Adding Intervals of intensity to your treadmills workout

Here is an interesting topic about interval training. Gives you a stronger heart and burns more calories. Here it is:

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Add intervals of intensity for a stronger heart
By Harvard Health Publications

When it comes to exercise, interval training offers the best of both worlds.

When faced with an arduous physical task, most people break up the work with short periods of rest. Piano movers alternate bursts of heavy lifting with rest breaks; people with severe heart failure stop every now and then when climbing stairs. Giving stressed muscles time to recover lets them work harder and longer. The same thing holds true for conditioning the heart. For people with various forms of heart disease, an exercise plan that alternates bursts of intense activity with periods of rest or gentler activity seems to be better than longer stretches of continuous activity.

This pattern, called interval training, has long been the province of sports trainers and competitive athletes. Now it’s slowly entering the realm of cardiac rehabilitation and fitness centers. Done formally or informally, interval training can strengthen healthy hearts and help heal damaged ones. It’s also a boon for people who are watching their weight and those battling diabetes.

Bursts of intensity

Interval training alternates bursts of more intense activity, like jogging, with periods of moderate activity or even rest. Adding spurts of vigorous activity burns more calories and benefits the heart and arteries.

Olympic start

Interval training emerged from Central Europe in the late 1940s, the brainchild of athletic trainers looking for ways to give their long-distance runners an edge. It spread to swimmers and other elite athletes. An interval training plan that involved swimming 50 meters as fast as possible, resting for 10 seconds, and repeating this swim-rest cycle two dozen times before stopping helped the U.S. swim team take 13 of 16 gold medals at the 1964 Olympics in Tokyo. Interval training is now an integral element of high-level sports.

It didn’t take long before a few forward-thinking cardiologists applied interval training to healing damaged hearts. In the early 1960s, Dr. Vojin Smodlaka, a cardiologist at Valley Forge Medical Center and Heart Hospital in Norristown, Pa., asked dozens of his heart patients to try interval training on a stationary bicycle. From these experiments, he concluded that interval training was as safe as regular, continuous exercise and reconditioned the heart more efficiently.

The idea of interval training for heart patients didn’t catch on, partly because many doctors at the time believed that people with heart disease needed rest, not activity. Today, even though exercise is considered essential for maintaining and rehabilitating the heart, interval training remains a footnote.

Over the years, though, a few research teams have extended the work of Dr. Smodlaka and his colleagues. German studies in 1997 and 2002, a Canadian study in 2005, one from Texas in 2006, and another from Norway in 2007 all show that interval training works for people with a range of cardiovascular conditions. It’s been tested for stable coronary artery disease (cholesterol-clogged and narrowed arteries), intermittent claudication (leg pain when walking), and heart failure (see “The promise of interval training for people with heart failure”). In each case, interval training bested traditional continuous exercise.

The promise of interval training for people with heart failure

The latest interval training study suggests that this form of exercise could counter some of the devastating consequences of post–heart attack heart failure. Norwegian researchers recruited a small group of heart attack survivors who had developed heart failure, the heart’s inability to keep up with the body’s demand for oxygen. For three months, some of the volunteers exercised in intervals: four minutes of treadmill walking fast enough to push their heart rates to 90% or more of their estimated maximal heart rate, followed by three minutes of slower walking. This was repeated five times, with a three-minute cool-down walk, for a total of 38 minutes of exercise. Others walked on a treadmill continuously for 45 minutes three times a week. The two regimens were designed to burn equal numbers of calories.

Interval training trumped continuous exercise in almost every aspect, from measures of cardiac fitness to the amount of blood the left ventricle pumped with each contraction (the left ventricular ejection fraction). It also reversed harmful changes in the heart’s size and shape. The results were published in the June 19, 2007 Circulation.

This one study doesn’t mean interval training cures heart failure. It merely shows it’s a possibility for people with this chronic condition. “While this is a compelling study, we don’t really know if more exercise is better for heart failure,” says Dr. Daniel Forman, who directs the exercise testing lab at Harvard-affiliated Brigham and Women’s Hospital. He is part of an ongoing study (Heart Failure — A Controlled Trial Investigating Outcomes of Exercise Training, or HF-ACTION), that is the largest to date to look at the impact of tailored exercise programs among a wide range of people with heart failure.

