The difference between parentheses and curly brackets comes about because R treats curly brackets as a “special” operator, whose arguments are not automatically evaluated, but it treats parentheses as a “built in” operator, whose arguments (just one for parentheses) are evaluated automatically, with the results of this evaluation stored in a LISP-style list. Creating this list requires allocation of memory and other operations which seem to be slow enough to cause the difference, since the curly bracket operator just evaluates the expressions inside and returns the last of them, without creating such a list.
The faster you lift, the better the results. If you're trying to increase size, fast lifts activate more of the muscle fibers that have the most potential to grow. If you're trying to become leaner, fast lifts do more to crank up your heart rate--and by extension your metabolism—than anything else. And if you're trying to grow stronger . . well, how many feats of strength can you list that are performed slowly and deliberately? Even if something looks slow from the outside, you can bet that the guy performing the feat is trying like hell to get it done as fast as possible.
The question vibrating below the surface of both docs is, has America become maddened by the need for victory? When our team is in the World Series, do we seriously give a damn what the home run kings have injected? We are devout in Congress but heathens in the grandstands. That is one of Bell's messages, and the other is that steroids have become demonized far beyond their actual danger to society. Which side do you vote on? Chris Bell marks his ballot twice: Steroids are not very harmful, but by using them, we reveal a disturbing value system.