Summary of 30 or 60 Grams of an After Exercise Protein Shake

  • Resistance-trained females consumed an after exercise protein shake of either 15, 30, or 60 grams of whey protein isolate.
  • Interestingly, the study revealed that consuming 30 g or 60 g of whey protein boosts muscle protein synthesis, while 15 g of whey protein shows no effect. Moreover, this ingestion extends the anabolic window over 24 hours.
  • Contrary to popular belief, more protein isn’t always better! Researchers observed no significant difference between the responses of 30 g and 60 g protein doses on muscle protein synthesis.
  • Consequently, women should include a minimum of 30 grams of whey protein in their after exercise protein shake.


In the world of fitness, protein has always been a hot topic. How much should you consume? Is protein better before or after a workout? What is the dosage for your after exercise protein shake? The optimal dose of high-quality protein to maximize post-exercise muscle protein synthesis (MPS) is reported to be between 20 and 40 grams.(Davies et al., 2019; Macnaughton et al., 2016; Witard et al., 2014) This range was derived from studies on healthy young men.

How Does Protein Help After a Workout?

After exercise, protein intake becomes essential. In fact, resistance exercise combined with protein after exercise results in elevated amino acid levels in the blood, boosting MPS. (Biolo et al., 1995) Furthermore, consuming protein after resistance exercise is crucial for optimizing the adaptation of skeletal muscles to the training, resulting in enhanced muscle growth. (Cermak et al., 2012)(Morton et al., 2018) This is a clear indication of how protein can help after a workout.

how does protein help after a workout after exercise protein shake is protein better before or after a workout

Furthermore, higher doses of protein have a greater effect. Macnaughton and colleagues found that young men who consumed 40g of protein post exercise experienced a 19% higher stimulation of muscle protein synthesis after resistance exercise than those who took in only 20g. This suggests a limit to how much protein the muscles can use for synthesis, a concept known as the “muscle full” phenomenon. (Macnaughton et al., 2016)

Is Protein Better Before or After a Workout?

Interestingly, several studies indicate that in young, untrained individuals, both men and women exhibit similar MPS when at rest and when in a fasted state. (Fujita et al., 2007) Additionally, young men’s and women’s MPS response to amino acids and insulin is comparable. (Smith et al., 2009) This suggests at rest there is a similar protein synthesis response in untrained athletes.  However, there’s limited evidence concerning the exact amount of protein needed to stimulate MPS after resistance exercise in trained women.

In the recent study titled “Protein dose requirements to maximize skeletal muscle protein synthesis after repeated bouts of resistance exercise in young, trained women,” the effects of different protein dosages (i.e., 15, 30, and 60 grams of whey protein isolate) after exercise were examined in trained women. (Mallinson et al., 2023) The research has provided some clear answers, especially for trained women. Let’s dive into the findings.

After Exercise Protein Shake: 15, 30, or 60 Grams?

The primary goal was to understand how does protein help after a workout in terms of muscle protein synthesis (MPS) after resistance exercise in trained women. In simpler terms, the researchers wanted to know how much protein women should consume post-workout in their after exercise protein shake (i.e., 15, 30, or 60 grams) to get the best muscle-building results. The resistance exercise protocol in the study involved two bouts of whole-body resistance exercises performed by trained women. Participants performed 3 sets of 8 repetitions at 75% 1RM for lat pull-down, single-leg press, and chest press with 2 minutes of rest between sets.

Key Findings of the Optimal After Exercise Protein Shake

Protein Dosage Matters… But Only Up to a Point: The study found that consuming either 30g or 60g of whey protein post-exercise increased muscle protein synthesis. Furthermore, there was no difference in protein synthesis after 30 or 60 grams of protein. This means that after a resistance workout, having a protein shake or meal can help muscle recovery and growth. However, 15 grams of protein post exercise is not enough, shoot for 30 grams.

The Anabolic Window is Real: The term “anabolic window” refers to the period post-exercise when your muscles are primed to absorb nutrients and grow. The study confirmed that protein consumption post-exercise can extend this window for up to 24 hours!

More Isn’t Always Better: Interestingly, there wasn’t a significant difference between the muscle-building effects of 30g and 60g of protein. So, you might not need to if you’re stressing about getting that extra scoop in your after exercise protein shake.

