Heart Rate Training: Discover the Different Energy Zones

All Posts

Heart Rate Training: Discover the Different Energy Zones

By: Heidi Harris, RD-N, CD-N, LD-N

What you’ll learn: In this blog, we will discuss the different heart rate zones, dive into the percentages of maximum heart rate and what type of nutritional support you can provide your body to help optimize your next heart rate training session.

How fast and how efficient your heart beats while you participate in different physical activity greatly affects your energy output and performance. In fact, many athletes specifically practice in different heart rate training zones to help hone their performance based on the demand of the training.

Heart rate training zones are ranges of heart rates that correspond to different intensity levels of exercise. Athletes use heart rate training zones to help maximize the benefits of each zone which include burning fat, improving endurance or even increasing speed. To really be able to accurately heart rate train, you need to know your resting heart rate, or your baseline heart rate and also your maximum heart rate. So, let’s get going and jump into heart rate training.1

What is Resting Heart Rate?

Whether you’re an athlete or not, we all have what’s called a resting heart rate. This is a baseline heart rate when you’re not expanding any energy output. We all also have what’s called a maximum heart rate. Heart rate training falls within these two values and correspond to training intensity and work output. In most cases, heart rate zones can be defined as percentages of your maximum heart rate.1

Heart rate zones are closely linked to your aerobic and anaerobic thresholds. We talked about threshold training in another blog. To learn more about identifying your personal threshold, check out our threshold training blog here.1‡

What is Heart Rate Training?

As I mentioned earlier, heart rate training is based on percentages of your maximum heart rate. Your maximum heart rate (Mhr) is the highest heart rate an individual can achieve. The ultimate goal of heart rate training is to improve cardiovascular fitness. There are five heart rate training zones that are unique to you and as you increase your pace, cadence and overall workload, you increase the demand of your heart and your heart will struggle to keep up – shifting you into a different heart rate training zone.1,2

The Low-Intensity Zone:

This is known as Zone 1. In this Zone you’re exercising at 50-60% of your maximum heart rate. At this intensity zone, you’re primarily using fat for fuel and you’re feeling able to sustain this type of exercise and heart rate training for the longest amount of time. Think of a brisk walk or a gentle jog – that’s what Zone 1 of heart rate training feels like.2

The Temperate Zone:

This is known as Zone 2. In this Zone, you’re exercising at 60-70% of your maximum heart rate. Zone 2 requires a little more intensity than Zone 1, but fat remains the primary source of fuel in this zone. Imagine, your gentle jog turned into a quickened run and you’re starting to breathe a little heavier. This is still manageable and you’re feeling good, but you can feel your body transitioning to a different energy zone, that’s Zone 2.2

The Aerobic Zone:

When you think of the word “aerobic,” think of the word “oxygen.” Your body uses oxygen in these zones to help create the energy molecule, ATP (adenosine-tri-phosphate) which your body then uses for metabolic activity that requires energy – that’s a lot. The aerobic zone encompasses 70-80% of your maximum heart rate and your intensity here is moderate.2,3

Zones 1 through Zone 3 include very light to moderate intensity this is where many distance athletes train. I’m looking at you long distance runners, cyclers and swimmers. This is a type of endurance training. The goal in these heart rate training zones is quite simple: How long can you last?1

Looking for something to help support that endurance training? Our Klean Endurance contains pure D-ribose to support the natural production of ATP. D-ribose is used to make ATP as it’s naturally part of ATP’s structure.4 Supplemental D-ribose may bypass the traditional pathway of generating ATP via purine metabolism, which occurs in the mitochondria. This process is more efficient, as it enables cells to efficiently reuse ATP metabolites to form new ATP molecules.4 Plus, supplemental D-ribose has been shown to support tissue energy repletion and improve recovery and performance in humans.5 This type of supplement may be helpful to have in your corner to help you up your distance game. Even distance athletes practice in Zones 4 and 5 of heart rate training to help up their speed and performance. Let’s look at why.

