044: Pre-Exercise Stretching Is Not As Bad As You Were Told

passive stretching Sep 21, 2021

Around twenty-five years ago, research began to emerge that suggested doing static passive stretches before dynamic activity negatively interfered with muscle performance. Thus, the recommendation was born to avoid static passive stretching and instead do only dynamic stretching during warm-ups. But was this one of the most overblown warnings to emerge from the stretching literature? Possibly.

In the past decade, many reviews have been published that criticised the unrealistic methodologies used by those early studies. Design flaws that have been highlighted include lack of comprehensive warm-ups before static passive stretching (most people, especially athletes, tend to do some warming-up activity), excessive stretching durations (most people hold their stretches for around 30 seconds per exercise, not twenty minutes), and testing maximum effort activities almost immediately after stretching (periods of several minutes or longer usually follow warm-ups and the main task of an event or discipline).

There is also the issue of both authors and readers blowing the size of the stretching-induced effect on muscle performance way out of proportion. The average decrease in force output, for example, is typically only 1.5 - 7%. It's doubtful whether any recreational gym-goer would even know what counts as a < 7% decrease in performance or what it feels like, yet there are countless 'experts' in the health and fitness space advising precisely those types of people to avoid pre-activity stretching because of the risk of reduced performance.

The anti-stretchers also like to skip over the research demonstrating positive effects on muscle performance following static passive stretching because it doesn't confirm their biases or they don't know such research exists. Even in studies that demonstrated a reduction in strength at short muscle lengths, there has been an observed increase in strength at long muscle lengths (McHugh et al., 2013; Balle et al., 2015). This is good news for people who would like to lower the risk of muscle strain injuries since they are more likely to occur at long muscle lengths.

In short, if you need to do static passive stretching in your warm-up to access the ranges of motion required in your workout, the trade-off with a potential reduction in performance is most likely worth it. If you want to be extra safe, limit the duration of your stretches to 60 seconds per muscle group and follow them up with dynamic stretches since that strategy means any impact on subsequent athletic activity is insignificant (Behm et al., 2016). Anyone who tells you different is about twenty years behind the research.

References

McHugh, M. et al. (2013) The Role of Neural Tension in Stretch-Induced Strength Loss. Journal of Strength and Conditioning Research volume 27, issue 5, pages 1327-1332.

Balle, S. S. et al. (2015) Effects of Contract-Relax vs Static Stretching on Stretch-Induced Strength Loss and Length-Tension Relationship. Scandinavian Journal of Medicine & Science in Sports volume 25, issue 6, pages 764-769.

Behm, D. G. et al. (2016) Acute Effects of Muscle Stretching on Physical Performance, Range of Motion, and Injury Incidence in Healthy Active Individuals: A Systematic Review. Applied Physiology, Nutrition, and Metabolism volume 41, issue 1, pages 1-11.