The author of the study was quoted., “In conclusion, 30 g and 60 grams of protein dosing regimens increased muscle protein synthesis; how ever, no changes were seen with 15 grams of  protein dose. While both 30 g and 60 g protein extended the post-exercise anabolic window above baseline, the magnitude of increased muscle protein synthesis with protein feeding was no greater with the 60 g dose suggesting that maximal muscle protein synthesis post whole-body resistance exercise was achieved with 30 g or greater of whey protein. Trained women should supplement with 30 g high-quality protein immediately following whole-body resistance exercise to support increased post-exercise muscle protein synthesis.”

how does protein help after a workout after exercise protein shake is protein better before or after a workoutHow does Protein help after a Workout?

The study found that ingestion of 30g or 60g of whey protein after resistance exercise increased muscle protein synthesis (MPS) and extended the anabolic window over 24 hours. This suggests that consuming > 30 grams of protein may be more effective in promoting muscle adaptation in trained women.

What Does This Mean for You?

Firstly, if you’re a woman into resistance training, this study offers some clear takeaways. The study demonstrated that 15 grams of protein is not enought, shoot for 30 grams or more. Secondly, ensure you get a good protein dose after your workout to maximize muscle growth. Thirdly, don’t overdo it. While protein is crucial, you don’t need to go overboard. Around 30g post-workout seems to be the sweet spot. Finally, stay consistent. The anabolic window’s extension means regular protein intake can benefit muscle growth even a day after your workout.


This study provides valuable insights for all women looking to optimize their fitness routines. Remember, while protein is essential, balance and consistency are key. So, the next time you hit the gym, you’ll know exactly how to fuel your muscles for the best results with your after exercise protein shake!

Happy training! 💪🥤


Biolo, G., Maggi, S. P., Williams, B. D., Tipton, K. D., & Wolfe, R. R. (1995). Increased rates of muscle protein turnover and amino acid transport after resistance exercise in humans. Am J Physiol, 268(3 Pt 1), E514-520.

Cermak, N. M., Res, P. T., de Groot, L. C., Saris, W. H., & van Loon, L. J. (2012). Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis. Am J Clin Nutr, 96(6), 1454-1464.

Davies, R. W., Bass, J. J., Carson, B. P., Norton, C., Kozior, M., Amigo-Benavent, M., Wilkinson, D. J., Brook, M. S., Atherton, P. J., Smith, K., & Jakeman, P. M. (2019). Differential Stimulation of Post-Exercise Myofibrillar Protein Synthesis in Humans Following Isonitrogenous, Isocaloric Pre-Exercise Feeding. Nutrients, 11(7).

Fujita, S., Rasmussen, B. B., Bell, J. A., Cadenas, J. G., & Volpi, E. (2007). Basal muscle intracellular amino acid kinetics in women and men. Am J Physiol Endocrinol Metab, 292(1), E77-83.

Macnaughton, L. S., Wardle, S. L., Witard, O. C., McGlory, C., Hamilton, D. L., Jeromson, S., Lawrence, C. E., Wallis, G. A., & Tipton, K. D. (2016). The response of muscle protein synthesis following whole-body resistance exercise is greater following 40 g than 20 g of ingested whey protein. Physiol Rep, 4(15).


Mallinson, J. E., Wardle, S. L., O’Leary, T. J., Greeves, J. P., Cegielski, J., Bass, J., Brook, M. S., Wilkinson, D. J., Smith, K., Atherton, P. J., & Greenhaff, P. L. (2023). Protein dose requirements to maximize skeletal muscle protein synthesis after repeated bouts of resistance exercise in young trained women. Scand J Med Sci Sports.

Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., Aragon, A. A., Devries, M. C., Banfield, L., Krieger, J. W., & Phillips, S. M. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med, 52(6), 376-384.

Smith, G. I., Atherton, P., Reeds, D. N., Mohammed, B. S., Jaffery, H., Rankin, D., Rennie, M. J., & Mittendorfer, B. (2009). No major sex differences in muscle protein synthesis rates in the postabsorptive state and during hyperinsulinemia-hyperaminoacidemia in middle-aged adults. J Appl Physiol (1985), 107(4), 1308-1315.

Witard, O. C., Jackman, S. R., Breen, L., Smith, K., Selby, A., & Tipton, K. D. (2014). Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am J Clin Nutr, 99(1), 86-95.


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