Why Endurance Athletes Should Prioritize Post-Workout Nutrition Over Pre-Workout

One of the problems I see with modern training is the pursuit of perfection over priority. With the ever-increasing range of products and theories on training, nutrition, recovery and other areas, some athletes get caught up in the minutia of perfecting every nuance of their training life. It becomes overwhelming and you can lose the sight of the big picture. When athletes are headed down this path – or are already all the way down the rabbit hole – I try to shift their approach to focus on prioritization over perfection. One way to understand this in practical terms is to look at pre- and post-workout nutrition.

Your nutrition choices before and after training can significantly influence the quality of your workout and your ability to recover and adapt. The simple answer to the question in the title of this post is: Both. But that’s how athletes drive themselves crazy. There are innumerable pre-workout foods, supplements, drinks, and techniques that promise to optimize your workout. And there are as many or more that promise to enhance your post-workout recovery. In extreme cases, athletes have pre-workout routines that stretch over 2+ hours before training and 4+ hours after training. I respect the dedication to performance, but it is easy to take it too far.

When I look at the bigger picture of pre- and post-workout nutrition, I place a higher priority on post-workout choices. Here’s why:

Pre-workout nutrition primarily affects perception

For endurance athletes, starting a workout hydrated and with full glycogen stores are the biggest determinants of whether your workout will be successful. It is difficult to significantly affect either of these in the hour before training. These are more affected by your day-to-day habits. At best, your immediate pre-workout choices will top off the tanks, so to speak. But they won’t fix systemic problems or large deficits in either glycogen or hydration. Rather, good pre-workout choices help you feel energized and focused for your workout. Poor choices leave you feeling sluggish, bloated, or hazy. It is important to make good choices that work for you, but if the energy and hydration are present, all you really need to do is keep it simple and avoid choices that leave you feeling sluggish.

There’s more time to work with after training

Post-workout nutrition is a greater priority because it sets the stage for everything that has to happen between today’s workout and your next training session. That could be just 12 hours if you are training in the evening and again tomorrow morning, or 48 hours if you’re training today and taking a full day off before your next workout. In this period you need to replenish your glycogen stores, nutritionally support recovery and adaptation, and ensure adequate hydration. The shorter the time period between workouts, the more focused you need to be on rapid replenishment. The longer the time between training, the more you need to focus on avoiding mistakes.

Optimizing sub-24 hour recovery cycles

The shorter the time period between workouts, the more proactive you need to be about recovery. For instance, athletes who train or compete two or more times in the same day have to prioritize the “glycogen window” more than anyone else. In the first 30-60 minutes after exercise your muscles open more “gates” to move carbohydrate from the blood into muscle cells faster. The rate of glycogen replenishment is fastest during this period and gradually slows as time goes on (but it’s not an on/off switch).

If you only have 12 hours (evening to next morning) between training sessions and you want to have high carbohydrate availability for your next workout, then you want to take advantage of the glycogen window. This means consuming either a carbohydrate-rich recovery drink and/or a carbohydrate-rich meal within about 60 minutes after training. You should also focus on replenishing fluids lost through sweat, particularly within the four hours post-workout.

Optimizing 24-48 hour recovery cycles

If you have 24 hours or more between workouts, then you have more than enough time to replenish the energy and fluids you depleted during your recent ride or run. Maintaining that replenished state is more of problem.

In years past, the glycogen window was overhyped, and I openly admit to playing a role in that. We used to push everyone to consume carbohydrate (and smaller amounts of protein and maybe caffeine) immediately after training in order to speed glycogen replenishment. The intentions were good, but the science shows glycogen stores will be fully replenished through normal dietary choices within 24 hours regardless of whether you prioritize carbohydrate consumption during the glycogen window or not. In recent years I have amended my recommendations to focus on specialized recovery drink consumption only when energy expenditure is likely to have significantly depleted glycogen stores (at least 1500-2000 kilojoules of expenditure).

When you have more than enough time to achieve full replenishment, your higher priority needs to be maintaining that replenished status until your next training session. You don’t want to focus on fluid replenishment in the first 12 hours and then become dehydrated again in the 12-36 hours before your next training session, which is a significant probability during the hot weather and/or at high elevations. Similarly, significantly restricting carbohydrate intake on the day between your workouts can reduce glycogen stores, even if they were previously topped off.

Summary

You have far more time between workouts than between your pre-workout snack/drink and your workout. That means you have more time to make decisions that will enhance recovery and adaptation, and more time to screw them up. Therefore, in the spirit of keeping things simple – because simple is less stressful and more likely to actually happen consistently – prioritize your post-workout nutrition habits over your immediate pre-workout choices. What you do during those longer hours between training session will have a greater impact on your next workout and your long-term progress than anything you do or don’t do in the hour before you start training.

Chris Carmichael
CEO/Head Coach of CTS