Zone 1 Heart Rate Training

Characterized by very low intensity physical activity or exercise, zone 1 is the first zone that will be discussed in this series. Although most of our training falls above this zone, and we probably never intentionally train in it, we do engage in activities of daily living (ADL), such as household chores and minor landscaping, as well as specific components of training that are in this zone, whether we realize that or not. The time this zone is most utilized in training is during warm-ups and cool-downs. Although this zone may not seem as interesting as zone 2 or higher, it is essential to understand that it does have a role in increasing health and fitness.

First, how is zone 1 calculated? Using your maximum heart rate (see the first blog post in the series for discussions on finding maximum heart rate), multiply it by 0.5 and 0.6. This will give you zone 1 training range, which is 50-60% of your HRmax (heart rate maximum). For example, a 30-year-old, let’s say, in good cardiovascular shape and exercises regularly, may have a HRmax of 194 (this doesn’t equal 220 minus age on purpose, as this formula is a generic estimate and can vary depending on health and lifestyle factors). To calculate their zone 1, we take 194 x 0.5 = 97 and 194 x 0.6 = 116, so this individual's zone 1 should be between 97 and 116 beats per minute (BPM).

What is the purpose of this zone? As mentioned, this zone is typically used in warm-ups and cool-downs, but can also be used in very low-intensity skill work for a variety of sports. For running specifically, drills such as A skips, B skips, bounding, and other techniques can be used to develop stride, cadence, and form. This zone is also excellent for recovery and to remove waste products like lactate and carbon dioxide. This zone primarily trains the oxidative phosphorylation energy system. This system is the king for base building and endurance training. Although it does not work independently of the other metabolic pathways for energy, it produces the highest yield of ATP (Adenosine triphosphate). Still, it takes the longest process to make that ATP readily available for the cells and muscles to use for contractions (to produce work). We will discuss the metabolic pathway in further detail next week and will discuss the other pathways throughout the series. However, one vital point about this pathway is that it can only be trained in low to moderate intensity, because it requires oxygen, meaning aerobic, for the process to take place, for example, constantly training at high intensities or anaerobically (without oxygen utilization for energy, meaning oxidative phosphorylation cannot take place since it requires oxygen) will not lead to increased base building and increased endurance.

Key physiological adaptations that come from training in this zone are vital for overall health and specifically endurance. Since this zone primarily trains the oxidative phosphorylation pathway that leads to increased mitochondria in the cells and also an increase in capillary density, the location where nutrient exchange takes place (putting good stuff into the cells (oxygen and water) and taking waste products out (lactate and carbon dioxide)). This system is also essential in the utilization of fat for energy (training at lower intensities can increase the use of fat for energy rather than relying heavily on carbohydrates). All of these adaptations improve cardiovascular health and efficiency. 

So, is there a place for zone 1 training? Yes. Is it heavily used? Not. Should it be incorporated more? This depends on the specificity of training; however, incorporating training in this zone can be beneficial for dedicated skill work and active recovery sessions or days, such as very easy jogging, walks, or even moderate hiking. 

-       PRC Founder, William C. Howerton