Sure, It’s a Workout. But, Oh, the Ospreys.

NEW YORK — Urban kayakers are easy to spot along the Hudson River, watched over by the skyscrapers and nonstop traffic of Manhattan. But for those who really want to get away from the city — while staying in the city — to do some paddling, there’s Jamaica Bay, in the New York City borough of Queens.

Here, at this 18,000-acre estuary near the Rockaway Peninsula, the New York state Parks Department sponsors free daily group kayaking activities, with varying distances and skill levels, through early fall.

“It’s really different from paddling in the city,” said Chris Wattembarger, 66, a Jamaica Bay regular for four years and a kayaker since age 7. “It’s much more natural out here. The paddling on Jamaica Bay is easier than on the Hudson River. There’s less currents to deal with, less boat traffic.”

But for those who want to kick back and relax on the water, kayaking might not be the right call. The idea that it is a leisurely afternoon on the water is a myth.

Kayaking is a full-body exercise that incorporates leg thrusts, core tightening, shoulder twists and side-to-side torso rocking.

“The biggest thing about kayaking is it’s sort of done backward from how it looks,” Wattembarger said.

“Everybody thinks you get in a kayak and you pull on one side and then you pull on the other. If you do that, you’re only using your little muscles and you’ll get tired very quickly.”

Wattembarger suggests that paddlers firmly hold the paddle with one hand and then push it with the other hand on top, which engages the whole body.

“I’ve been saying this for years — if you get this right and everything else wrong, you’re OK. If you get everything else right and this wrong, you’re messed up. It’s the single most important thing to know about kayaking.”

John Daskalakis, 47, the supervisory park ranger at Gateway National Recreation Area in Jamaica Bay, oversees the federal kayaking program, through which pass roughly 4,000 paddlers every season. His twice-a-day classes just ended (they start again in May, but through December, he will continue to accompany experienced kayakers who reach out to him through Gateway’s website, boats and paddles provided).

“It’s nice being in Brooklyn because you get everybody,” Daskalakis said. “They catch wind of us from Canarsie Pier, Broad Channel, sometimes in Rockaway. It’s an interesting mix of people.”

Peter Codrington, 52, of Brooklyn, was one of the locals who caught sight of the red and yellow kayaks one day and decided to investigate.

“I would see them going out on Canarsie Pier and was curious. Once I tried it, I was hooked,” he said. “It’s great. It’s something to get away from the city.”

Daskalakis instructs rain or shine, through high currents and strong winds, canceling only if there’s lightning. In fact, he prefers kayaking on gloomy days.

“It’s pleasant because you’re not getting fried by the sun,” he said. “It’s cool to watch the rain on the water.”

But sometimes the conditions can be problematic, he said. “You’ll have a little wind and current against you, and that’s kind of the great challenge.”

Every morning, along with a crew of park rangers, Daskalakis studies the weather patterns, observing lightning, wind gusts and water currents.

Beginners practice close to Gateway Marina in Dead Horse Bay, while the more advanced kayakers can do 5-mile excursions out to Gerritsen Creek, around White Island, and through part of the city park portion of the estuary. Park rangers are on hand to answer questions about the surrounding salt marsh, a vital ecosystem for New York City.

The experience of paddling through marshes lined with tall grasses and rocky shores is incredibly tranquil. Expect to pass by masses of seaweed, as well as ospreys, great egrets and oystercatchers. And then there are the kayakers.

“You meet a lot of great people,” said Amelia Knowles, 55, about her “little paddle family,” as she refers to the group. “I was taught by these guys, and they’re still yelling at me. I have blisters!”

The main draw of kayaking on Jamaica Bay is being in nature. But the hidden workout is a bonus.

“It’s like a dance almost,” Daskalakis said. “While the upper body is twisting, you’re engaging the hip on that side and then switching, so it’s this constant back and forth. You’ll feel the abs and muscles in the back.”

At the end of a recent group trip was there was one final obstacle, a floating limbo of sorts. Daskalakis anticipated a high tide for the return, and the group needed to cross under a low-lying bridge at the marina to get back to shore. One body-bending backward stretch at a time did the trick, and the group cruised toward the coastline.