Energy Systems and Performance

By Joel Jamieson

There is a trade off between the duration of an activity and the amount of power you can exert.

Different energy systems are capable of producing ATP at different rates and for different durations.

The two anaerobic systems (glycolysis and phosphocreatine hydrolysis) are utilized most for short duration activities with high power output.

The more efficient aerobic system, on the other hand, is capable of producing a lower power output for a much longer duration.

MYTH: anything explosive or requiring a massive amount of strength is an anaerobic event.
Not necessarily: the aerobic system predominates in activity lasting more than around 50 seconds, even though you may still be explosive or strong.

The contribution of the aerobic system to energy production increases over time.

What about events with repetitive tasks or movements (football, MMA, etc.)?
As an action/activity is repeated over and over again, it becomes more and more aerobic, which is why you slow down with each repeat.

Consequently, it's not surprising that most team sports have a huge aerobic component to them.

During all-out, max effort activities, the crossover to aerobic dominance occurs at around 20-30 seconds.

So how much speed/power does the anaerobic component account for?

Different people are able to produce a different amount of power anaerobically versus aerobically. This difference is called the anaerobic power reserve.

Anaerobic power reserve= max speed - max speed produced aerobically

Don't get confused by the equation: the anaerobic power reserve is simply the portion of your max speed that is not produced from your aerobic energy system.

The amount of your max speed produced aerobically versus anaerobically can predict how soon you will fatigue:
Those with a larger component of energy coming from the aerobic system are able to maintain speed a lot longer than those with a larger anaerobic contribution.

Coming Up Next: how different training methods can develop the aerobic side and improve your endurance.