How much protein do you need after a workout?

Post-exercise nutrient timing includes protein, which helps the individual adapt to training and support muscle protein synthesis. However, how much protein someone needs after a workout is a complicated question. There are many factors that come into play, including when and what the last meal was, overall protein needs, meal habits, and goals. For simplicity’s sake, this blog will consider post-exercise protein needs for strength training and muscle growth.

Does the anabolic window exist?

The anabolic window of opportunity refers to a short period of time – typically one hour or less – after weight training during which consuming protein is believed to maximize muscle protein synthesis and promote hypertrophy, which refers to an increase in muscle mass or size. This anabolic window initially drove sports nutrition recommendations that encouraged immediate protein intake once training was completed. And without it, many people believed the training session was even wasted.

A 2013 meta-analysis of randomized controlled trials did find that there was a small but statistically significant benefit to consuming protein within 1 hour of finishing exercise. However, the authors of the study speculated that the effect was likely the result of simply consuming more protein. This can be a great strategy to increase protein intake in those who struggle to consume enough, but as it turns out, muscles are sensitive to protein intake for 24 hours (or more) after training. This lengthened window of opportunity may be even longer in untrained individuals.

A 2017 study tested the theory of the anabolic window by providing pre- or post-training protein (25 g whey protein) to two groups of resistance-trained men following a 10-week resistance training program. Results showed that both groups experienced similar effects on measures like body composition, muscle thickness, and maximal strength. In other words, it didn’t matter if they consumed protein before or after – they both benefitted. However, the issue with consuming protein before exercise is that it can cause digestive issues like cramping and bloating. Therefore, it’s typically not advised to consume a protein shake before training unless it’s well-tolerated.

While it may feel a bit disappointing that there isn’t a concrete amount of time to maximize results from training, it could provide an opportunity to benefit from multiple “feedings” to support muscle growth.

Protein Priorities

Overall protein intake. While protein timing may not be all it’s cracked up to be, overall protein intake does matter. Optimal daily protein intake is in the range of 1.6 – 2.2g/kg body weight per day for those who are recovering from training (tip: to calculate your weight in kilograms, divide the number of pounds by 2.2).

Regularly spaced meals. The second priority for protein intake is likely regularly spaced meals with protein. Oftentimes, this covers post-exercise protein timing by default. Because of the anabolic effects of a single meal, which may last up to 6 hours depending on the meal composition, one could theoretically space meals 4-6 hours apart. But for many athletes, spacing meals 6 hours apart could make it difficult to meet energy and protein requirements. Nonetheless, it’s reassuring to know that there is some flexibility in meal spacing.

Protein timing. Post-exercise protein timing can be viewed as the “last squeeze” of a lemon. While the timing itself may not be entirely necessary, prioritizing protein after training can increase overall protein intake and ensure the athlete is not going an excessive amount of time without protein – distractions happen! This is also a great box to check for those who want to make sure they’re “covering all their bases.” A good rule of thumb for those who want to support muscle growth is to space the pre- and post-exercise meals 4-6 hours apart with training happening within that timeframe.

How much protein should be consumed after training?

The general recommendation for protein consumption after training is 25-40 g protein or 0.3-0.5 g per kilogram body weight. For those who are participating in endurance training or following a vegetarian diet, the upper endof that range may be a more appropriate goal. As with most nutrition recommendations, fine tuning and personalization is expected. For example, those in a smaller body may find that 0.3 g protein per kilogram body weight is a small amount of protein. In this case, they may be better off rounding up to the 25 g protein recommendation.

Importantly, more is not always better. A 2023 study looked at the amount of protein needed to maximize muscle protein synthesis in young, trained women following resistance exercise. In this study, the women completed repeated bouts of training sessions to simulate military training scenarios, and they consumed either 15 g, 30 g, or 60 g whey protein immediately after training. Measurements from saliva, blood, and muscle biopsies were taken at 4, 8, and 24 hours after exercise. Results showed that while 30 g protein and 60 g protein increased the myofibrillar synthetic rate – which would be associated with muscle hypertrophy – there were no difference between the two doses. This implies that more protein did not create better results. However, those taking 15 g protein did not experience these results and had a lower overall protein intake.

The important factor to consider is that over-consuming protein can displace other macronutrients that are important for performance and health.

Is whey or plant protein powder better for muscle growth?

Whey protein is rich in branched chain amino acids like leucine, which plays an important role in muscle growth as it activates cell signaling that increases muscle protein synthesis. However, many plant protein powders available today include a variety of protein sources to create a healthy balance of amino acids. Therefore, when choosing plant protein powders, it’s ideal to look for a product that includes several protein sources. Additionally, many brands will provide the amino acid breakdown, in which case striving for 1-3 gleucine per serving may be ideal. One 2022 randomized, double-blind study found that the muscle protein synthetic rate to 30 g plant protein – a combination of wheat, corn, and pea – did not differ from that of 30 g milk protein. In other words, choose whichever protein powder fits your needs and preferences best.

Who may benefit from immediate protein intake after training?

There are some instances when someone might want to consume protein immediately after training. This would include those who are training fasted or those with a low or irregular protein intake. Otherwise, flexible nutrient timing can allow individuals to prioritize meals with “real food,” skip protein shakes if they don’t enjoy them, and ultimately worry less about “wasted gains.”

This information is for educational use only. It is not intended to replace care from a healthcare provider or qualified nutritionist.