Training Myths: Long Slow Distance

One of the primary bastions of endurance sports training concerns “logging in the miles”. Many call this LSD training – LSD standing for Long Slow Distance.

I always like to keep one phrase firmly in the forefront of my mind - “long slow distance makes for long slow [insert here: runners, cyclists, etc]”. The human body adapts to the training demands imposed on it. With that said, if you are training at a slow pace, then it stands to reason that you will get really good at running at a slow pace. I have yet to meet an athlete that was training to get slower.

You have probably encountered this thinking before – put in a bunch of miles at a slower pace in order to “build your aerobic energy system”. This will then lead to gains in endurance sport performance – or so the theory goes.

The premise upon which the “long slow distance” mentality is built is primarily cardiovascular. This is actually quite closely related to the discussion of heart rate training in a previous post. Of course, this then leads to the assumption that the cardiovascular system is the limiter to performance, and/or is the best measure of training load along the way.

There is probably a higher correlation between injury risk and mileage than there is performance and mileage.

The traditional view of endurance is a very aerobic-centric one. But you have to go one step further in analysis, and that takes us to the level of the mitochondria. Mitochondria are known as the "cellular power plants". They generate most of the cell’s supply of ATP, which is used as a source of chemical energy.

Mitochondria can be found around active muscle fibers. There is little value in having a power plant when there is no demand for power, thus few around inactive muscle fibers. In order to generate more ATP, you need more mitochondria. In order to create more mitochondria, you need to have more active muscle fibers.

In order to gain endurance, you need to be able to have a greater supply of ATP. More active muscle fibers leads to more mitochondria, which leads to more ATP, which leads to greater endurance. But how do we recruit more muscle fibers? With increasing resistance or load – typically accomplished via faster running as opposed to slower running.

This is where the belief systems underlying most traditional endurance training programs come to the forefront. Even with the rationale from above, these program still opt for “long slow distance”. The debate is driven by beliefs more so than sports science.

The next time you do a track workout, remember this: you are not only getting faster, but you are building your endurance as well. 

Photo credits: pheezy