In the September article we discussed the importance and purpose of Zone 2 workouts. In today’s article we will discuss how including Heart Rate Zone 3 in your training plan will lead to improved performance and fitness.
The purpose of including Heart Rate Zone 3 workouts is to increase one’s endurance capacity. The higher the endurance base, the longer the athlete can maintain a race specific pace. A high endurance base is best obtained by training at a Heart Rate intensity of 75-85% of your Max Heart Rate. When an athlete increases their intensity into Zone 3, the energy system shifts from primary fat oxidation (Zone 1-2), to a higher contribution of carbohydrate oxidation (Zone 3). When an athlete’s performance is fueled by a high contribution of carbohydrate oxidation, the time spent in exercise can be time limited. This is because there is a limited amount of muscle and liver carbohydrate stores that can be utilized to fuel performance. Learning to fuel and run is an important part of training at this higher intensity. Endurance Zone 3 training improves the athlete’s ability to maintain a higher pace for a long duration of time without the accumulation of blood lactate levels, which is an important distinction for our next month’s discussion of Zone 4 workouts.
The best way to increase endurance is by running 20-25% of one’s weekly mileage in Zone 3. Zone 3 workouts include tempo runs. Tempo runs are defined by a steady effort level of 20-40min, with a pace slightly slower than 10k pace. Zone 3 workouts are best described as a comfortably hard effort during which the athlete can have a broken conversation.
Training Recommendation: Spend time in Zone 3 after you’ve built a large Zone 1-2 base. One to two days of Zone 3 tempo work per week on flat terrain and hills will increase your endurance and overall fitness. Build Zone 3 workouts into your training plan when you are ready to, “leave it all on the course” in your next race. Zone 3 is a race pace for ½ marathon to 50k races.
Cindy Stonesmith CMT ACSM/HFS
Owner and Endurance Running Coach