Gear: Aerobic machines target specific sports

All aerobic fitness machines help you elevate your heart rate and work up a good sweat. But the cardio contraptions reviewed here are designed to do that and more, offering great general fitness benefits while helping you to take your specific sport to a new level. If you ski, cycle, row or run, these products are designed to develop the specific muscles, coordination, skills, endurance and protection that’ll allow you to raise your game.

Set for the slopes

SkiXtreme: A simple, minimalist ski simulator designed by Ohio contractor and ski enthusiast John Scimone that is made of two pivoting foot platforms connected to a frame through several resistance springs. You balance by holding tall, upright handles as you sway from side to side at your own pace. It has no electronic or hydraulic components.

Likes: In seconds, my quads were on fire, just as they are on my first ski run of the season. An enjoyable and challenging workout that effectively replicates the lateral muscle action of skiing, SkiXtreme is easy to master — just hop on, grab the bars and sway your hips. It took me about 15 minutes to get enough self-control to let go of the handles and rely on my core for balance. A good all-round workout machine, its lateral motion makes it particularly effective for multi-directional athletes who play tennis, hockey, soccer and basketball. It arrived fully assembled (just put the poles in) and is compact (36-by-27-inch footprint), with foot platforms that are 16 inches off the ground. It has three levels of resistance (using two, four or six springs) and is offered with an optional snowboard attachment that requires tightening four bolts. It works as well as the Skiers Edge ski trainer, which costs $3,995 and takes up three times the floor space.

Dislikes: None.

Price: $599 ($899 with snowboard attachment). (650) SKI-HARD; https://www.skixtremeworkout.com.

The bike as coach

Wattbike: This stationary bike, used by a number of pro teams, delivers advanced feedback data, including power in watts and “polar view” — graphical animation that depicts left leg versus right leg pedaling output. Other downloadable data include average and peak power, cadence, average cadence, energy expended, distance covered and heart rate (when linked with a compatible heart rate monitor).

Likes: I found polar view, a rare feature available only in a couple of competing products, to be a fun, engaging and highly effective tool for smoothing and improving my pedaling. Translating the power delivered by each foot through the pedal circle, it depicts the “shape” of your pedal stroke on a graph. A pinched “figure-8” shape means that you mash the pedals and have gaping dead spots in your stroke; a “peanut” is smoother and a “sausage” is best. Seeing the ever-varying shape in real time tells you which leg is working less than the other and how to adjust. The solid-feeling 121.3-pound, 49.2-inch-long bike includes fully adjustable bars and saddle, a USB port for easy downloads, and compatibility with Garmin ANT+Sport and Suunto ANT heart rate belts. There are two same-priced models: the Trainer and the racer-oriented Pro, which has a higher resistance level.

Dislikes: Compared with other systems with polar view, the Wattbike is more expensive than the $1,500 CompuTrainer (which requires you to use your own bike) but far less expensive than a Velotron ($5,000). Its 170-millimeter cranks may be a problem for those who use 175mm. It does not come with 3-D courses.

Price: $2,995 plus shipping. (888) WATT-BIKE; https://www.wattbike.com/us.

Rowing on land

Concept 2 Dynamic Indoor Rower: It’s the epitome of the new wave of rowing ergometers that try to more accurately replicate the feeling of rowing on water.

Likes: According to coaches like Jeffrey Colletto of the Newport Aquatic Center, the Dynamic has a much improved “boat feel” over regular ergometers and promotes more accurate rowing form, concentration and body control. The result is more speed and fewer lower-back injuries. After just one session, Collette says, you are much smoother when you get in the water in a lightweight shell. That’s because the design has a movable flywheel (not fixed as on regular ergs) that forces your feet to do most of the moving instead of the seat, encouraging a smooth, controlled stroke rather than raw power. Like a real boat, the Dynamic tends to draw under you; you don’t pull your own body weight back and forth too much. A few other brands also do this but are more expensive and are limited to elite boathouses. At 76 inches, the device is a foot shorter than Concept 2’s standard models and so stores easily (although it does not fold in half). The two Dynamic models, the PM 4 and lower-cost PM 3, are set up for heart rate monitors, with only the former including a Garmin chest strap.

Dislikes: For non-rowers out for general fitness, conventional rowing machines may be a better choice, given their effectiveness and lower cost.

Price: Dynamic PM3 is $1,250, PM4 is $1,400, plus shipping. (800) 245-5676; https://www.concept2.com.

Running in water

Aquabilt A-2000: The underwater, non-motorized, plastic treadmill offers joint-friendly in-place running in your pool.

Likes: No matter what type of running workout you do — hard, easy, intervals or steady state — being in the water magnifies the work but minimizes the damage. The water provides 12 times greater resistance than air, jacking up effort and calorie-burn while providing floatation that greatly cuts impact. That makes the A-2000 ideal for recovery days, injury rehab and extra-long efforts. It’s also good for older runners who are trying to save cartilage. The lack of a motor forces you to propel yourself forward, as you must on land. It’s 38 inches long and 46 pounds, so you can get it in and out of the pool by yourself. If you leave it in, the one-piece polyethylene won’t rust or corrode. No assembly required; handrail installed in seconds.

Dislikes: The lack of numerical read-outs will disappoint data geeks.

Price: $1,299 plus shipping. (888) 282-2782; https://www.aquabilt.com.

Wallack is the author of Bike for Life: How to Ride to 100. roywallack@aol.com