In this case, research shows that eating protein (and thus elevating plasma amino acid levels) before training can help you build muscle faster. (legionathletics.com)
The rapid spike of amino acid levels in blood impact protein synthesis and protein degradation to a much greater degree than whey protein. (personaltraining4u.net)
However, most plants don't have all of the essential amino acids, which means you would have to be extremely careful to eat plants with the right amino acid levels. (completehumanperformance.com)