Credit: KayakPro

A paddling erg, like a rowing machine, can give you a great workout. But they are typically too big to have at home if you live in a small space, like an apartment. KayakPro's Compact Erg is one of the most advanced paddle sports trainers available — the company is the official erg supplier to the Olympics — but when you're done with your workout, it telescopes small enough to roll into a closet and stand on end for storage.

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Assembling the erg for the first time takes about 15 minutes and is a little bit like putting together a piece of IKEA furniture, but with easy-to-follow instructions and the parts for each step in specific baggies. Developed by Grayson Bourne, five-time Olympian, 67-time British National Champion, and World Champion kayaker, KayakPro's Compact actually simulates the feel of paddling. There's no delay in the catch, and no lag time mid stroke. Close your eyes and you actually feel like you're on the water. A single cable runs through the erg's inner mechanics — most companies use two — and connects to both sides of the paddle shaft. Combined with the company's patented variable resistance airbrake flywheel, this ergometer is smoother than any other we've used — unless it was another one of KayaPro's machines. (The company makes a dozen different ergs.) When you're in action, a digital display gives you speed, distance, intervals, length of session, calories burned, power generated, splits, and heart rate through the console. It also connects to ANT+ devices. So if you're a competitive boater, the Compact lets you do anything you could do on the water, from sprints to extended sessions, but it's also an ideal machine if you're just looking for a new way to train indoors.

You can customize the Compact to your liking. It comes with a low back carbon seat, but you can swap it for one of KayakPro's other seats or with the seat from your own kayak. The seat angle and height adjust, and like the footpegs in your boat, the footrest slides so you can find the most comfortable position. When you're done with your workout, undo two thumb screws and the erg compresses to about 4.5 x 1.5 feet — small enough to fit in the trunk of a car. Wheels in the base let you roll it into its storage space, where it can stand on end. When the trainer is fully extended, it's about 8 feet long.

We tested the kayak model, but KayakPro will soon have compact versions of its SLS Paddleboard, SwimFast, Outrigger, and Dragonboat Ergometers. You'll be able to swap out the resistance unit, so even if you're restricted in space, you can have multiple paddle trainers in one. [$2,550; kayakpro.com]