There is and there isn’t. What we found is that individuals over a certain weight simply can’t feel a big difference where a lighter person can after a repairing the same chair. Firmness has increased for one while the other can’t tell any difference.
This weight limit in our case studies was hard to determine because their height and build played a role in the results and varied greatly. The material itself isn’t the issue – it more about what an individual can feel. Strange I know… but it has always been the case.