Stretching: Static vs Dynamic

It's no hidden secret that we all stretch and get told to do so on a regular basis. But do we know why? Are we actually stretching at the right time or doing the right stretches? It’s time we delved into the evidence behind stretching and answered these questions.

What to do BEFORE exercise:

Dynamic stretching is commonly incorporated into the pre-exercise warm up routine.² But what is dynamic stretching and why is it preferred over static stretching before exercise?

Dynamic stretching involves controlled movement through the active joint range of motion required for a specific sport with repeated cyclical muscle loading and unloading.¹ Through the incorporation of an acute bout of dynamic stretching prior to activity the incidence of injuries among athletes is reduced and performance is enhanced.¹ This is due to a multitude of factors including:

• Net positive effect on joint kinematics (i.e. motion of the joint) and dynamic flexibility.^1,2 For example, a study conducted in 2023 outlined that dynamic stretching of the thigh, hip, hamstring and calf muscles for 30s on both legs increased range of motion during the forward and follow-through phase of the instep soccer kick.¹
• Lower levels of muscle stiffness allowing for greater energy absorption during activity and reductions in the severity of muscle soreness.1As detailed in a 2019 study, dynamic stretching of the hamstring muscle produces an immediate increase in knee range of motion and a decrease in hamstring stiffness, both independent risk factors for hamstring injury in sport.²
• Specificity to sport.¹ Dynamic stretching involves a number of joints replicating the movements required for a particular sport thereby preparing the body for activity.³ The muscle does not relax but rather is active through the movement.³ The degree of stretching required will depend on the type of sport.³
• Promotes the temperature-related benefits of warm up.³
• Psychological benefits.¹ Dynamic stretching may positively influence psychosocial stressors and alter the emotional state leading to decreased muscle tension and increased concentration or attention prior to games/competition.¹

In contrast, evidence shows consistently that static stretching prior to exercise impairs performance and compromises muscle function.³ A static stretch is slow and constant involving relaxation and concurrent elongation of the stretched muscle.³ It has been found that pre-exercise static stretching negatively affects maximal muscle strength, power and explosive muscular performance, running speed, reaction and movement time and strength endurance.^3,4 Furthermore, the ability to statically hold a stretch lacks sport specificity and can lead to reductions in muscle temperature.³ The above can be detrimental for competitive performance and therefore the use of static stretching during warm-up should be avoided.⁴

What to do AFTER exercise:

Evidence regarding cool down recommendations immediately post exercise is trivial and requires further investigation for a concrete conclusion to be drawn.⁵ However, there are some general protocols and recommendations in place which can be followed and used as a guide.

An active cool down is typically performed in preference to a passive cool down (i.e. no activity).⁵ However, the evidence supporting this belief is both limited and conflicting, suggesting that active cool downs are largely ineffective in facilitating post exercise recovery.⁵ Despite this, they may offer some benefits compared to passive cool downs.⁵ For example, active cool downs accelerate removal of lactic acid from the blood and enhance recovery of cardiovascular and respiratory systems.⁵ If an active cool down is to be performed post exercise it should be completed as follows:

• Dynamic activity performed at low to moderate intensity to increase blood flow but prevent additional fatigue.⁵
• Low to moderate impact to prevent development of further muscle damage and soreness.⁵
• Shorter then 30min performed within 1hr after training/competition.⁵
• Involve exercise preferred by the athlete.⁵

Static stretching and foam rolling is also typically performed in combination with an active cool down.⁵

Static stretching is performed with the aim of reducing post exercise muscle soreness and increasing range of motion.⁵ However, the above is only obtained if stretching is performed within 5-10 minutes after practice.³ This is due increases in elastic properties within muscles and tendons as a result of elevated muscle temperatures immediately post exercise.³

Foam rolling is also effective in increasing range of motion, reducing muscle soreness, enhancing next day performance and facilitating recovery from exercise.⁵

What to do LONG TERM:

To obtain longer lasting increases in flexibility and range of motion a stretching program is required.³ Stretching programs should include:

• 2-3x sessions/week for a minimum of 5 weeks.^3,7
• Static stretch duration of 30s repeated 2-4 times.^3,7
• Static stretch held at a position of mild discomfort (not pain).³
• All stretching sessions should be preceded by an active warm-up.^3,7

A systematic review published this year also found that the use of long-term static stretching not only increases range of motion but can also alter muscle architecture and function ultimately enhancing muscle performance.⁶

References:

1. Behm DG, Alizadeh S, Daneshjoo A, Konrad A. Potential Effects of Dynamic Stretching on Injury Incidence of Athletes: a narrative review of risk factors. Sports Med. 2023;53(7):1359-1373. doi:10.1007/s40279-023-01847-8
2. Iwata M, Yamamoto A, Matsuo S, et al. Dynamic Stretching Has Sustained Effects on Range of Motion and Passive Stiffness of the Hamstring Muscles. J Sports Sci Med. 2019;18(1):13-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6370952/
3. Baechle TR, Earle RW. Essentials of Strength Training and Conditioning. 3rd ed. Human Kinetics; 2008.
4. Simic L, Sarabon N, Markovic G. Does pre-exercise static stretching inhibit maximal muscular performance? A met-analytical review. Scand J Med Sci Sports. 2013;32(2):131-148. doi:10.1111/j.1600-0838.2012.01444.x
5. Van Hooren B, Peake JM. Do We Need a Cool Down After Exercise? A Narrative Review of the Psychophysiological Effects and the Effects on Performance, Injuries and the Long-Term Adaptive Response. Sports Med. 2018;48(7):1575-1595. doi:10.1007/s40279-018-0916-2
6. Panidi I, Donti O, Konrad A, et al. Muscle Architecture Adaptations to Static Stretching Training: A systematic review with meta-analysis. Sports Medicine – open. 2023:9(1):47. doi:10.1186/s40798-023-00591-7
7. Page P. Current Concepts in Muscle Stretching for Exercise and Rehabilitation. Int J Sports Phys Ther. 2012:7(1):109-119. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273886/