Is “boring” is the first word you’d use to describe your cardio workouts? Do you stare at the clock, counting down every second and willing it to tick faster?

If so, it’s time to shift gears and turbocharge your cardio routine. Struggling through a 30 minute elliptical session while trying to distract yourself with The Office is not the only way! We have three cardiovascular energy systems and each are trained in different ways. By mastering and training each of these systems, you'll rapidly improve your fitness and make your workouts more engaging.

It's time to work smarter, not harder, and make faster cardio progress.

Understanding The Three Cardiovascular Energy Systems

We have three primary energy systems that we use for cardio.

1. Phosphagen System (ATP-PCr System)

2. Glycolytic System (Anaerobic System)

3. Oxidative System (Aerobic System)

Here’s a great visual of these three systems:

We use a combination of these three systems for every activity. But each system is used primarily for different lengths of time:

1. Phosphagen System (ATP-PCr System) - 10 seconds or less

2. Glycolytic System (Anaerobic System) - 60 - 120 seconds

3. Oxidative System (Aerobic System) - > 120 seconds
   

Here’s a bit more on each system.

A. Phosphagen System (ATP-PCr System)

How It Works: Think of this system as your body's instant fuel reserve. It kicks in during short bursts of intense activity, like sprinting or lifting heavy weights. When you need a sudden burst of power, the phosphagen system delivers by breaking down stored ATP (adenosine triphosphate) and PCr (phosphocreatine) for rapid energy release.

Role in Short Bursts: Picture a sprinter exploding off the blocks or a power lifter hoisting a heavy barbell. These feats rely on the phosphagen system for that initial surge of energy. It's like a turbo boost for your muscles, allowing you to go all out for brief (< 10 seconds) but intense efforts.

B. Glycolytic System (Anaerobic System)

How It Works: When your activity demands more sustained power, but still falls short of endurance levels, the glycolytic system steps up. It converts stored glycogen (carbohydrates) into glucose, fueling your muscles with quick bursts of energy. This system operates without oxygen, making it ideal for activities like high-intensity interval training (HIIT) or weightlifting.

Role in Moderate to High Intensity: Ever felt that burn during a set of burpees or a fast-paced circuit? That's the glycolytic system hard at work, churning out energy to keep your muscles firing on all cylinders. It's like a rapid-fire energy factory, producing fuel for short to moderate (10 seconds-120 seconds) bursts of intense effort.

C. Oxidative System (Aerobic System)

How It Works: For sustained activities lasting longer than a few minutes, your body relies on the oxidative system. This powerhouse burns carbohydrates and fats in the presence of oxygen to produce energy. Whether you're jogging, cycling, or swimming laps, the oxidative system ensures a steady supply of fuel to keep you going.

Significance During Longer Activities: Consider a long hike through rugged terrain or a leisurely bike ride through the countryside. These endeavors tap into the oxidative system, which excels at providing endurance and stamina. It's like a slow-burning furnace, sustaining your efforts over extended periods with a steady supply of energy.

Benefits Of Training Each Energy System

1. Improved Performance

A balanced approach fine-tunes your engine for peak performance in every aspect of your life.

• A stronger phosphagen system means explosive speed

• A well-trained glycolytic system leads to better muscular endurance

• An optimized oxidative system translates to increased stamina over the long term.
  
  
  

2. Better Cardiovascular Health

Regular cardio training not only strengthens your heart but also improves blood circulation, reducing the risk of heart disease and stroke. Each energy system contributes to this by enhancing your body's efficiency in delivering oxygen and nutrients to working muscles.

3. Improved Metabolism

The metabolic benefits of cardio workouts extend beyond the gym, helping you burn calories and maintain a healthy weight.

4. Supports Overall Well-being

Beyond the physical benefits, cardio training has a profound impact on mental health. It releases endorphins, the body's natural feel-good chemicals, reducing stress, anxiety, and depression.

Sample Cardio Workouts For Each Energy System

A. Phosphagen System Workouts

• 10 seconds on, 110 seconds off x8-12 rounds

  • Intensity: Aim for 85-100% of your maximum power output during the 10-second bursts.

  • Example Exercises: Hill sprints, cycling, medicine ball slams, or rowing

• 3 reps, 90 second rest x6-10 rounds

  • Intensity: Keep the intensity high, aiming for max power for each rep.

  • Example Exercises: 3 rep back squat, deadlift, or power clean repeats.

B. Glycolytic System Workouts

• 20 seconds of maximum effort followed by 10 seconds of rest x8 rounds (Tabata)

  • Intensity: Push yourself to the max during the 20-second work intervals.

  • Example Exercises: Jump lunges, mountain climbers, or battle ropes.

• AMRAP (As Many Rounds As Possible):

  • Intensity: Choose 3-5 exercises and perform each for 15 reps, aiming to complete as many rounds as possible in 10 minutes. Maintain a fast pace throughout the workout, with minimal rest between exercises.

  • Example Exercises: Kettlebell swings, lunges, rows, and overhead press.

• 30 seconds of maximum effort followed by 30 seconds of rest:

  • Intensity: Maintain 80-90% max power for 30 seconds.

  • Example Exercises: Cycling, running, rowing

C. Oxidative System Workouts

• Steady-State Cardio:

  • Intensity: Maintain a pace that allows you to breathe comfortably and sustain the activity for 30-60 minutes. You should be able to say a full sentence without gasping for air, but you shouldn’t be able to comfortably read a Shakespeare sonnet.

  • Example: A 45-minute fast walk/jog around your neighborhood or a 60-minute bike ride.

• Interval Training - 6x4 min work/1 min rest at 60-70% max heart rate:

  • Intensity: Alternate between periods of moderate-intensity effort and rest.

  • Example Workout: Cycle for 4 minutes at a moderate pace, then rest for 1 minute. Repeat for 6-10 rounds

These sample workouts target each energy system, ensuring a well-rounded approach to cardio training that will maximize your aerobic fitness.

Wrap Up - If Nothing Else, Understanding These Energy Systems Will Keep Your Training Interesting 

By delving into the intricacies of the three cardiovascular energy systems, you've equipped yourself with the knowledge to optimize your cardio workouts. Training each energy system ensures a balanced approach to fitness, leading to improved performance, better health, and a stronger, more resilient body.

And if you don’t care about any of that stuff, and just want to stay in relatively good shape? It’s still helpful to know, because it will keep your training from getting stale.

You know that consistency is key to seeing results. Good luck staying consistent with 45 minute steady state sessions - over and over and over - for the next 50 years.

It’s mentally engaging to alternate between high, moderate, and low intensity sessions. It’s also a more productive way to train. If you commit to regular cardio training sessions that target all energy systems, your fitness levels will soar and your training will stay fresh.

Best,

John

P.S. Texas WR Xavier Worthy ran the fastest 40 yard dash in NFL Combine history last week.

Check out the difference in running form between him and the previous record holder. Athletic freaks continue to do freaky things, no matter their form, diet, coach, or anything else.

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