In another week the high intensity Gazelles and Leopards will be revving up their track workout engines with a high velocity VO2 max session while moderate and low intensity groups continue to concentrate on lactate threshold workouts. Although pure endurance and lactate threshold are the most important physiological variables for the half marathon and marathon distances, VO2 max workouts are still important to maximize half marathon and marathon performance and have been intermingled in the high intensity training schedules. So what is the difference between VO2 max and lactate threshold and why is VO2 max also important?
VO2 Max (VO2) workouts increase the amount of oxygen-rich blood your heart can pump to your muscles by increasing stroke volume and increase the amount of oxygen your muscles can extract from the blood. This is important because it determines your aerobic capacity. The higher you raise your VO2 max, the greater your ability to produce energy aerobically. The more energy you can produce aerobically, the faster pace you can maintain.
Your VO2 max is the maximum amount of oxygen that you can take in, process and use to provide the energy you need to run. The upper limit of your VO2 max (also known as aerobic capacity) is in large part genetically predetermined. However, most runners have not “maxed” out their functional aerobic capacities and well-designed training can have a significant impact on improving your VO2 max.
How do VO2 Max workouts differ from lactate threshold workouts? VO2 Max intervals are shorter…and faster than lactate threshold intervals. They are medium length intervals of 600 – 2000 meters at current 3k – 5k race pace. The recovery period between intervals is also longer. In between each VO2 max interval jog 50 – 90 % of the time it takes to run the repeat. These workouts will increase your aerobic capacity to its upper functional limit. Anywhere from 2 ½ to 5 miles worth of intervals should be part of every VO2 max session (for example 5 x 800 meters) At this running speed, your heart rate will generally be at 95 – 100% of maximum. VO2 Max workouts are more demanding on the body than lactate threshold workouts and usually require an additional day or two of recovery above and beyond what is required by lactate threshold workouts.
Tempo (T) and Lactate Threshold (LT) Runs are used to build stamina.
Lactate threshold and tempo runs train the body to tolerate moderate levels of lactic acid in the blood while running at significantly faster pace than aerobic, “easy” conditioning (where there is very little lactic acid production). Lactic acid is the by-product of “oxygen debt” when we try to run fast for any length of time. Lactate threshold training
Lactate Threshold runs can be performed as “Tempo” runs of 15 to 45 minutes, or long, “lactate threshold” intervals of 3 to 15 minutes with very short jog breaks in between. Lactate Threshold/Tempo runs enable you to run further at or near your lactate threshold running speed, improve the speed at which your lactate threshold occurs, run more comfortably at the same pace, improve your running efficiency at all race distances of 5k or longer and help prevent overtraining
Lactate threshold runs are slower than VO2 Max workouts….and when they are run as intervals, the recovery period is also shorter…usually 60 seconds. For a tempo run, recovery is nonexistent. Your lactate “threshold” is the speed just below the point at which lactic acid is being produced at a faster rate than it can be removed from the bloodstream, Threshold pace is at your 10-mile race pace, approximately 25 – 30 seconds/mile slower than 5k race pace, 10 – 15 seconds/mile slower than 10k race pace or 20 – 30 seconds faster than marathon race pace. This correlates with an effort of about 85 – 90 percent of maximum heart rate.
The two types of workouts also compliment each other. Lactate threshold is often expressed as a percentage of VO2 max. As you improve your lactate threshold, your pace becomes faster relative to your VO2 max. If you raise your VO2 max, it allows more leeway to raise your lactate threshold ceiling higher as well. Lactate threshold, however, can continue to improve many years after you maximize gains in VO2 max. It is very important that both VO2 max and lactate threshold runs are done exactly at or right below the appropriate pace. If you train too fast, the desire improvements will not occur and it will make it difficult to complete the entire workout at lactate threshold or VO2 max pace. It is also important to begin and end workout sessions of both types with a warm up and cool down.
Reference: Pfitzinger, P., and S. Douglas. 1999. Road Racing for Serious Runners.Champaign,IL: Human Kinetics.