Last week, Brigette Williams talked through the basics of building strength to do a pull-up. She says once you have mastered the TRX and assisted pull-up, you can move to a bar or pull-up machine.

“Be able to do a pull-up” is a common fitness goal, and if you work hard—with negative pull-ups, inverted rows, and more—someday you’ll get there. Go ahead, take a minute to celebrate. But don’t drop ...