Strength training is critical for diabetes prevention and is an excellent way to improve insulin sensitivity to promote a lean body composition. There is extensive research that strength training is as effective as aerobic exercise and likely provides significantly greater benefits for preventing diabetes and making sure your insulin is working at its best.
Even if you aren’t concerned about diabetes and insulin sensitivity, it’s likely you can inspire a loved one who is at risk for diabetes or already has the disease to train for a better quality of life and fewer negative symptoms. The evidence is convincing: resistance training not only improves insulin sensitivity and glucose uptake, it burns fat, supports heart health, helps people move better, and lowers depression in diabetics. In addition to training, there are a number of foods, micronutrients, herbs, and behaviors that can improve insulin sensitivity and prevent diabetes, which you need to be aware of.
Here, I review what insulin resistance is and provide research to support 13 strategies for preventing diabetes. This is Part 1, which highlights the ideal training protocols to prevent diabetes, and includes strategies for raising anabolic hormone levels that are critical for increasing insulin sensitivity. Tomorrow you’ll get Part 2, which will reveal diet and supplement strategies for diabetes prevention and a lean physique.
What is Insulin Resistance?
When you eat, glucose levels are elevated in the blood, leading the pancreas to secrete insulin. The insulin binds to cell receptors, which allow the glucose to enter the cell and be used for energy. Glucose that stays outside the cell is converted to fat for storage. Meanwhile, certain foods lead to high spikes of insulin, and if you have too much insulin secreted, the cells will become resistant to it, leading to fat gain and diabetes.
I’m A Lean, Built, Insulin Sensitive Machine. Why Should I Care?
Chances are, even if you have an excellent physique and perfect glucose uptake, you know someone who is not in as great shape as you. In fact, 8.3 percent of the American population already has diabetes and more than double that (80 million Americans) are prediabetic. I bet you have a loved one who would benefit significantly from this information and it may be of interest to you as you get older.
Additionally, there is interesting evidence from a study in Brownsville, Texas, which has a large diabetic population. The labor market and profitability are directly influenced by diabetes, meaning if you are a manager or business owner, your income may be affected by other people’s mismanagement of their own diabetes! The study found that individuals with diabetes are less productive and less likely to be employed than those without. Researchers suggest that prevention is most important and that individuals with diabetes need to be taught to better manage their disease in order to stay productive and in the work force—think diet and resistance training.
What is the Relationship Between Diet and Insulin?
Carbohydrates are the key to problems with insulin and glucose. Carbohydrates are converted into glucose after we eat them and then used as energy, once the glucose enters the cell. If the body is insulin resistant or the glucose can’t get into the cell, then you have a problem. I’ll get more into this in the tip section, but when it comes to diabetes prevention, you want to limit carbs, eat a high protein diet, and stay away from high glycemic foods such as refined grains because they cause a quick spike in insulin.
Tip #1: Resistance Train to Decrease Diabetes Risk and Improve Health
A new study compared the effects of a resistance training program with an aerobic program on individuals with prediabetes. The resistance program used nine exercises (three sets of ten reps at 65 percent 1RM), and the aerobic program exercised for 50 minutes at 65 percent of the heart rate maximum. Both programs had participants workout three days a week for eight weeks. The two programs were closely matched in terms of volume, frequency, and rate of progression.
Both groups improved blood pressure, and the resistance training group decreased waist circumference by 1.8 cm more than the aerobic group. Both groups improved general health as tested by physical and mental health measures, but the resistance training group had significantly greater improvements on physical and social function and a larger decrease in bodily pain than the aerobic training group. Researchers suggest that the resistance program was more effective at improving health and lowering diabetes risk factors because it increased the subjects’ ability to perform daily living activities and was not as monotonous as being on an aerobic exercise machine for 50 minutes.
Additionally, research shows training also results in strength development and fat loss from the waist. A second study on individuals who had diabetes or were prediabetic tested the effects of six months of resistance training on diabetes symptoms and risks. Participants had an average waist circumference decrease of two centimeters. They also improved on agility and strength assessments. Researchers suggest training is a critical component in diabetes management and quality of life.
Tip #2: Train with a Large Volume and High Intensity for Best Insulin Sensitivity Results
Use a large volume load and heavy lifts for best results in terms of insulin sensitivity and glucose uptake. A wave-like program that varies between a hypertrophy and strength protocol is probably most effective for insulin health and diabetes prevention. Of course, individuals who are starting to train for the first time need to develop basic strength levels, but research evidence points to key programming strategies that you need to be aware of.
