Heart Rate and Exercise Intensity
by Jeffrey H. Tucker, DC, DACRB
In part 3 of this article, let’s discuss heart rate and exercise intensity. It’s imperative to have baseline information on your patients to determine how to most efficiently assist them in achieving their fitness goals.
It’s very important you know their resting heart rate and maximum heart rate (MHR). During a workout, their heart rate is a very reliable indicator of their personal performance level or training load – not as absolute numerical values, but in relation to their own heart rate values.
Calculating Maximum Heart Rate
Miller Formula: 217 – (0.85 x age)
(0.85 x 45 = 38.25)
217 – 38 = 189 MHR
Recent research identified the following formula as more accurately reflecting the relationship between MHR and age:1 MHR = 206.9 – (0.67 x age).
It’s relatively easy to measure your heart rate at rest by feeling your radial pulse or by using a heart rate monitor while still in bed after a good night’s sleep. Once trained, our patients easily can determine their resting heart rate. However, a reliable measurement of maximum heart rate often requires a visit to a testing facility or a sports-minded chiropractor.
If you are experienced in fitness training and are enjoying good health, you also can do your own test with a maximum performance session in your favorite sport. After 15-20 minutes of warming up, do two or three maximum intensity work cycles of around 3-4 minutes and recuperate between them for 30 seconds. If it’s difficult to reach high intensity in your favorite sport (e.g., cycling, cross-country skiing, rowing), you can perform the maximum intensity sessions on a steep hill. The highest measured reading you can achieve is a good estimate of your maximum heart rate.
Target Heart Rate Zone
Your target heart rate zone is the number of times per minute your heart needs to beat to achieve a desired workout effect. It’s represented as a percentage of the maximum number of times your heart can beat per minute (MHR). Most research recommends working out at a target heart rate zone between 60 percent and 75 percent of your MHR.
You need to be able to progress a patient to higher levels of fitness and ensure they are sufficiently healthy to exercise at the desired intensity. Tests performed in different sports mostly indicate your maximum heart rate in that given sport, not necessarily an accurate and absolute value. For example, many people’s heart rate is 10-20 beats per minute (BPM) lower when cycling than when running and even lower when swimming; while cross-country skiing often is slightly higher than when running. When you know your resting and maximum heart rates, it’s easier to control your training intensity.
Xavier Jouven, MD, did a study with men and found those whose heart rates increased the least during exercise (less than 89 BPM) were six times more likely to die of sudden death from myocardial infarction than men whose heart rates skyrocketed. More importantly, men whose heart rates didn’t drop by at least 25 BPM within one minute after exercise also had a greater risk of cardiac death. The risk of sudden death from myocardial infarction was increased in subjects with a resting heart rate more than 75 BPM; an increase in heart rate during exercise of less than 89 BPM; and a decrease in heart rate less than 25 BPM, one minute after exercise.
The conclusion is that the heart-rate profile during exercise and recovery is a predictor of sudden death.2
How the Training Effect Works
How can we use this information to design a training session? Using the National Academy of Sports Medicine (NASM) template, we can create an “integrated performance profile.” Establish the patient’s current fitness level (unfit, fit, athlete, etc.) from your general and medical history, exercise history, body fat analysis and circumference measurements. Combine this information with heart rate and progress your patients to develop better results. Understand that different types of workout intensities are needed and have their own important role to play in developing your fitness level and achieving better results. We cannot let our patients do the same 30-minute walk day after day and expect progress. We have a responsibility to progress and challenge them.
Exercising below 60 percent of your maximum heart rate is relatively easy on your system. When it comes to fitness training, intensity this low is significant mainly in restorative training and improving your basic fitness when you are just beginning to exercise or after a long break. Everyday exercise – walking, climbing stairs, cycling, etc. – usually is performed within this intensity zone. These sessions, when lasting more than one hour, can develop endurance, may enhance recovery, but will not likely improve maximum performance.
Exercising at 60-70 percent of your maximum heart rate is considered the fat-burning zone. Peak fat oxidation has been shown to occur during exercise at 63 percent VO2 max. Peak fat oxidation progressively lessens above this point and was minimal at 82 percent VO2 max, which is near the lactate threshold of 87 percent.
The 60 percent to 70 percent zone improves your basic aerobic fitness level effectively. Exercising at this intensity feels easy, but workouts with a long duration can have a very high training effect. The majority of cardiovascular conditioning training should be performed within this zone. Improving this basic fitness builds a foundation for other exercise and prepares your system for more energetic activity. Long-duration workouts at this zone consume a lot of energy, especially from your body’s stored fat.3
Exercising at 70 percent to 80 percent of your maximum heart rate begins to be quite energetic and feels like hard work. This zone will improve your ability to move quickly and economically. In this zone, lactic acid begins to form in your system, but your body still is able to completely flush it out. You should train at this intensity at most a couple of times per week, as it puts your body under a lot of stress.
