Short duration, high intensity resistance exercise to increase muscle strength and mass shown beneficial.
Low muscle strength and obesity have been shown to be associated with higher incidence of insulin resistance in type 2 diabetes. Resistance exercise to increase muscle strength and mass has been found to increase insulin sensitivity in type 2 diabetes as well as healthy adults.
A recent study aimed to investigate the effects of six weeks of resistance exercise training, compromised of one set of each exercise to failure on insulin sensitivity and the time course of adaptations in muscle strength/mass was conducted. The study sample consisted of 10 men with excess weight. The participants were aged between 28 and 44 years old with body mass index between 26 and 32 kg/m2.
Resistance exercise training involved three sessions per week for six weeks. Each session involved one set of nine exercises, performed at 80% of 1 repetition maximum to failure where the muscle can no longer perform the action to perfect form. Sessions lasted 15-20 minutes. Oral glucose tolerance tests were performed at baseline and post intervention. Vastus lateralis muscle thickness, knee extensor maximal isometric torque, and rate of torque development were measured at baseline each week of the intervention and after the intervention.
Resistance training resulted in 16% increase in insulin sensitivity. In addition, increases in muscle strength, size, and rate of torque development at 50ms and 100ms but not 200ms and 300ms were also observed.
The study concluded that six weeks of single-set resistance exercise to failure results in improvements in insulin sensitivity and increases in muscle size and strength in young men with excess weight. Previous studies have shown that single-set resistance exercise to failure can increase muscle strength, and this study demonstrated that sessions lasting 15-20 minutes are effective, thereby involving a much smaller time commitment than most previous resistance training interventions, which generally involved multiple (2-4) sets of exercises for each muscle group. One of the major limitations of this study is that it only included men, thus it would be difficult to generalize these results to the whole population. In addition, larger randomized controlled trials are warranted to support this data.
A previous study done in 22 Latino adolescent males with excess weight that did include a control group further supports these findings. Patients were randomly assigned to either a twice-per-week resistance training group or a non-exercising control group for 16 weeks. Strength was assessed by one repetition maximum, body composition was quantified by dual-energy x-ray absorptiometry, and insulin sensitivity was determined by the frequently sampled intravenous glucose tolerance test with minimal modeling.
The study found that significant increases in upper and lower body strength were observed in the resistance training group compared with the control group. The resistance training group significantly increased insulin sensitivity compared with the control group (P<0.05), and this increase remained significant after adjustment for changes in total fat mass and total lean tissue mass.
In conclusion, the improvement of insulin sensitivity and prevention of type 2 diabetes via resistance training has a promising future.
- Short duration of resistance exercise through the week done on a regular basis can have substantial effects on improving insulin sensitivity, which therefore could reduce the risk of developing type 2 diabetes.
- From the results, it was concluded that resistance training can impact quality-of-life issues.
- Further research is required to investigate higher risk groups, patients who already have type 2 diabetes, and females.
Ismail AD, Aba Alkhayl FF, Wilson J, Johnston L, Gill JMR, Gray SR. The effect of short duration resistance training on insulin sensitivity and muscle adaptations in overweight men. Exp Physiol. 2019 Jan 29.
Shaibi GQ, Cruz ML, Ball GD, Weigensberg MJ, Salem GJ, Crespo NC, Goran MI. Effects of resistance training on insulin sensitivity in overweight Latino adolescent males. Med Sci Sports Exerc. 2006 Jul;38(7):1208-15.
Dahlia Elimairi, Pharm D student at UC Denver Skaggs School of Pharmacy