Patients with type 2 diabetes experience better glycemic levels if they perform both aerobic and resistance exercises, compared to patients with diabetes who don’t do them, researchers from Louisiana State University System, Baton Rouge wrote in JAMA (Journal of the American Medical Association). Patients who did just one or the other, either resistance training or aerobic exercise did not enjoy the same improvements, the authors added.

It has been known for a long time that individuals with type 2 diabetes benefit substantially from exercises. However, nobody has been very sure what type – aerobic or resistance – is best.

The authors wrote:

    “Given that the 2008 Federal Physical Activity Guidelines recommend aerobic exercise in combination with resistance training, the unanswered question as to whether for a given amount of time the combination of aerobic and resistance exercise is better than either alone has significant clinical and public health importance.”

Timothy S. Church, M.D., M.P.H., Ph.D., set out to find out what effect aerobic training, resistance training, or both might have on 262 sedentary male and female patients with type 2 diabetes. Specifically, they measured A1c levels (HbA1c, a minor component of hemoglobin and to which glucose is bound). HbA1c levels can tell the doctor and patient how well the diabetes is being controlled.

63% of the patients were female, the average age of all of them (male and female) was 56 years, they had HbA1c level of 7.7% and duration of diabetes of 7.1 years. 47.3% of them were not Caucasian.

Between April 2007 and August 2009 they entered the following exercise programs:

  • A non-exercise control group – 41 participants
  • Resistance training group – 73 participants
  • Aerobic training group – 72 participants
  • Combined aerobic and resistance training group (combination group) – 76 participants

The absolute change in HbA1c in the combination group compared to the control group was -0.34%.

The resistance group’s absolute change at -0.16%, and the aerobic group’s -0.24% were not considered significant.

The prevalence of hypoglycemic medication increases were 18% in the combination group, 22% in the aerobic group, 32% in the resistance training group, and 39% in the control group.

The authors wrote:

    “Only the combination exercise group improved maximum oxygen consumption compared with the control group. All exercise groups reduced waist circumference from [-.75 to -1.1 inches] compared with the control group.”

The combination group lost 3.7 lbs in mass fat compared to the control group. The resistance group lost 3.1 lbs compared to the control group.

The authors wrote:

    “The primary finding from this randomized, controlled exercise trial involving individuals with type 2 diabetes is that although both resistance and aerobic training provide benefits, only the combination of the 2 were associated with reductions in HbA1c levels. It also is important to appreciate 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.”

In an Editorial in JAMA, Canadian researchers, Ronald J. Sigal, M.D., M.P.H., Glen P. Kenny, Ph.D., and Dr. Sigal wrote:

    “Based on the results of the HART-D trial, patients with type 2 diabetes who wish to maximize the effects of exercise on their glycemic control should perform both aerobic and resistance exercise. The HART-D trial clarifies that, given a specific amount of time to invest in exercise, it is more beneficial to devote some time to each form of exercise rather than devoting all the time to just one form of exercise.”

“Effects of Aerobic and Resistance Training on Hemoglobin A1c Levels in Patients With Type 2 Diabetes – A Randomized Controlled Trial”
Timothy S. Church, MD, MPH, PhD; Steven N. Blair, PED; Shannon Cocreham, BS; Neil Johannsen, PhD; William Johnson, PhD; Kimberly Kramer, MPH; Catherine R. Mikus, MS; Valerie Myers, PhD; Melissa Nauta, BS; Ruben Q. Rodarte, MS, MBA; Lauren Sparks, PhD; Angela Thompson, MSPH; Conrad P. Earnest, PhD
JAMA. 2010;304(20):2253-2262. doi:10.1001/jama.2010.1710

Written by Christian Nordqvist