Heart Rate Training and the Science Behind Its Success

I have been a trainer for 17 years and have tried almost every workout imaginable. I've trained some of the greatest athletes in the world, and I've also worked with some very sick individuals. I have seen the gamut, from mental disorders to untreatable cancer.

While all of the individuals I've worked with have had very different health and fitness profiles, the key metric I've used for determining the right program for them has always been heart rate.

Learning Objectives:

1. Heart rate training and the science behind its success.
2. The ideals and principles that create the logic behind HR training... Trust your heart!
3. The logic behind heart rate training.
4. Heart rate zones overview.
5. Sample heart rate workouts.

Heart Rate Training for Athletes

Let's begin by looking at heart rate (HR) training and the science behind it from a healthy individual’s or athlete's perspective.  When we are working with a healthy, competitive adult, such as an amateur or professional athlete, it is critical to monitor their HR so that you understand how the athlete's body responds to intense exercise or heavy volume training.  Other than getting a muscle biopsy and knowing which type of fibers (fast or slow twitch) the body utilizes during activity, HR monitoring is the main tool that should be used for creating and shaping a program for active, fit individuals.

For instance, let's take an MMA athlete: He or she will have to be conditioned to wrestle, throw powerful punches and kicks, block punches, and so on for a 3-to-5-minute round and then try to recover within only one minute.  Monitoring the athlete's HR as you begin the program will show you how the body responds to particular exercises, how fast the athlete recovers, and/or if there is too much lactic acid build up (in which case, athletes may feel as though they "have lead in their legs").  

In contrast to how we might use HR monitoring for an MMA athlete, let's and look at a person who competes in triathlons. How does his or her body respond over time to different conditions and elements of an endurance competition? Is the triathlete efficient in biking and running but inefficient in the swim? Can the athlete handle the hills of a course and does he or she have what it takes to complete the run? At the end of the day, it doesn't matter. If we can gauge the triathlete's stress levels by monitoring his or her HR then we can develop a program around that athlete's strengths and weaknesses, allowing him or her to be as efficient and effective as possible in all areas of the sport.

Using Heart Rate to Prevent Overtraining

Additionally, we can reduce the risk of injury by preventing these athletes from overtraining. It sounds like a no-brainer, if you ask me!

According to Achten & Jeukendrup:

Effectiveness Heart Rate Training

Back in 2006, I undertook a study to determine the effectiveness of heart rate training. The intensity at which your heart beats during a workout plays a significant role in your metabolic rate. It indicates how many calories you will burn during a workout and even what fuel source your body is tapping into and using during that workout.

There were a few different objectives in the study, as follows:

The first objective in the study was to determine whether or not a unique exercise program utilizing heart rate training to achieve maximum benefits for all participants (regardless of age and/or fitness level) would have a significant impact on the subject's body composition, cardiorespiratory endurance, flexibility, balance and stability, strength and muscular endurance, resting heart rate, and blood pressure.

The secondary objectives were reached if the primary objective was achieved; these objectives were psychological and physiological in nature. Psychological/mental benefits include: Decreased stress, increased self-confidence, and increased self-esteem. The physiological benefits include: Increased lung capacity, increased actin and myosin cross bridges, increased HDLs, and increased total blood volume.

The results of the study were nothing short of phenomenal. At the 6-week follow-up time point, there were significant statistical changes in the following variables compared to baseline:

• BF%
• fat weight
• flexibility
• lean body mass
• core power (both sides)
• weight
• balance (both sides)
• upper body strength
• resting heart rate (RHR)

At the 12-week follow-up time point there were significant statistical changes compared to baseline:

• BF%
• fat weight
• flexibility
• HR at AT
• lean body mass
• core power (both sides)
• weight
• balance (both sides)
• NL EX diastolic BP
• NL EX HR
• upper body strength
• recovery diastolic BP
• recovery systolic BP
• resting heart rate (RHR)
• resting diastolic BP

Methods used: A paired t-test was used for variables that were approximately normally distributed. For those variables that were markedly non-normally distributed, the nonparametric Wilcoxon signed rank test for paired data was used.

An example of interpretation of one of the statistically significant findings is as follows: "The 34 subjects showed statistically significant decrease in BF% over time with medians of: 30.81%, 27.34%, and 25.78% for baseline, 6 weeks and 12 weeks, respectively, p<0.0001 for comparison of both time points to the baseline values. This indicates an overall 16% decrease in BF% at 12 weeks (i.e., 100% x (25.78 - 30.81)/30.81))."

Regardless of what an individual's goal is, to lose weight, increase strength, become more functional, repair the body, etc., incorporating heart rate training is a necessary component if not the most important component of an individual's program. It's pretty simple in my opinion; we have technology that can monitor an individual's heart rate, the duration of their training, how many miles they've completed, and even how many calories they've burned.

So, how do we get people to start monitoring their heart rate? It all starts with education -­ but that's easier said than done. For instance, a person's physician can tell them that they need to get onto a weight-loss program and that they need to get in shape, but they don't typically tell them how.

Many individuals who are told that they need to lose weight have never actually tried to lose weight before; they may have never watched what they ate or had a specific exercise regimen. These individuals are usually unclear on how to lose weight and many of them are fearful of going about it in the wrong way.

