Understanding heart rate training zones

Aaron Volkoff

This article will help you understand what is heart rate zone training, and how to incorporate it into your training plan. During any form of physical activity, as your muscles work, the cells will utilize energy in the form of free fatty acids (fat) or glycogen (carbohydrates) and oxygen to produce ATP. ATP is the energy currency of all cells in the body and is necessary for muscular contractions (1). As the intensity increases, the amount of energy and oxygen needed to maintain that level of exercise will increase. We will start breathing more frequently and deeply to gain more oxygen to fuel the breakdown of these molecules to form the energy. At low intensity exercise, most people will utilize fat as the primary energy source. This is a benefit because fat provides an ample amount of energy and the waste products are only carbon dioxide and water. (2) (Yes, we produce our own water, but at a very low rate). All of us have an ample amount of energy from our fat stores in our body. For example, if a person is 200 lbs. @ 15% body fat, they will have 30 lbs. of fat, which is somewhere around available 105,000 calories. In comparison, the same person, may have only up to 2,000 calories of stored glycogen (carbohydrates).

As our exercise intensity increases, so does our utilization of carbohydrates. This is because fat metabolism is a slow process and will not provide energy at a fast enough rate. If the exercise intensity is low enough the glycogen will be fully metabolized using oxygen, this is called aerobic metabolism, but is still a slow process. As exercise intensity continues to increase, eventually, we will start to produce energy both aerobically and anaerobically, or without oxygen. Anaerobic metabolism occurs at a much faster rate (3). The consequence with anaerobic metabolism is the production of hydrogen ions. Excess hydrogen ions causes our bodies to become acidic. Acidic conditions cause the enzymes in the body to not work as efficiently and also cause us to feel “the burn”. Coincidently, as this happens, so does the production of lactate. Eventually the cells produce more lactate than can be metabolized and the excess lactate ends up in the blood stream. This is called the lactate threshold (4). To clear things up, lactate is a usable energy source by the muscles, and other cells. It is not evil. During this entire process our heart rate continues to increase and so does our breathing. Eventually, we will reach a point where we are using as much oxygen as possible, this is called VO2Max, or the maximum amount of oxygen utilized.

TRAINING ZONES

There are two main methods of determining a person’s heart rate zones. The most common method uses a person’s maximum heart rate and historical data based off of other people to determine the zones. This is a best guess method and has about 33% accuracy. For the other 2/3’s of the people, the estimate is either too low or too high. Nowadays, smart watches and apps will do their best to guesstimate your training zones based off of your recorded workout metrics. In my experience, VO2max estimates from watches and apps are very inaccurate to the point of being useless. While there is some personalization, these systems are not much more accurate (5).

The second and only accurate method of determining training zones is by measuring oxygen utilization, called VO2 max, where oxygen utilization and carbon dioxide production is measured. As described in the introduction as intensity increases so does oxygen utilization and carbon dioxide production.

There are several different ways to categorize your training zones but In reality, there are only 4 training zones. Training zones are created based around a person’s aerobic (AeT) and anaerobic threshold(AT) or indirectly lactate threshold (LT). Zone 1 (low/blue) is the easiest zone where you are not breathing much faster or harder. This is often referred to as your recovery zone. Work in zone 2 (moderate/green) is still easy, but your breathing will increase in rate and depth. This would be a conversational pace and can be sustained indefinitely. The high end of this zone will be at your aerobic threshold (Aet). Zone 3 (hard/yellow) goes from the aerobic threshold to the anaerobic threshold. As intensity increases throughout this zone the blood will become more acidic until the anaerobic or lactate threshold is reached (6). This zone can be sustained for 20-60 minutes, depending on a person’s ability. Above the lactate threshold is zone 4 (Peak/red). While training in this zone, you will be riding the “pain train:. Training is this zone usually only lasts for a few minutes.

HEART RATE ZONE VARIABILITY

Heart rate zones are not a one size fits all. While there are genetic components that factor into your training zones which cannot be changed, this only plays a small part. Training zones can be altered by how you train. For example, heavy weightlifting is an alactate method of training. Individuals will not challenge aerobic or lactate energy systems. With the long rest periods, most of the lactate produced (if any) will be easily used by the body. This person would have a lower anaerobic threshold than if they were to incorporate moderate intensity training for a sustained period of time. A person that only performs high intensity training, such as HIIT style workouts will live between zone 4 and zone 2, only passing through zone 3 when transitioning from work to rest and back to work. This person would fit in the same category as the weightlifter.