Exercising at 80 percent to 90 percent of your MHR will prepare your system for competitive and high-speed events. Workouts in this zone can be performed either at constant speed or as interval training (combinations of shorter training phases with intermittent breaks; see my previous article on interval training). High-intensity training develops your fitness level quickly and effectively, but overtraining might result if it’s done too often or at too high an intensity.
Common warning signs of overtraining include:
- feeling washed-out, tired, lack of energy;
- mild, prolonged leg soreness, general aches and pains;
- pain in multiple muscles and joints;
- drop in performance;
- decreased immunity;
- decrease in training capacity/intensity;
- moodiness and irritability;
- loss of enthusiasm for the sport;
- decreased appetite; or
- increased incidence of injuries.
If a patient experiences these symptoms, the best prescription might be to recommend they take a break from their training program.
When your heart rate during a workout reaches 90 percent to 100 percent of the maximum, the training will feel extremely hard. Lactic acid will build up in your system much faster than can be removed, and you will be forced to stop after a few minutes. Athletes include these maximum-intensity workouts in their training program in a very controlled manner; fitness enthusiasts do not require them at all.
It’s important to note that a workout with a lower perceived exertion is not worse or less significant than a workout with a high-intensity value. Both are needed in balanced training. In fact, lower-intensity workouts are most important for endurance. Low-intensity training builds a foundation on which you can safely build workouts with a higher intensity.
Understand your body’s signals and how to react to them. Learn to recognize what the different heart rate zones feel like during your workouts and what kind of feelings different training effects cause in your body (sweating, ability to talk, muscle soreness). I encourage my patients to learn to notice when their heart rate differs from normal and how unusual situations (i.e., lack of sleep, stress, an oncoming flu) also affect their heart rates.
Using the NASM model as taught in the Corrective Exercise Specialist (CES) and Performance Enhancement Specialist (PES) courses, I implement an “Integrated Program Design” for my patients:
- Train them how to perform self-myofascial release using the foam roll.
- Train them how to perform specific stretching maneuvers.
- Discuss how to control heart rate, performance level and exertion during exercise. Take your heart rate and know your desired heart rate limits. Decide on a training effect target for your workout that day.
- Introduce training in the most sensible and result oriented way. This includes training programs that include core work, balance training, plyometrics, speed (straight-ahead speed), agility (lateral speed), quickness (reaction time) and resistance training.
Plan training wisely and with long-term vision. I don’t want my patients to go to a personal trainer for this type of information and intervention. I want to be able to design a training program with a personal trainer that matches my patient’s needs and goals. Most of my patients want to lose weight, “get in shape,” prevent osteoporosis or need to perform corrective exercises for musculoskeletal reasons. The problems I see most often in those who are working out is they have been doing the same workout without variety way too long. It’s worth saying again – help patients plan long-term.
As I work more and more closely with personal trainers, I see my role as helping each of my patients with injury prevention; maintaining a regular training schedule; an upward trend in strength, endurance, balance, etc.; a correct ratio between training and rest; variety; and keeping both of us motivated.
In part 4 of this series, I will discuss functional movement tests and corrective exercise training.
- Gellish RL, Goslin BR, Olson RE, et al. Longitudinal modeling of the relationship between age and maximal heart rate. Med Sci Sports Exerc, May 2007;39(5):822-9.
- Jouven X, Empana JP, Schwartz PJ, et al. Heart-rate profile during exercise as a predictor of sudden death. N Engl J Med, 2005 May 12;352(19):1951-8.
- Achten J, Jeukendrup A. Relation between plasma lactate concentration and fat oxidation rates over a wide range of exercise intensities. Int J Sports Med, January 2004;25(1):32-7.
by Jeffrey H. Tucker, DC, DACRB
This article is a real story about a client of mine, Sheldon, whom I am proud to call a very good friend. Last year, I was excited to find out that he was invited to play in the 2007 Maccabi Games (www.jccmaccabigames.org).
I want to personally share his story with you while educating you on the principles of rehab at the same time. Sheldon was given an opportunity to live a dream of playing in a basketball competition that few will ever experience. He came to me feeling confident with our past experiences I could help him recover from a serious injury and get him in shape for the tournament in about 12 weeks’ time. Like every client, Sheldon’s recovery and therapy required customization.