“There’s no question that exercise adds to health benefits beyond what pills alone can achieve,” says Dr. Forman. What works for healthy people, though, may not be best for those beset by heart failure. An important task for researchers is to find out what types of exercise cause the most beneficial physical and molecular changes in healthy and damaged heart muscle.

Why interval training is special

Walking is often held up as the gold standard for cardiovascular exercise. Most people can do it, it doesn’t require any special equipment, it’s easy on the knees and other joints, and a host of studies leave little doubt that walking strengthens the heart and lungs and improves the function of blood vessels. That said, there’s also at least as much research showing that more intense activities and exercises yield even bigger benefits. Yet many people shun the idea of taking up jogging or other forms of more intense exercise or don’t think they can sustain it. Interval training may offer the best of both worlds.

What makes this regimen special? For starters, it lets many exercisers spend more time doing a high-intensity activity than they could perform in a single stretch. Someone who couldn’t run full speed for 5 minutes straight might be able to run full speed for 10 minutes by doing it in ten 1-minute intervals and resting in between. Rest breaks give the body time to remove waste products that can make muscles sluggish, tired, or painful.

Working the heart and other muscles hard for brief spurts trains them to use oxygen more efficiently. It conditions them to work through brief periods when the demand for oxygen temporarily outstrips the supply. It helps the body create new muscle fibers. A handful of studies show that interval training also changes mitochondria, the tiny powerhouses that provide energy to cells, so they burn fat more efficiently.

Intense activity, even brief spurts of it, is better than moderate activity at turning on genes that promote the growth of new blood vessels, make blood vessels more flexible, intensify the body’s defenses against harmful antioxidants, and ease low-level inflammation.

All these changes have a tangible product: the ability to be more active. They also quietly guard against invisible forces that erode cardiovascular health — things like the entry of cholesterol into artery walls, the stiffening of arteries, or the accumulation of fat.

Resistance isn’t futile

To get the most out of exercise, put a little resistance in it by lifting weights, doing push-ups, or engaging in other muscle-building exercises. An update on resistance training, also called strength training, from the American Heart Association says it is a perfect mate for aerobic exercise for healthy folks and those with heart disease. In addition to strengthening the heart, resistance training builds bone, helps prevent falls, and makes it easier to do everyday tasks like getting dressed and carrying groceries.

Design your own

Outside of competitive sports, interval training isn’t a rigorously defined regimen. There’s no single formula for how long and how hard to exercise, or how long and how often to rest. You can try fartlek, a Swedish word that means speed play — you set the intervals based on how you feel on a particular day. Or you can set up a more scientific approach with help from a personal trainer or fitness expert. The main guidelines to apply are these:

* The high-intensity bursts should last long enough and be strenuous enough that you are out of breath. If you monitor your heart rate, it should be more than 80% of your maximum heart rate.
* Rest periods should be long enough that you are ready to go again, but not so long that your heart slows to its resting rate.
* Warm up before exercising and cool down afterward.
* Don’t do interval training on consecutive days. Let your muscles recuperate in between. Two or three times a week is plenty.

Interval training is most easily done on a treadmill, where you can tinker with the speed of the machine. But you can also do it anywhere you exercise — around the neighborhood, in a pool, on a bike ride or cross-country ski outing.

Say you usually walk for 30 minutes at a stretch. To add intervals, walk for five minutes to warm up. Then walk as fast as you can, or jog, for one minute. Go back to your usual pace, or even a bit slower, for three minutes. Repeat the fast walking–slower walking cycle five more times. Although the exercise session lasted 30 minutes, you burned more calories than you would have by walking continuously at the same speed and kicked off a series of small changes that, if you keep it up, will further strengthen your heart and circulatory system. Of course, that’s just a start. If you are in fairly good shape, you can spend more time walking faster or jogging and less time walking or resting.

If you are a jogger, bust out into a sprint now and then. If you swim, alternate fast and slow laps. If you bicycle, sprinkle your ride with a few Tour de France finishes.

A warning is in order. Interval training isn’t for everyone. Revving the heart rate way up could provoke cardiac arrest or other disasters in people at risk for them. So if you have heart disease, high blood pressure, or other risk factors, check with your doctor before starting interval training.

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Now you see a support on study on interval training, go workout with interval training.

Stay healthy and fit,

Jan Michael A. Buyco

P.S. set your timer on your treadmill into interval and have a great workout.