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Research > Theory to practice - Stretching: what is the most effective way?
Theory to practice - Stretching: what is the most effective way?
Issue: Volume 28 Number 2
Background
Over my many years of involvement in sports training, I have yet to talk to anyone or read any definitive paper that has examined the question of what is the most effective way to stretch. I have always wondered what is needed to get the most benefit from stretching: how long should I stretch for, what type of stretch should I do, and how often should I do it in a week? At last a study has attempted to answer these questions.
Research
A group of North American sport and exercise scientists compared the effects of three common stretching techniques on the length of the hamstring muscle group during a four-week training program. Subjects were 19 young adults between the ages of 21 and 35 years who had tight hamstrings — as defined by a knee extension (knee bent) angle greater than 20° while lying with the hip flexed (bent) at 90°. The participants were randomly assigned to one of four groups, with four to five subjects per group. Group 1 did self-stretching (laying on back with leg up and knee straightened by subject themselves), group 2 did static stretching (same stretch as group 1, but knee straightened and held by another person), group 3 did proprioceptive neuromuscular facilitation (PNF) (same stretch as group 2, but muscles tightening then relaxing to stretch), and group 4 was the control group that did no stretching. Each group received the same stretching dose of a single 30-second stretch three days per week for four weeks. Knee extension angle was measured before the start of the stretching program, at two weeks, and at four weeks.
Findings
Statistical analysis showed that all three stretching techniques increased hamstring length from the baseline value during the four-week training program. However, only group 2, which did the static stretching, was found to be significantly greater in hamstring length than the control group after the four weeks of stretching.
Coaches’ takeout
These results suggest that static stretching at least one repetition for 30 seconds, three days per week increased hamstring length in young, healthy subjects. The data also suggest that active self-stretching and PNF stretching one repetition for 30 seconds, three days per week is not sufficient to significantly increase hamstring length in a young, healthy population. Coaches and athletes should always consult a sports physiotherapist to ensure they receive the best advice regarding a sport and individually specific stretching program.
Reference
Davis, D, Ashby, B, McCale, K, et al. 2005, ‘The effectiveness of 3 stretching techniques on hamstring flexibility using consistent stretching parameters’, Journal of Strength and Conditioning Research, 19(1), pp. 27–32.
