Skip Navigation LinksHome > May 2008 - Volume 2 - Issue 2 > Weight Training Has A Good Rep For Cardiovascular Health
HEART Insight:
doi: 10.1097/01.HEARTI.0000319864.87202.03
Features: Fit & Happy

Weight Training Has A Good Rep For Cardiovascular Health

Fuerst, Mark

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Abstract

Your Heart Is The Most Important Muscle In Your Body!

You know that Old Wives' Tale that you shouldn't lift weights if you have heart disease or high blood pressure? Not so, according to recent research. In fact, a well-rounded physical activity program that combines strength training with aerobic activity is good for your heart — and overall health.

“Exercise is for everybody. If you can do aerobic activity, you should be able to do resistance [weight] training,” says Kerry J. Stewart, Ed.D., Director of Clinical and Research Exercise Physiology at Johns Hopkins University in Baltimore, MD.

Weight training strengthens the heart, as well as other muscles. Unlike aerobic activity, strength training dramatically increases muscle mass. You're not only going to get stronger, but your basal metabolic rate will go up — even when you're asleep. Strength training also gets results fast — do it twice a week for a few weeks, and you'll start to see and feel your body get toned, compared with three times a week with aerobics.

“Aerobic activity is not the only thing that's important. Muscle strength also has a potential benefit to the cardiovascular system,” says Robert H. Eckel, M.D., Professor of Physiology and Biophysics at the University of Colorado at Denver.

Muscle strengthening can help prevent and manage heart disease by reducing some of the risk factors. “There is good evidence that resistance training reduces total body fat. Weight training increases lean muscle mass and maintains body strength, so you're able to do more or higher levels of aerobic activity,” says Randy W. Braith, Ph.D., director of the Clinical Exercise Physiology Laboratory at the University of Florida in Gainesville.

Working out with weights can also reduce blood pressure by an average 3 mmHg (millimeters of mercury). Though modest, this drop may be enough to reduce your risk of a stroke or of dying of a heart attack. Blood pressure does increase slightly just as you lift a weight, but this fleeting stress on the heart is less than with aerobic activity, says Stewart.

And like aerobic exercise, strength training may also improve insulin sensitivity, particularly for those who have type 2 (adult onset) diabetes. “The more muscle, the greater the capacity and efficiency for using glucose, which is a primary fuel needed for life,” notes Stewart.

Weight training has other health benefits, too. Research shows muscle strengthening will protect you against bone loss and helps boost longevity. “Muscle strengthening helps prevent frailty and falls. Most people think weak bones cause fractures, but actually it's falls. Weight training can help prevent falls and improve bone mineral density so bones are less susceptible to osteoporosis,” Stewart says.

Best of all, your quality of life will improve. For one thing, if you're an older adult, you may be able to live independently for longer than those who do not exercise with weights. An Israeli study of 463 70-year-olds found those who were physically active were more likely to continue to live independently after seven years. “Muscle loss is the most deleterious consequence of aging. Older adults are more concerned about possessing enough strength to get out of a recliner, climb a flight of stairs or lift groceries. Strong legs enable the other organ systems of the body to operate at their full potential,” says Braith.

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HEAVY LIFTING

The American Heart Association (AHA) and the American College of Sports Medicine updated their guidelines on physical activity for healthy adults in August 2007 to emphasize weight lifting as a complement to aerobic activity. The guidelines recommend moderate aerobic activity — such as walking briskly, bicycling at 10–12 miles per hour, or shooting a basketball around — for at least 30 minutes five days a week — or vigorous aerobic activity for at least 20 minutes three days a week — and add weight training on two of those days, skipping at least one day in between to avoid muscle soreness or injury.

Your strength training regimen should include eight to ten resistance exercises that work the major muscle groups in the arms and legs. A typical strength training program includes chest press, shoulder press, triceps extension, biceps curl, pull-down, lower back extension, abdominal crunch, quadriceps extension or leg press, leg curls and calf raise. Ask a trainer at your gym to explain these exercises, and show you how to make sure you're not cheating by using muscles other than the ones you are supposed to be working to assist you in the lifting or exertion phase of the exercise.

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You can perform these exercises using free weights, such as dumbbells or barbells, or with a weight machine. For beginners, a weight machine may be more effective than free weights because they also work the muscles through the full range of motion, which better develops the muscles and helps to prevent injury. “Free weights are a bit more cumbersome and don't guide you through a full range of motion. Also, you might drop the weight on your foot,” says Stewart.

If you are too weak to use the lowest setting on the weight machines, start out with resistance bands (these are made of latex and look like long sashes or huge rubber bands), or consider weighted balls that range from one to six pounds. As you get stronger, you can progress to weight machines.

