Aerobic System Development for the Fitness Athlete

I’m really excited this week to have Josh Jeffery of Carolina Performance Training join us to discuss the need for fitness athletes to develop their aerobic energy system. This is often skipped over in the fitness world but greater aerobic fitness will improve performance greatly. Josh does a fantastic job sharing the need to develop aerobic fitness, the limiters of the aerobic system, and how he programs aerobic work at VertexPT.

In need of an Aerobic Capacity building program? We’ve got you covered with our Aerobic Capacity Running program that has helped hundreds of athletes build their aerobic base!

Aerobic Capacity For the Fitness Athlete

  • What is the Aerobic Energy System?

    • Our body’s way of utilizing oxygen to generate ATP (energy)
    • The aerobic system is responsible for long term energy production
    • Supports anaerobic metabolism – a better developed aerobic system will flush out the metabolic byproducts of anaerobic metabolism
  • Why Developing the Aerobic System is Important for CrossFit athletes

    • CrossFit uses all energy systems to various degrees
    • Typical CrossFit workouts have repeated bouts of high-intensity exercise and developing the aerobic system will help with quicker recovery between bouts and sustain bouts for a longer duration
    • Increase anaerobic threshold which will allow athletes to work out at higher intensities before producing the metabolic byproducts of the anaerobic system
  • What are the Limiters of the Aerobic System?

    • Oxygen supply and delivery
    • More oxygen uptake from the blood into the working tissue
    • Substrate/enzyme availability
  • Protocols to Improve These Limiters

    • Long slow distance (>30 minutes)
      • Via one mode (ex: long-distance run) or multi-modal (combining carries with rowing for long duration for example)
      • Heart rate 120-130 beats per minute (will vary by individual)
    • High-intensity intervals
    • Threshold training 3-10 minutes right at anaerobic threshold or slightly below, then rest and repeat. With focus on learning where your anaerobic threshold is and staying below, it NOT kicking into anaerobic metabolism
    • Resistance training with high time under tension


Be sure to follow Josh Jeffery and Carolina Performance Training. Josh does weekly talks on his Instagram covering topic such as this one that is incredibly valuable for any coach or athlete wanting to improve their fitness. He also does group and custom exercise programming that is as good as anyone’s programming you’ll find!