Dynamic stretching definition
Dynamic stretching is a type of stretching that is defined as “controlled, sport-specific movements that are designed to increase core temperature and enhance activity-related flexibility and balance,” according to the American College of Sports Medicine. Unlike the more familiar static stretching where you hold a stretch like a statue, dynamic stretching involves moving your body through a range of motion in a repetitive pattern. Do not confuse this with ballistic stretching because dynamic stretching is done in a controlled manner. The ballistic version is done in a fast and uncontrolled way, which includes bobbing and bouncing.
However, Paul Ingraham of PainScience.com argues that “If an exercise doesn’t involve elongating muscles to the point of feeling significant tension for several seconds at least, it’s not stretching.” While the word “stretching” in dynamic stretching does not really fit into the dictionary definition or our common notion of stretching, the term is already stuck in most textbooks, many websites, and guidelines from several fitness organizations.
How to choose your dynamic stretching exercises
Because dynamic stretching is sports-specific and does not have a specific guideline, such as the number of reps and duration, or a to-do list, you can do almost any type of repetitive movement that fits your activity. Exercise physiologist Len Kravitz at the University of New Mexico gave an example that a volleyball player would “do some shoulder flexion/extension actions prior to playing in a volleyball game.” Other examples would include soccer players doing leg swings in various planes of motion and or a wushu practitioner doing figure-8 arm swings to mimic strikes and sword swings. Therefore, dynamic stretching exercises should be close to the activity that you are going to do.
Dynamic stretching exercise examples
There are probably scores of exercises that you can do, and you can make up new ones that fit your activity. The following list are common examples that can help you get started.
This exercise has several variations, including the upright trunk twists and bent over version. Because many sports and activities involve trunk rotation, this can be an ideal warm-up to start. You can experiment with using a stick, a towel, or simply your bare hands.
Because many sports involve the lunge position in a variety of angles and planes of motion, the multiplanar lunge warms up your body to be more prepared for such sports, such as volleyball and baseball. You start from a standing position and you lunge to the front, side, and with a rotation. The degree of turning you do can vary from about 45 degrees to 180 degrees.
Another variation you can do include adding a torso twist or a reach toward the ground as you lunge.
This dynamic stretching exercise warms up your entire lower body that can be done in multiple planes of motion. The key is to keep the swings in control within your own range of motion.
Running butt kicks
Running butt kicks involve rapid kicking motions toward your butt with your heel, which is supposed to warm up your legs. While this seems like a reasonable exercise to warm up before you run, Track USA suggests that it may be a poor choice for warm-ups because it “teaches athletes to point their knee downward and puts more stress on the hip flexors and quad muscles when they drive the knee and foot forward while running.”
This ties back to the concept of the SAID principles (specific adaptations to imposed demands), where you get better at specifically what you train to do. The closer to the actually activity you are going to do, the better the warm-up’s transferability. However, you could still do butt kicks as a general warm up if you do not plan to run or sprint.
High Knee Drills
High knee drills is an alternative to butt kicks if you are a runner because the motion emphasizes on placing your heel in front of your body rather behind you.
Old-school jumping jacks never really go out of style. It does not specific target any muscle groups or emphasize specific movement patterns, but it gives an overall full-body warm up. If you want a variation of this exercise, Coach Nick Tumminello demonstrates the reverse jumping jacks.
There are plenty of other dynamic stretching exercise that you can do for your specific activity. Sometimes you can just
What does scientific evidence say about dynamic stretching?
A 2016 systematic review pooled data from 84 qualified studies on the acute effects of dynamic stretching. First, the researchers found a mixed-bag of results in the scientific literature that shows dynamic stretching is better than static stretching for increasing range of motion and vice versa. “These conflicting results could be ascribed to the different natures of stretching, which that renders comparisons difficult,” they wrote. So, there is no clear evidence that one type of stretching is better than another to increase flexibility, even if the effect is temporary.
Likewise, the review found that dynamic stretching for athletic performance, such as vertical jumps, balance, and VO2 max, also have mixed results. Many of the studies have found “significant enhancement” of force and power or no difference.
They also cited four studies that found dynamic stretching could decrease performance. These negative studies have mixed protocols, such as including passive and active stretching and mixing up the term “ballistic stretching” with dynamic stretching.
When comparing standing stretching with walking stretching, the researchers found that the latter led to better sprint time, agility, and specific movement patterns than the former. They hypothesized that the walking stretches “could help rehearsal of specific movement patterns allowing muscles to be excited earlier and faster,” which decreases sprint time and increase power and speed. An increase in muscle temperature could also contribute to increased muscle and other connective tissues viscosity and more synchronized muscle contractions.
The researchers cited some problems with the review and the studies, including the lack of quality in reporting of how the studies were conducted (e.g. gender comparison, mixed control groups) and different terms to describe dynamic stretching. Some of the studies did not explain their methodology clearly, which can skew data and misinterpret the results.
While there are no updated systematic reviews of the scientific literature of dynamic stretching yet, a few recent studies found mixed results on its effect on athletic performance. A 2019 study from Qatar University found dynamic stretching alone can decrease performance among young male handball players. Minor muscle damage from the stretching could explain the primary cause, which can last up to 24 hours.
By using isokinetic and isometric testing, they found the average force output from knee extension and flexion is lower immediately and 24 hours after the test than before the test. However, there is a large overlap in the confidence interval among all three measurements that we can’t really say it has significant detriments to performance.
Another study from Franklin Pierce University that was published in early 2020 found similar results in increase ankle dorsiflexion by using foam rolling, dynamic stretching, or a combination of both techniques.
They concluded, “Due to the lack of statistically and clinically significant results from an acute application of these interventions using only a convenience sample, the authors recommend further study looking at long-term application of these interventions on subjects that represent the general population with restricted [dorsiflexion range of motion]. The outcomes of this study can serve as a pilot study to direct further research and determine if one technique results in a significant increase in [dorsiflexion range of motion] to reduce [lower extremity] injuries.”
They also suggested that the intervention used should be based on “each individual patient’s ability, preference, and response to treatment.”
Conclusions about dynamic stretching
So far, there is no right or wrong way to do dynamic stretching, and the large body of evidence suggests that there are moderate to little benefits to using this method to improve athletic performance or range of motion. Like treatment for pain and reduce disability, it is likely that everyone would have different adaptations and responses to dynamic stretching or any kind of intervention because of our individual differences, such as anatomical and movement variability.
Feature photo credit: Staff Sgt. Thomas Trower, U.S. Air Force