Stretching as pre-intervention can improve aged muscle's response to a resistance training intervention

Abstract

Sarcopenia represents an important problem in older women affecting their physical function. Resistance training interventions in older adults have been widely investigated, and the effect they have in this population have shown to be positive but blunted compared to young adults. Muscle stiffness in older adults is greater than in younger populations and this could be aiding to cause a blunted response to resistance training, and as it has been shown that stretching can decrease muscle stiffness, it may benefit older adults. The purpose of the study was to determine if a pre intervention of stretching followed by a resistance training intervention, would produce a larger effect in older adults, than a pre intervention of resistance training followed by a resistance training intervention. Isokinetic plantarfexor torque and combined volume of the medial and lateral gastrocnemius were used to determine this effect. Sixteen healthy women (average age, 75.44 years) were randomly divided in 2 groups: resistance training + resistance training (RT + RT), and stretching + resistance training (S + RT). The RT + RT group performed 16 weeks of resistance training, and the S + RT performed 8 weeks of stretching followed by 8 weeks of resistance training. Isokinetic plantarflexor torque was measured with 1 set of 5 repetitions in a dynamometer at 60 degrees per second. Muscle volume was measured with b-mode ultrasound of the medial and lateral gastrocnemius. There were no statistical significant differences found in torque and volume when comparing both 16 week treatments. The only significant time by group interaction found was when comparing torque values of the pre-intervention of RT + RT group with the resistance training portion of the S + RT group, however the results are driven by a drop in mid-test values. In conclusion based on our findings performing a stretching intervention prior to a resistance training program doesn't enhance the response to resistance training more than resistance training alone in older adults. However these findings may have been influenced by a low effort when performing the strength assessments, and other limitations identified, which is something that need to be considered with future research.