Painful back problems are a common hazard in the NFL, where the average career lasts three and a half years, so trainers monitor players closely. And recently they've discovered that the very exercises once prescribed to protect the back and spine – and the same ones men everywhere have embraced to build six-pack abs – are of little or no use. "We always thought that strong abs helped protect your back from injury," says Jon Torine, a former strength and conditioning coach for the Indianapolis Colts. "Now we think that's less likely the situation."

Take the case of one of his most reliable linemen (he asked that his name be withheld, so we'll call him Q). "Anytime he was weight training, his lower back hurt," Torine says. So Q tried a range of abdominal workouts – bicycle crunches, oblique crunches, Swiss ball sit-ups – intended to strengthen and align the spine and protect the back. "Those exercises were done to no avail," says Torine. So the trainer prescribed a new program: no traditional ab workouts of any kind. "If they weren't preventing his injury," he says, "then why do them at all?"

The notion that strong abs prevent back injuries can be linked to an Australian study from the mid-1990s suggesting that people with pain-free backs also had well-developed abdominal muscles. Pro athletes everywhere latched on to this and began crunching their way to what they expected would be a healthier spine. But after watching athlete after athlete who had been prescribed ab workouts end up on the sidelines with a back injury, fitness pros began to realize that a healthy spine isn't the result of an overly strong midsection – it's the result of an evenly strengthened body.

The abdominal muscles, says Gray Cook, a physical therapist and orthopedic clinical specialist, compose much of the core (the muscles between the upper thighs and the pecs), and the core "is a neurological mechanism that engages when we so much as take a step, turn our heads, or simply blink." Strong abs are a foregone result of neuromuscular timing, alignment, and poise. In other words, sit-ups are useless, while functional movement exercises – those that replicate sports and work the whole body evenly (including your abs) – keep you balanced, which is proven to prevent injury.

With that in mind, Torine has done away with traditional crunch-intensive workouts that used to account for about a quarter of the team's exercise regimen. Instead, he has the Colts focusing on a routine of movements athletes might use on the field. "Sometimes it's just a matter of pushing or pulling a player to one side so that he can right himself," says Torine. "That movement in itself engages the core in a way that's applicable to the game." It's no coincidence that the Colts' injury rates have decreased. Not only did Q's back pain go away, but his range of motion and quickness also improved.

"Hopefully people will start to realize that a healthy spine is not about, 'Do 50 crunches and call me in the morning,' " says Cook. "It's about creating a fit body through natural movements."