By Dr. Aaron Case BSc, DC (December 2006)
Simply stated, if you want to increase your speed, you must make one of your weekly runs faster and one run slower than you would normally run.
1) Faster Run: For example, if your current shortest speed interval is 2 minutes, occasionally make it 1 minute or even 30 seconds (gradual transfer). This could also mean just running faster up or down a hill on a regular route.
2) Slower Run: To optimally recover from these faster runs and to train other biochemical fuel systems, run slower (and farther) than you normally would one or more times per week. If you are already running a long and slow run each week, add an easy (short) run during the week.
