• Future Students
• Current Students
• Alumni
• Faculty and Staff

• Arnold School Home
• Welcome
• Academic Departments
• Administrative Departments
• Office of Research
• Centers & Other Programs
• Communications
• News Archives
• Online Giving
• Contact Us

For people with type 2 diabetes, a new study in JAMA sheds light on effects of aerobic exercise, resistance training

November 24, 2010

Performing a combination of aerobic exercise and resistance training has been found to improve glycemic levels among patients
with type 2 diabetes, compared to patients who did not exercise,
according to a study in the Nov. 24 issue of the Journal of the American Medical Association.

The level of
improvement was not seen among patients who performed either aerobic
exercise or resistance training alone.

Dr. Steve Blair, an Arnold School researcher, was one of the authors of the study, led by Dr. Timothy S. Church of the Pennington Biomedical Research Center of Louisiana State University.

Although it has been generally accepted that regular exercise provides
substantial health benefits for individuals with type 2 diabetes, the
exact exercise type (aerobic vs. resistance vs. both) has been unclear, said Blair, who has faculty appointments in the Arnold School's Departments of Exericise Science and Epidemiology and Biostatistics.

"This research is supportive of the 2008 Physical Activity Guidelines from the U.S. Department of Health and Human Service," he said. "The study has significant clinical and public health implications."

Blair, Church and colleagues from the University of Missouri, Columbia, and Maastricht University Medical Center in the Netherlands conducted the HART-D trial,
which included 262 sedentary women and men with type 2 diabetes. They studied the effect of aerobic training, resistance training, and a combination
of both on change in hemoglobin A1c levels.

HbA1c is a minor component of
hemoglobin, the substance of red blood cells that carries oxygen to the
cells, and to which glucose (blood sugar) is bound. HbA1c levels are
used to monitor the control of diabetes mellitus.

Study participants
were 63 percent women, 47.3 percent nonwhite, average age of 56 years,
HbA1c level of 7.7 percent and duration of diabetes of 7.1 years.

The
individuals were enrolled in the nine-month exercise program between April
2007 and August 2009. Forty-one participants were assigned to the
nonexercise control group; 73 to resistance training sessions; 72 to
aerobic exercise sessions; and 76 to combined aerobic and resistance
training. 





The researchers found that the absolute change in HbA1c in the
combination training group vs. the control group was -0.34 percent. In
neither the resistance training (-0.16 percent) nor the aerobic (-0.24
percent) groups were changes in HbA1c significant compared with those in
the control group. The prevalence of increases in hypoglycemic
medications were 39 percent in the control, 32 percent in the resistance
training, 22 percent in the aerobic, and 18 percent in the combination
training groups.

Among the study's findings:

• Only the combination exercise group improved maximum oxygen consumption
compared with the control group.
• All exercise groups reduced waist
circumference from three-quarters of an inch to slightly more than an inch, compared with the control
group.
• The resistance training group lost an average
of 3.1 pounds fat mass and the combination training group lost an average
of 3.7 pounds, compared with the control group.

• Although both
resistance and aerobic training provide benefits for people with type 2 diabetes, only the combination
of the two were associated with reductions in HbA1c levels.

The study also found that that the
follow-up difference in HbA1c between the combination training group and
the control group occurred even though the control group had increased
its use of diabetes medications while the combination training group
decreased its diabetes medication uses.

The findings could change the recommendations that physicians and other healthcare professionals make for people with type 2 diabetes, Blair said.

"I hope that health professionals will give more attention to recommending a combination of aerobic and resistance

exercise programs," he said. "This research does support the value of combined exercise regimens for patients with type 2 diabetes."