Protein Timing for Enhanced Athletic Performance: Insights from a Casein Timing Trial

A casein timing trial found that both pre-sleep and immediate post-exercise casein (≈30 g) improved anaerobic performance in highly trained soccer players with no timing strategy clearly superior, supporting flexible recovery timing for anaerobic athletes.

This result aligns with protein's role in supporting overnight and post-exercise muscle protein synthesis and recovery. Because casein delivers a sustained amino acid release overnight yet still supports post-exercise anabolism, the trial strengthens the rationale for timing flexibility rather than rigid windows and supports accommodating athlete preference and logistics.

In a randomized controlled trial of 24 highly trained male soccer players, researchers measured countermovement jump (CMJ), the Illinois Agility Test (IAT), and the RAST battery at baseline and 24 hours after a standardized high-intensity resistance session. The protocol used a fixed ~30 g micellar casein dose given either immediately post-training or 30–60 minutes before bedtime.

Both timing strategies improved CMJ and multiple RAST power metrics versus control, and direct comparisons showed no statistically significant differences between pre-sleep and post-exercise ingestion—indicating equivalent effectiveness across the measured endpoints.