Training Your Body's Energy Systems For A Maximal Metabolism | figureFIT

Training Your Body's Energy Systems For A Maximal Metabolism

Training Your Body’s Energy Systems for a Maximal Metabolism

by Liz Nierzwicki, BS, ACSM-CPT, E-RYT

This article was published in the June 2014 issue of Paleo Magazine. 


“Today, we’re training our ATP & glycolytic systems.” 

Would you know what that meant if you walked into a room and that’s what your trainer said to you? I don’t know about you, but most people wouldn’t.  I love to learn as much about the body as I can and I also believe in educating my clients, so this is how I talk to them.  I believe it’s best to educate them as to why we are training the way we do; otherwise they just think I’m trying to torture them. LOL.  The more they know, the better they take care of themselves and the better they feel.  

Most people know as much about their body’s energy systems as they know about their car’s engine.  They know that it’s important to eat healthy, workout, and I’m sure they could tell you a bunch of other misnomers about building their metabolism such as; eating more frequently builds metabolism, caffeine burns more calories, and the list goes on and on.

Many people simply don’t know much about the body’s energy systems let alone how to eat for optimal health because it’s not something they studied and they don’t teach us this stuff in middle or high school. So that’s my mission, I want to teach people as much as I can, in a very simple way, so they can apply these proven training tactics to their life in order to feel better, look better, and be healthy!

So what is the science behind our body’s energy systems and how do we maximize our workouts for the best metabolism? Well let me help you understand this not so complicated subject.  

Introducing the Powerful Three / Energy Systems Timeline

Let’s say you’re headed outside to sprint and you want to see how fast and hard you can run before you start tuckering out. Here’s what happens:

0-10 seconds: ATP-CP System

The moment you start sprinting, all three energy systems begin to work, but the first to fire up is the ATP-CP (or phosphagen) system. This is the stored ATP within the working muscles. There is not much of this so we burn through it in less than 10 seconds.

10-75 seconds: Glycolitic System (Aneorobic System)

Once ATP-CP has started to run out, the glycolitic system ramps up and takes over for the next minute or so before it too begins to run out of fuel. Glycolosis relies on energy converted from stored carbohydrates (glucose) into ATP.

75 seconds – 10 or more minutes: Oxidative System (Aerobic System)

The oxidative system has been generating energy this entire time the first two systems are at work, but it’s also busy fueling other bodily projects such as cardiovascular function, digestion, and toxin elimination via sweat. The oxidative system uses fat as its primary fuel but since fat takes longer to convert to energy than glucose, you’ll be compelled to slow down. Once this system kicks in, it can generally stay on the job for quite a while if you are well trained. 

All three metabolic energy systems are switched on during physical activity but each one plays a different role depending on the activity and it’s demands. All three systems affect metabolism, fat loss, and muscle building efforts. Let’s take a closer look at these three amazing systems and how they work.

First Responder: The ATP-CP System

The first responder is the adenosine triphosphate-creatine phosphate (ATP-CP) system or phosphagen system.  There is a small amount of ATP stored away in our muscles that is ready for fast and quick movements. This system is the fueled by our muscles and it is the first, yet very brief, source of energy.  The ATP system is the most prepared for emergencies or fast explosive movements, and kicks in when the body’s normal oxidative system is not prepared for the task.

Examples would be: a max weight squat, a single burpee, jumping up to get the phone, quickly reaching to stop a vase from falling. The energy of this system lasts for less than 10 seconds.

All three energy systems ultimately run on ATP: it’s the fuel source for all physical functions, from breathing to sprinting up a hill. Your other two systems (glycolitic and oxidative) make APT when they are waiting to be used.

Next Up: The Glycolytic Energy System

The 2nd system to be tapped into is the glycolytic system.  This system is fueled by glycogen (stored carbs/sugar) provides energy for activities of slightly longer duration such as strength training and high intense intervals.

Training the glycolitic system will strengthen all three systems and help them work together more efficiently. In addition, you will burn more fat in the long run, because the recovery period from training this system requires work from all three energy systems. So when you are done doing a workout that trains the glycolitic system, your body is still burning fuel for up to 48 hours to recover.

If you’ve ever tried to sprint the entire way around a track, you’re aware of what it feels like to exercise the glycolitic system; it’s tough! The discomfort and effort that comes from training the glycolictic system is well worth it because if you want to lose fat, gain muscle, and get the most out of your precious gym time this is the system to train.

Last & Long Burning: The Oxidative System

The 3rd system to be tapped into is the oxidative system.  This system is fueled by fat and glucose but is the only system that requires oxygen to function.  The oxidative system is always at work and is the system that sustains all of our bodies’ functions. Although the oxidative system is continuously active, the process of converting fat into usable energy can take a while. Once it gets started though, it’s your body’s most sustained source over long periods of time.

Exercise physiologists used to believe that long, slow cardio exercises practiced for an hour or more several times a week was the best way to train this system but research has proven that the oxidative system works very hard to help you recover after anaerobic (glycolitic) training, therefore, concluding that unless you are a competitive endurance athlete, loads of long, slow cardio is probably not the best way to train your aerobic system.  Through higher-intensity training, you can significantly increase the capacity of your aerobic system and burn more fat.

