This is by far the best fitness product I have purchased. I've bought kettlebells using Pavel Tsatsouline's Simple and Sinister routine (even the beast kettlebell) which wasn't very effective at engaging the full muscles. Also bought 300+ in free weights with bench and full bar bell which was fun fitting into my studio apartment. Gains some muscle with that following a 5x5 routine for most core free weight exercises (bench, squat, dead lift) a couple times a week but got a frozen shoulder eventually that took 1.5 years to heal. Anyway, by using the x3 bar, I'm able to get all the gains I could through free weights (plus more) with no chance of injury. Plus it's portable and takes only 10 minutes a day (if done quickly...more like 20 minutes with stretching and catching your breath). It mirrors your muscle's strength curve so only one rep is needs and exhausts you far more that a simple free weight would. If you need more persuading or a more academic approach, check out Dr. John Jaquish's book, Weight Lifting Is A Waste of Time which is a quick and cheap read.... Again I have no affiliation with the company, just love the product and the results I have gotten:

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