The purpose of this article is threefold, (1) to help you recognize the reason that you exercise, whether it is for your health or the love of a sport; (2) the type of exercise for the health enthusiast opposed to the training for the competitor; and, (3) to provide knowledge of High Intensity Interval Training (HIIT) .

As a health professional that has trained kick boxers and a holder of three black belts with the continuance in Ed Parkers’ Kenpo Karate, I have learned that I must distinguish between an individual that wants to achieve better health, confidence and discipline from the individual who wants to excel in a sport because s/he loves the sport and wants to train to win.  These two types of individuals demand experienced coaching.

For the person that wants to exercise for health, the coach should purpose a fundamental principle of exercise for health that is best stated by James O’Keefe: “A daily exercise habit is the single most powerful therapy for improving both the quality and quantity of your life (that is something that adds years to your life and life to your years). Getting just 30 minutes daily of moderate or vigorous physical activity can cut your risk almost in half for premature death, diabetes, Alzheimer’s disease, depression, and heart attack. People who regularly engage in physical exercise have markedly lower rates of disability, and an average life expectancy that is about seven years longer than sedentary people.”1

For the individual that will train because s/he loves the sport, the coach will see the enthusiasm for the need to win. Remember Mike Tyson after one of his losses? He was heard saying, ‘I just don’t want to do it any more’. That statement did not detract from his excellent skills as a boxer, nor remove the fact he is a champion. But, what it did do is take the ‘love’ of the sport away, i.e. to train to win.

I hope I am making you understand how you fit into the exercise arena; i.e. exercise because of health and training because you love the sport. Let me place this in context from other experts that had an interview with Runners World in 2012.  From the interview with Chip Lavie and James O’Keefe:

“So ask yourself: Why am I running marathons? If you are doing it for your health, you can do better by not overdoing it. I tell people who ask me about the advisability of running a marathon, ‘If you really want to do a marathon, go ahead and train up for it and do one. Then cross it off your bucket list, and get into exercise patterns that are more ideal for promoting overall health and longevity’.”1

Its not that a single marathon is necessarily bad for you. A number of sudden-death studies have shown low rates of deaths in marathon running. But we think its maybe not so good, for your health, to do 10 or 15 marathons a year for 20 years.  But as a general point, if you exercise hard for 3, 4, or 5 hours, a number of people may have adverse effects. If you do it for a love of sport, thats one thing. We understand that. But thats not the same as doing something for your health. If youre just interested in your health, you can do a lot less, and that may even be what brings you the maximum benefit. Not just in terms of your longevity, but also in terms of joint health and maybe your immune system. We all know that a lot of runners get colds and flu after they run marathons.1

The last thing we want to do is give the average American another lame excuse to continue his or her favorite exercisecouch surfing while watching television. Our paper on the potential dangers of excessive endurance exercise is meant to shed light on a largely underappreciated risk of extreme exercise such as marathons, and ultra-marathons. Over years to decades this type of prolonged strenuous running can take a toll on cardiovascular health, in essence causing premature aging, scarring, stiffening, thickening of the heart and blood vessels.1

The requirement before engaging in any type of activity is to keep in tune with your doctor scheduled physicals. A determinant factor to understand whether you are a candidate for endurance exercise as opposed to exercising for heath is to listen closely to your body, i.e. after an endurance exercise routine  you may feel some ill effects (such as palpitations, irregular heartbeats, chronic fatigue, and slower recovery) especially as you get into middle age. If this occurs it is time to re-evaluate your exercise goals under a doctor’s supervision.

The cardiac muscle is striated and with the same cellular components only in varying proportions as the skeletal muscle. In exercise the heart muscle will pump against increased resistance and for cardiac tissue to adapt it will increase in size and strength. However aerobic activity does not place the same resistance as weight training on the cardiac tissue. The cardiac tissue will adapt to the aerobic activity by increasing the volume of blood it will pump on account of the greater volume of blood demanded by the working muscles. The greater volume will result from an increase in the size of the left ventricle of the heart.2

Tom Kelso3 , exercise physiologist with the St. Louis metropolitan Police will inform you that endurance cardio can damage the heart. Tom points that a marathon is normally viewed as the essence of fitness and the ultimate test of endurance. However, he will tell you it puts an unusual stress on the heart. Mr. Kelso refers to a study at the Canadian Cardiovascular Congress in Montreal, where it was reported that regular exercise reduces cardiovascular risk by a factor of two or three. However, the vigorous demand of running a competitive marathon increases cardiac risk by seven-fold. Within Mr. Kelso’s same report was research on a Club where members had run at least 100 marathons. The research on these centennial marathoners uncovered heart muscle scarring.

