When it comes to flexibility, there are several misconceptions that are spread around by well-meaning athletes and fitness enthusiasts. In order to improve flexibility and ultimately health, one must consider scientific research that is available as well as utilize a basic understanding of exercise physiology to make logical decisions. Many people consider flexibility and stretching to be synonymous to each other. The truth is that stretching is not the only way to improve flexibility and it may not always be an effective way to improve flexibility.
Holt et al. defined flexibility as “an intrinsic property of body tissues that determines range of motion achievable without injury at a joint or group of joints,” (1996). Static and/or dynamic stretching, when performed appropriately, may be an effective way to improve range of motion or flexibility. However, strength training through a full range of motion has also shown to improve flexibility. James Whitehead, EdD, of the University of North Dakota in Grand Forks conducted a study wherein college-age volunteers participated in either strength training or stretching regimens for five weeks. Results suggested that full-range strength training regimens can increase flexibility as well, or perhaps better than, typical stretching regimens (2010). The concept of people participating in strength training becoming “muscle-bound” is outdated and incorrect. Furthermore, Santos et al. (2010) concluded sedentary women were able to significantly increase their flexibility from baseline after eight weeks of strength training. In addition, Fatouros et al. concluded that inactive men between the ages of 65-78 years were able to significantly increase their range of motion through strength training (2006).
A review of scientific literature conducted by Thacker et al. (1996) concluded that no sufficient evidence exists to either endorse or discontinue routine stretching before or after exercise. Perhaps the biggest mistake made when stretching (which almost makes the activity unadvisable) is to stretch to the point of pain. When tiny intrinsic fibers inside of muscle spindles are stretched too hard and too fast, they automatically send a signal to the spinal cord, which relays a signal to larger extrinsic fibers to contract. This is known as the Stretch Reflex. What does this mean? When we stretch our muscles to the point of pain, that muscle is automatically contracted (shortened), giving the opposite effect of the initial objective. Some guidelines can be found through the link below:
http://www.webmd.com/fitness-exercise/guide/how-to-stretch
Anyone who wants to improve flexibility may be most effective in doing so by strength training slowly and under control through a full range of motion. Fast, ballistic movements risk initiating the Stretch Reflex and can decrease flexibility. Anyone still wishing to participate in traditional stretching movements would be wise to do so to the point of tension but not pain, and to perform stretches after exercise. This can be a great way to relax the muscles after vigorous activity, which can reduce blood pooling and have a calming effect on the mental and emotional state of the exerciser.
Fatouros, I.G., Kambas, A., Katrabasas, I, Leontsini, D., Chatzinikolaou, A., Jamurtas, A.Z., Douroudos, I., Aggelousis, N., Taxildaris, K. (2006). Resistance training and detraining effects on flexibility performance in the elderly are intensity-dependent. Journal of Strength & Conditioning Research, 20, 3, Retrieved July 8, 2014, from http://journals.lww.com/nsca-jscr/abstract/2006/08000/resistance_training_and_detraining_effects_on.27.aspx
Holt, J., Holt, L.E., Pelham, T.W. (1996). Flexibility redefined. Biomechanics in Sport, 13, 170-175
Santos, E., Rhea, M.R., Simao, R., Dias, I., De Salles, B.F., Noveas, J., Leite, T., Blair, J.C., Bunker, D.J. (2010). Influence of moderately intense strength training on flexibility in sedentary young women. Journal of Strength & Conditioning Research, 24,11, 3144-3149
Thacker, S.B., Gilchrist, J., Stroup, D.F., Kimsey, C.D. (2004). The impact of stretching on sports injury risk: a systematic review of literature. Medicine and Science in Sports and Exercise, 36, 3, 371-378
Whitehead, J.R. (2010). Resistance training improves flexibility, too. WebMD Health News, Retreved July 8, 2014, from http://www.webmd.com/fitness-exercise/news/20100604/resistance-training-improves-flexibility-too