Can inadequate protein intake after exercise cause rhabdomyolysis (rapid breakdown of skeletal muscle tissue)?

From the Guidelines

Inadequate protein intake after a workout does not directly cause rhabdomyolysis, as this condition is typically the result of more severe factors such as extreme muscle trauma, intense exercise, or severe dehydration. Rhabdomyolysis is a serious medical condition characterized by the breakdown of skeletal muscle tissue, releasing myoglobin into the bloodstream, which can potentially cause kidney damage 1. The available evidence suggests that to optimize protein synthesis for repair and adaptation after exercise, meals and snacks should be scheduled to achieve intakes of 20–25 g of high-quality protein at 3–4 hour intervals 1.

While proper protein intake is crucial for muscle recovery and growth, the absence of adequate post-workout protein would more likely result in slower recovery and potentially reduced muscle growth rather than rhabdomyolysis. It's essential to note that rhabdomyolysis requires extreme circumstances that cause direct muscle damage, and simply missing a post-workout protein intake would not lead to this condition. If concerns about exercise recovery exist, consuming protein within a few hours after working out is beneficial for muscle repair, as indicated by the recommendation to consume 20–25 g of high-quality protein at regular intervals 1.

Key points to consider for post-workout recovery include:

• Consuming 20–25 g of high-quality protein at 3–4 hour intervals to optimize protein synthesis for repair and adaptation 1.
• The potential benefits of consuming 30–60 g of casein protein prior to sleep to enhance overnight protein synthesis, although this is based on emerging evidence 1.
• Being aware that while postexercise protein intake increases protein synthetic rates and net protein accretion, this is a slow process with little evidence of acute improvements in muscle function 1.

If severe muscle pain, dark urine, or weakness is experienced after exercise, it is crucial to seek immediate medical attention, as these could be signs of rhabdomyolysis from other causes.

From the Research

Inadequate Protein Intake and Rhabdomyolysis

• There is no direct evidence to suggest that inadequate protein intake after a workout can cause rhabdomyolysis 2, 3, 4, 5, 6.
• Rhabdomyolysis is a serious syndrome due to direct or indirect muscle injury, resulting in the death of muscle fibers and the release of their contents into the bloodstream 3, 4, 6.
• The current literature emphasizes the importance of preventing rhabdomyolysis and finding the benefits of sodium bicarbonates and mannitol in its prevention, but does not mention protein intake as a factor 4.
• Protein intake is important for maintaining lean body mass, especially in athletes, and inadequate protein intake may offset the muscle protein synthetic response after physical activity 2, 5.
• However, there is no evidence to suggest that inadequate protein intake can cause rhabdomyolysis, and the condition is typically associated with other factors such as trauma, excessive exercise, or certain medical conditions 3, 4, 6.

Protein Intake and Muscle Damage

• Inadequate protein intake may reduce the possible benefits of an active lifestyle for muscle mass, but it is not a direct cause of rhabdomyolysis 2.
• Protein supplementation can improve lean body mass and reduce fat mass in physically active older adults, but it does not appear to have a direct impact on the risk of rhabdomyolysis 2, 5.
• The International Society of Sports Nutrition recommends a protein intake of 1.4-2.0 g/kg body weight per day for athletes, but this is for maintaining lean body mass and supporting muscle growth, not for preventing rhabdomyolysis 5.

Rhabdomyolysis Prevention and Treatment

• The prevention and treatment of rhabdomyolysis typically involve aggressive fluid resuscitation, monitoring of renal function, and management of electrolyte imbalances 3, 4, 6.
• Bicarbonate and mannitol have been used in the treatment of rhabdomyolysis, but their effectiveness is unclear and they may not be beneficial in all cases 3, 4, 6.
• The use of bicarbonate and high-volume fluid therapy may actually be associated with worse outcomes in patients with rhabdomyolysis, including a higher incidence of acute kidney injury and mortality 6.