Role of Protein Supplementation in Knee Injury

Protein supplementation plays a crucial role in muscle recovery and strength development, particularly in individuals undergoing rehabilitation for anterior cruciate ligament (ACL) injuries. Following an ACL rupture, quadriceps muscle loss and strength deficits are common, impacting knee function and prolonging recovery. Adequate protein intake, especially in combination with resistance training, may help mitigate muscle atrophy and enhance rehabilitation outcomes.

Importance of Protein in Muscle Recovery

Protein is essential for muscle repair, growth, and overall recovery following injury. In the context of ACL rehabilitation, maintaining sufficient protein intake can:

• Support muscle protein synthesis and reduce muscle breakdown.
• Enhance muscle hypertrophy, especially when combined with resistance training.
• Improve functional recovery by promoting quadriceps strength and knee stability.

Whey Protein Isolate (WPI) and Its Benefits

Whey protein isolate (WPI) is a high-quality protein source rich in branched-chain amino acids (BCAAs), particularly leucine, which is known to stimulate muscle protein synthesis. Studies suggest that WPI may:

• Accelerate muscle recovery following resistance training.
• Enhance muscle hypertrophy and strength gains when combined with eccentric training.
• Improve muscle function in individuals recovering from ACL injuries.

Protein Supplementation in ACL Rehabilitation

Research indicates that combining resistance training with protein supplementation may augment strength and muscle mass. However, in ACL rehabilitation, findings remain inconsistent due to:

• Variability in protein intake: Many individuals consume insufficient protein, limiting its effectiveness.
• Short intervention periods: Most studies assess protein effects over weeks, while muscle adaptation requires longer durations.
• Differences in protein dosages: Optimal protein intake levels for ACL rehabilitation remain unclear.

Challenges and Considerations

Despite the potential benefits of protein supplementation, certain factors may influence its effectiveness:

• Total daily protein intake: To maximize benefits, individuals should aim for at least 1.6 g/kg/day of protein.
• Timing of protein consumption: Distributing protein intake throughout the day may optimize muscle protein synthesis.
• Individual variability: Response to protein supplementation varies based on factors such as training intensity, diet, and overall health.

Conclusion

Protein supplementation, particularly whey protein isolate, may support muscle recovery and strength gains in ACL rehabilitation. However, its effectiveness depends on adequate intake, duration of supplementation, and proper training protocols. Future research should focus on optimal protein dosages, long-term effects, and individualized approaches to maximize recovery outcomes for individuals with ACL injuries.

Reference: https://pubmed.ncbi.nlm.nih.gov/32152642/