Below is an example of two individuals of similar age but very different training methods. Person #1 mainly participated in bootcamp/HIIT style of training. While person #2 had a much more varied method of training, using different modalities throughout the weekly plan. Person #2 has a much higher heart rate for each of the training zones. The higher heart rates allows this person to work at a higher intensity for longer periods of time. What that means, is person #2 can maintain a faster pace for a longer period of time. Any competition over 2 minutes, assuming all other things are equal, person #2 will win every time.

HOW TO IMPROVE YOUR TRAINING ZONES

In order to improve your training zones, it takes a goal and plan. The goal will determine your focus. For example, an novice marathoner may focus on aerobic zone training, while a person with an upcoming 5k race would have a focus on anaerobic/lactate threshold training. The CrossFitter or obstacle racer would need to focus on all three. In a nutshell, training at or near your aerobic and anaerobic thresholds causes adaptations which that will shift your zones in a beneficial way(7).

HOW NUTRITION AFFECTS TRAINING ZONES

As described in the intro of this article, as a person increases exercise intensity, their heart rate increases and so does the carbohydrate utilization. A person that uses carbohydrates at a lower intensity, some even at rest will both run out of energy and will become acidic quickly. A metabolically efficient or flexible person will be able to maintain fat utilization at higher a higher exercise intensity.

70 - 80% of a person’s energy (fat vs carbohydrate) utilization is associated with diet (9). In order to shift towards fat utilization at a higher intensity, the best method is following a diet that avoids insulin spikes. One that is low in processed grains and added sugars. The diet should be well balanced with a 2:1 or 1:1 carbs to protein ratio.

CALORIES AND TRAINING ZONES

Whether it is proper fueling for an endurance event, or maintaining proper caloric intake to lose or maintain weight, heart rate training will allow for a person to easily calculate how many calories they burnt during their training session. Unfortunately, without a metabolic assessment, including RMR and VO2 max, calculating the calories burnt during exercise is nearly impossible. Using apps to calculate your energy expended during exercise is even much less accurate than using it for heart rate zones and will over or under estimate the calories burnt most of the time.

CARDIO EQUIPMENT TRAINING ZONES

Many gyms and homes have cardio equipment such as treadmills that have a graphic interface of training zones. Most include categories, like “fat burning or weight loss”, “aerobic or cardiovascular” and “anaerobic or peak”. These machines also will calculate your calories “burnt” during exercise. While this these features are a benefit for the user as a rough estimate, but have very little accuracy. Only will a VO2 test provide you the accurate training zones. Also, understand that calories is a measurement of energy. Similar to a watt, joule or BTU. When machines such as an assault bike displays calories, this is in reference toward the energy generated by the bike and not the calories you have burnt during exercise.

SUMMARY

− We use fats at a low intensity exercise and carbohydrates as intensity increases.

− High intensity work makes your blood more acidic causing you to breathe faster to get rid of the waste.

− Heart rate zones determine your specific intensity training zones.

− Heart rate zones are changed by your training modalities.

− The aerobic zone is before any discomfort starts.

− The anaerobic/lactate zone is uncomfortable but sustainable for a while.

− The peak zone cannot be sustained for more than a few minutes.

− Everyone’s training zones are different, specific and adaptable.

− A person’s diet will have an effect on carbohydrate vs fat use.

− Tracking calories burnt & consumed is important to maintaining a healthy balance.

SOURCES

(1) Maddaiah VT. Exercise and energy metabolism. Pediatr Ann. 1984 Jul;13(7):565-72. PMID: 6472907. https://pubmed.ncbi.nlm.nih.gov/6472907/

(2) Berg JM, Tymoczko JL, Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. Section 30.4, Fuel Choice During Exercise Is Determined by Intensity and Duration of Activity. Available from: https://www.ncbi.nlm.nih.gov/books/NBK22417/ (3) 16.4: Fuel Sources. Last updated: Aug 13, 2020.

https://med.libretexts.org/Bookshelves/Nutrition/Book%3A_Human_Nutrition_(University_o f_Hawaii)/16%3A_Performance_Nutrition/16.04%3A_Fuel_Sources

(4) Ghosh A. K. (2004). Anaerobic threshold: its concept and role in endurance sport. The Malaysian journal of medical sciences : MJMS, 11(1), 24–36.

