Exercise physiology is essentially the study of the anatomy and physiology of exercise activities. Sure, there is more to it than that--lots of details for technical experts to obsess over that are confusing to the layperson who may just want to know what they need to do to improve their 10K time--but we really don't need to know everything to make good use of the physiological principles upon which modern systems of training are based. Although the result is an oversimplification for those who want to fully understand the mechanistic details, we can usefully distill the aspects of exercise physiology that are most important for the layperson.
The [very] Basic Primer
Because, running is a composite physical activity that involves several aspects of our physiology that come into play at different running intensities, training for optimum performance at a given fitness level can logically be broken down three ways, based on running intensity. In turn, we develop these aspects of our physiology by working/running at a range of different intensities and durations.
I like to break it down as follows, recognizing that this is a vast oversimplification of what is going on. Still, I think this is about the simplest way to think about our physiology with respect to training.
- Aerobic (VO2Max training): develops the body's capacity to deliver oxygen to the muscles, so they can work aerobically. The more you develop this system, the greater capacity you have for aerobic activities (long slow/moderate pace running).
- Threshold training: develops our muscles ability to use the oxygen that is delivered, allowing us to function at a higher intensity for longer periods.
- Strength and speed training: improves our energetic efficiency (running economy), by developing an economy of motion.
Exercise Physiology and Training for the Runner
In truth, the benefits of each type of training have some cross-over to different aspects of our physiology, but in general if you run long distances regularly at an easy intensity, you will develop a lot of endurance and develop your ability to run long distances, but your speed will not increase very much. If you also then do speed work, your strength, motion and coordination improve and you can develop a more efficient way of running, but you won't be able to maintain this more efficient form for very long. If you also include some threshold/tempo workouts that push up your lactate threshold, you can develop the stamina needed to maintain higher intensity efforts for longer periods of time.
Essentially, we do all three types of training, because it turns out that when athletes don't, they don't reach their peak performance. Athletes whose workouts are biased toward one type of training or the other, usually see improvements in their overall performance when they increase training of the other types and reach a better balance in their training. So, these types of training are like pieces in the puzzle that represents out personal running performance.
There are areas of disagreement in where our training emphasis should be, and the connections between what we understand about physiology and how we apply that to our training remain largely theoretical, but despite these, the results are predictable enough. With the right types of evaluation, we can determine which aspects of our physiology are likely limiting our performance most, and adjust our training appropriately to achieve something closer to our optimum performance.
It's pretty cool stuff, really.