Strength Training to Combat Type 2 Diabetes

Obesity rates around the world continue to rise, and with it has come a stark increase in the number of cases of prediabetes and Type 2 diabetes. In fact, the Center for Disease Control estimates that over 100 million Americans are either diabetic or prediabetic. ^[1]

Recent studies have shown that building muscle, a.k.a. making gains, may be an effective strategy to lower an individual’s’ of developing the disease or reducing its progression. And, this really comes as no surprise, as researchers have known for quite some time that building muscle via resistance training also confers many other benefits including increased cognition, elevated mood, better body composition, and improved lipid profiles. ^[2][3]

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But the latest research indicates that you don’t need to devote yourself to team “no days off” in order to build muscle and reduce your risk of type 2 diabetes. In fact, even moderate amounts of strength training significantly lower a person’s risk.

This is particularly noteworthy as many individuals commonly cite a “lack of time” as one reason why they don’t engage in structured resistance training more often. Well, as we’ll discuss in more detail below, the amount you need to do isn’t nearly as much as you might think.

The Study

Researchers collected data from 4,681 adults from the cohort study’s beginning in 1981 until its conclusion in 2006. At the outset of the trial, none of the subjects had type 2 diabetes.

Study participants took part in muscular strength tests (chest and leg presses) as well as maximal treadmill exercise tests between January 1, 1981, and December 31, 2006. ^[4]

Due to the large age span of individuals in the trial (20-100 years old, median age 43.3±9.5) measurements tracked were adjusted for age, gender and body weight since they could be potential confounders. Average follow-up time for the participants from initial testing was 8.3 years.

The Results

After collecting data of the 25-year cohort study, researchers noted that 4.9% of the 4,681 participants (229 total subjects) developed type 2 diabetes. ^[4]

Subjects with a “moderate” level of strength had a 32% lower risk of developing the disease compared to individuals of lower levels of strength, after adjusting for the aforementioned confounding variables.

One particularly interesting finding from the study was that participants who gained moderate strength experienced reductions in their risk of type 2 diabetes independent of other lifestyle choices such as drinking, smoking, cardiorespiratory fitness, or other health issues like hypertension (high blood pressure) or obesity.^[4]

Angelique Brellenthin, Ph.D., a co-author of the study, remarked on the findings:

“Increasing or maintaining muscular strength does not need be complicated. The physical activity guidelines for muscle-strengthening activities are to engage in these activities two times per week, and to hit all your major muscle groups. Beginners can see improvements in strength with simple at-home bodyweight exercises like squats, lunges, push-ups, and core exercises. As you gain strength, you can consider adding extra tools like elastic bands, machine weights, or free weights.” ^[4]

In other words, you don’t have to dedicate yourself to the temple of the iron to build muscle and strength, even doing as little as two full body sessions per week is enough to realize moderate increases that can significantly reduce your risk of developing diabetes.

The Power of Muscle & Strength

Additional studies in past years have found inverse relationships between the amount of muscle and strength (relative to body size) an individual has and the prevalence of prediabetes, insulin resistance, and metabolic syndrome. ^[5][6]

In other words, the more muscle and strength an individual has the less likely they are to develop insulin resistance, metabolic syndrome, and type 2 diabetes.

In fact, one study from 2011 noted that for every each 10% increase in the skeletal muscle index (ratio of muscle mass to total body weight) an individual has, there is a 12% drop in prediabetes and an 11% decrease in insulin resistance. ^[5]

So, what is it about building muscle and strength that helps stave off the progression of these metabolic maelstroms?

Let’s discuss.

Exercise, Muscle Mass, and Insulin Sensitivity

As we stated previously, researchers have known for several years that the more muscle a person has, the more insulin sensitive they are. This is due to the fact that the more muscle an individual has, the larger “sink” they have available in which to store glucose -- increasing their glycemic control. ^[7]

Science has also shown that both aerobic exercise (cardio) and resistance-training increase insulin sensitivity. In fact, a single bout of exercise has been noted to enhance an individual’s insulin sensitivity for up to 48 hours post-training, depending on the type of exercise. ^[9]

And as a side “benefit”, regular exercise also helps reduce visceral adiposity, which is quite often associated with insulin resistance. ^[8]

But, even if you are overweight (and/or have diabetes), resistance training still has been shown to increase insulin sensitivity in those individuals too. ^[10][11]

So, in other words, everyone should be exercising...that is if they want to avoid insulin resistance and the host of complications that stems from it.

Only recently though have researchers begun to understand the many different ways through which exercise boosts insulin sensitivity.

First, during actual exercise, repeated muscle contractions lead to increases in AMPK activity, deactivating protein TCB1D1, which boosts GLUT4 translocation, ultimately enhancing glucose uptake into skeletal muscle. ^[12]

Another mechanism by which exercise boosts insulin sensitivity comes via the increased capillarization that occurs in skeletal muscle as a result of exercise. ^[12] This increased network of blood vessels provides a separate (and independent) adaptation that heightens insulin sensitivity.

And, exercise also increases β cell activity. Β cells are special cells in the pancreas tasked with producing and secreting insulin.

More recently, scientists have another one of the exact mechanisms by which resistance training enhances insulin sensitivity -- it amplifies the effects of a protein in the body that regulates blood sugar absorption in the body called APPL1. ^[13]

For those of you curious what APPL1 stands for -- Adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1.

Now, do you really need to know the myriad of ways exercise helps build muscle, increase strength, and improve insulin sensitivity.

No, not really.

But, it is worth it to understand that when you exercise with intensity, you’re doing something incredibly good for your body, and in more ways than one.

Exercise helps reduce fat, build muscle, enhance strength, heighten insulin sensitivity, uplift mood, amplify productivity, and significantly reduce your risk of chronic disease.

So, what are you waiting for?

Stop reading this article and get moving!

References