An AHA Scientific Statement on weight training regimens for people with and without heart disease recommends that healthy adults can do 8 to 12 repetitions for each of the eight to ten resistance exercises using a weight that doesn't cause straining. If you have to jerk the weight in order to lift it, or your veins pop out of the sides of your neck, then you're straining. The recommended amount of weight to start with is 30 to 40 percent of the most you can lift one time for upper body exercises and 50 to 60 percent of maximum for lower body exercises. Ask a trainer to help you figure out how much you can safely lift.

If you have been diagnosed with heart disease, are over the age of 50 or are frail — that is, you get very little physical activity, walk very slowly and have weak grip strength — you should limit yourself to 10 to 15 repetitions with a weight that is no heavier than 40 percent of the most you can lift one time for all exercises. Remember, even if you start out doing more reps at a lower weight, by working each muscle group until it's fatigued, your strength will increase over time — and so too will the amount you will be able to lift.

You don't have to do an endless series of repetitions of each exercise to get results. Just one set of reps will do the trick. “You can do a full muscle-strengthening routine in 15 to 20 minutes,” promises Eckel.

If you enjoy getting wet — or just want a change of pace — you could also hit the pool and do a regimen of water-based aerobic and resistance exercises that are done standing up, sometimes wearing a weighted belt or vest to keep you from floating around. A study published last year in American Heart Journal with people who have coronary artery disease found that resistance exercises done standing in a pool are just as effective as those done standing on the floor. After four months, the 32 study participants had improved muscle strength, and had lost an average of four pounds, lowered total cholesterol by three to four percent and lowered triglyceride levels 10 to 12 percent — whether they exercised in the pool or in the gym. One caveat: If you have coronary artery disease and want to get in a few laps along with strength training in the pool, check your pulse from time to time so you know your heart rate is within the range your doctor recommends.

The most efficient way to combine strength and aerobic workouts may be circuit weight training. For this, you move quickly from one weight training exercise to the next and do a short burst of aerobic activity (jog in place, jump rope) for 30 seconds in between. “This helps maintain enough muscle tone and strength training to provide the health benefits,” says Stewart. His pioneering research with patients in cardiac rehab, first published in the Journal of the American College of Cardiology in 1986, demonstrated that three days a week of weight training for 10 weeks improved strength 24 percent. Several studies since then also showed similar benefits for those with metabolic syndrome (a combination of several heart disease risk factors, such as obesity and high cholesterol) and older people who have high blood pressure. Stewart is now investigating whether type 2 diabetics will be helped by weight training as well.

When it comes to muscles, the old expression “use it, or lose it” certainly applies. Muscles don't care how you work them, as long as you do work them. “Once you start lifting more weight, you'll gain self-confidence and be able — and want — to do more,” says Stewart.

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Weight Training Dos And Don'ts

If you have been diagnosed with heart disease, or are taking medications for a heart-related problem, get a complete physical and your doctor's approval before starting a strength training program, emphasizes Kerry Stewart, Ed.D., of Johns Hopkins University. Here are some tips to get the most out of your weight training workouts:

DO:

▪ Warm up with an aerobic activity, such as a brisk walk or jogging for 10 minutes first.

▪ Use a weight heavy enough that you can do only 8–12 repetitions of each exercise.

▪ Alternate between upper and lower body work to allow for adequate rest between exercises.

▪ Work out rhythmically at a moderate-to-slow, controlled speed through a full range of motion.

▪ Breathe freely. Exhale during the contraction or exertion phase of the lift, and inhale during the relaxation phase. Holding your breath during the lift can raise your blood pressure.

▪ Maintain a secure — but not too tight — grip on weights to prevent a rapid rise in blood pressure.

DON'T:

▪ Continue exercising if you feel dizzy, short of breath, have chest pain or irregular heart beats.

▪ Hold your breath while lifting.

▪ Start a weight training program if you have unstable heart disease, uncontrolled high blood pressure or irregular heartbeats, infections in and around the heart or Marfan syndrome (a genetic disorder that can cause the heart valves to allow blood to leak backward into the heart and can weaken the aorta, increasing the risk of an aneurysm forming in the wall of this artery that carries blood from the heart to the rest of the body). Weight training may put too much strain on the heart for people who have these conditions.

▪ Lift more than 80 percent of what you can heft at one time if have proliferative retinopathy, a complication of diabetes in which tiny blood vessels grow on the surface of the retina, as you will raise your blood pressure and cause these vessels to burst and leak.

© 2008 American Heart Association, Inc.

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