Revolutionary in form and function! The new Xco Trainer effectively builds and tones muscle while strengthening the surrounding connective tissue and stabilizing the joints. Provides a total-body workout. Perfect for home, clinic, gym or club use. Improves muscle tone and definition while enhancing cardiovascular fitness. Strengthens the entire 3-dimensional structure of muscle and connective tissue. Xco Training produces results based on the principles of Reactive Impact and 3-Dimensional Freedom of Movement. Its sleek design consists of an anodized aluminum tube filled with a special granulate. The Xco Trainer, being sold in North America by Fitterfirst, caught our eye recently as something totally different from anything at all out there. Actually from The Netherlands, the Xco Trainer ("Ex-Co") is a tube in two lengths and two diameters, encompassing four different weights. The sleek anodized aluminum tube is filled with a mass of sand-like beads or grains that are loose inside and therefore move toward one end or the other when you move the tube sharply in different directions as a part of an exercise movement. That created what the company calls "reactive impact," meaning there is a delayed soft-impact of the grains inside, causing a muscle overload that forces you to react and use your muscles dynamically. The point at which this overload occurs is at a change in muscle fiber use, thus also bringing the connective tissue into play. That's the theory at least. We found by the way that all that physiology gobbledy-gook aside, it also works in balance and core exercises since the sharp shift of the grains forces you a bit off-balance and therefore forces you to use your core quite actively. We tried the set of nine exercises that Fitter has in a brochure that comes with the Trainer and each time we did one we thought about what the Fitter person told us: "Go for the 'thunk.'" That means you need to move the tube quite sharply and really feel and hear the grains shift and sort of thunk hard into the opposite end. We also were using the medium trainer that weighs only 1.3 pounds and is 16 3/4 inches long. We found one of our smaller testers, albeit still strong, liked some of the movements, especially ones that forced core use, whereas some of the movements seemed somewhat contrived and difficult to feel much good in doing. We also created our own, using the off-balancing of the "thunk" while on a balance board or sitting on a ball. That our smaller tester liked quite a bit. Our larger male tester sorta shrugged and said, "What am I supposed to feel?" The medium trainer was obviously not enough for him. On the European website, we found quite a bit of information on using the tube for sport-specific training such as for tennis. We can see how this sort of reactive impact might suit training for things like tennis, golf or baseball because of the swing involved. We also heard the European group is working on a group-exercise program. That too could work well since a leader could combine it with all kinds of other movements and exercises, whereas this limited list of nine exercises is, well, limited. (If you can read or understand German, go to www.xco-trainer.com.) All in all, we must say the product seems like a nice idea, assuming the correct weight is used by the right person and perhaps that user has some background or creativity in exercise movement. It can be a great tool to add into a program for sport-specific or core training and balance exercises. We hope for the general user there will be a complete program or even an instructional DVD to go with it soon.