Date of Defense
12-5-2025
Date of Graduation
5-2026
Department
Human Performance and Health Education
First Advisor
Julie Raedy
Second Advisor
Carol Weideman
Abstract
Protein plays a fundamental role in muscle repair, growth, and athletic performance, which has led to increased interest in how different protein sources compare, particularly as plant-based diets become more common among athletes and physically active individuals. The debate surrounding plant-based versus animal-based protein sources primarily focuses on differences in protein quality, amino acid composition, digestibility, and potential long-term health implications. This paper examines current evidence comparing the effectiveness of plant and animal protein sources in supporting muscle protein synthesis (MPS), resistance training adaptations, recovery, and performance, while also considering broader health and environmental outcomes.
Protein supports muscle growth by providing essential amino acids (EAAs), especially leucine, which plays a key role in activating anabolic signaling pathways involved in MPS. Animal-based proteins are traditionally classified as high quality due to their complete amino acid profiles, high bioavailability, and greater leucine content, allowing them to efficiently stimulate MPS and support recovery. However, consistent consumption of animal proteins, particularly red and processed meats, has been associated with increased cardiovascular disease risk, inflammation, and negative environmental impacts. In contrast, plant-based proteins often have lower digestibility and may be limiting in one or more EAAs, which may reduce the effectiveness of MPS if sources are not carefully combined. Despite these limitations, plant-based diets provide additional benefits, including higher fiber intake, greater antioxidant consumption, improved cardiovascular and metabolic health, and reduced environmental burden.
Recent randomized controlled trials demonstrate that when total protein intake, essential amino acid availability, and leucine content are matched, plant-based and omnivorous diets produce similar outcomes for MPS, muscle hypertrophy, and strength gains. These findings suggest that protein source alone does not independently determine training adaptations. However, achieving comparable outcomes with plant-based proteins often requires greater total protein intake, careful protein combining, strategic nutrient timing, and, in some cases, supplementation. Vegan athletes may also be at increased risk for deficiencies in nutrients such as vitamin B12, iron, zinc, iodine, calcium, and omega-3 fatty acids, all of which can influence performance, recovery, and long-term health if inadequately addressed.
Overall, both plant-based and animal-based protein sources can effectively support muscle growth and athletic performance when protein quantity and quality are sufficient. The choice between protein sources should be guided by individual goals, health considerations, ethical values, and environmental concerns. Continued research using longer interventions and more diverse populations is needed to better understand the long-term implications of protein source on muscle function, performance, and overall health.
Recommended Citation
Stachura, Claudia, "Plant vs. Animal Protein: Effect on Recovery, Performance, and Long-Term Health" (2025). Honors Theses. 4056.
https://scholarworks.wmich.edu/honors_theses/4056
Access Setting
Honors Thesis-Open Access
Presentation