Nutrient Timing: Does It Matter?

Take a closer look at this popular fitness practice, how it works, and the research behind it so you can see if it would be effective for you!

Nutrient Timing: Does It Matter?
Photo by Sandra Seitamaa / Unsplash
María Rubio María Rubio
5 min read

When it comes to eating for your fitness goals, you probably already know what to eat and how much to eat – plenty of nutrient-rich foods and the amount of protein, carbs, and fats that your body needs for your specific goals. But there’s a third thing that comes into play when you’re an active person, and that’s when to eat.

This is known as nutrient timing, and just like the name suggests, it involves eating certain nutrients at certain times to better support your body and goals. For example, eating carb-rich food before an intense weightlifting session or a loaded protein shake right after.

Nutrient timing for muscle gain has been around for many years and it was thought to be a crucial element in any active person’s diet and routine… But is it really? How does nutrient timing actually affect your body and what do experts say? We’ll show you everything you need to know about this practice, so keep reading!

The science behind nutrient timing

Nutrient timing isn’t just a made-up term to get you to eat more macronutrients – it’s mostly based on your body's processes and how it metabolizes food. One big aspect of this practice, and what most active people based their own nutrient timing on, is the anabolic window.

The anabolic window refers to the short period post-workout in which your body it’s at peak condition for absorbing nutrients. Also known as the “window of opportunity”, this short period lasts for about 15 minutes to an hour after you finish your workout, making it the perfect time to replenish your body with nutrients – more specifically protein and carbs.

After a workout, two things happen:

  • Your energy is almost or fully depleted and you need carbs that your body can turn into new energy, both for recovering post-exercise and to be ready for the next workout
  • Your muscles get damaged during exercise, so your body needs protein that can be synthesized to repair the damage and grow new muscle tissue on top

That said, human metabolism is much more complicated than this. And not only that, but each body is different and everyone has different lifestyles and body processes going on. So, while there’s some truth to nutrient timing, there’s also a lot of inconclusive information.

Carb and protein replenishment

Let’s take a closer look at your body’s needs for carbs and protein post-workout. As we said, you need both macronutrients to replenish your body after each workout for different reasons, but you don’t necessarily need to consume these nutrients right after your workout.

When it comes to carb replenishment, research shows that muscle glycogen stores get replenished at a lower rate the more you wait to ingest carb-rich foods or supplements. [1] In simpler terms, it means that carbs are absorbed and stored as energy faster right after exercise, as opposed to waiting for a couple of hours.

This process directly supports nutrient timing – but there’s a catch! You only really need to replenish your energy faster if you have a high level of physical activity, such as an athletic event with multiple rounds or stations. But if you’re only working out once a day, as most people do, your body will have plenty of time to synthesize carbs from your regular daily meals, so carb timing isn’t actually necessary.

Protein replenishment works in a similar way, except that no studies are backing up protein timing post-workout, which means that eating protein right after your workout or later than that produces the same results. Studies show that when it comes to protein, eating high-quality protein in adequate amounts is what you should focus on, instead of when to eat it. [2]

On top of this, researchers that have studied nutrient timing have found two important limitations when considering how effective it is:

  • Nutrient timing research is mostly based on short-term blood markers, which measure the body’s response to something, meaning that the findings are not conclusive for long-term benefits
  • The majority of test subjects are high-endurance athletes with intense training routines, and this doesn’t represent the majority of gym-goers and active people with regular workout routines that might be interested in nutrient timing

This means that, even though there has been some research backing up nutrient timing, it’s not extensive or conclusive enough to be applied to most people. And even if it were to be applied to regular active people, there aren’t any practical benefits to using the anabolic window and consuming proteins immediately post-workout.

Does nutrient timing matter at all?

Well, it does, but maybe not in the way that you might think! The anabolic window part of nutrient timing doesn’t really matter as long as your workouts aren’t too close to one another, such as having multiple workouts a day. You can still practice this kind of nutrient timing if you prefer doing so – just because it’s not particularly beneficial doesn’t mean that it’s bad!

That said, keeping a healthy diet is necessary if you have certain fitness goals in mind, such as muscle building and weight loss. And with a healthy diet comes a healthy eating schedule, which you could consider as nutrient timing if you’re keeping track of your macros.

Here are some instances where knowing when to eat and when not to eat can make a difference:

  • Eating a balanced meal with plenty of carbs and protein around an hour or two before your workout can help improve your performance by increasing your energy levels
  • For those on a fat loss journey, doing the contrary might be even more effective, since fasted workouts prompt your body to tap into your fat storage for energy, burning more fat in the process
  • If you track your macros, knowing how to effectively distribute your meals throughout the day is key to making sure you’re eating the right amount of protein, carbs, and fat for the day to support your fitness goals
  • Eating right before bed can make digestion more difficult, causing heartburn and interrupting your healthy sleep schedule, which in turn can impact your workout the next day

On top of that, you should always make sure to eat enough carbs and protein after your workouts, whether it’s right after or later in the day. Maybe the anabolic window isn’t that important, but replenishing all those lost nutrients definitely is!

Focus on what you eat rather than when

Nothing will make more of a difference than paying close attention to the foods that you eat and making sure they’re nutrient-rich and full of the vitamins and minerals that your body needs to function properly. Nutrient timing can be useful when used correctly according to your goals and lifestyle, but the quality of what you eat is what’s truly going to make a difference.

If you’re an elite athlete or need to replenish your energy levels or promote muscle protein synthesis right away for another activity, you can make the most out of the short anabolic window by choosing complex carbs and lean proteins that can support your fitness goals in more than just one way!

Need some help deciding which foods to eat for your goals?

Fit With Iulia has you covered! You can use our Macro Calculator to find out how many proteins, carbs, and fats you should be eating daily to support your health and goals by answering a few simple questions about yourself. Then you can check our Kitchen feature on the Fit With Iulia app to search for foods and ingredient ideas for your meals according to your macros, as well as check if they’re vegan, vegetarian, lactose-free, or gluten-free. Try it now!