Prowling the weights floor with a shaker in hand is merely macho posturing and has little to do with, well, proper posture.
So the short answer to your question is no, it doesn’t pay to swill between sets. The long answer is that not only does it yield little benefit, it can actually hamper muscle recovery.
Research suggests that amino acid levels in your bloodstream need to rise in order to maximise muscle growth. Drinking a shake during your hour-long workout won’t deliver that spike. Chugging afterwards – when your metabolism is at its highest – will. Don’t go buying into the idea that protein on the go will give you a strength-endurance boost, either.
For that, you’re better off swigging on a BCAA supp.
In other words, think before you drink.