Strength training is proven to lower blood glucose in type 2 diabetics [1, 2, 3]. The magnitude of the decrease in blood glucose varies, but the highest average decrease in hemoglobin A1c (a measure of blood glucose over three months) that I have seen in research is 1.1% [1, 2]. This change is especially impressive when considering that the comparison groups, whom did not strength train, experienced changes in the other direction. Not only does strength training prevent the progression of type 2 diabetes, it reverses the condition.
These studies used two or three sets per exercise. I train my clients and myself using one set per exercise. I prefer single set training for the efficiency - my clients are busy people, as am I, and the single set training allows us to directly train all major muscles twice per week in only two or three 20-minute workouts. Working out for such little total weekly time also leads to a high rate of adherence, which is an area that people generally struggle with.
For type 2 diabetics who have little free time, don't like exercise, or prefer a single set routine for other reasons, can using one set per exercise improve your blood glucose?
Single Set Training for Diabetics
To answer this, I'm going to talk about a client experience, then discuss some research.
Ron was a 68-year old man who had diabetes over 10 years. Besides daily house work, he performed no exercise and followed no dietary guidelines. Ron and I worked together three times per week performing one set till complete fatigue for five exercises: the leg press, row, chest press, shoulder press, and biceps curls. Each workout required about 10-15 minutes.
Within six months, Ron's hemoglobin A1c decreased from 6.5% to 6.1%. This is enough of a change to bring Ron from a diabetic to a prediabetic range. I found this change to be impressive considering that Ron made no other lifestyle changes, including diet (at his preference).
Ron is one of several diabetics whom I have used single set routines with while during the process of their transformation from a diabetic to prediabetic or healthy blood glucose range. However, the others made other lifestyle changes, so it's hard to quantify exactly what the role of strength training is.
In regards to research, I have come across one study that used a single set routine with type 2 diabetics . This study, published in The Journal of the American Medical Association (JAMA), studied diabetics who had an average hemoglobin A1c of 7.7% and averaged 56 years old. The strength training group performed nine exercises per workout - one set per exercise - with a frequency of twice per week. The study lasted nine months.
The trainees experienced decreases in hemoglobin A1c ranging from 0.3 to 1.0%. Forty-one percent of the group either experienced an improvement of 0.5% and/or were able to decrease their diabetic medications. In total, the strength training program required only 30 to 40 minutes per week.
However, there's one catch: the participants also walked briskly for about 100 minutes per week. Therefore, I can't say that single set strength training is proven to be enough of a stimulus for improvement by itself.
Putting the Information to Use
Who doesn't enjoy a good anecdote when looking for answers? Ron's success shows that people can improve their blood glucose with single set training. However, anecdotes aren't scientific or generalizable.
The results of the JAMA study show that single set training can produce major improvements when combined with an activity as simple as walking. The diabetic men and women that I work with support single strength training as an effective pair with another lifestyle change (typically diet). If you have type 2 diabetes, I highly recommend single set training, but complement your training with another lifestyle improvement at some point.
I'll discuss more research-based lifestyle changes for type 2 diabetics in future posts.