Step into just about any gym in the UK and you\'re bound to find shaker bottles scattered by the water machine. It’s so normal now that none of us ever stop to wonder why it’s effective. Seems there\'s a real, legitimate reason it\'s survived, while other trendier products have silently disappeared. Whey protein powder affects three things just about anyone who works out seriously cares about: strength, recovery, and having enough energy to get through a day. Here\'s a proper look at what it does, how it fits into a routine, and what\'s worth checking before you buy a tub.