The idea behind heart rate training is instead of training at a specific pace or perceived effort level, you train within specific heart rate ranges whereby each heart rate zone focuses on specific adaptations within the body. By taking the scientific approach to your training you can get the correct balance of intensities to maximise your fitness quickly, effectively and efficiently, without needless stress on your body.
To understand heart rate training, you must first understand the two main categories of energy systems (there are more but for simplicity we’ll focus on the two main ones), aerobic and anaerobic. For each system, your effort level, respiration, heart rate and fuel source differ.
Aerobic fitness, simply means ‘with oxygen.’ While training aerobically, breathing and heart rate can be maintained for a sustained period of time, for example; long distance running, cycling or swimming. During aerobic exercise, the primary fuel source is oxygen and the body's fat stores, of which even the leanest among us have infinite stores for exercise.
Anaerobic or ‘without oxygen’ activities involve shorter and more intense efforts. During anaerobic exercise, the body requires a more immediate fuel source. When it cannot get enough oxygen to fuel the work it switches to the more limited fuel, glycogen, a form of glucose that’s stored within the body. It’s worth noting that this isn’t an on/off switch. When working aerobically you will still be using some glycogen as fuel and when working anaerobically you will still be using oxygen and fat as a fuel. Both systems can work at the same time on more of a sliding scale. Only when working at maximum effort for around two minutes could someone be 100% anaerobic.
The graph below shows the results of a VO2 max test. During the test, the participant’s levels of oxygen usage and heart rate are recorded through increasing levels of intensity over time. The test is able to identify the exact intensities at which the body switches between the different types of energy systems from aerobic to anaerobic.
Once the aerobic and anaerobic thresholds plus the peak heart rate and VO2 max are identified, you are then able to map out the heart rate ranges in which to apply unique zones to your workouts. These zones are specifically designed to improve each area of fitness, including your Aerobic Threshold, Anaerobic Threshold and VO2 Max.
Most text book theories or apps and gadgets will just take a guess at either the anaerobic threshold or peak heart rate and then divide ones zones up into even blocks. Unfortunately that just isn’t the way the body works. The width of each zone can vary greatly depending on the condition of each athlete.
HR Zone: Moderate
Training: Long & Steady
Sustainable Workout time: 1-3 hours, however, this really depends on your fitness, endurance athletes can hold this intensity for many hours non-stop.
By exercising in the moderate zone, you will increase endurance and improve overall aerobic fitness. This intensity should make up the bulk of a training plan and builds a ‘base’ fitness to then add higher intensity work onto.
HR Zone: High
Training: Tempo/Threshold - Long Intervals or one hard effort e.g. 10 minute intervals or a 5km hard effort.
Once you have a solid base fitness adding higher intensity work at or above your anaerobic threshold can improve stamina and sustained pace.
HR Zone: Peak
Training: Short intense intervals
Sustainable Workout time: 30 seconds - 6-8 mins per interval depending on fitness.
VO2 max intervals look to further grow your aerobic engine by working at your maximum level of oxygen uptake.
If you’re serious about training and achieving your best results, we highly recommend taking a VO2 Max test to discover your heart rate zones and create a specific training plan tailored to you. Below is a link to our endurance coaching specialists friends, Enduraprep, where you can book in a test and have a personalised training plan developed.
