How to Add More Cardio in Your Workout (It's Not Just About Running)

An airman rides his bicycle to work as part of his cardio program.
Master Sgt. Benjamin “Paul” Horton, 21st Civil Engineer Squadron explosive ordnance disposal program manager, cycles to work as part of his cardio program while working out at the academy. (Airman Rose Gudex/U.S. Air Force photo)

There are typically three types of people within the large variety of fitness genres -- those who love cardio, those who tolerate it and those who do everything they can to avoid it.

For the most part, cardio activity has gotten a bad rap because many confuse "cardio" with long, slow, distance running (or other) events. However, basically everything is "cardio" if you consider that to make the energy we need to lift, run, swim and even live, our bodies must breathe. There is a large variety of cardio activities we should consider in order to receive the health and performance benefits from this often-maligned activity.

If you avoid "too much cardio" so you do not want to "lose your gains," you should ask yourself these questions:

  1. How do you get your heart/lung activity? Purely anaerobic activity? High intensity interval training? This is a form of cardio that operates on a different energy system, but that is fine. It is still cardio but not a relaxing form of cardio activity, which has many benefits for long-term health.
  2. Are you avoiding the impact of running? Consider non-impact cardio events (bike, elliptical, rowing, swimming). Many people avoid cardio just because they hate running or cannot run due to weight issues or joint impact problems with previous injuries. That is fine. There are plenty of activities that can yield the same benefits below and avoid the impact of running.

Benefits of steady and lower heart-rate cardio

It is understandable if you avoid cardio because you are a "hard gainer" and have had to focus on increased calories and lifting weights in order to put on mass. However, a run or short 15- to 20-minute cardio activity is literally only 150-200 calories burned, depending on the intensity of the activity. You can make that up with a Power Bar or half a protein shake after training and actually gain some of the heart, lung and stress-busting benefits of steady state/lower heart-rate cardio activity. Here is a list of benefits that easy or steady-state cardio can give you:

  1. Easy recovery tool: It is easy to do. Great for beginners, but also a great recovery tool day as back-to-back-to-back HIIT (high intensity interval training) days require some time in between. Breathe deep, inhale/exhale and engage the parasympathetic nervous system for a change. See mobility day, too.
  2. Builds endurance: It is great to push hard in workouts, but how about pushing hard in workouts for longer? Working the aerobic system regularly will help you do that and engage that inner cardio animal in you.
  3. End of workout recovery: Conclude your workout with a steady cardio event like jogging or -- even better for the joints -- non-impact cardio like biking, swimming, rowing or elliptical. You will notice the recovery effect. You can cool down and start the recovery process for the next workout with a quick dose of easy cardio.

Also, having days between high-intensity training is good if you want more of the long-term health benefits below:

  • Provides a steady calorie burn
  • Metabolizes fat as primary energy sources (see energy systems below)
  • Promotes a healthy heart and lungs (circulatory system)
  • Promotes brain function (focus, productivity, creativity)
  • Relieves anxiety, depression and generally reduces stress
  • Helps battle long-term stress symptoms like heart attack, stroke, diabetes, etc.

Do you do mostly long-distance running, swimming or another activity (one- to two-hour workouts)? If you are nearly entirely focused on only aerobic activity, you, too, need to diversify your training and add in more resistance training to work the body's other energy systems. Plus, the benefits of resistance training will help you build strong bones and muscles so you can continue your love for pure cardio activities longer and be more durable for unforeseen challenges and falls.

Cardio comes in all types of packages

When you think of the varieties of exercise activities, they all involve some form of "cardio" -- either aerobic or anaerobic activity. Think about the way the body burns energy -- using the three energy systems and the types of activity associated with all three:

  • Phosphagen system: During high-intensity speed, agility and powerlifting-type events, much energy is required quickly. This is HIIT training at its toughest and will wipe you out very quickly. The fastest way our body makes this energy is from stored creatine phosphate in the muscle to build what all systems use as energy: ATP (adenosine triphosphate). This process is done without oxygen and is considered an anaerobic process. This type of working out requires intense and short bursts of energy, combined with a rest and recovery period between bouts.
  • Glycogen system (glycolysis): This is the quick energy/go-to fuel that is used from our current levels of blood sugar and stored glycogen in our muscles and liver. This is also an anaerobic process that does not require oxygen to make energy. The byproduct of using glycolysis is lactic acid, or lactate. The better you get at faster running, strength training and higher intensity interval training, the more efficiently your body is able to buffer this lactate and you build a more endurance-strength body. This system typically is used for all activities lasting from 30 seconds to two minutes, followed by short recovery periods. ATP is made quickly in this process, too.
  • Aerobic system: This is where lots of energy comes from, but it takes longer to create, making it ideal for longer duration cardiovascular events (running, swimming, biking, rucking, etc.). This process includes the Krebs cycle and the electron transport chain (see video link below). But in easier terms to understand, this process breaks down blood sugar, glycogen and fat stores to make ATP within the muscle cells. If you are a highly conditioned cardio athlete, you will perform at fast levels but at a low heart rate, enabling the aerobic/fat burning system to operate effectively for you. 

The food that we eat and the fat in our bodies are the primary fuel sources for all activities in our bodies, but all forms of exercise have to transform this food or stored fat/glycogen into usable fuel through a complex physiological process known as the Krebs Cycle and Glycolysis/Electron Transfer Chain -- The goal being ATP Resynthesis. (see fun reference video and biology lesson for more details).

Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to

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