The Cooper Institute
 

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH

 
 

Can Just a Little Bit of Resistance Training Help to Prevent Metabolic Syndrome?

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Live well

Thursday, May 10, 2018


In the past, we’ve posted a couple of blogs on the topic of metabolic syndrome (MetSyn). Just to refresh your memory, MetSyn is a common condition where at least 3 of the 5 following cardiovascular disease risk factors are present. This is sometimes referred to as ‘risk factor clustering.’

 
  • Fasting blood triglyceride level >150 mg/dL                                                                                  
  • Blood HDL cholesterol level <40 mg/mL in men or <50 mg/dL in women                 
  • Waist circumference >40 inches in men or >35 inches in women                                           
  • Resting blood pressure >130/85 mmHg or on blood pressure medication                    
  • Fasting blood glucose level >100 mg/dL or on diabetes medication
Currently, just over one-third of U.S. adults have MetSyn; which is strongly related an increased risk of developing type 2 diabetes and cardiovascular disease. One of the root causes of MetSyn is a condition known as insulin resistance; where the body is producing insulin but the tissues are resistant to its effects. Insulin resistance is most commonly seen in middle-aged to older adults who are sedentary and overweight, but it can be seen in younger individuals as well. Genetics can also predispose individuals to be insulin resistant.    

Cardiorespiratory fitness (CRF) is defined as the body’s ability to utilize oxygen at the cell level and can be objectively measured by maximal treadmill exercise testing. The treadmill test is an important cornerstone of the preventive medical exam at Cooper Clinic. It has been well-known for many years that individuals with moderate to high levels of CRF are substantially less likely to currently have or to develop MetSyn in the future. The Cooper Center Longitudinal Study (CCLS) has made very important contributions to this area of research. To put it simply, having a moderate to high level of CRF makes insulin work better. Rather than being insulin resistant, fit individuals tend to be insulin sensitive. In other words, a little bit of insulin goes a long way if you are fit.   

However, much less is known regarding the effect of resistance training on the risk
 of developing MetSyn in the future. Part of the Cooper Clinic exam includes a detailed medical history questionnaire, which includes many items regarding the frequency and duration of resistance exercise and aerobic exercise over the preceding 3 months. Researchers decided to examine data from the questionnaires in order to see how self-reported physical activity related to the risk of developing MetSyn in the future. They were particularly interested in self-reported resistance training. So, an important difference between this study and most other CCLS studies is that researchers were not looking at an objective measure of CRF (the treadmill exercise test), but rather at self-reported physical activity from a questionnaire. 

The study consisted of 7418 healthy men and women with a mean age of 46 years who completed two preventive exams at Cooper Clinic between 1987 and 2006. At the time of their baseline exam, none of the subjects had MetSyn, and 62% of the sample reported doing no resistance training over the preceding 3 months. The entire group returned to Cooper Clinic for another preventive exam an average of 4 years after their baseline exam. At this second exam, 1147 of the 7418 patients were found to have MetSyn.

Results are shown below in the Figure.



Patients who reported no resistance training are the reference group. Patients who self-reported doing any level of resistance training (>1 minute per week) at the time of their first exam were 17% less likely to develop MetSyn than those who reported doing no resistance training, even after taking their aerobic physical activity into consideration. Patients who reported meeting public health guidelines for resistance training (>2 days per week) had a similar reduction in risk. Patients who reported meeting public health guidelines for both resistance training and aerobic training (at least 150 minutes per week at a moderate intensity) at the time of their baseline exam were 25% less likely to develop MetSyn compared to those who did not meet either guideline.



Overall, the researchers felt that the most significant finding in this study was that any amount of self-reported resistance training was associated with a significantly lower risk for development of MetSyn, independent of aerobic exercise. It should be noted that exercise training, in general, makes the muscles more sensitive to the effects of insulin; which in turn helps to decrease the risk of developing MetSyn.   


The bottom line: For prevention of MetSyn in a middle-aged population, the best bang for the buck is to perform both aerobic and resistance training at levels recommended in current public health guidelines. However, any level of resistance exercise, even as little as a few minutes per week is significantly associated with some level of protection against the development of MetSyn.  


Reference
Bakker, E., Lee, D., Sui, X.,
Artero, E., Ruiz, J., Eijsvogels, M., Lavie, C., Blair, S. 2017. Association of resistance exercise, independent of and combined with aerobic exercise, with the incidence of metabolic syndrome. Mayo Clin Proc, 92(8):1214-1222.   doi: 10. 1016/j.mayocp.2017 .02.018