A trio of experts are attempting to show me how it's done. With the backing of a German manufacturer of slacklines, the men are trying to raise the sport's profile by touring the U.S. giving demonstrations. This is a bit like bringing coals to Newcastle, as the invention of slack lining is attributed to a pair of rock climbers in Yosemite Valley more than 20 years ago. By stretching a length of nylon climbing webbing a short distance off the ground between two tree trunks and attempting to walk on it, the climbers created a simple sport.
Originally homemade, slacklines are now made by several manufacturers. The kits, which start at about $65, include webbing and a tensioning device. The lines are not exactly slack; "springy" is a better description. The resulting trampoline effect, requiring active balancing, is what makes slacklining such a good core exercise and is helping fuel the sport's growth.
Linda Givler, a product manager at outdoor retailing giant REI, says that sales of slacklines are expanding, especially with younger customers and nonclimbers.
Much of that growth seems to be spreading virally, through friends seeing friends slacklining and giving it a try, or watching YouTube videos and ordering a slackline kit.
This mind-clearing requirement to completely focus on the present in slacklining is one of its attractions. A form of meditation, say slackline enthusiasts, it's like Zen or tai chi on a tightrope. Some advanced practitioners perform yoga poses on slacklines.
Harder than it looks
While slacklining is harder than it looks, Welsch says, "most people can manage to walk from tree to tree on their first day." That seems a tall order on this sunny weekend day at a park in Westlake Village. Spectators watch as the pros balance and bounce on the lines -- and as I flail and fall. Peggie Hart, an elementary school teacher and tutor, steps forward to give it a try.
"They make it look so easy," says Hart, who tried slacklining for the first time with the Gibbon group. "It was definitely one step at time. You couldn't look too far in front of you and expect to get to the other side right away." With some assistance from Welsch -- he provided a helping hand and a shoulder on which to lean, the sport's version of spotting -- Hart did make it to the end of the line.
The dangers from slacklining are not to participants as much as to trees. Wrapping lines around the trees can damage bark; the tension on the lines, compounded by repeat use, can even bend smaller trees.