Caption

Energy to the max
Everyone wants to get more from their work out. Sgt Rob Orr gives his first lot of tips for what to concentrate on

Energy
The body requires energy to power the muscles and organs, and for many the terms "'aerobic" and "anaerobic" are not new. This edition we will take a closer look at the energy systems and their roles within metabolic conditioning (running, swimming, cycling, etc) and resistance training.

Firstly, a misconception must be addressed. Although called the energy systems, the three systems discussed do not provide energy directly to the tissues. Rather, they supply energy for the formation of a molecule known as adenosine triphosphate or ATP. It is only ATP that can provide energy directly to the tissue. So, in essence, the energy systems are supporters of the true energy currency, ATP.

ATP
To provide energy for muscle contractions the energy molecule ATP is broken down. This breakdown creates energy and it is this energy which causes a muscle to contract. With this in mind, however, there is a very limited supply of ATP in the body. In fact, reference varying, there is only enough ATP to provide from one, to several seconds worth of energy. The good news is that once broken down it can be reformed. This is the role of the energy systems.

Anaerobic Energy Systems
Anaerobic systems are those that do not require oxygen (at a cellular level, so whether you actually breath or not is unimportant) to function. There are two of these systems, the ATP-PCR (alias Phosphocreatine, Creatine Phosphate, Phosphate or Alactic) system and the Anaerobic Glycolytic (alias lactic acid) system.

The ATP-PCR system utilises a molecule known as phosphocreatine to restore ATP.

As the chemical reactions required are simple, this system activates rapidly and is therefore the primary source of energy for explosive short duration events (picking up a weight, running 100m, swimming 25m). Unfortunately, it too is limited in capacity and lasts for only 15 to 20 seconds at a maximum pace.

The system does recover quickly however, requiring only two-to-three minutes to be at full capacity once again (take note of this recovery as it sets the basis for interval training and weight training recovery later).

The anaerobic glycolytic system is a little slower than the ATP-PCR system and only becomes a dominant energy supplier after about 15-20 seconds when the ATP-PCR system is spent.

While it does last longer than the ATP-PCR system, the chemical reactions to carry out the process are slower. This means that the anaerobic glycolytic cannot withstand as high an intensity demand as ATP-PCR.

This is why performance intensity cannot be maintained at the same rate as for ATP-PCR activity (why an 800m time is slower than 8x100m time) Furthermore, the anaerobic glycolytic system provides its energy through the incomplete breakdown of glucose/glycogen (mostly from carbohydrate).

As this glucose/glycogen breakdown is incomplete, a by-product known as lactic acid is formed. It is due to this incomplete process that the system can only maintain maximal efficiency at high intensity for about 45-60 seconds.

Recovery is also a lengthy process, taking from 45-to-60 minutes (this is why progression in a warm up is so important. If you develop lactic acid in the warm up by starting too hard, too fast, you are stuck with it until the end of the session).

The Aerobic System
The final system is the aerobic system. aerobic meaning it requires oxygen as part of its chemical equation to function. This system breaks down glucose and fats completely and is therefore a slower reaction.

This means it can take from one to five minutes before the system is functioning effectively (one of the reasons why we warm up). Although slower, it is very effective and efficient. Theoretically the aerobic system can last indefinitely until the body has utilised all its fats and carbohydrates (and even proteins). Recovery of the aerobic system is solely dependent on diet and food intake (why your nutrition is so important).

Systems and Dominance
The ATP-PCR system is the fastest energy system and is hence the most dominant system during activities like a 100m running sprint. The anaerobic glycolytic (lactic) system is the second and dominant energy supplier in the 400m running event. The aerobic systems come on line last and this provides the energy for events lasting longer than three or so minutes (depending on your fitness level).

However it is important to realise that at any stage, in any event, all three systems are always working. It is the intensity of effort which determines how much oxygen is available in the cells for utilisation, the less the cellular oxygen the greater the anaerobic dominance.

To to sum up so far...
The three different energy systems and their capabilities determine how fast you can go.

Warming up correctly at progressing intensity levels is a vital part of exercise, for your energy systems it ensures that the aerobic energy system is working optimally and that you do not develop lactic acid before to even commencing with training.

All three systems are always working, so even for sprint training an effective aerobic system which aids in your recovery is vital (so yes you do need to warm up for sprints).

The type of system you use has limitations and restrictions (like how long it can last and how long it takes to recover), which is why adherence to specific training guidelines (like rest times in intervals and between weight training sets) are important.

Finally, good nutrition is important as it influences the energy systems which influence ALL physical activities.

Next edition we will look at how to train these systems and improve your physical activity performance, from sports and 2.4km run times to strength and endurance.

.