Lactic Acid - increase your lactate threshold

Do you know what lactic acid is? Do you know you can increase your lactate threshold?

Energy is required to perform exercise. There are three systems which provide the body with energy:-

ATP-PC (anaerobic phosphate system )
This provides the body with sudden bursts of energy from ATP stored in the muscles. The bodys first supply of energy. Maximum suppy is 10 seconds. For energy to last the body has to access it from other energy sources.

Sprinters use this system. Think of the men's 100m sprint - totally using this anaerobic system).

Lactic acid
Also provides the body anerobically by using glycogen (carbohydrates) to resynthesise ATP - this is called anaerobic glycolysis. In anaerobic glycolysis the body’s glycogen stores are broken down into glucose, pyruvic acid and a waste product called lactic acid. The energy released during this process is used to resynthesise ATP.


Aerobic
ATP is resynthesised with oxygen. As long as you have sufficient oxygen supplies, your energy levels will remain. The by products of this process are water and carbon dioxide ( co2 exhaled by the lungs, h20 used to help the body cooling system).

After 2-3 mins your body is able to provide oxygen to working muscles for production of ATP. This occurs in the mitochondria (cells powerhouse). The presence of o2 inhibits the build up of lactic acid. The final stages of aerobic metabolism from fats and carbohydrates occur in the mitochondria in a complicated series of reactions within the Krebs cycle. (Also know as the Citric acid cycle).


COMBINING THE SYSTEMS

The 3 energy systems usually combine to provide energy for our muscles when exercising.

E.g. Walking and Jogging – the main energy system used is the oxygen system / Aerobic system. However, if during the run you go up a hill or set of stairs, you will have to choose one of 2 things
1. To continue at a slower rate
2. Walk or Jog at the same pace

If the hill / set of stairs is long then a sustained effort cannot continue as there is too much of a demand of the Lactic acid system as in this intense form of activity this is the dominant energy system. You will notice that the breathing rate will increase and the onset of fatigue will come quickly. When the stairs are climbed or the hill conquered the heart can again provide the muscles with enough oxygen and the dominant system will become the Aerobic system.

Therefore it is correct to say that the energy system used will depend on the intensity and type of the activity being performed.

Energy production for the first stage of exercise comes from either the
ATP – PC system or the Lactic Acid system. Continuation of exercises requires the aerobic breakdown of Fats or carbohydrates to produce ATP.

Most Lactic acid (produced during anaerobic glycolysis) is taken from the muscle to the liver where it is concerted back to glucose or glycogen. Some lactic acid accumulates inside the muscle. After exercise extra oxygen is needed to break down this LA inside the muscle. The oxygen is also needed to make more ATP- PC and glycogen and payback the oxygen borrowed from the blood. This payback of additional oxygen to restore body systems to their previous normal state is called Post exercise Oxygen consumption OR Oxygen debt. This means that your heart and respiratory rates will remain elevated for a period of time after you stop exercising. If there is no Cool down then the LA will build up and effects such as Cramping, reduced flexibility and muscle soreness are likely consequences.