An article published in the European Heart Journal reported ‘exercise-induced right ventricular dysfunction and structural remodeling in endurance athletes’ and concluded “Intense endurance exercise causes acute dysfunction of the right ventricle, but not the left ventricle.” 4

What type of exercise favors cardiovascular benefits without potential long-term heart damage? For the individual that exercises for health there is the following information obtained from Dr. Mercola:

  • Brief and demanding sessions consisting of intermittent work and rest, such as interval training.
  • Circuit-type strength training. Youll get muscle strength and an elevated heart rate. It is the total package.
  • Training no more than four days per week. Build in recovery days. Allow the body time to heal. Your biology demands it.
  • Simple progression. Over time, increase the number of bouts, intensity of effort, and/or decrease the recovery time between bouts.
  • A whiff of common sense. If youre exhausted, you sense potential injury, or youre not feeling fully recovered, take an extra day of rest. It is better to err on the side of caution to maintain training longevity.5

Dr. Mercola summarizes his findings and reports:5

Long cardio workout sessions can cause more harm than good, leading to the release of the Stress hormone cortisol, which when produced excessively may contribute to a catabolic state, in which your tissues break down, as well as chronic disease.

Too much cardio, such as marathon running, raises cardiac risk by seven-fold, and can lead to heart muscle scarring, and increased blood levels of cardiac enzymes, which are markers for heart injury.

To get the most benefits of exercise you need to push your body hard enough for a challenge while allowing adequate time for recovery and repair to take place; one of the best ways to do this is to follow a fitness regimen that includes short bursts of high-intensity activities, which can be done using an elliptical machine, recumbent bike or even free weights.

When you work out, it is wise to push as hard as you possibly can a few times a week, but you need to wisely gauge your body’s tolerance to this stress, and give your body time to recuperate using rest and proper nutrition.

Time Magazine 6 discussed the pros of treadmill use inclusive of easier on your joints than running on hard pavement,  ability to control the difficulty level by increasing the incline, and more advanced machines even allow you to simulate a custom race environment. The downside to continuous use of the treadmill is it leads to inability to adapt to uneven ground. Additionally muscle utilization may be less when walking on a treadmill compared to running outdoors.

There is training that purposes the proper utilization of the cardio equipment that has proven to strengthen yet not impair the function of the heart muscle. This training is called High Intensity Interval Training (HIIT), which  has proven to be far more efficient and effective. You can complete an entire HIIT session in 20 minutes, and you only need to do them twice or three times a week. HIIT is safer for your heart as well. While exercise has been shown to prevent heart disease as effectively as medication,7 regularly exercising intensely for extended periods of time may actually do more harm than good, especially if you have a history of heart disease.

“High-endurance training, such as running for an hour at a time, puts extraordinary stress on your heart. And while stressing a muscle usually makes it stronger, extremely high, prolonged stress can have the opposite effect. “8

Dr. Mercola suggests the following take-home message:  “Be mindful of your current fitness level and don’t overdo it when you first start out. The speed is completely individual, based on your current level of fitness. Some may reach their anabolic threshold by walking at a quick pace, while others may need to perform a mad-dash to get the same effect. Also remember that recovery is a key factor of high-intensity workouts. Again, as you increase the intensity, you can decrease the frequency. It’s really important to allow your body to fully recuperate in between sessions, so it’s NOT recommended to do high-intensity exercises more than three times a week.8

More in-depth understanding on anabolic threshold, intensity work-outs and frequency of HIIT can be obtained from Dr. Mercola’s interviews with Phil Campbell and Dr. Doug McGuff .”9, 10

Before I explain what HIIT is, it is important to know how to determine your target heart rate.  The American Heart Association has published the following 11:

Hittin’ the Target

As you exercise, periodically:

  • Take your pulse on the inside of your wrist, on the thumb side.
  • Use the tips of your first two fingers (not your thumb) to press lightly over the blood vessels on your wrist.
  • Count your pulse for 10 seconds and multiply by 6 to find your beats per minute. You want to stay between 50 percent to 85 percent of your maximum heart rate. This range is your target heart rate.

Know Your Numbers

This table shows estimated target heart rates for different ages. Your maximum heart rate is about 220 minus your age.

In the age category closest to yours, read across to find your target heart rate. Heart rate during moderately intense activities is about 50-69% of your maximum heart rate, whereas heart rate during hard physical activity is about 70% to less than 90% of the maximum heart rate.