The most important thing a trainer can do at this point is to help decrease their fears about exercise. Movement is necessary so why not give the client a tool that will monitor and inform them on how their body is responding to exercise? You can and should incorporate a heart rate monitor at this point. If you look deeper into the equation, a client's sympathetic and parasympathetic system is going to be on full alert when beginning a program. Their fear alone will trigger an adrenaline rush and an increased heart rate probably before they even begin.

Having a HR monitor will help ease the client's mind and will be the main guide as he or she begins his or her program. Additionally, a heart rate monitor will allow him or her to begin a baseline program while you begin educating him or her on what and how to exercise, as well as how to incorporate it into his or her daily life.

Overview of Heart Rate Zones

Overview of the LIGHT Zone

• The LIGHT zone (<60% of your maximum heart rate or MHR) is where the body is primarily burning fat as a fuel but at a negligible rate.
• The body is doing this because the intensity of the workout is VERY LOW to the point at which it has time to use fat as the primary source of fuel.
• This zone is best used for just getting your body moving and moving more consistently.
• An example of working in this HR zone is walking or a leisurely bike ride on mostly flat or moderately hilly terrain.
• You can tell you are in this zone when you can easily hold a conversation with someone.
• You may (or may not) sweat mildly have a very mild increase in your breathing rate.
• The drawback of this zone is that it will take a very long exercise session paired with a very high frequency of workout sessions to begin making a noticeable dent in your fat stores. For example, you may need to take one or two daily walks for 3 months in order to see a difference in your weight.

Overview of the MODERATE Zone

• The MODERATE zone (60%-70% of your MHR) is where the body is still primarily burning fat as a fuel, with a slight increase in its use of carbohydrates as a fuel.
• The body is doing this because the intensity of the workout is MODERATE to where it still has time to use fat as the primary source of fuel with some small assistance from carbohydrates.
• This is a very efficient way for beginners to advance their exercise program because these levels can still be reached with low impact and slower steady state movements.
• The best example of this is brisk walking or slow jogging.
• You can tell you are in this zone when you can still easily hold a conversation with someone, but there is a noticeable increase in your perspiration and breathing rate.
• This is where most people start to see the benefits of this type of conditioning.

Overview of the HARD Zone

• The HARD zone (70%-80% of your MHR) is where the body is burning a more equal mixture fat and carbohydrate stores for energy.
• The body is doing this because the intensity of the workout is getting to a level where fat is not the most efficient fuel source for the energy demands and the faster burning carbohydrate begins assisting more in meeting the body's energy needs.
• This is a very efficient way to maximize weight loss efforts because the body is now equally losing fat energy and carbohydrate energy.
• An example of training in this zone would be a moderate run.
• You can tell you are in this zone when you can still hold a conversation but you are breathing heavily, and you are sweating a lot more.
• It may take time for beginners to get to this zone but consistency will ultimately allow you to stay in this zone much longer as the weeks progress.

Overview of the VERY HARD Zone

• The VERY HARD zone (80%-90% of your MHR) is where the body is burning very little fat and mostly carbohydrate stores for energy.
• At this level of intensity, the body has a very hard time processing fat quickly enough to use it as energy, so in order to meet the body's immediate energy needs, carbohydrates become the primary fuel source.
• This zone is best reserved for building up your body's muscles, including your heart muscle (the moderate and hard zones provide moderate heart conditioning while this zone specifically conditions the heart to be stronger).
• Examples of training in this zone consist of hard running or sprinting.
• You can tell you are in this zone when you are on the verge of not being able to speak and breathing is accelerated and challenging.
• This zone is best reserved for short interval style bursts or seasoned runners and can be used to spur fat loss if implemented correctly.

Overview of the MAXIMUM Zone

• The MAXIMUM zone (90%-100% of your MHR) is where the body is in its highest aerobic state and is beginning its switch to the anaerobic state.
• At this level the body is burning pure carbohydrate to meet the body's energy needs.
• This heart rate zone is best utilized for building up your body's muscles and lactate threshold (this is the where your legs begin to burn and exercise cannot be maintained for very long).
• An example of training in this zone is short distance, hard sprinting.
• You can tellyou are in this zone when you cannot speak and your breathing is at its fastest. Working in this zone cannot be maintained for long as it is far too laboring on the body.
• This zone is reserved for short interval style bursts ONLY and can be used to spur fat loss and build muscle if implemented properly.

Conclusion 

Utilizing heart rate training allows you to create an effective and efficient workout that is personalized and meaningful to the client. It allows you to create a fitness program -­ regardless of training type or sport - and see how well the body responds.

You have the opportunity to instill confidence and hope in someone who is trying to lose weight but fears exercise. You can help them understand that it is safe to exercise as long as they stay within specific heart rate zones or if they do not go above a specific heart rate.

Once you understand how the client's body responds, you can begin to work on their weaknesses and make their strengths even stronger. Imagine the amount of confidence you can give someone by teaching him or her how his or her body works and responds to exercise. You can help an athlete reach his or her peak athletic potential or even help a sick or injured person get healthier by teaching him or her how to use a heart rate monitor and how to use heart rate zones.

The bottom line: Educated individuals become confident individuals. In the case of exercise, the more your clients know and the better they feel, the higher the chance is that they'll make exercise a daily part of their regimen for life!

References

Achten, J., & Jeukendrup, A. E. (2003). Heart Rate Monitoring: Applications and Limitations. Sports Medicine, 33,  517-538.