Expressions used in Everyday Spoken English in Social and Professional contexts
When we 'beef something up', we increase it or make it stronger. If you 'beef up security', for example, you might add more security staff or improve surveillance technology. There aren't many applications of this term, because it doesn't automatically apply to everything you want to improve. You wouldn't say that you want to 'beef up' your staff, for example, because this might sound more like making them individually stronger rather than widening your team of employees! In this sense, people might also talk about a weightlifter 'beefing up', but 'bulking up' is more suited to this aspect of developing strength.