The Most Useless Exercise Ever is Crunches.

If you want to scream any time you see an ad for some ab exercise contraption that’ll “guarantee a flat stomach!”—we feel you. Does anyone still believe crunches help burn belly fat? (If so, they’re an idiot.)


Here’s more evidence: A recent study published in the Journal of Strength and Conditioning Research found that simply performing sit-ups, crunches, and other ab exercises won’t do much (correction: anything)

One group of study subjects performed ab exercises 5 days a week while the control group did nothing. At the end of 6 weeks, there was no significant change in stomach fat in either group. Everyone was told not to change their diet.
In short: Ab exercises didn’t flatten people’s stomachs. In fact, they were just as effective as doing absolutely  jack.

So if you want flat abs, what should you do? It’s not as simple as plodding on the treadmill for 20 minutes a day: New research reveals some types of exercise burn more fat than your local steakhouse—while others only burn up your time.

Fat-Loss Myths

It’ll take you 250,000 crunches to burn a pound of fat. Now that’s a situation, and not the kind you’ll find at the Jersey Shore.

“Aerobic activity must be a part of the exercise prescription. Crunches and such are great to increase abdominal and core strength, but just performing these alone will not increase caloric expenditure above that which is needed to facilitate sizeable fat loss,” says study researcher John Smith, PhD., HFS, an assistant professor at Texas A&M University-San Antonio.

Steady-state aerobic exercise alone isn’t particularly great for weight loss, either. One study published in Obesity found that after a year of hourlong cardio sessions for 6 days per week, people only lost 3.5 pounds. (The study asked participants to leave their diets unchanged.)

“Research has shown over and over that steady-state aerobic exercise alone has a minimal effect on fat loss,” says Jeff Halevy, NYC-based celebrity trainer & CEO of Halevy Life. “With all due respect, because I do truly respect their accomplishments, how many recreational marathoners and half-marathoners cross the finish line with a little belly in tow? Looking at the typical finish line, plenty of them.”

Go Fast to Blast Fat

You’ve heard a million times that you can’t spot-train fat. And while that’s true in terms of, say, crunching for flat abs, research shows that certain modes of training affect overall fat loss more than others.

One of them: High-intensity training. A study out of the Department of Kinesiology at McMaster University found that men who performed sprint interval training for a total of 2.5 hours (including recovery) over the course of 2 weeks has the same results as the group who performed endurance training for a total of 10.5 hours over the same time period.

More evidence: A study of 15 women found that high-intensity exercise (40 to 45 minutes approximately four times weekly at a mean HR of 163 bpm) reduced body fat by about 5 percent over the course of 15 weeks versus a virtually unchanged percentage in the group that performed exercise at a lower heart rate (132 beats per minute).