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On the 11th Day of Fitness, HH Fitness brought to me…

Yesterday I talked to you about too much cardio can make you fat. I don’t want you to fear cardio. I want you to ultimately use it in your training to your advantage. If you are looking to run a half marathon your body requires more of a specific energy system. Knowing how to train appropriately can help you reach your goals.

What is an energy system?

Energy systems are the various ways the body generates and uses energy throughout day to day activities. When it comes to training your energy systems is primarily based on your training goals. These goals may include, but are not limited to, fat loss, being more athletic, improving general aerobic fitness, being able to keep up with your kids, etc. These goals may overlap depending on where you are at in your journey.

We have three primary energy systems. The Phosphagen (immediate sources of energy), Glycolytic (somewhat slower energy sources, uses carbohydrates), and Aerobic (slow energy sources, may use either carbohydrates or fats).  The body’s three energy systems work synergistically with each other and not independently of each other.


Phosphagen System

This energy system will consist of short, very fast sprint like movements. Sprints may last 5-30 seconds in length followed by long rest periods of 3-5 minutes between each set. The longer rest allows for the complete replenishment of creatine phosphate in the muscles to be used during the next set.

An example of this would be 6 sets of 15 second sprints with 3 minutes of recovery between each set.


Glycolytic System

This energy system will utilize fast intervals that are 30 seconds to 2 minutes followed by a bout of active recovery (i.e. walking around) that is twice as long as the fast interval period. This is a 1:2 work to rest ratio.

An example of this would be 30 seconds of running followed by 60 seconds of walking for 10 sets.


Aerobic System

The aerobic energy system can be trained with both intervals and continuous bouts of exercise. Typically speaking, these bouts of exercise are for greater than 60 seconds when performing intervals and range from 20-60 minutes for continuous work. Training is usually based on max heart with training zones being 70-90% of predicted max heart rate.

The first example of training this system is tempo split squats of 45 seconds of work and 45 seconds of rest for 3 sets per leg.  Heart rate should be 80-90% of max heart rate while performing the split squats.  Another example would be a 20 minute steady run with your heart rate ranging 70-90% of your max heart rate.


All three energy systems are needed by the body during training sessions. They each dominate during different components of training and do not work independently of each other. The energy system being used is based on the intensity and duration of the activity being performed.



“Help us to not merely listen to Your Word, and so deceive ourselves. Help us do what it says.” – James 1:22-25


Heath Herrera, M.Ed., CSCS
Head Coach

HH Fitness, Inc.


P.S. – DO NOT LIMIT YOURSELF, IF YOU ARE LOOKING TO IMPROVE YOUR ENDURANCE FITNESS SEND ME A MESSAGE OR GO HERE TO SIGN UP FOR THE ENDURANCE ATHLETE TRAINING PROGRAM. Seriously, I absolutely despised running… mostly because I am not good at it.  Now, thanks to this program, running a mile is no longer impossible… This is the same program I used to complete my first Half Marathon 2 years ago and the protocol I used to prepare for the MS 150 a little over a year ago



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