By Guy Noble.
Today we are going to have an overview of the bodies’ basic energy systems and how they relate to athletic performance and training programs.
Ultimately energy is derived from the macro and micro nutrients (ie; carbs, proteins and fats) that we must digest on a daily basis. This enables a person or more importantly an athlete to perform a given workload, which generally means contracting the muscles against a resistance.
Basically all foods are broken down into what’s called ATP or Adenosine Triphosphate. The conversion of ATP into another energy source ADP+P is what allows the body to perform its daily functions which require muscular contractions. This energy source is very limited and must be continually replenished to allow ongoing physical activity
There are three energy systems which allow for the replenishment of ATP supplies depending on the physical activity, intensity and duration being performed. This affects the way in which you should train for your given sport if you wish to achieve optimal performance gains from the supplementary training you do, ie weights and in our case Kettlebell training.
The first of the 3 systems is the ATP-CP or Adenosine Triphosphate, Creatine Phosphate system.
The ATP-CP system uses energy very quickly when strenuous exercise begins and lasts approximately 8 – 10 seconds. A good example of this is the 100m sprint which uses predominantly the ATP-CP system but also another system called the lactate system. This system is used in intensive events lasting up to 120 seconds. After the critical 8 – 10 seconds this lactate system kicks in breaking down muscle cell & liver glycogen which releases energy to re-synthesize ATP from ADP-P. The familiar burn sensation you feel in the muscles is from the large build up of lactic acid in the muscles causing fatigue and if continued it will stop the physical activity you are performing.
Both the ATP-CP and lactate system come under the general banner of the anaerobic system. Phosphogen restoration occurs fairly quickly and after approx 30 seconds 70% is achieved. Full restoration takes place after approx 3 -5 minutes.
The aerobic system is the main source of energy for events that last between 2 minutes and 2 to 3 hours. A good example of this is a marathon; in this system glycogen is broken down in the presence of oxygen and therefore produces little or no lactic acid. Whereas phosphogen is replenished quickly full glycogen restoration is a lengthy process which can take days to achieve.
In a typical strength training or interval training session up to 40% can be restored in 2 hours with only just over 50% some 5 hours later. Full restoration will take 24 hours. In continuous events or training of relative high intensity, times for restoration are even longer.
Anything longer than 3 hours and the body starts to break down stored protein and fats to replenish the various systems. This breakdown produces carbon dioxide and water as by products which are eliminated through respiration and perspiration.
The intensity of the exercise will dictate which energy source is depleted and except for extremely short activities both systems are used to a lesser or greater degree. From this, it must be concluded that the anaerobic and aerobic energy systems overlap.
From tests, higher levels of lactate in the blood indicate a greater contribution from the anaerobic or lactate system and lower levels indicate a greater contribution from the aerobic system.
As an example the 100m sprint will use 99% from the ATP-CP/ lactate system and only 1% from the aerobic system.
A 3000m event will use 60% from the ATP-CP/lactate system and 40% from the aerobic system.
You may be surprised to know that tennis uses 90% from the ATP-CP/lactate system and only 10% from the aerobic system.
Just because a match can last hours you have to look at exertion levels within the game itself and most rally’s in tennis fall under the ATP-CP/lactate system.
Football derives an even greater amount from the ATP-CP/lactate system.
So in theory if your sport is of relative short exertion duration your training should match this with interval training to suit. Unfortunately this is not true as having a high aerobic capacity means that less lactic acid is produced at higher intensity training and recovery is greater between interval sets and workloads.
To optimise training responses from the daily and weekly programs you do, it helps if you have an understanding of the basic energy systems of your sport and how energy fuel is used for that system and how long it takes to restore energy fuels used in your training program.
Next time we will look at training programs for different sports and how to increase strength and power to optimise your performance.
Tudor O. Bompa. Periodization – theory and methodology of training, 4th edition
Fox, Bowers and Foss 1989, the physiological basis of physical education and athletes
Macdougal 1974, limitations to anaerobic performance