Research reveals the top exercise for building core strength, and it's not sit-ups

Many of us opt for exercises like crunches and sit ups when training our abdominal muscles. Although these are useful ways to build more muscular abs, new research has found that squats could be the best way to develop core strength.

There's always a place for tools like the best abs rollers, especially since these lightweight wheels are portable and great for a quick abs blast whenever you have a spare moment. But now we know there's another highly effective way to train your core.

This is thanks to a new study published in the Journal of Strength and Conditioning Research, which investigated the core-building differences between three lower-body exercises; leg presses, free-weight squats, and Smith machine squats.

The team recruited 19 women with almost five years of resistance training experience for the trial. They were asked to perform each exercise at their three-rep maximum (3RM), the highest load they could lift for three repetitions without failure.

The researchers measured core activation with electrodes attached to the skin above the abdominal muscles during the exercises. This is a form of electromyography (EMG), where monitors pick up electrical signals produced by muscle contractions.

After analyzing the results, the team found that the women could lift an almost 50% greater weight using the leg press move than during the two squat exercises, but it also activated their core up to 59% less than the free-weight and Smith machine squat.

You can use a barbell to learn how to deadlift, but for bench presses or squats, it can be dangerous to lift heavy loads without a spotter to take the weight if it becomes too heavy. The Smith machine helps you train independently without putting yourself at risk.

It's a common sight at many gyms or fitness centers, consisting of a barbell attached to two vertical rails. There are slots along the rail where you can place the weight with a slight wrist rotation, preventing the load falling onto your body or trapping you.

The study's authors found that the participants could lift 5% more using the Smith machine than with free weights and that there was "no evidence that greater stability requirements [of free weights] will result in greater core muscle [activation]."

It's ideal for beginners to develop strength and get used to the exercises, but these results slightly contradict earlier research. According to a 2009 study published in the Journal of Strength and Conditioning Research, free weight squats achieve 43% more core activation than Smith machine variations.

It's worth noting, though, that both studies had small sample sizes—just 19 women in one, and six recuits in the other—and all the participants had previous resistance training experience, totaling almost half a decade of training for some. 

There are many other ways to train your core, too, like the best workouts for abs. Adding these to your routine strengthens your core, which promotes circulations, aids stability, and improves your performance in multi-muscle compound moves.

And before diving into free weights exercise, refreshing yourself on how to lift weights will help you perfect your form and avoid injury. It also makes training with a set of the best adjustable dumbbells more effective, so you'll get stronger abs in no time.