Zone 2 Heart Rate Training For Longevity and Performance
Zone 2 training! You may have heard of it and wondered what is zone 2 training, what are training zones, how many heart rate zones there are, what are the significant benefits and lastly, how you can incorporate it into your exercise regimen and training program?
In this blog, we will dive into the basics of zone 2 training!
Quick Tip: Hop on a bike or a treadmill and read this blog while you do some zone 2 training!
What is Zone 2 Training?
To begin, zone training is based on your heart rate.
Typically there are 5 Heart Rate Zones. Zone 1 is considered to be the easiest low hr training with minimal effort. Most likely the zone you are in currently (unless you are reading this while doing zone 2 training) and Zone 5 is you doing an all-out sprint which lasts around 15-30 seconds, typically during high intensity training.
Each of the heart rate zones differs because they rely on different energy systems to different extents, depending on exercise intensities.
Zone 2 is harder than zone 1 however; still under your aerobic threshold. This means that you are still able to use oxygen to fuel your activity and therefore rely primarily utilize fat for fuel. Furthermore, this means your lactate accumulation is still relatively low. In terms of HR, your HR is around 60-70% HRMax.
Zone 3 would be above your first lactate threshold, meaning lactate is accumulating faster than removed and will slowly start to build up. This will affect the body’s physiology.
What are the 5 Zones?
Zone 1: 50-60% of maximum heart rate. This zone relies on burning fats for fuel and uses oxygen
Zone 2: 60-70% of maximum heart rate. This zone relies primarily on fats for its energy source and uses oxygen. This is considered to be your endurance zone.
Zone 3: 70-80% of maximum heart rate. This is the zone where fats start to decrease as an energy source and carbohydrates start to increase as an energy source
Zone 4: 80-90% of maximum heart rate. This zone uses mainly carbohydrates as an energy source
Zone 5: 90-100% of maximum heart rate. This zone will use carbohydrates as an energy source and some stored PCr (phospho-creatine)
Why is Zone 2 training important?
During zone 2 training the body is primarily using Type I muscle fibres. Type I muscle fibres compared with type 2 fast twitch fibres have lots of mitochondria and prefer fats as their fuel source. Type 2 muscle fibres are more glycolytic and prefer glucose.
Glucose is used much quicker and is the preferred fuel source as exercise intensity increases. At lower intensities, such as heart rate zone 2 fats and type I muscle fibres are preferred. The good thing about this is that lactate which is a byproduct of using glucose as fuel is not being accumulated.
By training in heart rate zone 2, you can change your physiology to adapt to higher training intensities over time, so that fats are used as fuel for longer and lactate accumulation is spared.
With training, if you can use fats at higher intensities you can conserve glycogen and glucose for longer and will be able to sustain a higher exercise intensity for longer durations.
The effects of Zone 2 training on metabolic health
One interesting fact is that training in Zone 2 will help improve Zone 3/4/5, however, training in Zone 4 doesn’t seem to improve Zone 2 to the same degree.
Zone 2 training has many metabolic adaptations, including but not limited to an improvement in mitochondrial number, mitochondrial function, metabolic flexibility (ability to use different fuels to produce energy) and metabolic efficiency (use different substrates – glucose, lactate, fat).
Metabolic inflexibility is the body not being able to use fat as energy and use glucose which is correlated with several different health outcomes. The mitochondria are the powerhouse of our cells and the location where food energy gets transferred into chemical energy for our bodies to do work aka live, function, move etc.
Zone 2 training increases the number of mitochondria and therefore can increase the body’s capacity to create ATP (the energy currency in the body).
Furthermore, zone 2 training has been shown to lower resting heart rate, decrease BP, and improve insulin resistance. Since the body is better able to use glucose for energy in the muscles, this improves the body’s response to carbohydrates and improves insulin production.
To improve one’s cardiovascular health and reduce their risk of developing heart disease, it is essential to partake in zone 2 training, where you are working at the same pace, burning fat, and increasing your aerobic capacity.
Performance Benefits of Zone 2 Training
As mentioned above, there are numerous benefits of zone 2 training. In addition, there are a number of athletic performance benefits. Whether you are elite athletes, an endurance athlete, or looking to build more skeletal muscle, zone 2 training should be included in your training program.
Building up one’s aerobic fitness and aerobic base will in turn improve performance during intense exercise. With an increase in your aerobic base, you can sustain a higher training zone, without burning glucose, relying on fat oxidation, maintaining a steady pace and having a decreased perceived exertion. With this improved capacity your cardiovascular system will be stronger and your overall health will improve.
It also improves substrate utilization. Essentially the body will be able to burn fat at higher-intensity sessions. In addition, training in Zone 2 will improve your recovery. The body is able to flush out lactic acid that is accumulated during your training sessions, resulting in less DOMS (delayed onset muscle soreness). This can allow you to train again sooner and push further in subsequent training sessions.
Overall, zone 2 training can improve your athletic performance, endurance, your resilience to increasing load, decrease your risk of injury and improve longevity.
Methods to calculate your training Zone 2 heart rate
In the past, 220- age was the formula used to measure max hr, however, there is a new more accurate formula used to date. 208 – (0.7 x age) would be the recommended formula to use to predict your max heart rate.
From there would would want to multiply your predicted max HR by 60-70% to get an HR range. From there you can calculate your different training zone.
For example, if you are 30. 208 – (0.7×30) = 187 (predicted HR max)
60-70% of that would be 112-131 bpm
How do you know when you are in Zone 2 training?
A good way to know if you are in training zone 2 is if you can breathe in and out of your nose or if you can have a small conversation with someone, also known as the talk test. Zone 2 training is harder than just sitting or going for a leisure walk, however, the intensity is not extreme and you need to take big breaths from your mouth all the time.
Using the RPE scale (rate of perceived exertion), if 1 is really low and 10 is an all-out sprint, zone 2 training would fall around 3/10.
How often should you do zone 2 training per week?
Some professionals recommend that 70-90% of an endurance athletes training should be in zone 2.
Start with once a week and slowly add on a few more sessions. You can go for a fast-paced walk, walk up hills, or walk with a weighted vest on, you can also swim go for a bike ride or use a rower at the gym. The mode of training doesn’t matter, the more important aspect is keeping your HR under zone 3 and above zone 1.
With time you will notice you can go a little harder, faster, or add more resistance without your HR increasing. This will be a sign that you can work at a higher exercise intensity while still maintaining a zone 2 heart rate.
How long should a zone 2 training workout be?
I would recommend starting small, going at a slow pace, keeping the same pace for around 20 minutes and then working your way up in 10-20-minute increments. Training consistently, you will be able to sustain 30-180 minutes a few times a week.
Please Avoid Overtraining
Remember to have fun with it, put on a podcast, do some movement meditation or chat with a friend!
Article to read for more information
Polarized training for everyday runners
Other Athletes Kitchen Blogs to Reference
Power of Sleep by Athletes Kitchen