.e., essential amino acids) of meals after a training program matter for muscle growth? Does the timing of protein matter if you consume adequate daily calories/protein sources throughout the day?
Factors to Consider
First, for those that insist that you consume a protein shake immediately after exercise, it has been found that gastric emptying, or the rate at which stomach contents are released from the stomach, is delayed after intense exercise.
It was found that amino acids and glucose were slower to rise in the blood when consumed 5 minutes after intense exercise than 30 minutes after exercise. In sum, immediate consumption of a nutrient-rich drink is better absorbed 30 minutes after exercise than immediately after exercise.(3)
I would put less emphasis on this study as hundreds of studies have had subjects drink whey protein drinks immediately after exercise, and there was no effect of shorter timing having any negative effects on muscle protein synthesis. In a 2013 meta-analysis, it was concluded that there was a lack of evidence to support bodybuilding nutrient timing, and there was a broad range of flexibility for protein intake.(4)
Total Protein Intake is More Important than Nutrient Timing
A second meta-analysis of the literature by Schoenfeld, Aragon, and Krieger found that total protein intake was more important for muscle hypertrophy than timing. The benefits of nutrient timing were due to the increased protein intake per day rather than a timing effect. The authors concluded, ” Current evidence does not appear to support the claim that immediate (≤ 1 hour) consumption of protein pre-and/or post-workout significantly enhances strength- or hypertrophic-related adaptations to resistance exercise.”(5)
International Society of Sports Nutrition Position Stand Nutrient Timing
The ISSN’s official stance on protein timing for exercise is that the timing of protein is to be considered of lower priority than the ingestion of optimal daily protein intake (1.4-2.0 g/kg/day). However, not consuming protein post-workout (e.g., waiting several hours) offers no benefits. (6)
Instead of referring to bodybuilding nutrient timing as a narrow window, it should be considered a much larger time from, more analogous to, a garage door. The 45-minute protein timing myth should be put to rest! In an excellent review of the literature titled “Nutrient Timing: A Garage Door of Opportunity?”
The authors suggested that training stimulus and total protein intake are the base of the cake for performance and muscle growth, much like baking a cake. Bodybuilding nutrient timing is the “icing on the cake.”(7). Meal timing for muscle growth is less important than the total protein consumed throughout the day.
Total protein intake is more important than nutrient timing for muscle growth.
There are no downsides to consuming a protein shake immediately after post-exercise
Once thought of a window of opportunity, nutrient timing is now recognized as a garage door (i.e., a much larger time frame than previously thought).
1. Bonilla DA, Pérez-Idárraga A, Odriozola-Martínez A, Kreider RB. The 4R’s Framework of Nutritional Strategies for Post-Exercise Recovery: A Review with Emphasis on New Generation of Carbohydrates. International Journal of Environmental Research and Public Health. 2020;18(1):103.
3. Kashima H, Sugimura K, Taniyawa K, Kondo R, Endo MY, Tanimoto S, et al. Timing of post-resistance exercise nutrient ingestion: effects on gastric emptying and glucose and amino acid responses in humans. British Journal of Nutrition. 2018;120(9):995-1005.
6. Kerksick CM, Arent S, Schoenfeld BJ, Stout JR, Campbell B, Wilborn CD, et al. International society of sports nutrition position stand: nutrient timing. Journal of the International Society of Sports Nutrition. 2017;14(1).