Interval Generator
Generate a structured interval session tailored to your race goal, current pace, and training level. Speed, endurance, tempo, or mixed sessions available.
10 minutes warm-up + 10 minutes cool-down are automatically included.
Track your interval sessions precisely
Interval training works best when you can monitor pace and heart rate in real time. A GPS watch makes a significant difference.
Garmin Forerunner 265
Workout mode with programmable intervals — warm-up, reps, rest, cool-down in one sequence.
View on AmazonGarmin Forerunner 255
Reliable pace and HR data during intervals. Training load tracking flags when you're overreaching.
View on AmazonHow it works
Enter your session duration, training focus, target race distance, current race pace, and fitness level. The generator calculates interval distance, duration, target pace, and rest periods based on established intensity targets from sports science research.
Frequently asked questions
How often should I do interval sessions?
Most training plans include 1–2 interval sessions per week. More than that without adequate easy running leads to accumulated fatigue and injury risk. The 80/20 principle suggests 80% easy running and 20% hard — intervals fall in that 20%.
What is the difference between interval and tempo training?
Intervals are run at or above VO2max effort (hard breathing, typically 3–8 minutes) with recovery between reps. Tempo runs are sustained at threshold pace (comfortably hard) for 20–40 minutes continuously. Both improve performance but in different ways.
Should I warm up before intervals?
Yes — always. At minimum, 10 minutes of easy running plus dynamic stretching before your first hard rep. Skipping warm-up dramatically increases injury risk and reduces workout quality.