Resistance level at 100% and 200% elongation means how much resistance the band provides at two to three times its unstretched, original length. For instance, a tube is 4 feet long. If you stretch it to 8 feet, you have stretched it to twice its unstretched length (100%).

NOTE: the pounds of resistance applies to any part of the band stretched, not just the entire length. For example, if you stretch a one foot section of tubing to three feet you have stretched it to three times its unstretched length (200%).

CAUTION: This product has inherent risks attached to its use under normal circumstances. This product will fail if it is abused in any way. Such abuse includes but is not limited to stretching in excess to 2 times its relaxed length, use of excessive weight or force, use with shoes of all types, use on rough surfaces, doubling up to increase resistance, storage in direct sunlight, etc. USE AT YOUR OWN RISK.