My Friday night
fitness group (Fri-Rox) is now 2 months old and we have had some amazing sessions down there. Anyone who has been consistently has made massive improvements already, including myself. Come and join me every Friday on battersea park track, more
info here>>. During a few of the sessions I have explained the body’s energy systems and how it fits in to the training plan. The body has three main energy systems:
The Creatine System – This provides instantaneous energy, e.g. if you jump once in the air, it is all creatine based. You have about 2-10 seconds before this energy system is used up and then it needs a few minutes to recharge it. This is why strength & power athletes take creatine so they have a bit more of it in the system.
Anaerobic system – The next fastest method to produce energy is through the breakdown of carbohydrate without using oxygen. While this provides fast energy it also has the by-product of lactic acid. This is what creates the burning sensation of exercise and is mostly what is responsible for all the pain you would have associated with fitness. This system is limited by the amount of carbohydrate you have in your muscles vs threshold of lactic acid produced.
Aerobic System – Through taking in oxygen from the air you are able to use carbohydrates and fat to produce energy. This production happens at a slower rate than the previous two systems but when trained well it can produce energy for very long periods of time, e.g. marathons. Through extensive training it can produce energy at pretty fast rates even though it is the slowest of the three systems, e.g. look at how fast good marathon runners go at.
The majority of exercise that most people do involves the aerobic system, such as jogging, cycling, walking etc. Terminologies you may have heard around aerobic fitness may include the following:
Aerobic Threshold – This is the point when the body begins to produce lactic acid while exercising as you tap into carbohydrate metabolism. At this point, you can still sustain exercise for long periods as there is only low levels of lactate in the system.
Lactate Threshold – This is the point after which using higher exercise intensities significantly increase lactic acid, causing exercise to hurt and creating fatigue.
VO2 Max – This is the max amount of oxygen you can use within the body. The more you can use, the more efficient your energy systems and therefore the fitter you are as a person. Peter Attia and other health gurus speak a lot of VO2 Max due to its correlation with quality life years and life expectancy.
Economy / Technique – This links into how prior training affects your VO2 max being put into actual performance. Much of genuine fitness comes back to how well the muscles can transmit force. Cyclists spend plenty of time on their technique and runners develop feet muscle to impact the ground better. For example, Lance Armstrong ran a marathon while still being near the peaks of his fitness in 2005 yet finished almost an hour behind the world record (2 hours 59 mins). A later attempt he ran it in 2 hour 46 mins. The world record currently stands at 2 hours and 35 seconds. Your VO2 needs to be tailored to the specific activity you are focusing upon.
Heart Rate Zones – Aerobic training produces fairly consistent individual data for the intensity you are exercising at and the training benefits. This allows you to set training plans off heart rate.
Tempo / Threshold Training – These refer to the intensity of training you are doing in a session, are you at the aerobic, lactate or VO2 max intensity. It is a little confusing however as people use similar sounding terms for different intensities, or do a workout at ‘one intensity’ yet their heart rate is in a completely different range.
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Fatigue – There are various reasons you will get tired from exercise. For most people it will be that they are unable to handle lactic acid. This is what will stop you in the moment, however, it may be a consequence of an under developed aerobic system. The tiredness you feel from exercise can be caused from your central nervous system too. In the great book
Endure which I covered previously by Alex Hutchinson delves into the science of what limits performance. He found that at well trained levels there are many different reasons why we get tired during exercise and it is not usually due to the actual energy systems running out of steam but rather pain, perception and other factors on top of the energy systems being stressed.
What Does This Mean For You?
The main thing to take away from this should be how to apply your training to the knowledge of the energy systems. In general, you just need to consistently challenge the different energy systems. For example, to get good at running you would have some short and sharp sessions alongside some longer efforts at a low intensity. More advanced training plans would have you exercising at the specific thresholds outlined to imrpove performance.
Photo – Some track session photos –