(5) Stefanie Passler , et al. Validity of Wrist-Worn Activity Trackers for Estimating VO2max and Energy Expenditure, Technical University of Munich, 22 August 2019

(6) Koike, D. Weiler-Ravell, D. K. et. Al. Evidence that the metabolic acidosis threshold is the anaerobic threshold. A. 01 JUN 1990. https://doi.org/10.1152/jappl.1990.68.6.2521 (7) Laurent A. Messonnier, et. al. Lactate kinetics at the lactate threshold in trained and untrained men

(8) Laurent A. Messonnier, et. al. Exercise Physiology Laboratory, Department of Integrative Biology, University of California Berkeley.14 January 2013

(9) Sunny Blende. METABOLIC EFFICIENCY: BECOMING A “BETTER-BUTTER-BURNER”. 01/06/2014. https://ultrarunning.com/features/metabolic-efficiency-becoming-a-better butter-burner/

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INTRODUCTION Setting goals is a powerful tool for personal and professional development. Whether aiming for better relationships, professional growth, or personal health achievements, having clear goals provides direction, purpose, and motivation. This article delves into the essence of goal setting and outlines strategies to craft and achieve relational, professional, and personal health/performance goals. GOAL TYPES Each person has different aspects in life where goal setting is an important role in creating success. I feel that there are several different areas in each person’s life where goal setting is important. Interpersonal/Relational: A goal based centered bettering relationships Professional: A goal centered around work Personal (health/performance): A goal centered around completing or improving a race/competition Intrapersonal: A goal focusing on improving oneself. PURPOSE OF GOAL SETTING The purpose of having a goal setting plan is multifaceted and essential for personal growth, professional development, and overall success in various aspects of life. Here are several key reasons why having a goal setting plan is crucial: CLARITY AND FOCUS Goal setting provides clarity about what you want to achieve and where you want to go in life. It helps in setting clear priorities, enabling you to focus your time, energy, and resources on tasks and actions that align with your objectives. MOTIVATION AND DIRECTION Having specific goals gives you a sense of purpose and direction. It motivates you to take action and stay committed, especially during challenging times, as you have a clear target to strive for. MEASUREMENT AND PROGRESS TRACKING Goals allow you to measure progress. They act as benchmarks against which you can track your achievements, providing a sense of accomplishment as you make progress towards your desired outcomes. ACCOUNTABILITY AND RESPONSIBILITY Setting goals holds you accountable for your actions. It encourages self-discipline and responsibility, fostering a sense of ownership over your choices and efforts to achieve the set objectives. PERSONAL GROWTH AND DEVELOPMENT Goals challenge you to step out of your comfort zone, promoting continuous learning and growth. They push you to acquire new skills, expand your knowledge, and develop as an individual. TIME MANAGEMENT AND PRIORITIZATION Goal setting helps in effective time management by prioritizing tasks that are essential for reaching your objectives. It assists in organizing your daily activities, ensuring that you allocate time to activities aligned with your goals. INCREASED RESILIENCE AND ADAPTABILITY Having a goal setting plan encourages adaptability and resilience. It enables you to adjust your strategies or set new goals when faced with unexpected challenges or changes in circumstances. ENHANCED CONFIDENCE AND SELF-ESTEEM Achieving set goals boosts self-confidence and self-esteem. Each accomplishment serves as a building block, reinforcing your belief in your abilities to succeed. IMPROVED DECISION-MAKING Goals provide a framework for making decisions. When faced with choices, you can evaluate them based on whether they align with your goals, making decision-making more focused and purposeful. OVERALL WELL-BEING Pursuing and achieving meaningful goals contributes to overall well-being. It brings a sense of satisfaction, fulfillment, and happiness, contributing positively to mental and emotional health. CRAFTING A SMART GOAL Crafting a SMART goal involves creating a specific, measurable, achievable, relevant, and time-bound objective. Here's a step-by-step guide on how to create a SMART goal: SPECIFIC Clearly define your goal. Be precise about what you want to accomplish. Ask yourself the five "W" questions: - What do I want to achieve? - Why is this goal important? - Who is involved? - Where will it take place? - Which resources or constraints are involved? Example: "I want to improve my overall fitness by running a half-marathon in six months." MEASURABLE Establish criteria for measuring progress and success. Quantify or define how