The Interference Effect

Training different aspects of fitness efficiently

In general, athletic requirements for most sports and physically demanding hobbies fall into one of three categories:

1 - aerobic fitness (long distance runners, swimmers, cyclists etc)

2 - anaerobic fitness (sprinters, strength athletes, powerlifters, bobsleigh etc)

3 - both aerobic and anaerobic fitness (rugby players, crossfit athletes, middle distance athletes)

However, there is nearly always some degree of crossover between these two types of athletic fitness.  Endurance runners mostly require fantastic aerobic ability with a degree of anaerobic ability, whereas sprinters require fantastic anaerobic strength / power but also a good aerobic base.

In the process of training these two main energy systems athletes might encounter a phenomenon called the interference effect.  This is basically where one type of training can affect (interfere with) the adaptations from the alternate type of training.

The body adheres to the SAID principle - Specific Adaptation to Imposed Demand, whereby the body basically becomes better (more efficient) at the things it is consistently asked to do.  So, it seems rather obvious that an athlete focusing solely on lifting heavier and heavier weights will become stronger and stronger but will almost certainly not improve their ability to run a marathon. Conversely you don’t see many, if any, endurance athletes entering strongman competitions.

But, and it is a big but, all athletes will benefit from some degree of crossover: endurance runners benefit from strength training to help their bodies withstand the impact forces of running for extended periods of time.  Equally, strength athletes will benefit from some aerobic training so that they can strength-train for greater periods of time.

The issue here then is how to best manage the interference effect in order to maximise athletic development, and this falls into three main categories: micro (short), meso (medium) and macro (long) cycles.  The microcycle describes a singular training session, the mesocycle is a few sessions over one or a few weeks and macrocycles are months long.

So next time we’ll take a look at how you might schedule your training accordingly to minimise this interference effect.