The greater metabolic demand of a heavy, high volume protocol means the body uses more muscle glycogen, which increases glycogen resynthesis and storage capacity, promoting glucose uptake. Also, muscle contractions have a positive effect on the protein mechanism that gets glucose into cells, supporting insulin sensitivity. A study compared four protocols on prediabetic individuals, all using eight exercises: Moderate Single Set (one set of 12-15 reps at 65 percent of 1RM); Moderate Multi-Set (multiple sets of 12 to 15 reps at 65 percent of 1 RM); Heavy Single Set (one set of 6-8 reps at 85 percent of 1RM); or Heavy Multi-Set (multiple sets of 6-8 reps at 85 percent of 1RM).
All protocols improved fasting glucose and insulin sensitivity. The multiple set bouts resulted in significantly greater decrease in fasting glucose and the Heavy Multi-Set protocol was by far the most effective at improving insulin sensitivity. A second study compared using three sets of a heavy load with a moderate load. The third set of both protocols was to failure, while the Heavy program was at 85 percent 1RM with 8 reps for the first two sets, and the Moderate program was at 65 percent 1RM with 12 reps for the first two sets. The total volume load was 35 percent greater with the Moderate program, leading to greater insulin sensitivity for up to 23 hours after training. The Heavy program also improved insulin sensitivity significantly more than a control group.
It’s not possible to make definitive conclusions about the very best program for insulin sensitivity because the protocol designs have significant differences: the second study included lifting to failure, and even though the loads compared were similar (65 percent for moderate and 85 percent for heavy), the exercises and overall volume were different. No matter, clearly a
large total volume is necessary for the best insulin response and it requires more energy, burns more calories, builds more muscle and promotes a strong endocrine Growth Hormone release. Use of heavy lifts is suggested, at least occasionally, to support insulin health and trigger testosterone—low levels have been directly linked to diabetes risk.
Tip #3: Prevent Diabetes by Raising Testosterone Levels by Strength Training
Low testosterone (T) is repeatedly linked to decreased health in men, and a Spanish study confirmed that men with lower T levels had a greater incidence of type 2 diabetes and glucose intolerance. All of the study’s participants had T levels in the normal range for their ages (36 to 85), but those on the lower end of the normal range were more likely to have diabetes or be pre-diabetic. The participants with testosterone levels in the lowest quartile were 2.5 times more likely to be insulin resistant than those with hormone levels in the top quarter.
Researchers suggested that regardless of common factors that contribute to diabetes such as age and high body mass index, men with low T levels have increased risk of diabetes, meaning that even young men with ideal body composition and low anabolic hormone levels are at greater risk. This is significant because it indicates a direct role of T in male health and insulin sensitivity, rather than as a multidirectional factor with fat and muscle mass composition.
To naturally raise your T levels, make sure you perform large muscle group exercises (squats, deadlifts, power cleans, etc.) at the beginning of your workout, and a large volume load with heavy lifts. Longer rest periods appear to be most effective (at least 1-2 minutes) because they allow for recovery and heavier weights. Circuit training or supersets may be a good choice depending on your goals.
Tip #4: Strength Train to Increase SHGB and Decrease Diabetes Health Risks
Research shows that in patients with diabetes, lower sex hormone-binding globulin (SHBG) levels were related to a higher rate of nonalcoholic fatty liver disease (NAFLD), a common byproduct of insulin resistance. SHBG is directly related to testosterone and low SHGB leads to low T, more body fat, and a worse metabolic profile. Even though the study in question didn’t involve resistance training, it points to SHBGs role in accelerating disease symptoms related to insulin resistance. One simple strategy to raise SHBG is to perform resistance training because we know training can significantly raise T.
In the study, low SHBG levels were also related to degree of hypertension, body mass index, waist circumference, C-reactive proteins and chronic inflammation, low testosterone, and high estradiol levels. Despite the relationship between SHGB and all of these health conditions, low SHGB was independently associated with NAFLD. The odds of having high-grade NAFLD decreased significantly with increasing SHGB levels.
Tip #5: Get Adequate Magnesium to Improve Insulin Sensitivity
A review from the journal Biological Trace Element Research reports that magnesium plays an important role in carbohydrate metabolism, while influencing the activity of hormones that control blood glucose levels. Low
magnesium can cause insulin resistance, which may result in the kidneys being unable to retain magnesium during episodes of high blood sugar, creating a downward spiral of magnesium deficiency, fat gain, and subsequently diabetes. Researchers stress the critical importance of adequate magnesium in diabetes prevention and treatment.
Be aware that low magnesium is also directly linked to low testosterone. And remember we just looked at how low T leads to low SHBG, liver disease, and bad health. Everything is interrelated: If you’re magnesium levels are subpar it’s almost guaranteed that you won’t be producing enough testosterone, which not only leads to fat gain and a decrease in lean muscle mass, but insulin resistance and diabetes—Not good!
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