But experts say if you take time to explore this wallflower of the fitness center, you'll discover a smooth operator that's easy on the joints and endowed with a powerful burn.
Hosea, an orthopedic surgeon based in New Brunswick, N.J., has rowed since college. He said the rowing machine actually burns more energy per hour than running or swimming.
"The average person can easily burn 700 to 750 calories per hour going at a pretty moderate pace," he said.
So why is the rower ignored? Hosea thinks part of the problem may lie in the less-than-dignified position of the exerciser.
"When you're rowing you're sitting down, and everyone's towering over you," he said.
Then there's the learning curve. In the gym physical prowess rules, but the rowing machine requires patience.
"It takes time to learn proper technique," Hosea said. "It looks really easy, but people don't know how to row in an efficient manner so tend to avoid that machine."
Power in rowing comes from the legs, Hosea said, but many people think it depends more on the arms and back.
"They get discombobulated if they don't understand that you drive with the legs first."
Another mistake, he added, is putting so much resistance on the machine that core strength is compromised, and the lower back is stressed.
Richard Louis, a trainer at Crunch gym in New York, uses the rower with clients.
"For some people one half-hour of cardio is unthinkable," he said. "This gets them to start with short periods."
Louis likes to do intervals.
"Row hard for 30 seconds, rest for 30 seconds and gradually increase rowing and decrease rest," he said. "Work hard, back off."
Tom Spring, a Detroit-based trainer who works with high-risk populations, seniors and the chronically ill, uses rowing machines and recommends them, but he cautioned that the under-instructed are at risk for back issues.
"I cringe when I see the way people sometimes use rowing machines," he said. "That said, rowing machines are underutilized."
Proper technique is key: Here's what a rowing stroke should look like when done correctly.