One of the more popular pieces of nutrition advice is eating (especially protein and to a lesser degree carbs) close in time to one’s workout. This episode takes a look at what the evidence says for nutrient timing as related to better performance outcomes or increased muscle mass.
What is nutrient timing?
Nutrient timing refers to when during the day one eats – such as what time do you eat lunch? The problem is, if someone doesn’t eat at a certain time, this may change the overall quantity of food eaten that day. Quantity refers to the calories or macros consumed.
If you skip lunch, do you end up eating the same overall calories? Maybe you eat less, or maybe you’re so hungry that you eat more. And so this is where it can be hard to tease out: are we looking at an issue specific to timing – or quantity?
For the purposes of this discussion, quantity is assumed to be constant (e.g., 2000 calories a day). Timing then would be: does it matter if you eat all 2,000 at one time? Or is it better to eat four equal 500 calorie meals? Or can the meals be mixed of various quantities?
Regarding performance, much of the timing discussion has focused around the “anabolic window.” This would be eating say within 90 minutes of a workout. The theory being, you just used energy stores as well as stressed the body. Fuel immediate after may be best timed to maximize recovery and adaptation.
What does the science say?
We have to clearly define what outcome we are concerned with. In many cases, individuals say they want performance improvement but are swayed by science looking at non-performance indices.
As an example, if someone wants to get a better deadlift, the nutrition intervention would be considered successful if at the end of the program the person has a heavier deadlift. Pretty straight forward! But many times, individuals cite studies relative to MPS – muscle protein synthesis.
The body is continuing to break down and rebuild muscle throughout the day; it’s in a state of constant turnover. Rebuilding new protein is muscle protein synthesis, and this is often measured in research studies. They may have the research subjects perform some exercise, then give them a protein shake, then measure the MPS up to four hours after the exercise.
Various factors have influenced the rate of MPS such as whether or not the person consumes protein and how much. Around 20-40 grams of protein after exercise has been found to maximize MPS rates post-training.
Aha! So timing does matter!
Not so fast. That’s not a performance outcome. While yes, many athletes want to be stronger, there are many steps between having an increased rate of muscle protein synthesis 4 hours after a workout versus actually having more overall muscle mass in the long term versus having that muscle mass transfer to performance improvement. Not every pound of muscle changes performance significantly because performance is dependent on so many other things such as technique, mindset, and training readiness.
So this is how you have to stay laser-focused on whether the research is analyzing the outcome you want versus part of the outcome you want. It is very tempting to assume that MPS leads to increased performance or even muscle mass, yet that is not what the research shows. Instead, the differences of protein timing are only significant when it changes the total quantity in the day.
This is one of the reasons why individuals are best focusing on being consistent on the total quantity of the food they eat in the day, not when exactly they consume that food each day.
What about the timing of carbs? Does it ever make sense to focus on nutrient timing?
Get the answers to these topics by listening to the full podcast episode!
Use the on-screen player, or the links to your favorite host scrolling back to Jan 2022 for this episode.
Referenced Articles
Antonio et al., 2017. Casein morning or night study.
Aragon and Schoenfeld, 2013. Nutrient timing and post-exercise nutrition.
Arent et al., 2020. Nutrient timing as an opportunity.
Baty et al., 2007. Cortisol and creatine kinase, but not performance, changes with a pre-workout supplement.
Berardi et al., 2006. Glycogen resynthesis and performance.
Schoenfeld et al., 2013. Meta-analysis of protein intake for strength or body composition.
Schoenfeld et al., 2017. Pre- versus post-workout protein study.
Referenced Episodes
On Digesting & Absorbing Protein
On Protein Timing & Muscle Protein Synthesis
On the Supposed Benefits of Fasting
On How to Fuel Performance
