In general, different groups of people have different stretching needs. For example, weight trainers may present with patterns of tightness that may vary from a runner. A gymnast may need greater than “normal” hamstring flexibility but hamstrings that are too flexible may be a detriment to the athlete trying to avoid ACL injury.1
It is important that within groups there will also be individual variation. One size does not fit all when deciding how to incorporate static stretching into an exercise program.
The intention of this article is to provide a very general introduction to static stretching which is an effective way to improve and maintain flexibility.
For the purpose of this article I will define acute stretching as a single bout of stretching, let’s say 1-3 sets of 30 second holds. This may be performed before or after an activity.
Chronic stretching would be a series of acute bouts of stretching accumulated over weeks/months. An example would be stretching tight hamstrings every day for 2 months.
Acute stretching before activity: Performance, Injury Risk, Muscle Soreness
Effect on Performance: Some literature suggests that stretching before activity may be detrimental to force and power production.2 This is true for longer durations of stretch >60s. Experimental studies show that shorter duration of stretching (approximately 30s or less) probably do not have a profound negative OR positive effect on these markers of performance.2,3
Effect on Injury/Muscle Soreness: Acute static stretching by itself does not seem to decrease overall injury risk or muscle soreness.4,5 There is some evidence that it may reduce muscle strain injuries.6
Should I static stretch before activity? I would say that this depends. If you are a gymnast or ballet dancer it may be appropriate to warm-up with static stretching. The gymnast/dancer will need to be prepared to passively stretch during their actual event.
If you are involved in a traditional team sport I do not see an issue performing a shorter duration of stretch as part of a comprehensive warm-up. Sample recommendation:7
light jog–>static stretching (30 seconds)–>dynamic/skill warm-up–>sport
Skipping the static stretch pre-exercise and performing post-exercise probably wouldn’t be an issue either.
If you are relying on power and strength it is probably not advisable to static stretch immediately prior to the event. For example, stretching (>60s) right before a high jump, or sprint has been shown to decrease performance.8, 9 Stretching in the racing blocks for a few seconds before a sprint will probably not have much of an impact.3
Chronic stretching: Performance, Injury Risk
Performance: A gymnast who is unable to do a split is probably not performing as well as they could. Utilizing static stretching is a good tool to improve and maintain flexibility for sports such as gymnastics.
Regular stretching is associated with improvements in force and power which are markers of performance.10 Chronic stretching seems to have a positive effect on force and power production while acutely performing static stretching prior to an event tends to have a negative effect.
Injury Risk: In a study of military recruits that stretched their tight hamstrings multiple times a day over 13 weeks there were significantly reduced lower extremity overuse injuries when compared to a control group.11 This is a demonstration of how addressing muscle tightness through chronic stretching may be helpful for injury reduction.
Acute Static Stretching
Shorter duration static stretching before activity may not necessarily increase or decrease performance. There may be benefit in some cases for decreasing muscle strain injuries. It is probably not in the athletes best interest to static stretch immediately before a task requiring power such as a sprint or high jump.
Chronic Static Stretching
The culmination of many bouts of acute stretching over time or chronic stretching, may help performance and decrease risk of injury when targeted to tight musculature. Relative tightness is individual and flexibility exercise should be tailored accordingly. There are normal values of flexibility established but keep in mind that gymnasts have different requirements than a runner.