Three things that anyone can do to prevent this would be
understand myths about working out
look for inexpensive classes in the area
take a physical education course at school
Most barriers to exercise revolve around becoming discouraged/depressed about the results due to having unrealistic and high expectations. Learning about what you can expect realistically from a set routine will greatly increase motivation and prevent such barriers. The same applies to learning which routines and diets work best and all of this can be learned by taking physical education courses or classes near you.