The figures are averages, so use them as general guidelines.

Age Target HR Zone 50-85% Average Maximum Heart Rate, 100%
20 years 100-170 beats per minute 200 beats per minute
30 years 95-162 beats per minute 190 beats per minute
35 years 93-157 beats per minute 185 beats per minute
40 years 90-153 beats per minute 180 beats per minute
45 years 88-149 beats per minute 175 beats per minute
50 years 85-145 beats per minute 170 beats per minute
55 years 83-140 beats per minute 165 beats per minute
60 years 80-136 beats per minute 160 beats per minute
65 years 78-132 beats per minute 155 beats per minute
70 years 75-128 beats per minute 150 beats per minute


Important Note: A few high blood pressure medications lower the maximum heart rate and thus the target zone rate. If you’re taking such medicine, call your physician to find out if you need to use a lower target heart rate.”11

So what is HIIT? Specialists in exercise physiology were interviewed by Dr. Mercola. From the interviews we have the following protocol. However, there are safety risks to be understood when doing HIIT on a treadmill. It is necessary to take safety precautions when using a treadmill so you don’t fall off, as the treadmill will keep going at the speed you set it to, and you have to press a button to alter the speed setting. Your safest bet is to start and finish by placing your feet on the side rails. Here’s a summary of how to perform an interval cardio session on a treadmill:


Each challenge is a 60-second power walk followed by a 30-second jog, and then a 15-second modified sprint, with slow strolling in between to recover. Start out with slow strolling, then raise the speed setting to a comfortable power walk stride. Power walk for one minute, then raise the speed setting again for your jog. The technique for the 30-second jog is to lean forward, keep your core tight, and bounce softly off the balls of your toes. Your heels may not hit the tread at all. This assures that more of the jolt of your stride will go into your muscles rather than your bones, joints, and ligaments. To create a sprint type effect for the last 15 seconds, simply drive your knees high while you squeeze your upper body muscles tight. The sprint is merely a more intense version of the jog by driving your knees as high as possible. This way, you don’t have to alter the speed setting on the treadmill. At the end of the 15-second sprint, hop onto each side rail with your feet as you hold on to the handle bars. Reduce the treadmill’s speed to a slow recovery pace. Also, bring your incline down to zero for the recovery phase. Let the tread slow down a few seconds before you start walking on the tread to recover.”7


If you use an elliptical that allows you to change the incline, you will be able to work out all of your different leg muscles. Here’s a summary of the core principles:7

  • Warm up for three minutes
  • Exercise as hard and fast as you can for 30 seconds
  • Recover for 90 seconds, still moving, but at slower pace and decreased resistance
  • Repeat the high-intensity exercise and recovery 7 more times. (When you’re first starting out, depending on your level of fitness, you may only be able to do two or three repetitions of the high-intensity intervals. As you get fitter, just keep adding repetitions until you’re doing eight during your 20-minute session)
  • Cool down for a few minutes afterward by cutting down your intensity by 50-80 percent


  • Do you want to exercise to improve your health or to win in the sport you love?
  • Endurance training can have negative impacts on the heart muscle.
  • HIIT is the better alternative for the aerobic workout when you exercise for health.


1Chip Lavie, James O’Keefe. Q&A with the “Potential Adverse Effects” of Endurance Exercise Authors. Runners World. Reported by Amby Burfoot June 2012

2Clark, RJ. NFPT Study and Reference Manual, 1996 and 6th edition 2014

3Tom Kelso. Endurance Training is bad for Your Heart. Breaking Muscle

4André La Gerche , Andrew T. Burns , Don J. Mooney , Warrick J. Inder , Andrew J. Taylor ,

Jan  Bogaert , Andrew I. MacIsaac , Hein Heidbüchel , David L. Prior. Exercise-induced right

ventricular dysfunction and structural remodeling in endurance athletes. Published on line

December 2011

5 Dr. Mecola. Too Much Cardio Can Cause a 7-Fold Surge of Heart Problems.

http:\ June 01, 2012

6 Time April 23, 2015

7 British Medical Journal 2013;347:f5577

8 May 2015. Peak Fitness: Reap the Benefits of High-Intensity Interval Training.




David Brancato

Dr. Brancato’s cumulative experience in nutrition, alternative medicine, chemistry, toxicology, physiology directed him to holistic approaches in human physiology to correct system imbalances. He maintains his professional certifications as a Naturopath from the American Naturopathic Medical Certification and Accreditation Board; the National Federation of Professional Trainers; Black belts in Kick Boxing and Kenpo.