If an athlete wants to perform to the best of his or her ability then it is important to have an understanding of the sports science that will underpin their ability to strive for peak performance.
If you want to improve your levels of physical conditioning you have to understand the building blocks.
The Athletic Energy System
Food produces energy, but this energy can only be used when it is in the form of ATP (adenosine tri-phosphate).
Unfortunately our muscles can only store relatively small amounts of ATP at a time, so to cater for all the activities that we undertake our bodies have to keep making it.
If the level of activity means that our muscles use up our ATP faster than we can make it then we will get tired and have to slow down or stop what we are doing.
In simple terms, if you are trying to run faster than your body can provide ATP to make your muscles work then you’ll either have to slow down and stop or let the body replenish its stores of ATP.
To provide our bodies with energy as we use it up, we have three different energy systems – the Creatine Phosphate System, the Anaerobic Glycolysis System and the Aerobic Glycolysis System.
1.Creatine Phosphate System
This energy system is for 0 to 30 seconds of hard explosive work – it is used in sprinting, 100m, 200m and up to 400m for some us.
This system is the body’s immediate supply source, providing energy far more quickly than the other systems. However due to the way it works it can only provide energy for very short periods.
The creatine phosphate system is THE system for sprinter and they therefore train hard to improve it.
Following a full-out sprint of 100m or 200m we must rest for several minutes to allow our body to replenish its creatine phosphate store.
2. Anaerobic Glycolysis System
This system is used for stamina – used in middle distance running, 400m, 800m and 1,500m for some of us. It provides one to two minutes of hard work.
This system can provide energy relatively quickly but is not long lasting., so the muscles tire quickly as waste products build up in them, causing fatigue and pain.
When we exercise for more than 10 seconds we start to breathe heavily and deeply, simply because our muscles require more oxygen. Due to the time it takes for this oxygen to get into the bloodstream and to the muscles, any ATP or creatine phosphate stores will have been depleted. It is then that the lactic acid system provides energy until the required amounts of oxygen arrive.
The lactic acid system uses glycogen as an energy source. Glycogen is produced from a breakdown of carbohydrates. It is then stored in the muscles and in the liver.
However when glycogen is broken down to produce the demanded energy, lactic acid (lactate) is also produced as a waste product. As more and more of this waste is produced the muscles begin to feel fatigued, eventually forcing us to slow down or stop.
The lactic acid system cannot be sustained for long. The length of time is highly dependent upon the person, gender, age, and of course fitness level. However the “lactic threshold” can be trained to increase it, meaning that an individual athlete can continue for longer and longer with lactate building up in their muscles.
3. Aerobic Glycolysis System
This system is used for endurance – used in long distance running, 5Km and over. This system can provide energy indefinitely provided sufficient fuel is available. However it must have oxygen to work and therefore requires energy expenditure not to exceed a certain level.
Due to the fact that the aerobic system provides energy far slower than the other systems, it is the one that we use for the majority of our daily activities. However the drawback is that it provides energy far too slowly for intensive activity, hence the requirement for other systems.
The aerobic energy supplies are almost limitless, dependent upon the individual body type, length of activity and availability of food.
The aerobic system is essential for exercise over a long periods of time such as for triathlons, long-distance, marathons and ultra-marathons.
Simply put, the system works by using oxygen in the breakdown of carbohydrate and fat to produce energy, but without any waste products that stop the process reoccurring (as in the lactic acid system). However the big caveat is that the aerobic system can only sustain its energy production when enough oxygen is being supplied to the muscles.
Energy System Interaction
Unsurprisingly, the body doesn’t use the three athletic energy systems independently. All three systems are used in conjunction with each other. The amount each system is used will depend on the intensity of activity at that point, as well as how long the activity lasts.