Most people can build muscle through strength training, it has long been thought — even people in their 80s who have never hoisted a dumbbell.
However, this doesn't mean older women are off the hook from working out — the study also found that despite the lack of muscle growth, the participants could lift more weight after the weight training program.
The study focused on two small groups of women: six in their 80s, and nine in their late teens and early twenties, which acted as a control group. Both completed a 12-week strength training program that focused on high-intensity, progressive resistance training for their quadriceps, or thigh muscles. Thigh muscle size was measured via MRI at the beginning of the workouts and the end, and biopsies of thigh muscles were taken to see if the muscles changed at the cellular level. Researchers looked at fast- and slow-twitch muscle fibers; the first is used in explosive movement, while the second is employed in endurance activity.
At the start of the study, the older women's thigh muscles were 23% smaller than those of the younger women, and the older women had 36% less strength in their knee extensors. MRI results showed that after the training session, muscle size in the older women stayed the same, while younger women showed improvement. The biopsies also revealed that muscle fibers did not increase.
However, the older women were able to lift 26% more by the end. Researchers believe the change could be due to a more efficient nervous system that was better able to stimulate the muscles and coordinate them to get the job done.
Though the results are somewhat disappointing, it demonstrates the importance of maintaining a regular exercise program throughout life to prevent substantial muscle loss. The study was done out of the Human Performance Laboratory at Ball State University in Tennessee, and was published in the February issue of the Journal of Applied Physiology.
-- Jeannine Stein
Photo credit: Yoshikazu Tsuno / AFP/Getty Images