4. Concentrating intensity
Intensity is essential but should be clearly concentrated into specific workouts.

Playbook
- Objective: Improve speed and threshold without overload.
- What to do: Schedule clearly defined hard workouts.
- How to do it: Intervals, tempo runs, or structured workouts with proper recovery.
- Frequency: One to two times per week.
- Progress indicator: Gradual improvement in demanding paces.
- Common error: Adding extra intensity to easy sessions.
Generic mini caseA runner improves a personal best after limiting hard efforts to key workouts.