When is protein consumption most effective – before, during, or after exercise?

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By J. E. Hinners, MD MPH

When is the most effective time to ingest protein? Before, during, or after working out?


Well, the answer, in part, depends on how you define “effective.” “Effective” in doing what? A Sports Medicine literature review by van Loon, published in May of 2014, indicates that:

  • If you are looking for immediate enhancement in athletic performance, then the timing of when you ingest protein may not matter so much.
  • If you are looking to better facilitate your muscle recovery after the protein breakdown that occurs with exercise, you may consider consuming protein before and/or during prolonged exercise (although we all know that exercise need not be longer than 30 minutes!).


Why we need protein to accompany exercise

Exercise involves substantial use of our skeletal muscles. These muscles are made up of protein filaments and have a most amazing capacity to adapt in size and strength, depending on use or disuse. The rate at which we build these muscle proteins and increase muscle size and strength is controlled by both physical activity as well as ingestion of protein.

While physical activity improves overall muscle protein balance by increasing protein synthesis and decreasing muscle breakdown, a muscle’s net protein balance becomes negative after exercising unless additional protein is provided to the body by way of food or supplements.

Nutrition increases protein synthesis and aids the recovery process after muscle breakdown in physical activity so that muscle’s net protein balance becomes positive, allowing muscles to grow in size and strength.

How to optimize the timing of when we ingest protein 

To be clear, making sure you are incorporating any protein at all into your diet – regardless of timing – is still better than skimping out on protein altogether (heads up to you vegetarians!). And, in fact, ingesting protein after working out has many of the same wonderful benefits of increasing protein synthesis rates and aiding muscles in the post-workout recovery process.

The difference when protein is consumed before or during exercise is that these protein synthesis rates begin increasing during exercise – thus, potentially decreasing the amount of muscle breakdown that normally occurs during exercise.

How does protein ingestion affect performance?

Studies do not consistently indicate that protein ingestion during physical activity enhances athletic performance. Some studies measuring time to exhaustion appear to support the notion that the addition of protein to carbohydrate ingestion during exercise improves endurance; many of these studies used sports drinks as the protein/carbohydrate medium.

However, Van Loon emphasizes that the evaluation of sports drinks on athletic performance is better assessed by measuring time trial performance, a “more valid” measurement trial that more accurately mimics athletic performance stimulation.

Several studies using time trial performance measurements have also investigated the effects of immediate protein ingestion on acute athletic performance and could not confirm that protein + carbohydrate ingestion during exercise improves endurance any better than simply ingesting carbohydrates alone.

Takeaway tip

While ingesting protein before, during, and after exercise will all help to rebuild muscle proteins that break down during workouts, consume protein before or during your workout if you want to minimize muscle breakdown and get a head start on recovering your muscles from workout stress.