In mid-September 2007, Sheldon, a 49-year-old male presented to my office with left lower-posterior leg and ankle pain made worse with walking. He indicated to me that the pain was in the Achilles tendon region and attachments at the calcaneus. He had been recently invited to play for the U.S. basketball team at the 11th Pan American Maccabi Games in Buenos Aires, Argentina, in December 2007. He decided to make the trip to Argentina a family vacation. Sheldon was not unfit, yet he was not in condition for a world-class competition. The ankle injury had occurred as a result of his overexertion in preparing for the tournament.
He came to my office with an immediate goal of pain relief so he could practice basketball again. His bigger goal was a structured exercise program to get him ready for Argentina. The patient was diagnosed with pre-insertional Achilles tendonitis with a partial tear. His past history was remarkable for low back pain and previous diagnosis as a pre-diabetic. The goals of a complete chiropractic/rehabilitation training program for this client were to: decrease pain and body fat, increase strength, endurance, flexibility, lean muscle mass and performance; and prevent injury.
Sheldon’s treatment was guided by measurements such as bioelectrical impedance analysis (BIA), weight loss, heart rate, exercise intensity, ratings of perceived exertion, interval training timing and meal plans. The tools I used to decrease his pain as quickly as possible were a class IV, high-powered warm laser, sound-assisted soft-tissue mobilization (SASTM) as taught by David Graston, joint mobilization/manipulation and myofascial therapy. I had his MD prescribe ketoprofen cream, an anti-inflammatory used to massage into the Achilles area.
As part of his overall program to achieve the above goals, I recommended and initiated food plans, supplementation and a corrective exercise program. Diet is the best tool for fat loss. I have found the Mediterranean diet is easy for clients to follow and offers the best results.
The need for supplements depends upon the individual sitting in front of you. However, there are specific nutrients we can recommend for each individual to take on a daily basis. For example, Sheldon was instructed to take 3 grams of EPA/DHA per day for pain relief and to support joint and bone health, glucose and insulin homeostasis, and the integrity of neurological cells. He was instructed to take daily essential vitamins and minerals, and to increase his protein intake using a bioactive, pure whey protein powder concentrate.
Exercise creates changes in the musculoskeletal system, increasing strength and performance, along with stimulating physiological processes. However, we may not all agree on the best type of exercise to make such changes. In this article and the next, I will discuss these topics and much more, clarifying the connections between fat loss, fat-free mass, exercise and performance.
Measurement and Weight-Loss Basics
Within three weeks, Sheldon was walking without pain. At the end of the third week, he could jog with slight to moderate pain after 10 to 15 minutes of intermittent stops and starts, as in playing basketball. Once his pain diminished enough that he could jog, it was time to get serious and implement a corrective exercise program. We all recognize the value in measuring blood pressure, height and weight. As part of my workup before starting an exercise progression or before starting a weight-loss program, I measure body fat percentage and lean body mass. When I ask a client, “How much do you weigh today?” I often hear remarks such as, “10 pounds too much.” Then I ask, “But how much do you weigh now?” and get the usual response of, “I don’t know, I never weigh myself.”
Maintaining a healthy body weight includes maintaining healthy functioning immune, hormonal and reproductive systems without any traces of an eating disorder. It is also a weight that you can realistically reach and maintain with healthy lifestyle efforts. To effectively manage body weight and body composition, it is important to know your daily caloric requirements. A BIA test can tell us body composition and basal metabolic rate. Accurate assessments using BIA allows me to determine each client’s unique personal caloric requirements and to better plan and evaluate weight management/exercise programs. As mentioned above, I utilize therapeutic lifestyle changes (TLC) including food plans, supplements, exercise and relaxation that can be evaluated using objective measures before and after beginning my nutritional and/or exercise program.
Body Composition Measurements
In my practice, I use a body composition machine, which is a portable, battery-powered bioimpedance analyzer. Patient assessments are conducted using a connection between the analyzer and the wrist and ankle of the patient. Connections to the patient are through standard ECG sensor pad electrodes. Resistance and reactance, the two components of impedance, are measured directly from the body.
On Sheldon’s initial office visit, he was 78 inches tall and weighed 215 pounds. A look at some of the results from Sheldon’s BIA test revealed the following:
|Fat Mass (FM)
|Fat-Free Mass (FFM)
|Body Mass Index (BMI)
|Intracellular Water (ICW)
|Extracellular Water (ECW)
Body weight is the sum of your body fat or fat mass (FM) and your lean body mass or fat-free mass (FFM). FFM consists of dry lean mass and total body water (TBW). TBW is divided into water inside the cells (intracellular water – ICW) and water outside the cells (extracellular water – ECW). TBW is the sum of intracellular water and extracellular water (ICW + ECW = TBW). Keeping these components appropriately balanced is the key to staying fit and healthy. Compositional imbalance in the body is closely related to obesity, malnutrition, edema and osteoporosis. It also will contribute to suboptimal athletic performance.
