Resistance Training vs. Static Stretching: Effects on Flexibility and Strength
Morton SK, Whitehead JR, Brinkert RH, Caine DJ. Journal of Strength and Conditioning Research. 2011 Sept 30
It is important for both athletes and non-athletes to have adequate range of motion (ROM) in their muscle-joint complexes. Long-standing beliefs of how static stretching and resistance training affect strength and flexibility are now being challenged by recent research. The purpose of this study was to determine how full-range resistance training affected flexibility and strength compared to static-stretching of the same muscle-joint complexes in untrained adults. The authors posit that static-stretching increases flexibility compared to control, but those gains would not be superior to resistance training. The study design included a five-week intervention with pre- and post-strength and flexibility testing of hamstring extension, hip flexion and extension, shoulder extension flexibility, and peak torque of quadriceps and hamstring muscles. Volunteers were randomized to a resistance-training group or static stretching group. Subjects then performed 5 weeks of either strength training or static stretching. The enrolled subjects were provided supervised training in their chosen group. The control group consisted of inactive volunteers. No difference was found between the 2 intervention groups in hamstring flexibility, hip flexion, and hip extension, but both groups demonstrated superior ROM gains compared to controls. The resistance-training group had improved knee extension peak torque compared to controls. There were no differences found between any of the groups with shoulder extension flexibility and knee flexion peak torque.
Most athletes are involved in an exercise program with goals of improving their performance and preventing injury. Weight training and stretching are two important components of this. Proper stretching is usually emphasized before, during, and after resistance training to maintain flexibility. The results they obtained supported their hypothesis that resistance training does not decrease flexibility. The authors recognize the limitations of this small, pilot study and acknowledge it in their discussion. One other possible limitation of the study is the type of weight-training used. Athletes use a variety of regimens, varying the number of repetitions in each set and the amount of weight used to match their goals for their specific sport. It would be interesting to see if a lower repetition workout with higher weights would give the same results as a higher repetition, lower weight workout that was likely used in this study. In this study design, these athletes were instructed and observed to ensure that they maintained full range of motion throughout all exercises in the resistance-training regimen. Most athletes do not have constant monitoring during their workouts to ensure proper form. If these findings are consistently replicated in future studies, it might change our clinical recommendations regarding the type of exercise required to maintain flexibility. It would also be interesting to study the combination of strength training and static stretching since this is common practice for all athletes. I agree with the authors that further studies are needed to make any change in recommendations at this time. How do you view and/or instruct stretching with your athletes? Do you feel resistance training can increase flexibility without any stretch or soft tissue mobilizations?
Written by: Kris Fayock, MD & Marc I. Harwood, MD
Improved Ankle Range of Motion is Sustained After Stretching but not Stiffness
Morton SK, Whitehead JR, Brinkert RH, & Caine DJ (2011). Resistance Training vs. Static Stretching: Effects on Flexibility and Strength. Journal of Strength and Conditioning Research PMID: 21969080
This review is very interesting to me as flexibility has been a hot topic for many of years. I know this is just a pilot study, but it was interesting to see that there was no difference in ROM when comparing the static stretching group to the resistance training group. This is definately going to help me with my clinical practice as getting athletes to stick to a stretching program is much more difficult than staying with a resistance strength training program. Thank you.
I agree with you that no matter why you exercise, your ROM in your muscle-joint complexes should be adequate. It's important, because joint pain are extremely hard to cope with. Luckily flexibility training sessions come to help those who need to increase their mobility and avoid painful injuries.
Thanks for the comments JT and Lucy! I agree. I think the nice thing with the resistance training is that we also will see improved muscle strength and probably neuromuscular control at the ends of our ROM as it increases. It will be very interesting to follow this line of research.
Thanks for the comments, hopefully these studies will lead to more so we can better prevent injuries for athletes.
Thanks for the comments jt and Lucy! I agree. I anticipate the nice affair with the attrition training is that we additionally will see bigger beef backbone and apparently neuromuscular ascendancy at the ends of our rom as it increases. Personal Trainer Directory
I think these findings are also very relevant to hot topics in research today. However it would make sense that resistance training increases flexibility greater than a control group did. During resistance training the muscle undergoes concentric and eccentric contractions of which allow the contractile units of the muscle to shorten and lengthen/elongate. This action would increase the blood flow as well as put stress/tension on the contractile and non-contractile components of skeletal muscle during both concentric and eccentric movements. If the exercises are done through the entire available range of motion and specifically at the end ranges of motion it would mimic that of a typical stretch and thus should improve flexibility as the exercises would take advantage of the viscoelastic properties of muscle over time as the small pilot study demonstrated. Very interesting study and outcomes!
I also believe that resistance training can improve flexibility without stretching or soft tissue mobilization. In our typical activities of daily living it is not all that common for us to carry out tasks at the end of our available ROM of which an increase in flexibility can be achieved. To do so would be biomechanically inefficient. By proper instruction on resistance training through the entire ROM with a total volume of exercise that does not result in substantial tissue remodeling I feel it is very possible to achieve increased flexibility. The patient or athlete would be using controlled motion at the end ranges of which they are not accustom to using. Additionally the increased temperature of the muscle associated with resistance training increases the ability of the muscle to utilize it's elastic capacity. I would be interested as well to see the impact on flexibility when the volume and intensity of the resistance program had the primary goal of increasing power, hypertrophy, strength, or some combination of the three.