Zone 4: Hard Effort

In this Zone, you can feel your body change over from aerobic exercise to anaerobic exercise. This means that in this zone your body stops using fat for fuel and reliance on oxygen to generate ATP via mitochondrial pathways and transitions to using glycogen, the storage form of glucose, and generates ATP without relying on oxygen.6

In Zone 4, you are at 80-90% of your maximum heart rate. This zone is reserved for quick explosions of energy. If you’re in an all out sprint, sucking down air and can’t wait to reach the finish line – you know you’re in Zone 4.1

Zone 4 isn’t meant to last for a long time. Rather, it’s a great one to practice increasing your speed and performance. Many distance athletes will choose to practice sprints to help quicken their pace and improve their strides. Practicing in different heart rate training zones help support optimal performance no matter what area of exercise you focus in, running, swimming, weightlifting and even boxing.1

Remember, as with any type of exercise, you may start to deplete your electrolyte stores through exhaling, sweat and overall usage to help generate energy. Our Klean Electrolytes replenishes important minerals in the body during or after exercise. The loss of sodium, potassium, chloride, calcium and magnesium may lead to fatigue, dehydration and muscle cramps. Not to mention, our Klean Electrolytes make it easy to customize the dosage to meet individual training and performance needs.

Zone 5: Maximum Effort

Welcome to your ultimate anaerobic zone where your cardiorespiratory system works at maximum capacity. This means, that your heart is working at 90-100% of your maximum heart rate. This zone is meant for short bursts of intense energy output – think powerlifting – that right there is Zone 5. In this zone, lactate builds up in your blood faster than it can be removed, which is part of the reason why this zone is unsustainable for longer periods of time.1

This is the zone where our Klean Creatine may come in handy. If you’re an athlete that takes part in a sport with repetitive bursts of intense energy and muscle power, creatine has been studied to help increase body strength, build muscle mass and recover from the strenuous exercise Zone 5 requires.7‡

Nutrition for Training

There are a few different ways to help fuel before your workout. A few tips to keep in mind include eating about 2 hours before you exercise. Choose foods such as healthy carbohydrates including whole grain cereals, whole wheat toast, yogurts, whole grain pasta, rice, fruits and vegetables. Remember to hydrate before, during and after exercising and when you’ve finished your training, healthy lean proteins are a great option to help repair and grow your muscle mass.8

If you only have 5-10 minutes before you exercise, choose a piece of fruit such as an apple or banana. These are a great choice because they are easily digested and can quickly be used as a source of energy to help limit the potential for feeling sluggish during your workout.8

Looking for a little help on the post-workout protein front? Klean Athlete offers a variety of different Klean Isolate protein powders from flavorless to chocolate, vanilla and even strawberry. Whatever flavor you’re in the mood for, Klean Athlete has you covered!

The Final Zone

Now you’re familiar with the different heart rate energy zones. In addition, you’re aware of the different types of nutrients that may help support these energy zones and your overall training to optimize your peak performance. Not to mention, Klean Athlete offers a wide variety of NSF certified for Sport products all available at your fingertips. Which products will you try next?


  1. Running heart rate zones | The basics. (2016, April 19). Polar Blog. https://www.polar.com/blog/running-heart-rate-zones-basics/
  2. Cleveland Clinic. (2021, May 12). Exercise Heart Rate Zones Explained. Health Essentials from Cleveland Clinic. https://health.clevelandclinic.org/exercise-heart-rate-zones-explained/
  3. Jäger et al. Journal of the International Society of Sports Nutrition 2014, 11:28
  4. Wagner S, Herrick J, Shecterle LM, St Cyr JA. Prog Cardiovasc Nurs. 2009 Jun;24(2):59-60.
  5. Seifert JG, Brumet A, St Cyr JA. J Int Soc Sports Nutr. 2017 Dec 20;14:47
  6. Chamari, K., & Padulo, J. (2015). “Aerobic” and “Anaerobic” terms used in exercise physiology: a critical terminology reflection. Sports Medicine – Open1(1). https://doi.org/10.1186/s40798-015-0012-1
  7. Williams MH, Branch JD. J Am Coll Nutr. 1998 Jun;17(3):216-34.
  8. Food as Fuel Before, During and After Workouts. (n.d.). Www.heart.org. https://www.heart.org

If you currently have an account on shop.kleanathlete.com, click here to browse & place your order.

Add a Comment

Your email address will not be published.

* Required