Warm-ups and Cool-downs: Not stretching the truth

This week will be a bit of a shorter episode, but still an important one! Over the years, there has been a lot of controversy about the utility of stretching, warm-ups, and cool-downs. In the search to uncover the truth, there are two main questions we hope to answer: “Can it improve my performance?”  and “Can it help reduce the risk of injury?”  To answer these, we will look at a few different modalities of warming-up, notably static stretching (holding a single pose for a sustained duration) vs dynamic stretching (mobile, light range of motion exercises).  We will primarily be looking at meta-analysis. These represent research articles that combine several similar, high-quality studies in an effort to validate the conclusions by increasing the overall sample size and amount of data collected. So, let’s see what the science says.

The Warm-up

Broadly speaking, warm-ups in general have been found to lead to a significant reduction in injury risks. In a recent meta-analysis, both upper and lower body injury risks were reduced when participants engaged in any warm-up intervention program, including stretching, sports-specific movements, or balancing exercises (1). That said, is there a preferred ‘warm-up’ intervention we should be taking?

In an even more recent study, static vs dynamic stretching were compared to assess changes in muscle range of motion and performance (in jumping). While the changes in this study were small, both stretches were able to help increase range of motion, but dynamic stretching (when compared to static stretching) resulted in improved performance (2). Indeed, in an earlier study among soccer players, static stretching was associated with slightly reduced performance immediately afterwards, but dynamic stretching was associated with improvement (3).

The Cool-Down

Analyzing the effect of the cool-down can be a bit more difficult, as it relies on more subjective measures (we are no longer monitoring performance) but looking at how it may help with recovery and/or soreness.

While there is some evidence that athlete’s feel better after cool-down stretching, it’s a much different question to determine if they do better (4). An active cool-down has been associated with helping to reduce lactate levels in the blood (feel free to read the lactate threshold episode for more info here!), and help the heart and lungs return to their resting states (5).

In a study of military recruits, static stretching was associated with a fairly small (1 point on a 100 point scale) reduction in soreness, and about a ~5% reduction in injury risk. In this study, neither of these findings were statistically significant (6).

What about static stretching?

So dynamic stretching and mobile exercise is great, is there much data for static stretching? To be honest, a lot of the data here is poor and there is need for continued research in this field. While static stretching was traditionally the mainstay of pre- and post-exercise regimens, there really isn’t much data that it makes a significant difference on its own. That said, there is some evidence that it can still be beneficial. When done over the long term (we’re talking about regular static stretching for weeks to months), it has been associated with improvements in muscle stiffness and muscular power (7).

Conclusions

Alright, that was a lot of mixed data, so, how can we sum it up? Ultimately, both static and dynamic stretching are relatively safe activities that may help you feel better and perform better, but the data for dynamic stretching is much more robust that the traditional static stretching we’re used to. A majority of the research suggests that a warm-up regiment consistent of dynamic stretching and gentle exercise can reduce injury and improve performance. I highly recommend this before every work-out, and even considering a ‘re-warm-up’ after long breaks (such as halftime). After exercise, take a few minutes to cool-down with a few minutes of gentle exercise (think jogging/walking after a run).

Lastly, if you have time, consistent static stretching can still lead to improvements in mobility/flexibility over the long run. For consistency, it may be easy to add a few minutes of this after your regular exercise or consider adding a program like yoga or tai-chi, which will incorporate a bit more mobility, static holds, and bodyweight exercise all rolled into one.

And there you have it – the ups and downs of warm-ups and cool-downs. Stay warm, stay cool, and stay active!

Sources and Further Readings:

1. Ding L, Luo J, Smith DM, Mackey M, Fu H, Davis M, et al. Effectiveness of Warm-Up Intervention Programs to Prevent Sports Injuries among Children and Adolescents: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health. 2022 Jan;19(10):6336. 

2. Esteban-García P, Abián-Vicen J, Sánchez-Infante J, Ramírez-delaCruz M, Rubio-Arias JÁ. Does the Inclusion of Static or Dynamic Stretching in the Warm-Up Routine Improve Jump Height and ROM in Physically Active Individuals? A Systematic Review with Meta-Analysis. Appl Sci. 2024 Jan;14(9):3872. 

3. Hammami A, Zois J, Slimani M, Russell M, Bouhel E. The efficacy, and characteristics of, warm-up and re-warm-up practices in soccer players: a systematic review. J Sports Med Phys Fitness. 2016 Nov 30;58(1–2):135–49. 

4. Afonso J, Olivares-Jabalera J, Andrade R. Time to Move From Mandatory Stretching? We Need to Differentiate “Can I?” From “Do I Have To?” Front Physiol [Internet]. 2021 Jul 21 12. Available from: https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.714166/full

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 Jul 1;48(7):1575–95. 

6. Andersen JC. Stretching Before and After Exercise: Effect on Muscle Soreness and Injury Risk. J Athl Train. 2005;40(3):218–20. 

7. Arntz F, Markov A, Behm DG, Behrens M, Negra Y, Nakamura M, et al. Chronic Effects of Static Stretching Exercises on Muscle Strength and Power in Healthy Individuals Across the Lifespan: A Systematic Review with Multi-level Meta-analysis. Sports Med. 2023 Mar 1;53(3):723–45.