This one piece of gym equipment is the best for getting a total body workout

Here's why rowing machines work nearly 85 percent of your body, giving you "more bang for your buck," as an expert rower says.

It works 85 percent of your body, giving you "more bang for your buck," says an expert.

By Michael Martin, Metro

Among the countless excuses we give ourselves to skip the gym, the hardest to overcome is probably the time commitment. Muscle growth that refuses to obey an overbooked schedule is the bane of many a city dweller. But science has finally found the most effective and efficient workout — and it's nothing trendy.

The rowing machine is the most effective piece of equipment at the gym, beating back the most advanced ellipticals and high-intensity treadmill regimens. Rowing is the "most time efficient total-body workout," says Dr. Cameron Nichol, a former Olympic rower and two-time world silver medalist.

Yup, the contraption your grandpa has in his closet. "As a rowing industry, we've known for decades that we're responsible for not communicating how to row well," Nichol told Business Insider. "It's a really valuable movement, but the problem is we don't grow up with it, whereas we do running and cycling."

In an experiment, Nichol had equally fit athletes use either a treadmill or a rowing machine for 20 minutes. Researchers measured a number of data points with electrodes, including calories burned and muscle activation.

What does a rowing machine work?

The team found that rowing was more effective than running, activating nine muscle groups, or 85 percent of your body. "Rowing gives you more bang for your buck," says Nichol. A growing body of evidence agrees with him. One Ohio University study found that rowers' lungs used oxygen more efficiently than other athletes. And alert gramps: Other studies have shown that rowing can strengthen bones.

“Historically, I don’t know why people haven’t used them. It’s a great exercise,” Todd Miller, director of George Washington University’s Weight Management and Human Performance Lab, told the "Washington Post" about rowing machines. “The vast majority of aerobic exercise that people do — treadmills, cycling, steppers — all that stuff is primarily lower-body exercises. It doesn’t really engage the upper-body musculature, so rowing does that. I think that’s the best thing about it.”

Rowing can burn up to 600 calories an hour, on average — about 10 to 15 percent more calories than cycling at the same exertion level, says Frederick Hagerman, director of the Work Physiology Lab at Ohio University. There's a reason the rowing machine is a part of the cult of CrossFit, and not just because it looks vaguely like a medieval torture device.