Nearly every athlete is looking for a “magic” workout, the one intensity that will cause the most improvement. However, one training intensity will not be most effective let alone “magic”. In fact any single training intensity used exclusively is a very ineffective way to train. If you search the training literature or consult different coaches, you will find hundreds of different approaches. So which is best? If we knew the single best approach, then we would be making fortunes training world champions. I am sure if you asked the coaches of the medalists at the most recent Olympics you would get a myriad of approaches. With this said, we do have a point of view and it is based on the theories of Jan Olbrecht. We call it high/low. Dr. Olbrecht does not have a name for this approach but it consists of several different elements that have the objective of training the energy systems to a proper balance.

First, developing aerobic capacity to a maximum level. There is probably never enough aerobic capacity for an athlete. However, how does one maximize it for an athlete on the day of the race?

·         High – In order to train every fiber one must train near VO2 max and there is research to show that high level training is very effective at building aerobic capacity. But if too much high level training is done then it is possible to break down aerobic capacity rather than build it up. Training is a process of breaking down and building back up. Thus, too much of a good thing can have negative effects. In these triathlon examples the “high” rarely gets above 15% of total volume and is often near 10% of total volume.

·         Low – Long slow distance workouts help build aerobic capacity because they speed the process of regeneration and also because they have a positive effect on other cellular processes that help with aerobic capacity. Long workouts at low intensity will work all the slow twitch fibers. Thus the “low” is very good for the training of the slow twitch fibers.

Second, develop anaerobic capacity to a proper level. Unlike aerobic capacity anaerobic capacity has to be carefully adjusted. The right level of anaerobic capacity to produce maximum energy production for a race depends on the strength of the aerobic system and the race itself, primarily the length of the race. In general short races require high anaerobic capacity and long races require low anaerobic capacity. This is what we mean by balancing the systems. For a long distance triathlon the level has to be fairly low but see the comments in these various slides for the proper level. For the Olympic length triathlon the athlete will need a moderate to good level of anaerobic capacity. It will not be as high as a competitive swimmer, rower or middle distance runner but it cannot be too low.

Anaerobic capacity cannot be trained as readily as aerobic capacity but it is possible to build or suppress it with certain types of training. Dr. Olbrecht’s book discusses this in detail. But some specifics are:

·         Sprints are an excellent way to build anaerobic capacity but must be used only in small amounts each week. The stronger the anaerobic capacity the more sprints the body can tolerate and are probably not ideal for long endurance athletes targeting Ironman or a marathon.

·         Long slow distance and intervals near the maximum lactate steady state are excellent ways to suppress anaerobic capacity. Endurance athletes have fairly low anaerobic capacities for two reasons. One is that genetically they don’t have the predominance of fast twitch fibers that is necessary for high anaerobic capacity and second is that long slow distance and anaerobic threshold training is common for many distance athletes and both these training techniques lower anaerobic capacity. It is possible to take athletes with fairly high anaerobic capacities and lower them so that they are good endurance athletes. Many triathletes are ex-swimmers and competitive swimming is a sport where most successful athletes have good anaerobic capacities. It is unlikely that athletes with naturally low anaerobic capacity can be made into good sprinters, but the reverse is possible.

The intense workouts near the maximum lactate steady state are only used sparingly and only when necessary to reduce anaerobic capacity. An example of this would be before a major competition and primarily for distance events.

Another benefit of higher anaerobic capacity that Jan Olbrecht has found is that an athlete will be able to withstand more intense workouts if his/her anaerobic capacity is higher. Thus, he recommends raising it during preparation phases of training but reducing it to the appropriate level prior to the race for which the athlete is competing. This is why you will see recommendations for higher anaerobic capacity during base training. This higher level of anaerobic capacity will cause the athlete to compete at a lower pace during this time because they know that their lactate threshold is lower. But the athlete knows that anaerobic capacity can be lowered later on prior to the important race. This will raise the LT and, allow the athlete to compete at a higher percentage of VO2 max.

My own version of HI/LOW is a bit more simple – when looking at your training week, you never want to schedule back to back HI intensity workouts and so we will build a week with this HI/LOW concept in mind. Alternating HI intensity days (like hill repeats and intervals) with LOW intensity or cross training.