By Dr. Mercola
Exercise is a key factor of optimal health; it's particularly important for controlling your blood sugar and normalizing your insulin levels. I often recommend viewing exercise as a drug that needs to be properly prescribed and "taken" at a proper dosage.
When done correctly, exercise can oftentimes act as a substitute for some of the most common drugs used today for things like diabetes, heart disease and depression.
All of these conditions will improve with exercise and the help of an experienced natural health care clinician. High intensity interval training (HIIT), which is a core component of my Peak Fitness program, is key for reaping optimal results from exercise.
There are many versions of HIIT, but the core premise involves maximum exertion followed by a quick rest period for a set of intervals.
My Peak Fitness routine uses a set of eight 30-second sprints, each followed by 90 seconds of recovery, as taught by Phil Campbell who is a pioneer in this field. Also, while I typically recommend using an elliptical machine or recumbent bike, you can just as easily perform a high intensity routine without any equipment at all.
The Scientific 7-Minute Workout
A recent article in the American College of Sports Medicine’s Health & Fitness Journal1 shows how you can fulfill the requirements for a high intensity exercise using nothing more than your own body weight, a chair, and a wall.
Best of all, this science-backed routine only requires a seven minute investment, as the program calls for as little as 10- to 15-seconds of rest between each 30-second exercise, which should be performed in rapid succession.
As reported by the New York Times2:
“'There’s very good evidence that high-intensity interval training provides “many of the fitness benefits of prolonged endurance training but in much less time,' says Chris Jordan, the director of exercise physiology at the Human Performance Institute in Orlando, Fla., and co-author of the new article.”
The health benefits of high intensity interval training are well-established at this point, and include:
Significantly improving your insulin sensitivity, especially if you're on a low-processed food, low-sugar/low-grain diet Optimizing your cholesterol ratios, when combined with a proper diet Boosting fat metabolism and optimizing your body fat percentage (as a result of improved conservation of sugar and glycogen in your muscles) Virtually eliminating type 2 diabetes and high blood pressure Naturally boosting your levels of human growth hormone (HGH) Increasing your aerobic capacity
One of the added boons of this 7-minute program is that since you don’t need any equipment, you can easily take this routine with you when traveling. You’d be hard-pressed to find a hotel room that doesn’t at least have a chair in it. When done at the appropriate intensity, which should hover around 8 on a scale of 1-10, the following 12 exercises, which are outlined in the report, equate to doing a long run and a weight-training session.
The exercises are ideally done in the following order, as this allows for opposing muscle groups to alternate between resting and working in each subsequent exercise.
I believe most people can perform high intensity exercises, provided you listen to your body and work out according to your current level of fitness and ability. I personally modified the Peak 8 to a Peak 6 this year as it was sometimes just too strenuous for me to do all eight repetitions. So by listening to my body and cutting it back to six reps, I can now easily tolerate the workout and go all out. That said, the authors stress that there are some contraindications for their program:
“Because of the elevated demand for exercise intensity in high intensity circuit training protocols, caution should be taken when prescribing this protocol to individuals who are overweight/obese, detrained, previously injured, or elderly or for individuals with comorbidities.
For individuals with hypertension or heart disease, the isometric exercises (wall sit, plank, and side plank) are not recommended. The isometric exercises can be substituted with dynamic exercises.
For all individuals, the Valsalva maneuver should be avoided, particularly for the isometric exercises. Proper execution requires a willing and able participant who can handle a great degree of discomfort for a relatively short duration. It is also essential that participants in an HICT understand proper exercise form and technique. As with all exercise programs, prior medical clearance from a physician is recommended.”
I firmly believe that most people would benefit from high intensity exercises but the key is to start very slowly if you have any of the risk factors listed above. You might actually require several months to work up to a high intensity level. But as long as you start at a safe level and continue to push yourself to progressively higher levels, you will eventually reach a level of intensity that will provide the benefits.
