I wish to find out if a new exercise program is effective in improving fitness levels among college and university students throughout south Florida. I select two campuses per county in Miami-Dade, Broward, and Palm Beach counties. From each school, students age 18 to 24 may opt to take part in the exercise program which lasts for 1/2 hour, four times per week over the course of one semester. The intervention includes cardiovascular fitness, muscular fitness, stretching, relaxation, and motivation. I am aiming to recruit 100 students from each campus, recruiting via flyers and word-of-mouth. I collect demographic information, weight, BMI, muscular endurance, flexibility, skin fold (body fat) measures before and after the intervention to see if there are any changes in fitness levels.

• 1. Is this a randomized controlled trial (classic experimental design)? Why or why not?
  2. Does this have high external validity? Internal validity? Explain.