TARGET ZONE intensity % of hrmax example interval durations physiological benefit/training effect
5 MAXIMUM 90-100% 0-2 minutes > Tones the nuromuscular system
> Increases maximum sprint race speed
4 HARD 80-90% 2-10
minutes
> Increases anaerobic tolerance
> Improves high speed endurance
3 MODERATE 70-80% 10-40
minutes
> Enhances aerobic power
> Improves blood circulation
2 LIGHT 60-70% 40-8/0
minutes
> Increases aerobic endurance
> Strengthens body to tolerate higher intensity training
> Increases fat metabolism
1 VERY LIGHT 50-60% 20-40
minutes
> Helps and speeds up recovery after heavier exercises