Intervening Constraints are forces that prevent a Participant from engaging in an activity they have chosen.
These influencing factors would include family obligations, income, time, health status, opportunity, and social systemization (ethnicity, gender, and race).
These constraints exist outside the participantsí ability to control and regulate.
There have been studies as to not only why someone would participate in a Liesure activity, but the level that they would participate. An example would be Jeff (H8) would not get the same experience out of running in a Jeep Jamboree because of the level of expertise he has attained. So, chances are that he would not participate in an event like this. At the same time, a beginner would not get the same experience trying to participate in an event at the level Jeff is at until they have became comfortable at that level.
People like to be challenged, but they do not move on to the next level until they have mastered the level before.
The roofing nails would just be another Intervening Constraint.