Pre-Workout Nutrition >> Post-Workout Nutrition

No that wasn't a typo in the post title. A pre-workout meal, even just a protein shake, is almost twice as beneficial as a post-workout shake. TWICE!

Physiologic Hyperinsulinemia Enhances Human Skeletal Muscle Perfusion by Capillary Recruitment

Feeding causes a spike in insulin. An insulin increase from food enhances glucose uptake by muscles (think: more energy in your muscles) AND increases capillary blood volume and decreases capillary blood velocity (think: more nutrient rich blood, staying longer in your muscles). Basically, a pre-workout meal (even protein alone causes a modest spike insulin) enhances muscle perfusion (nutrient delivery).

Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise.

In addition! Pre-workout and post-workout amino acid (protein) and carbohydrate consumption increases amino acid delivery to muscles within the two hours after exercise. BUT where they differ is that the pre-workout supplementation SIGNIFICANTLY increases amino acid delivery and uptake in muscles over the post-workout supplementation. Plus, you get the added benefit that this increase occurs twice: once during exercise and again after exercise (see graphs on page 5).