Body Mass Index
Body mass index (BMI) is a common measure expressing the relationship (or ratio) of your body weight to your height. BMI is more highly correlated with body fat than any other indicator of height and weight, but it is not recommended for use as the sole measurement of your body composition. It does not apply to infants, children, adolescents, pregnant/breastfeeding women or adults over 65 years of age.1
BMI Measurements and Ranges: You can calculate your BMI using the formula: BMI = weight (kg)/[height (m)].2
BMI <18.5: This calculation may indicate an underweight status and may be associated with health problems for some people. This client may need to have a consult regarding diet or other health-related issues.
BMI of 18.5 – 24.9: This zone is the preferred range as it is associated with the lowest risk of illness. The client is living life in a way that improves health.
BMI of 25 – 27: This zone may be fine if you are physically active. You likely have lots of muscle mass and may be overweight but not overly fat. However, a BMI over 25 may be associated with health problems for inactive people. This client will need to consult with a doctor.
BMI of 27 – 29.9: This is a health risk zone and is associated with increased risk of heart disease, high blood pressure and diabetes. At this point diet, nutrition and exercise must be implemented.
BMI > 30: This is obesity. Clients must be provided with a program of balanced eating, supplements, regular exercise and reduction of stress.
Sheldon’s BMI was 25.5, putting him between 25 and 29.9. Although he is only 0.5 over, this still falls within the overweight range. Being overweight increases your risk for heart disease, diabetes and other serious health problems. I was not concerned about Sheldon being overweight, but I was concerned that he would be under stress from the workouts ahead and was on a tight time schedule to get ready for Argentina. Within the first week of treatment, I had discussed the Mediterranean food plan with Sheldon to promote healing and increase strength.
Table 1: Risks of cardiovascular disease relative to body mass index and waist circumference3
|Body Mass Index (BMI)
Men = 102 cm (40 inches)
Women = 88 cm (35 inches)
Men > 102 cm (40 inches)
Women > 88 cm (35 inches)
|Underweight = <18.5
|Normal weight = 18.5-24.9
|Overweight = 25-29.9
|Obese = 30-34.9
||Very High Risk
|Obese = 35-39.9
||Very High Risk
||Very High Risk
|Extremely obese = 40+
||Extremely High Risk
||Extremely High Risk
The BMI ranges are based on the relationship between body weight and disease and death.4 Overweight and obese individuals are at increased risk for many diseases and health conditions, including hypertension, coronary heart disease, stroke, type 2 diabetes, gallbladder disease, osteoarthritis, sleep apnea and respiratory problems, some cancers (endometrial, breast and colon), and dyslipidemia (high LDL cholesterol, low HDL cholesterol or high levels of triglycerides).
There are three types of muscle: cardiac, visceral and skeletal muscle. The quantity of skeletal muscle is most affected by exercise, particularly by strength-training programs. By comparing the percentage of body fat mass and skeletal muscle mass in each body component, the level of fatness or obesity can be measured in a more proactive and exact manner. An essential part of my program is to teach my clients how to train and lift free weights. By teaching Sheldon corrective exercises and a free-weight training program, I expect his muscle mass to increase and the body fat to decrease.
We will follow Sheldon’s progress in part 2 of this series and look at metabolism and the benefits of interval training.
- Mei Z, Grummer-Strawn LM, Pietrobelli A, et al. Validity of body mass index compared with other body-composition screening indexes for the assessment of body fatness in children and adolescents. Am J Clin Nutr, 2002; 75(6):978-85.
- Garrow JS, Webster J. Quetelet’s index (W/H2) as a measure of fatness. Int J Obesity, 1985;9:147-53.
- Gallager DG, Heymsfield SB, Heo M, et al. Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. Am J Clin Nutr, 2000;72(3):694-701.
- Prentice AM, Jebb SA. Beyond body mass index. Obesity Rev, August 2001;2(3):141-7.
- Gallagher D, Visser M, Sepúlveda D, et al. How useful is BMI for comparison of body fatness across age, sex and ethnic groups? Am J Epidemiol, 1996;143(3):228-39.
- World Health Organization. Physical Status: The Use and Interpretation of Anthropometry. WHO Technical Report Series. Geneva: World Health Organization, 1995.