Active stretching involves contraction of the muscle group (agonist) that is in opposition of the muscles that you are stretching (antagonist). Some sources say that active stretching is more than just increasing flexibility; it is a way to warm-up and prepare your muscles for whatever activity you are going to do. However, what does scientific evidence say about active stretching and athletic performance?
Active stretching vs. static stretching
First, let’s clear up some terms to avoid confusion. Active stretching is a type of static stretching while static stretching is a broad term that includes all forms of stretching where you hold a stretch in a fixed position for a specific time period. Since active stretching is under the umbrella of static stretching, the guidelines for static stretching could be applied the former.
Active stretching vs. passive stretching
Unlike passive stretching, active stretching does not need external forces to increase range of motion. Instead, when you “actively” contract a muscle group, you “relax” the opposite muscle group which allows more range of motion. This idea is based on reciprocal inhibition: when the agonists are under voluntary contraction, the antagonists have reduced neural activity which allows the muscles to stretch further.
However, one Brazilian study in 2011 found that there is hardly any difference in knee extension flexibility between active and passive stretching among a group of 60 men.
The researchers concluded, “The results from the study showed that CR [contract-relax] PNF stretching using an uninvolved muscle contraction produced the same immediate ROM gain as traditional CR PNF stretching. It was hypothesized that uninvolved or target muscle contraction may produce a distraction effect, resulting in increased ROM, although the precise mechanism is yet to be determined. The clinical importance of this study is that stretching of a muscle using the CR PNF procedure may not require a maximal contraction of that muscle.”
What does science say about active stretching and athletic performance?
A 2012 review by Dr. Danny Riley and Dr. J. M. Van Dyke of Medical College of Wisconsin compared previous research on active stretching and passive stretching on muscle loss prevention. A majority of the research—in animal and human studies—found that passive stretching had little to no effect on preventing muscle atrophy, but active stretching could.
However, a few human studies that they summarized do find benefits of passive stretching, such “significant changes in knee extension range of motion.” Passive stretching has been shown to decrease muscle stiffness for 10 to 20 minutes and improve greater range of motion in knee extension than dynamic stretching.
Although the literature offers mixed results, the weight of the current evidence leans toward active stretching as one intervention to minimize muscle atrophy. This could be beneficial for those who are bed-ridden or recovering from an injury.
More recent research also found contradicting evidence to Riley and van Dyke’s review, like one randomized-controlled trial in Japan in 2015. The researchers compared the effects of passive stretching and active stretching on hamstrings flexibility—with a control group. A t otal of 54 subjects were randomly selected for the passive, active, or control group with an equal distribution of nine men and nine women.
In the experimental groups, they laid supine and bent their hips and knees at about 90 degrees as their starting position. They gradually extended their knee until they started to feel a stretch in the hamstrings. In the passive stretching group, a researcher extended the knee further to a tolerable stretch.
In the active stretching group, the subjects extended their own knee by contracting their quadriceps. In both groups, the stretch was held for 10 seconds and flexed the knee slowly for 10 seconds. They repeated the exercise for 3 sets. The control group did not stretch.
While both experimental groups had improved flexibility and the control group hardly had any increase, the researchers measured the results and found that the passive stretching gained more than double the amount of knee flexion (+15.8 degrees) than the active stretching group (+7.0 degrees).
The drawbacks of this research include having young, healthy subjects in their twenties, so we don’t know if this study can be applied to older populations. Future studies should also compare different stretch times.
Active stretching exercise examples
Supine hamstrings stretch with quadriceps contraction
Lie on the floor on your back with both legs extended toward the air with your knees slightly bent. Flex your toes toward your face. Lower one of your legs toward the ground while keeping the other leg in the same position by contracting your quadriceps.
Stop lowering when you feel a stretch in the opposite hamstrings. Hold this position for about 10 to 15 seconds, and then raise your leg back to its starting position. Repeat this exercise for 5 to 6 times one each leg. You may perform 2 to 3 sets.
Standing quadriceps stretch with hamstrings contraction
Stand on one leg and flex one of your knee so that your foot is close to your buttocks. Contract your hamstrings and glute with a slight hip extension to increase the stretch if needed. Hold this position for 10 to 15 seconds and bring your leg down to standing position. Repeat the stretch on the second leg and perform 2 to 3 sets.
Lunge hip flexor stretching with glute contraction
Stand with one foot on top of a 2- to 3-foot high box or step, and lean your weight toward the front foot. Contract your glutes to increase the stretch in your hip flexors for 10 to 15 seconds. Then shift your weight back to the starting position and repeat the stretch on the opposite side. Repeat the stretch for 2 to 3 sets.
You may include stretching your lower back turning your torso toward the flexed hip as you hold the stretch.
Triceps stretch with biceps contraction
Raise your right arm over your head and flex your right arm to touch your right hand to the back of your neck. You should feel a slight contraction in your right biceps. Contract your biceps to increase the stretch of your triceps. Hold the stretch for 10 to 15 seconds and repeat the stretch on the opposite arm. Repeat the stretch for 2 to 3 sets.
Biceps stretch with triceps contraction
Extend your right arm to your side with your right palm facing away from your body. Contract your triceps as you maintain the stretch for 10 to 15 seconds. Tilt your head to you left to increase the stretch if needed. Repeat the stretch on the opposite side, and repeat it for 2 to 3 sets.
Conclusions about active stretching
Active stretching has its place in general fitness and rehabilitation. Given the small number of studies and reviews about stretching relative to other types of stretching, like dynamic and passive, active stretching could be a part of warm-ups or a gradual way to regain strength and delay muscle atrophy if you are injured. However, most of the studies on humans focus on the knee and hip joints, so no one is really certain about how muscles in the torso would respond to active stretching compared to the limbs.
If muscle physiology and neurology is very similar throughout your body in relation to active stretching, then we could say that is likely to have similar effects. Meanwhile, we could take some of the research based on static stretching as a reference.