Do Carbohydrates Support Post-Exercise Anabolism At The Same Rate As Protein in Underfed Participants?
Overview
- What did they test? The researchers tested the effect of consuming essential amino acid (EAA) enriched whey protein along with carbohydrates vs. EAA enriched whey protein with additional EAAs on muscle protein synthesis (MPS) and breakdown following resistance training in healthy, young participants in both energy balance and energy restricted conditions.
- What did they find? Consuming 24 grams of EAAs with an amino acid enriched whey protein supplement improved whole body MPS compared to consuming 24 grams of carbohydrates with the amino acid enriched whey protein supplement and this effect was more pronounced during a 30% energy deficit compared to when participants were in energy balance.
- What does it mean for you? There has been some debate about the role of carbohydrates and EAAs post-exercise. Some research has suggested that EAAs offer an advantage while others suggest that consuming carbohydrates post exercise spares amino acids for energy metabolism and may improve MPS relative to EAAs.
The findings of this study suggest that EAAs promote greater post exercise MPS compared to a similar amount of carbohydrates among individuals on energy restricted diets. Therefore, it may be advantageous to include additional protein/EAAs post-exercise while following an energy restricted diet.
What’s the problem?
Purpose
During energy restriction and weight loss it is important to retain muscle mass to promote a healthy body composition. However, energy restriction induces anabolic resistance which reduces muscle protein synthesis and can favor muscle loss 1. A strategy to counteract this effect is increasing the consumption of amino acids 2.
However, there has been recent debate whether consuming carbohydrates may be a more effective approach for increasing MPS due the amino acid sparing effect of carbohydrates being oxidized for energy 3. It is also unclear whether the effect of amino acids and carbohydrates is influenced by caloric balance.
Therefore the purpose of this study was two fold: 1) To determine if 24 grams of carbohydrates added to a EAA enriched whey protein drink impacts MPS compared to an EAA enriched whey protein drink taken with 24 grams of additional EAAs. 2) To assess if responses were different when participants were eating an energy maintenance diet vs. a 30% energy deficit diet.
Hypothesis
The authors hypothesized that 24 grams of carbohydrates added to an EAA enriched whey protein supplement would be more effective for stimulating MPS than additional EAAs during an energy deficit.
