The Latest Science on Acute Effects of Static Stretching on Muscle Strength and Power

The effects of static stretching on subsequent sport performance and strength have been hotly debated in sport science. Internet gurus loudly offer their wisdom that there is no use of stretching and it can even be detrimental. However, the science of stretching has also changed within the past decade. Researchers from the University of Postdam in Germany recently clarified the role of static stretching in a recent review. https://www.frontiersin.org/articles/10.3389/fphys.2019.01468/full

The general belief until the 1990s is that stretching promoted flexibility and improved athletic performance. This was due to its effect on greater ROM, which was thought to improve the movement economy. However, since the late 1990s up to the early 2000s, researchers have started discussing the potentially harmful effects of stretching on subsequent sports performance. Several studies from the past two decades demonstrated that static stretching could reduce muscle strength and power performances. Thus, sports scientists have recommended not to perform static stretching before sports game or strength- and power-related activities. Dynamic stretching exercises were promoted.

However, more recent evidence suggests that when performed as a single-mode treatment or when integrated within a full warm-up routine including aerobic activity, dynamic-stretching, and sport-specific activities, short-duration stretching (≤60 s per muscle group) does not significantly impair subsequent strength and power activities (change within 1–2%). But, longer stretching durations (>60 s per muscle group) appear to induce substantial and relevant declines in strength and power performances (change of 4.0–7.5%).

Recent evidence suggests that when included in a full warm-up routine, short-duration static stretching may even contribute to lower the risk of sustaining musculotendinous injuries, especially with high-intensity activities (e.g., sprint running and change of direction speed). It seems that during short-duration stretching, neuromuscular activation and musculotendinous stiffness appear not to be affected compared with long-duration stretching. This effect could be due to an elevated muscle temperature induced by a dynamic warm-up program, among other factors. More specifically, elevated muscle temperature leads to increased muscle fiber conduction-velocity and improved binding of contractile proteins (actin, myosin). Thus, the previous understanding of harmful stretching effects on subsequent strength and power activities needs to be updated.

Short-duration static stretching should be included as an essential warm-up component before the uptake of recreational sports activities due to its potential positive effect on flexibility and musculotendinous injury prevention. However, in high-performance athletes, short-duration stretching has to be applied with caution due to its small but still prevalent adverse effects on subsequent strength and power performances, which could have an impact on performance during competition.