Reuters Health just published an article regarding a study done by Dr. Ronald Sigal, an endocrinologist at the University of Calgary in Canada. In this study, people with type 1 diabetes were monitored while exercising.
Type 1 diabetes is a condition, usually diagnosed in children, in which the body does not produce its own insulin, a hormone needed to convert food into fuel. Because of this there is a risk of low blood sugar during exercise. So if the people in this study had blood sugar levels below a certain level, they had to stop and eat a snack.
Researchers found that if a participant did aerobic exercise first, their blood sugar level fell to a dangerous level very quickly, but if they did weight lifting first, they were able to exercise much longer without the need to stop for a snack.
This agrees with previous research showing that aerobic exercise causes a more rapid decrease in blood sugar than weightlifting.
There were only 12 people in the study, so it needs to be repeated with more participants, but it makes an interesting point: People with type 1 diabetes who tend to develop low blood sugar during exercise should consider weight lifting first.