Heart Rate for Aerobic Power (VO2 Max) Workouts
While running at lower intensities is great for building an endurance base and for recovery between hard workouts, optimum improvements in aerobic fitness occur when running is performed at an intensity over 90 percent max HR. Training at this high intensity targets improvements in VO2 max. Aerobic intervals, running periods lasting more than two minutes separated by short rest periods, are primarily used to accomplish this goal by targeting cardiac factors associated with VO2 max (e.g., stroke volume, cardiac output, heart contractility, etc.).
More: 3 Workouts to Increase VO2 Max
Since VO2 max occurs at or very near 100 percent max HR, you should perform these intervals at or very close to 100 percent max HR. However, you need to be careful here, because if a 6:00 mile elicits max HR, surely a 5:45 mile will also elicit max HR. However, because the purpose of the workout is to target VO2 max, the goal of the workout is achieved by running the mile repeats in 6:00 each. Running faster only adds more fatigue to your legs.
Remember, the goal of training is to provide the least stressful stimulus that will elicit the desired adaptation. Intervals in this HR zone are typically performed during the competitive phase of your season.
More: How to Peak at the Right Time for Your Race
Heart Rate for Anaerobic Glycolysis Workouts
Anaerobic intervals, intense running periods lasting 30 seconds to 2 minutes separated by long recovery periods, trains the muscles' ability to tolerate and buffer muscle acidosis, and trains the recruitment of fast-twitch muscle fibers to enhance speed. Using heart rate is typically not valid in this case since you will be running at a speed that is much faster than that which will elicit max HR. In addition, if the interval is short enough, HR will not even have time to increase to maximum levels.
More: How to Increase Anaerobic Threshold
Table 1 summarizes the different types of workouts and their corresponding heart rate guidelines to be used during the training year. Although there are different theories and opinions concerning the precise order of workouts during the training year, the goal of the individual workout and the corresponding heart rate should always match.
Table 1: Heart Rate Guidelines During the Training Year
|
Type of Training | Example of Workout | Heart Rate | Time of Year | Purpose |
| Aerobic Capacity (Endurance) | Distance running: 5 to 10 miles | 70 to 75 percent | Base phase; during entire training year as recovery days between harder workouts; unloading days before competitions |
- Improve aerobic endurance - Muscle cell adaptation - Enhance economical functioning of metabolic system |
| Lactate Threshold | 20-minute tempo run | 85 to 90 percent | Late base phase/early competitive phase |
- Raise lactate threshold - Elevate intensity of running at which athlete begins to feel discomfort |
|
Maximum Oxygen Consumption/ Aerobic Power (VO2 max) | Long intervals (3 to 5 minutes) with short rest periods | 95 to 100 percent | Early to mid-competitive phase |
- Improve VO2 max - Increase heart's max stroke volume - Increase max cardiac output |
| Anaerobic Glycolysis | Short intervals (30 to 90 seconds) with long rest periods | N/A | Mid- to late- competitive phase |
- Improve anaerobic endurance - Improve muscles' ability to buffer acidosis - Increase lactate removal from muscle |
| ATP-CP (Phosphagen) System | Very short intervals (5 to 15 sec.) at close to top speed with long rest periods | N/A | Mid- to late- competitive phase |
- Increase muscle power production - Improve speed by recruiting fast-twitch muscle fibers |
