If you’re serious about adding muscle, you better get serious about making protein a regular part of your daily routine. Protein drinks and protein bars are two of the most important weapons in an athlete’s arsenal, as are high-protein foods such as meat, beans and nuts. But not all proteins are the same. Whey proteins are better taken just before and just after working out. That is because your body digests them quickly, allowing them to work in conjunction with your exercise. But casein protein, which helps with muscle regeneration, is best taken later in the day. That’s because it is a slow release protein that takes hours to get into the bloodstream and reach its peak. This ensures your body keeps working long after you’ve hit the showers, even helping you sustain muscle growth overnight while you sleep.