It in itself doesn't boost strength, though it may improve the amount of nitrogen in you muscles.
Its just the fact that when recovering your body uses it to build the muscle back. It builds it back much easier if it has plenty of protein to draw upon. Not only that but once you have aquired a great deal of lean muscle mass. Protein is neccesary just to keep the gains. Otherwise the body does not get enough to maintain the muscles.
Out of the 3 types of food, Carbs,fats,protein.
Protein is the most important. followed by fats then carbs.
While carbs are great the body can convert protein into glucose so they are not essential. Your health would be fine if you didn't really eat carbs though your energy levels would be down. Since the body would first need to convert protein to glucose (which is much harder than carbs to glucose) before its ready to be used as fuel.
Fats are essential. If you ever go 0 fat your hair begins to get brittle you skin dry's its like a lubrication.
and protein well protein is the GOD of muscle building nutrients.
You don't need to supplement w/ protein drinks ect... You can get plenty of protein from a normal foods. Its just as you get bigger (and some people are insanely huge) you protien needs are harder to meet and people would like to eat other things besides MEAT MEAT MEAT MEAT MEAT. Supplementing with protein powder helps them meet their protein needs faster sparing those extra calories for other foods they enjoy.
Also 50grams? that very low. You would have to eat carb heavy foods all day. I.G. pasta,
Reccomended amount by the FDA is 100 (8grams of protein is 8% of daily amount according to a label I saw)
But thats for normal muscle maintence on a 2,000 calorie a day diet not the increased muscle bearing and building load that body builders endure.
Also while dieting you need even more protein than you would while bulking simply because your body has a greater tendancy to use the protein as fuel instead of using it to supply muscle growth.
Search the net on how protein is used for muscle repair and recovery. Theres been infinite amount of studies on protein. Mainly stemming from arguments on which is the best. ANSWER they all are kinda all have benifits and all have disadvatages, though common thought is that if your going to supplement Whey is the best kind. Since its supposedly the fasest absorbed making it good to take in after working out while the muscles are in the greatest demand for protein synthesis.
You will find shitloads of reasons to take each type protien though. Still pretty undifined as the correct answer. Since theres alot of marketing hype and alot of things we just do not fully understand yet.
What gets me is that every type of food intake is catgorized into either protein,carb,or fat. But that simply isn't always the case. certain things cross the lines between the 3 showing symptons of being one things while displaying other symtons of being another and at the same time not having enough symptons to be classified. One thing that comes to mind is Glyceron or Glycerol or whatever its called. You'll find it in the low carb protein bars. Its in there at 4 calories a gram but isn't officially classified as anything yet. Its quite interesting.