A scientific statement released Monday by the American Heart Association indicates that weight lifting, also known as resistance training, can provide multiple benefits for patients with heart disease and can be safely performed if certain guidelines are followed.

"Just like we once learned that people with heart disease benefited from aerobic exercise, we are now learning that moderate weight training also has significant benefits," Dr. Mark A. Williams, chair of the AHA writing group, said in a statement.

"Resistance training not only enhances the benefits of aerobic fitness, but it appears to provide the added benefit of increased functional capacity and independence. It helps people better perform tasks of daily living -- like lifting sacks of groceries," Williams, from Creighton University School of Medicine in Omaha, Nebraska, added.

Resistance training is also associated with improvements in quality of life and reduced disability in people with and without heart disease, according to the AHA statement, which will appear in the journal Circulation.

In the report, the writing group discusses the impact that resistance training has on the structure and function of the heart and how it modifies known risk factors for heart disease. For doctors, the report shows how to evaluate potential candidates for resistance training and details initial training recommendations.

Key recommendations for patients starting resistance training include:

--Perform exercises in a rhythmical manner at moderate to slow speed.
--Exhale during the exertion phase of weight lifting and inhale during the relaxation phase to avoid breath-holding and straining.
--Alternate between upper- and lower-body training to achieve adequate rest periods between exercises.

The statement also describes the appropriate resistance or weight load for patients initiating resistance training. For instance, the initial load should allow healthy sedentary adults to perform 8 to 12 repetitions per set.

"The emphasis at the early stage of training is to allow time for the muscles to adapt and to practice good technique, thus reducing the potential for excessive muscle soreness and injury," Williams explained.