Protein Intake for Muscle Gain: How Much is Enough?

Protein Intake for Muscle Gain Summary

Protein intake for muscle gain was similar for athletes consuming 0.73 grams per pound of body weight and 1.45 grams per pound. However, increasing protein intake beyond 0.73 grams per pound did not result in significantly greater muscle mass gains.
The study also touched on the “interference effect,” where resistance exercise plus cardio training might dampen muscle gains compared to resistance training alone. Despite this, the study showed that adequate protein intake (.7 grams per pound), muscle mass, and performance improvements were similar across both training modalities, highlighting the importance of balanced nutrition in overcoming potential training interferences.

Protein Intake for Muscle Gain: How Much Do You Need?

There is no doubt that protein intake for muscle gain plays a crucial role in building muscle. Athletes and bodybuilders often prioritize protein intake for muscle gain, sometimes to an extreme degree, believing that more is always better. However, research suggests that additional protein intake for muscle gain does not necessarily translate into further muscle gains after a certain threshold.¹ A new study, titled “Association between changes in lean mass, muscle strength, endurance, and power following resistance or concurrent training with differing high protein diets in resistance-trained young males” by Reza Bagheri and colleagues, challenges the notion that more protein intake equals more muscle.² While the study confirms that high protein intake is beneficial, it also suggests that consuming beyond a specific amount may not yield extra muscle mass.

Review of the Literature on Protein Intake for Muscle Gain

The relationship between protein intake for muscle gain has been extensively studied. Early research established that protein intake is essential for muscle repair and growth, especially after resistance training.³ However, recent studies have questioned the “more is better” mindset. For instance, a meta-analysis showed that muscle gains plateaued after a daily protein intake of around 1.6 grams per kilogram of body weight, equivalent to about 0.73 grams of protein per pound.⁴

However, others have suggested that trained individuals should consume about 0.91 g/lb/day to meet their daily requirements.⁵ It is essential to note that these recommendations are primarily derived from studies involving resistance exercise, and the necessary dietary protein intake may be higher for those performing combined aerobic and resistance exercise due to the larger training volumes associated with this modality.⁶

Overview of the Study Protocol

The study by Bagheri and colleagues was conducted over 16 weeks, involving 48 resistance-trained young males randomly assigned to one of four groups. These groups were categorized based on their training regimen and protein intake for muscle gain:

Aerobic Exercise and Resistance Exercise + protein intake at 0.73 g/lb/day: Concurrent training with moderate protein intake.
Aerobic Exercise and Resistance Exercise + protein intake at + 1.45 g/lb/day: Concurrent training with high protein intake.
Resistance Exercise Alone + 0.73 g/lb/day: Resistance training with moderate protein intake.
Resistance Exercise Alone + 1.45 g/lb/day: Resistance training with high protein intake.

The participants underwent a structured training program. The resistance training groups engaged in periodized resistance exercises based on 90% of their one-repetition maximum (1-RM) for weeks 13-16, with rest intervals not exceeding two minutes between sets. The aerobic and resistance exercise groups performed resistance training followed by endurance training four times a week. Both groups received dietary guidelines to ensure consistent protein intake corresponding to their assigned group.

Results of the Study on Protein Intake for Muscle Gain

The results of the study revealed significant increases in both upper and lower body lean mass across all groups, from baseline to post-test:

Lean Mass:

All four groups demonstrated significant increases in both upper and lower body lean mass. The increases in lean mass were statistically significant. Still, they did not differ significantly between the groups, indicating that both levels of protein intake (.7 grams per day and 1.4 grams per day) effectively supported lean mass gains in both resistance exercise and resistance exercise plus cardio settings.

Muscle Strength:

Significant improvements in muscle strength were observed across all groups. Both absolute and relative chest press and leg press strengths increased substantially from baseline to post-test. The study found no significant differences between groups, indicating that different protein intake levels did not significantly influence strength gains.

This finding suggests that both levels of protein intake for muscle gain (0.73 g/lb/day and 1.45 g/lb/day) were effective in supporting muscle growth, but consuming more protein did not result in superior muscle gains.

Discussion on Protein Intake for Muscle Gain

The findings of this study align with previous research suggesting that there is a threshold for protein intake for muscle gain, beyond which no additional muscle mass gains are achieved. While the study confirms the importance of adequate protein intake for muscle growth, it also highlights the diminishing returns of consuming excessive amounts. This is particularly important for athletes and bodybuilders who might believe that continually increasing protein intake will lead to greater muscle mass.

Practical Applications for Protein Intake for Muscle Gain

For fitness enthusiasts and bodybuilders, the implications of this study are clear: more protein intake is not necessarily better. While protein is essential for muscle repair and growth, consuming it excessively will not result in greater muscle gains. Instead, focusing on meeting the protein intake for muscle gain threshold of around 0.73 grams per pound of body weight should be sufficient to support muscle growth when combined with a well-structured training program. This finding is especially valuable for those who may be over-investing in protein supplements, thinking it will give them an edge. The study suggests they can achieve similar results with a more moderate protein intake, potentially saving money on protein supplements.

References

1 Bagheri, R., Kargarfard, M., Sadeghi, R., Scott, D. & Camera, D. M. Effects of 16 weeks of two different high-protein diets with either resistance or concurrent training on body composition, muscular strength and performance, and markers of liver and kidney function in resistance-trained males. J Int Soc Sports Nutr 20, 2236053 (2023). https://doi.org:10.1080/15502783.2023.2236053

2 Bagheri, R. et al. Association between changes in lean mass, muscle strength, endurance, and power following resistance or concurrent training with differing high protein diets in resistance-trained young males. Frontiers in Nutrition 11 (2024). https://doi.org:10.3389/fnut.2024.1439037

3 Tipton, K. D. & Wolfe, R. R. Protein and amino acids for athletes. J Sports Sci 22, 65-79 (2004). https://doi.org:10.1080/0264041031000140554

4 Morton, R. W. et al. 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, 376-384 (2018). https://doi.org:10.1136/bjsports-2017-097608

5 Antonio, J. et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women – a follow-up investigation. Journal of the International Society of Sports Nutrition 12, 39 (2015). https://doi.org:10.1186/s12970-015-0100-0

6 Camera, D. Evaluating the Effects of Increased Protein Intake on Muscle Strength, Hypertrophy and Power Adaptations with Concurrent Training: A Narrative Review. Sports Medicine 52 (2021). https://doi.org:10.1007/s40279-021-01585-9