MUNCIE, Indiana—Octogenarian women were unable to increase muscle mass after a 3-month weight lifting program targeted at strengthening the quadriceps, according to a new study from the Journal of Applied Physiology.¹ The results are surprising because previous studies had shown that resistance training would increase muscle mass, even for people who are into their 70s.

Senior author Scott Trappe, PhD, FACSM, told MSKreport.com, “The good news is that the octogenarians still got stronger. The bad news is that even though they get stronger, we can't get the muscles to grow in women in their 80s.” Dr. Trappe is John and Janice Fisher Professor of Exercise Science and Director of the Human Performance Laboratory at Ball State University in Muncie, Indiana.

The results in the octogenarians were something of a surprise, since earlier work with subjects in their 70s had shown gains in both strength and muscle mass from resistance training. “We expected that everyone would respond with increased muscle growth. Our findings were a surprise, in view of our previous work with people only a decade younger, and the fact that the study population were quite healthy, independently living subjects.”

The researchers suspect that the octogenarians were able to lift more weight after the training program because the nervous system became more efficient at activating and synchronizing muscles.

No change in muscle mass

Biopsy results confirmed the MRI studies that showed no change in the size of the individual muscle strands, pre-training versus post-training. This confirmed that the increase in the amount the women could lift with the quadriceps was unrelated to improvement in muscle strength.

In an earlier study, the researchers had found that the muscles of octogenarian men also failed to gain strength with the exercise program. Together, the studies show that the muscles of octogenarian men and women are far less responsive to improving with exercise, even compared to people only 10 years younger.

Dr. Trappe suspects that this might be due to higher levels of “basal stress” in those in their 80s, who also have different gene expression profiles than those in their 70s. “Perhaps the muscle is switched on and is already doing all that it can do in these subjects,” he said.

Muscles and aging: Translating research into practice

For clinicians, Dr. Trappe said that the important point is to urge patients to build as much muscle mass as possible while still in their 60s and 70s.

“Bank as much muscle as you possibly can,” he said. “Remember, skeletal muscle is not just a locomotor tissue. It is the largest metabolic reservoir in the body, intricately involved in our overall health. Sarcopenia creates problems for general health as well as for getting around.”

Reference

1. Raue U, Slivka D, Minchev K, Trappe S. Improvements in whole muscles and myocellular function are limited with high-intensity resistance training in octogenarian women. J Appl Physiol. 2009; [epub ahead of print] 26 February 2009; doi:10.1152/japplphysiol.91587.2008.