Key Takeaways
- Running pace is expressed as time per mile or kilometer (e.g., 8:00/mi)
- The Riegel formula predicts race times: T2 = T1 x (D2/D1)^1.06
- Most training should be at easy pace (60-70% effort)
- Even pacing or negative splits lead to better race results
- Training zones help structure workouts for optimal improvement
Understanding Running Pace and Race Predictions
Running pace is the foundation of every training plan and race strategy. Whether you're training for your first 5K or aiming for a marathon PR, understanding your pace helps you train smarter and race better.
What is Running Pace?
Running pace is typically expressed as the time it takes to cover one mile or one kilometer. For example, an 8:00 per mile pace means you complete each mile in 8 minutes. This metric helps runners maintain consistent effort throughout their run and plan race strategies effectively.
Pace = Total Time / Distance
How Race Predictions Work
This calculator uses the Riegel formula, developed by researcher Peter Riegel in the 1970s. The formula accounts for the fact that running speed decreases predictably as race distance increases due to physiological factors like glycogen depletion and fatigue.
T2 = T1 x (D2/D1)1.06
Understanding Training Zones
- Easy/Recovery (60-70% effort): The majority of your training should be at this pace. It builds aerobic base while allowing for recovery.
- Aerobic/Endurance (70-80% effort): Long run pace that builds stamina and teaches your body to burn fat efficiently.
- Tempo/Threshold (80-90% effort): Comfortably hard pace that improves lactate threshold and mental toughness.
- Interval/VO2max (90-100% effort): High-intensity efforts that improve speed and running economy.
Pro Tip: The 80/20 Rule
Elite runners and coaches recommend spending 80% of your training at easy pace and only 20% at moderate to hard intensities. This approach builds aerobic fitness while minimizing injury risk and burnout.
Tips for Using Split Times
Split times help you maintain even pacing throughout your race. Most successful races are run with even or slightly negative splits (second half faster than first). Use the split times as a guide, but also listen to your body and adjust based on how you feel, terrain, and weather conditions.
Common Race Distances
- 5K (3.1 miles): A popular beginner-friendly distance, typically taking 20-35 minutes for recreational runners.
- 10K (6.2 miles): Requires more endurance, usually taking 45-70 minutes.
- Half Marathon (13.1 miles): A significant challenge requiring dedicated training, typically 1:30-2:30 for recreational runners.
- Marathon (26.2 miles): The ultimate endurance test, requiring 3-6 months of training for most runners.