Test the ability to apply the FITT principle to create a 6-week cardiovascular training program for a high-school cross-country runner. Students must produce a week-by-week schedule specifying Frequency, Intensity (HR zones/paces or RPE), Time (session durations), and Type (long runs, intervals, tempo, recovery, cross-training), show progressive overload and recovery strategies, justify choices based on athlete age and performance level, include monitoring metrics (HR, RPE, pace) and safety/injury-prevention measures, and give one practical modification for common constraints (illness, limited time).