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Understanding Basic Cardiovascular Training

Cardiovascular training can seem complex and often misunderstood in the realm of fitness. Many individuals discover themselves training within a zone that fails to optimize their efforts, resulting in meager returns on their invested time and energy. In this article, we intend to illuminate the various types of cardiovascular training practiced at Zona Performance and help you grasp the reasons behind the integration of diverse forms of cardiovascular training into fitness programs. Before we delve into specifics, let’s begin by simplifying how the human body generates energy and exploring the confines of our energy systems.

Our body generates energy via different pathways based on the intensity of our physical activity. These pathways predominantly involve the combustion of fat, sugar, or stored energy, recognized as ATP. For brief, high-intensity bursts of movement lasting about 7 seconds, the body relies on the phosphocreatine system, which leverages the energy stored within cells. Recovering 70% of this stored energy takes approximately 90 seconds, with full recovery taking around 3-5 minutes. Muscles with explosive characteristics primarily depend on the phosphocreatine system.

In scenarios of more sustained and intense activities, such as completing a strenuous lap around the track, the body turns to sugar (glycogen) as a source of energy. This process is rapid, anaerobic (requiring no oxygen), but unsustainable over extended periods. It is referred to as glycolysis, producing 2 ATP molecules per cycle but also generating a significant quantity of byproducts, which ultimately constrain endurance.

The third energy system generates energy at a slower pace and necessitates oxygen for sustainability. This is the oxidative phosphorylation system, occurring within the mitochondria, often referred to as the cell’s powerhouse. Oxidative phosphorylation yields an impressive 36 ATP molecules per cycle, albeit at a slower rate.

Now, with a grasp of these three energy systems, it becomes evident that each demands distinct training approaches due to their unique characteristics regarding recovery, energy production, and byproducts.

Glycolytic Training:

Sustained high-intensity workouts primarily rely on the glycolytic energy system. As this system is engaged, cells become more acidic owing to the increased presence of byproducts like hydrogen ions. This acidity can hinder energy delivery and potentially reduce strength. The body instinctively seeks rest to restore pH levels and prepare for further high-intensity work. Extended rest periods facilitate more intense sustained efforts, whereas insufficient rest leads to diminished performance. Effective glycolytic function can be improved through interval training. The work-to-rest ratio depends on the muscle fibers targeted, with faster-twitch muscles typically requiring a 1:4 to 1:2 ratio, and fast-ish twitch and slower twitch muscles favoring a 1:1 to 3:1 ratio.

For example:

  • Training Faster Twitch Muscles:
  • Perform 6 rounds
  • Work intensely for 30 seconds in each round
  • Rest for 1 minute and 30 seconds between rounds
  • Training Slower Twitch Muscles:
  • Complete 10 rounds
  • Work for 45 seconds in each round
  • Rest for 15 seconds between rounds
Intervals to improve glycolytic fitness

Oxidative Phosphorylation:

Enhancing mitochondrial function holds significance for all athletes. Zone 2 training enhances mitochondrial performance, increases vascular density, and bolsters cardiovascular health. This form of training may incorporate short bursts of energy (polarization) to benefit the phosphocreatine energy system. These adaptations hold value for various training regimes, especially for activities demanding prolonged effort such as running, rowing, and swimming. Endurance athletes should refrain from exclusively focusing on sustained threshold workouts, as they provide an incomplete gauge of overall fitness.

For example:

  • Zone 2 Training may involve:
  • 45 minutes of work at 60-70% of maximum heart rate
  • 7-second bursts of energy at minutes 8, 16, 32, and 40, followed by a return to zone 2 pace
Zone 2 training performed on a stationary bike at 60-70% of heart rate max.

Phosphocreatine Training:

For targeting the phosphocreatine system, we employ highly intense intervals with a 1:5 work-to-rest ratio to overload cells with hydrogen ions. These intervals are exceptionally demanding and cater to individuals engaged in intense sprinting (e.g., 100 meters or less) and sports like CrossFit, running, or football.

For example:

  • Highly Intense Phosphocreatine Training:
  • Execute 6 rounds
  • Engage in 30 seconds of intense work in each round
  • Rest for 2 minutes and 30 seconds between rounds
  • Give your all in every set
Phosphocreatine Training
HR of an individual performing 5 rounds of: 1 minute max work, 5 minutes rest


In summary, an effective basic cardiovascular training program should incorporate exercises tailored to each energy system. By understanding these systems and adjusting your training accordingly, individuals can maximize their fitness gains and steer clear of the “no man’s land” of unproductive workouts. While proving to be an unsexy daily protocol, the results are eye turning. If you are looking to improve your cardiovascular training, schedule an appointment below.