Remember, while your body needs regular amounts of stress like exercise to stay healthy, if you give it more than you can handle your health can actually deteriorate. So it’s crucial to listen to your body and integrate the feedback into your exercise intensity and frequency. When you work out, it is wise to really push as hard as you possibly can a few times a week, but you do need to wisely gauge your body's tolerance to this stress.
Why High Intensity Interval Training May Be Ideal for Most
Contrary to popular belief, extended extreme cardio, such as marathon running, actually sets in motion inflammatory mechanisms that damage your heart. So while your heart is indeed designed to work very hard, and will be strengthened from doing so, it’s only designed to do so intermittently, and for short periods—not for an hour or more at a time. This is the natural body mechanics you tap into when you perform HIIT.
Repeatedly and consistently overwhelming your heart by long distance marathon running, for example, can actually prematurely age your heart and make you more vulnerable to irregular heart rhythm. This is why you sometimes hear of seasoned endurance athletes dropping dead from cardiac arrest during a race. I ran long distance for over four decades. So please learn from my experience and don’t make the same mistake I did.
Compelling and ever-mounting research shows that the ideal form of exercise is short bursts of high intensity exercise. Not only does it beat conventional cardio as the most effective and efficient form of exercise, it also provides health benefits you simply cannot get from regular aerobics, such as a tremendous boost in human growth hormone (HGH), aka the “fitness hormone.”
What Makes HIIT so Effective?
Your body has three types of muscle fibers: slow, fast, and super-fast twitch muscles. Slow twitch muscles are the red muscles, which are activated by traditional strength training and cardio exercises. The latter two (fast and super-fast) are white muscle fibers, and these are only activated during high intensity interval exercises or sprints. The benefit of activating these fibers is that they will produce therapeutic levels of growth hormone, which many athletes spend over a $1,000 a month to inject themselves with. So there is no need to pay the money or take the risks when your body can produce growth hormone naturally through high intensity exercises.
Getting cardiovascular benefits requires working all three types of muscle fibers and their associated energy systems -- and this cannot be done with traditional cardio, which only activates your red, slow twitch muscles. If your fitness routine doesn't work your white muscle, you aren't really working your heart in the most beneficial way. The reason for this is because your heart has two different metabolic processes:
- The aerobic, which requires oxygen for fuel, and
- The anaerobic, which does not require any oxygen
Traditional strength training and cardio exercises work primarily the aerobic process, while high intensity interval exercises work both your aerobic AND your anaerobic processes, which is what you need for optimal cardiovascular benefit. This is why you may not see the results you desire even when you're spending an hour on the treadmill several times a week. So when it comes to high intensity exercises, less really is more...
For Optimal Health, Add Variety to Your Exercise Program
In addition to doing HIIT a couple of times a week, it’s wise to alternate a wide variety of exercises in order to truly optimize your health and avoid hitting a plateau. As a general rule, as soon as an exercise becomes easy to complete, you need to increase the intensity and/or try another exercise to keep challenging your body. I recommend incorporating the following types of exercise into your program on days when you’re not doing high intensity anaerobic training:
- Strength Training: If you want, you can increase the intensity by slowing it down. You need enough repetitions to exhaust your muscles. The weight should be heavy enough that this can be done in fewer than 12 repetitions, yet light enough to do a minimum of four repetitions. It is also important NOT to exercise the same muscle groups every day. They need at least two days of rest to recover, repair and rebuild.
For more information about using super slow weight training as a form of high-intensity interval exercise, please see my interview with Dr. Doug McGuff.
- Core Exercises: Your body has 29 core muscles located mostly in your back, abdomen and pelvis. This group of muscles provides the foundation for movement throughout your entire body, and strengthening them can help protect and support your back, make your spine and body less prone to injury and help you gain greater balance and stability.
- Stretching: My favorite type of stretching is Active Isolated Stretching (AIS) developed by Aaron Mattes. With AIS, you hold each stretch for only two seconds, which works with your body's natural physiological makeup to improve circulation and increase the elasticity of muscle joints. This technique also allows your body to repair itself and prepare for daily activity. You can also use devices like the Power Plate to help you stretch.