I’d venture to say that nailing double-unders is 25 percent timing, 25 percent endurance, and 50 percent the right jump rope. Before settling on the Crossrope Bolt set, I ordered a custom rope with large, ergonomic handles and a thicker cable, thinking that the weight of the rope would provide more feedback and make timing easier. But all that resistance was exhausting, and I’d end up needing a break after 30 reps. I also experimented with a lighter rope, but I felt like I was pinching, not gipping, the skinny metal handles.
Once I started using Crossrope’s Bolt handles and the one-ounce sprint rope, my double-unders clicked. The hollow aluminum handles are big enough to grip comfortably, but they weigh just two ounces, so my forearms don’t immediately cramp up or burn out. You can trim the rope based on your height, and the ball bearing attachments allow for fast, fluid movement. According to Crossrope’s website, the sprint cable is technically for advanced jumpers, but if you can already string together a few double-unders, go ahead and make the switch. The steel cable is coated in kink-resistant nylon, so tripping up won’t hurt — as much, anyway. [$59; crossrope.com]