5 Running Interval Workouts to Build Fitness & Speed Quickly

Increase endurance and speed with these 5 super-effective running interval workouts (plus a full guide on interval training for runners).

Treadmill Speed Training

Interval Track Workout to Increase Speed — Lea Genders Fitness

Treadmill Interval Training Workouts

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5 Running Interval Workouts to Build Fitness & Speed Quickly