Let’s Take a Look at How to Train Your Energy Systems for Maximal Metabolic Functioning:

Training Your ATP-CP System
How to Train It: Heavy/Max weight strength training, medicine-ball throws, jumps, short sprints, and sports-specific drills.
Sets: 3-8 of each

Reps: 1-2 reps in strength training activities and 0-15 seconds in max effort exercises.

Rest: Longer rest between sets (up to five minutes); for a full recovery between efforts.

How Often Should You Train This System: Up to three times a week

ATP-CP athletes are fast, strong and explosive, specializing in brief, single-effort activities.  Training the ATP-CP energy system will not increase the stores of ATP-CP in the muscles but it will improve your explosive speed and power, so you can jump higher, sprint faster, and throw further. Training this system is the best way to increase your power and speed.

Training Your Glycolytic System
How to Train It: Medium-intensity strength training; interval training; running stadium stairs or hills; shaking “battling ropes”; kettlebell workouts; plyometrics
Sets: 3-4

Reps: 8-12 in strength training and 20-40 seconds in max effort exercises. In my classes I will have many of my female do 12-15 because many are afraid to go heavy on weight.  If they are using a good, heavy weight then 8-12 is the rep range I will have them work.

Rest: Short rest between sets (two minutes or less); for a partial recovery between efforts.

Frequency: Twice a week per muscle group or area of the body trained.

Glycolytic athletes specialize in activities lasting 30 seconds to two minutes or so. They’re fast and seemingly tireless — though perhaps not quite as strong as the ATP-CP athlete, nor as enduring as the oxidative athlete — and they tend to be muscular and lean. This type of training is ideal for burning fat (in recovery/when you’re not working out) and building muscle mass.

Training Your Oxidative System
How to Train It: Light circuit training; running five minutes or more; long-distance cycling; traditional cardio machines; long, slow swimming.
Sets: 3-6 sets

Reps: 3-5 minute intervals (medium intensity)

Rest: 3-5 min rest in between sets


Sets: 1-3 sets

Reps: 8-20 minute intervals (medium intensity)

Rest: 5-10 min rest in between sets

Frequency: One to three times a week

Although it’s last to kick in, the oxidative system is the most important energy system of all. If it doesn’t work, neither do you. Oxidative athletes are typically leaner and lighter than the other two athletic types. They can go on forever at a slow-to-medium pace, burning mostly fat — the ultimate high-efficiency, slow-burning fuel. Oxidative training is essential for endurance sports, but all athletes should train this system. Done in moderation, oxidative training is also great for helping you recover from other, more intense forms of exercise.

Training all three systems is extremely important, but it’s been proven that training the first two systems will automatically strengthen the third (oxidative) system; meaning it is highly at work when you are recovering from those high-intense training sessions. There are numerous studies showing that people who only train their oxidative system with long bouts of cardio are actually harming their body. So do some mental pep talking and prepare to work HARD for shorter bouts of max effort intensity. Make it easy on yourself and sign up for the figureFIT! Lifestyle Program. Every month Liz creates 3 different workouts that you will do over the course of the month. These workouts incorporate all the different techniques listed above, they are tough but over the course of the month you will work up to getting the entire workout done. Beginners start slow. Advanced athletes simply add more weight to make the workouts tougher. 

It’s important for you to train at your level and give yourself time to increase your metabolic capacity. Don’t overdo it, set a goal to train each system at least once per week in the beginning and then increase your training sessions each week until you are at a max training schedule. The body is amazing and will respond SO FAST to this type of training regimen.



Liz Nierzwicki, BS, ACSM-CPT, E-RYT 

I'm an entrepreneur and one of my missions is to help people find their inner peace and cultivate balance between life, spirituality, and perfect health. I'm the founder of Solace Yoga Studio and creator of the online figureFIT! Lifestyle Program ( At any given time, I have about 7-8 balls in the air, I'm a visionary and entrepreneur and have turned the things I'm passionate about into my career. I am a single mom (by choice), experienced yoga teacher and Director of Solace Yoga School's 200-Hour yoga teacher training program, expert personal trainer, author, and transformation coach to many clients all over the globe via my online figureFIT! Lifestyle Program. One of my favorite things to help people with is - balance - as a single mom and multi-business owner, I have learned how to balance my time between work, keeping a level head, staying fit, family, reading, traveling, and that is what I want to help you achieve. Much of my own success was due to getting my mind right, knowing my purpose, and what my mission is on this planet and THAT is another thing I help clients with. 

To truly transform your life and break your bad habits while learning new healthy habits, sign up for my figureFIT! Lifestyle Program to change your lifestyle and develop a healthy life based on the science of the psychology of change, nutrition, physical training & energy system training via my workouts, and meditations to help you etch in stone this new lifestyle. It's time to create your best self. Also, I invite you to sign up for my newsletter. It’s only via my newsletter where you will receive exclusive video blogs, podcasts, workouts, yoga videos, and meditation audios; in addition, announcements of my upcoming books, seminars, and global retreats.

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