you will determine when the goal is achieved. Ask yourself: - How much? - How many? - How will I know when it is accomplished? Example: "I will measure progress by tracking my running mileage weekly and aim to increase it by 10% each week until reaching the half-marathon distance." ACHIEVABLE Ensure that the goal is realistic and attainable. Assess if the goal is within your capabilities and resources to achieve. Consider factors like skills, time, and resources available. Example: Considering my current fitness level and commitment to training, running a half-marathon in six months is achievable with a structured training plan." RELEVANT Align the goal with your values, objectives, and long-term plans. Ensure that the goal matters and contributes to your overall objectives or broader goals. Example: "Training for a marathon aligns with my desire for a healthier lifestyle and supports my long-term goal of maintaining physical well-being." TIME-BOUND Set a specific timeframe for achieving the goal. Define deadlines or target dates to create a sense of urgency and focus. Example: "I will complete the half-marathon in six months, with intermediate goals set for reaching specific mileage targets each month." ACTION STEPS TO ENSURING GOALS ARE ATTAINED QUARTERLY GOAL REVIEW Every three months, review progress. Take time to assess how far you've come in achieving your goals. Reflect on what's working and what needs adjustment. ADJUST & REFINE Modify strategies or action plans if necessary to align with changing circumstances or new insights gained. SET MONTHLY MILESTONES Break down your goals into smaller, achievable milestones for each month. Evaluate monthly progress: Review your achievements against the monthly milestones and make necessary adjustments to stay on track. WEEKLY GOAL SETTING At the beginning of each week, review your plan with a set specific tasks aligned with your goals for the week. PRIORITIZE TASKS Organize tasks based on their importance and relevance to your goals. DAILY ACTION Dedicate time daily towards tasks or activities that contribute to your goals. REFLECT & ADAPT At the end of each day, reflect on what was accomplished and how it aligns with your goals. Adjust plans for the following day accordingly. SEEK SUPPORT AND ACCOUNTABILITY Engage with your coach or accountability partner: Regularly discuss progress, challenges, and strategies with someone who can provide guidance and hold you accountable. ADAPTABILITY AND RESILIENCE Be flexible: Adapt plans when necessary, considering unforeseen circumstances or changes. Maintain resilience: Stay motivated and persistent, even during challenging times or setbacks. REFLECTION AND GRATITUDE Regular reflection: Take time to reflect on your journey, celebrate achievements, and learn from setbacks. Practice gratitude: Acknowledge and appreciate the progress made, fostering a positive mindset. GOAL LENGTH The duration of a goal greatly depends on its intended purpose. Goals spanning 5 to 10 years typically suit long-term financial, business, or educational aspirations. On the other hand, shorter-term goals are often employed for tasks involving habit changes or those with inherent deadlines. Long-term goals are well-suited for relatively static objectives such as retirement planning. However, in areas like fitness, I've struggled to maintain interest in goals spanning 5 to 10 years. My priorities tend to evolve, making lengthy goals less appealing. Hence, I lean more towards setting 1-year goals. They offer a more defined start and end point, making the deadline feel more tangible compared to a distant 10-year horizon. CONCLUSION Effective goal setting is a cornerstone of personal and professional development. It provides direction, motivation, and a roadmap for success in various facets of life. Whether aiming for improved relationships, career advancement, or health goals, setting clear objectives is essential. The article highlighted the multifaceted purpose of goal setting, emphasizing clarity, motivation, measurement of progress, accountability, and overall personal growth. Crafting SMART goals involving specific, measurable, achievable, relevant, and time-bound parameters serves as a strategic guide. Furthermore, the action steps outlined, including quarterly reviews, monthly check-ins, weekly planning, and daily commitment, ensure continual progress toward goals. The importance of adaptability, resilience, and reflection throughout the journey was underscored, along with the significance of gratitude in fostering a positive mindset. Regarding goal duration, while longer-term goals suit certain areas like financial planning, shorter-term goals are preferable for areas like fitness due to evolving priorities. Ultimately, blending both short-term and long-term goals cater to diverse objectives, ensuring a balanced and progressive path towards achieving success.