People that are 120 pounds or less that don’t normally engage all the springs unless jumping very high should be careful on which rebounder they pick out. If picking out a single purpose rebounder it doesn’t matter like picking out a multi purpose rebounder or bungee cord rebounder. People that are very light weight will have a problem doing the Health Bounce if the mat is too jarring or too firm. The mat simply won’t displace the mat low enough to generate the G force needed for lymphatic flushing. If choosing a multi purpose rebounder, I would research the Cellerciser. This is one of our highest grade multi purpose rebounders. The Cellerciser has a large belly spring (middle of the spring) that holds up to 100 pounds and then the 2nd tier kicks in. The triple tiered spring would be the most responsive for someone who is light weight. The soft bounce type springs may require to utilize too much of the middle spring as it has more coils before the tapers at the end and the user may not feel that “pop” at the bottom of the bounce but instead a more “throwing in the air” motion. If the spring is set at 290 Newtons and the person’s weight is only subjecting the springs to 210 Newtons, then the smaller tapered tiers on the end won’t engage and the user won’t feel what is needed to open on the one way valves in the lymphatic system.