On May 20, Tenafly resident Alan Tannenbaum expects to take off on his bicycle from the George Washington Bridge and pedal 104 miles through the hills and valleys of Bergen and Rockland counties as a participant in the Gran Fondo New York race.

But before he undertakes the course, Tannenbaum will have spent hours training during the off-season, the winter months when road conditions are less than ideal for outdoor cyclists. In cold weather, many hard-core cyclists hang up their helmets and turn to different workout routines that ensure they'll stay in shape year-round.

Tannenbaum trains in his home on his outdoor bike — by fixing what's known as a "trainer" to the back wheel, which converts it into a stationary bike — and by taking spinning classes.

"I do work out at home, but there's better motivation and I find I go longer and harder if I'm in a class," said Tannenbaum, who's been a cyclist for six years.

He said when he does use his trainer at home, he'll put on an episode of "CSI" or a longer television show so he'll have something to focus on while riding. But mostly he'll head to MAXFIT spinning studio in Cresskill for an hour-long class.

Chris Miller, owner of MAXFIT, said he sees a lot of veteran outdoor cyclists in his classes come winter.

"People get bored if they're just training in their home by themselves," said Miller, who's been teaching spinning for 15 years. "When you're in a class with 30 other people and an instructor pushing you, there's a lot more motivation and energy."

He added that sometimes a spinning class can be even more intense than an outdoor ride. With spinning there's constant resistance for the whole hour, but if you're outside there are instances where you'll be coasting down a hill or riding on a flat surface.

"Spinning involves mostly a cardio workout, but also building up leg strength," Miller said. "So it's ideal for cyclists, but plenty of other people take our classes to burn a lot of calories."

The primary health benefit of riding a stationary bike is giving your heart a good workout — depending on how fast you're pedaling and how much resistance you're pedaling against, you can burn 500 calories or more in an hour-long class. Added benefits include building leg strength and toning your hamstrings and quadriceps.

However, those with chronic back problems should be wary of spinning — leaning too far over the bike or hunching your shoulders can aggravate problems or put pressure on disks, according to Livestrong.com, a fitness site started by cyclist Lance Armstrong.

Christopher Russo of Demarest takes Miller's class from December to February to stay in shape. He's also participating in Grand Fondo New York, and said he wouldn't stand a chance on the course if he didn't train in the off-season.

"When you come back outside in the spring, you can tell the guys who haven't been spinning," Russo said. "Usually the guys who have been training are a lot stronger on hills."

Russo said he's also done his share of in-home trainer workouts and notes there are a lot of options now for cyclists in the off-season, including ride-along DVDs and computerized bikes that mimic going up and down hills.

Keith Adelsohn, manager of Ridgewood Cycle Shop, said while computerized bikes can cost thousands of dollars, a simple trainer is usually around $180.

"There are a lot of different kinds now, some have progressive resistance as you pedal, others you can manually adjust," he said. But he recommends using a home-training tire with a trainer instead of your road tire, since the trainer will wear it down faster.

Those who aren't training for an intense race or marathon can easily pick up a spinning class. Numerous local gyms offer one each day of the week (usually very early in the morning), each class lasting 45 minutes to an hour.

Elizabeth Boos, group fitness director at Westwood Health and Fitness, said spinning doesn't require a certain skill or fitness level.

"Spinning is very much what you make of it," she said. "You're working hard the whole time whether you're a beginner or training for an Iron Man [triathlon]."

Email: connor@northjersey.com

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