Base Phase

The Base Phase is probably the most important phase. It's the longest phase. It is where the main gains are made, both for the short term and long term goals. The specific phase that follows aims to fine tune the fitness built through the base phase for racing. As a result that fitness built has the biggest influence.

I find it best to simplify the multitude of elements that go into the concept of fitness. Depending on how you categorise things, it is possible to fill pages of all the different aspects of fitness if you were so inclined. That doesn't work for me. Much better to combine all those aspects into two or three key objectives to focus on.

Those objectives to develop are:

1. Anaerobic Threshold
2. Aerobic Endurance
3. Biomechanics

No individual session is the be all in developing any of this. All training sessions and recovery go into influencing each of those objectives. Some types of runs will have a greater effect over one objective than the others. As fitness develops over time, the training will have to adapt as well.

Anaerobic Threshold

I use a working definition for the anaerobic threshold (AT) as an intensity range where lactic acid is produced at a higher rate than can be cleared or metabolised by the body. The further above threshold the intensity is, then the quicker fatigue develops due to acidosis.

Progress of the AT is two-fold, first it that I can run at a faster pace and second is to be able to hold said pace for longer. As for holding this intensity range for longer, that is influenced a good deal by the aerobic endurance and biomechanics. Therefore most of the AT training is directed to raising the pace I can run at. These runs will mainly be close to AT intensity itself as sustained efforts or long intervals. Running at faster speeds approaching VO2max also provides a strong stimulus

Aerobic Endurance

The bread and butter of the endurance running. In an attempt to simplify and define this area I choose to use what tends to approximate the aerobic threshold or 1st lactate threshold. My working definition is the intensity at which the highest rate of fat oxidation occurs. This isn't easily measured without a laboratory, but tends to be a bit slower than marathon race pace. Refer to my post all the way from 2008 for some extra details, Training and Fat (the recommendations are out of date).

Training to enhance this element is what most distance runners enjoy. Long runs, steady comfortable runs and then those sustained not quite so comfortable longer runs. It all adds up. Some of these runs will have definite pace goals and progress over time in both distance and speed.

Biomechanics

This encompasses most things that allows me to train well to enhance the anaerobic threshold and aerobic endurance. It includes injury prevention, good technique and appropriate range of motion supported by good strength and power levels. A little bit can go a long way in this area. The mixture of flexibility training, tissue work, strength training, hill sprints, technique work and fast running all combine together. It can be easy forgo a lot of this work for the preference of just fitting more kilometres running. In the short term that can actually bring my running for an impending race, but history has shown it eventually catches up with me further down the track. So they can't be considered as extras during base training, they are a necessity.

The main difference to the introductory phase is I am now adding is some specific pace goals and will make a concerted effort to progress the training stimulus of runs. The average paces and distance will gradually increase and I expect there will be plenty of moderate fatigue carrying from one run to the next. The sessions from the previous six weeks are not replaced, but they are built upon. There will still be the easy runs and some short intervals. As my fitness improves these runs will have a different effect than they did earlier. There's a lot of work t be done.