New Research Suggests Runners Are Eating Protein on the Wrong Days
From a nutrition perspective, most endurance athletes are focused on getting through their training, rather than recovering from it. Serious athletes put great consideration into their carbohydrate timing and overall intake, especially around workouts. Eating the right amounts from the right source at the right time could mean the difference between a PR and a miserable run.
While the importance of protein has made its way into the endurance world, it can still be an afterthought to many. Protein can still be considered something that solely helps to build muscle, rather than aid in recovery for the next training session.
A new study by Witard et al. had some interesting insights into endurance training and protein intake.
The paper found that protein needs increase on recovery days compared to the training days themselves. Most people put an emphasis on protein on the days they work out. This new research suggests that it is the subsequent days that are even more important.
Researchers used the indicator amino acid oxidation (IAAO) method to measure protein needs. This is considered by many to be a better measure of protein needs than the widely used nitrogen balance method. They found that protein on standard training days should be 1.8g/kg of body weight, but over 2.0g/kg on recovery days. If you are training in a low carb state these numbers get even higher, since protein would potentially be used for fuel rather than repair.
This makes logical sense when you think about it. It's not as if you train, go to sleep, wake up the next day, and the recovery process is just finished right then and there. Recovery can take 24 hours or more. We sometimes get locked into thinking about things day to day rather than a continuum.
The study also found that higher protein intakes don't really help with glycogen resynthesis, unless your overall carbohydrate intake is low. In addition, consuming protein during training does not boost muscle protein synthesis, since the energy demands of exercise are too high.
Some people purposely train in a low carb state to increase metabolic flexibility. Basically, they want to be efficient in using carbs and fats for energy. Eating more protein does not impair your ability to do this, so if you are in this situation you can rest easy. You can protect your muscle without sacrificing this adaptation.
The broader takeaway from this research is that protein for endurance athletes deserves the same strategic thinking that carbohydrates have gotten for decades. The recovery day piece alone is probably enough to change how a lot of athletes are currently eating. So between your gel packs and pasta dinners, make sure you're mixing in some chicken and steak too.
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This story was originally published May 7, 2026 at 9:28 AM.