Exercise is important for people with diabetes -- especially type 2 diabetes -- because it helps regulate blood sugar and provide cardiovascular fitness that protects against heart and artery disease.
But which type of exercise is best? Cardio, weights, walking -- or perhaps a combination of aerobic and resistance training?
That's apparently what a team of scientists at the University of Calgary attempted to find out by evaluating 251 adults, aged 39 to 70, all with type 2 diabetes and whom were not regular exercisers. The scientists formed four groups and gave them different programs:
- One group did aerobic (cardio) exercise for 45 minutes, three times each week.
- Another group did resistance (weights) training for 45 minutes, three times each week.
- A third group did both cardio and weights for 45 minutes each and three times each week.
- A fourth group did no exercise at all.
The study team measured a key indicator of blood glucose levels in type 2 diabetics, known as A1c, before and after the various exercise programs. A1c is an indicator of blood glucose over the previous 2 to 3 months.
Would it surprise you to hear that A1c dropped by twice as much in the group that did the combined cardio and the weights? Well, that's exactly what occurred. . .but they did twice as much exercise didn't they? The results for the cardio or weights groups alone were similar to each other and the A1c lowering effect was doubled in the combined group.
While this story created headlines all around the world, did it really answer the question "which exercise is best?" No it did not, but what it did suggest is that either aerobic or resistance training is equally good at lowering A1c.
And, that doing both provides an additive effect, which may not have been as obvious an outcome as it first seems.
Source: Sigal RJ, Kenny GP, Boule NG, et al. Effects of aerobic training, resistance training, or both on glycemic control in type 2 diabetes: a randomized trial. Ann Intern Med. 2007 Sep 18;147(6):357-69.