Objectives: The objectives of this study were to determine the effects of a strength-training program on walking speed and relative muscular stress, as measured by normalized integrated electromyographic (nIEMG) activity, while carrying a box of groceries and standing from a chair.
Design: Prospective intervention study.
Setting: Volunteer subjects from the community of Birmingham, Alabama.
Participants: Fourteen healthy women aged 60 to 77 years.
Intervention: Sixteen weeks of total body strength conditioning.
Measurements: Before and after 16 weeks of strength conditioning, the following variables were evaluated for all subjects: (1) strength, six isotonic tests and two isometric tests; (2) walking velocity; (3) nIEMG of the biceps while carrying a box of groceries; and (4) nIEMG of the rectus femoris while standing from a chair.
Main results: After the strength training program, subjects' isotonic strength increased significantly, an average of 52% on the isotonic tests and 31% on the isometric tests. Walking velocity also increased significantly (18%). nIEMG of the biceps decreased 36% while carrying a box of groceries. Rectus femoris nIEMG decreased 40% while standing and 47% while sitting.
Conclusions: After strength conditioning, healthy older women showed not only substantially increased strength but also improvements in walking velocity and the ability to carry out daily tasks such as rising from a chair and carrying a box of groceries.