First off, many athletes erroneously cling to the notion that six-pack abs are a sure sign of a strong core. More to the point, it’s unclear whether core-specific training benefits athletic performance at all. In one study, a group of collegiate rowers who added an arduous eight-week regimen of core exercises to their regular rowing workouts wound up with stronger, tauter cores. But they didn’t become better rowers: their performance levels remained the same. Similarly, researchers at Indiana State University measured core strength among a group of Division I varsity football players and then had them complete sets of standard exercise drills like shuttle runs. The researchers found almost no correlation between a supercharged core and athletic performance.
What’s more, the crunch, that ubiquitous exercise that promises a solid midsection, is often harmful, because many gym rats are pumping them out with terrible form. When researchers simulated crunches using spines from pig cadavers, the spinal disks usually ruptured after a couple thousand reps. “Crunches are totally unnecessary,” says Thomas Nesser, a professor of physical education at Indiana State University.
Get over it: Core strength is important, but most people get what they need simply by practicing their sport. Common routines like squats, deadlifts, and kettlebell drills add plenty of core strength. And new studies show that running—long thought to provide little or no core benefit—does work your midsection. “Train for your sport and core strength will develop,” advises Nesser.