Explainer | What are aerobic and anaerobic zones and how should they shape trail or ultra running training?
- Training should be split 80/20 ‘easy’ and ‘hard’, even if you have limited time to dedicate to running
- The understanding behind anaerobic thresholds and oxygen intakes is evolving
Training at the correct intensity for the right amount of time is one of the most important, but one of the most commonly misunderstood, parts of a training programme for trail or ultra running.
A knowledge of the biology behind the intensities will help to shape your training schedule.
What are aerobic and anaerobic systems?
Adenosine triphosphate (ATP) is what makes your muscles contract for movement – the aerobic system produces 36 ATP per cycle, compared with just two per anaerobic cycle.
Traditionally, it was thought that the aerobic zone was when your muscles work with oxygen; anaerobic was when your muscles work without oxygen. New studies suggest that when you reach a certain intensity you are working quicker than the aerobic cycle can keep up because the aerobic cycle produces a lot of ATP but slowly, and the anaerobic cycle produces a little but quickly. So, you supplement the aerobic system with the anaerobic system – it is not to do with oxygen, or lack thereof.
The threshold between the two is not as simple as the commonly thought lack of oxygen and has been the subject of endless debates in sports science.
