Is stretching beneficial for endurance athletes?

Practitioners in health, sport & exercise often get asked whether acute stretching is beneficial for endurance athletes. Physiotherapist & friend of PURE SPORTS PERFORMANCE, Chris Lelliott, explores this question in more depth.

It’s a challenging & controversial question. It has been argued that warm-up routines have become habitual rather than effective (Hutchinson, 2020) & that pre-exercise stretching may not only fail to enhance performance, but may also be counter-productive. Stretching has historically formed an integral part of an endurance athlete’s toolbox and is often the cornerstone of warm-up sessions. As a physiotherapist, I regularly prescribe stretching exercises. The effectiveness of stretching following periods of deconditioning or immobility after surgery or injury are well established in improving range of movement & returning individuals physical function. However, what benefits will stretching provide a highly trained endurance athlete?

Since the 1980’s sport medicine professionals have promoted stretching as a way to improve physical performance, flexibility & reduce injuries (Shrier 2005). Interestingly, no robust empirical evidence had existed to support this thinking. Taking this into consideration it’s important to challenge these assumptions & shine a critical light on the current available evidence.

Is static stretching beneficial for endurance athletes?

Have we become conditioned to stretch because it has become ingrained in our psyche or does it actually provide a tangible benefit? 

Let’s look at some key areas:

 Warming-up

The American College of Sports Medicine (ACSM) defines flexibility as “the ability to move a joint through its complete range of motion (ROM)”. Traditional beliefs held that to improve performance & reduce injuries athletes should be flexible & use stretching to improve their flexibility (Behm 2002). Typically, stretches are incorporated into warm-up or cool-down routines with static stretching being the most familiar and popular. The ACSM guidelines recommends a static stretch be held for 10 to 30 secs. It involves holding a single position placing a muscle at the most lengthened position and allowing the muscle and tendon fibres to “relax”, therefore reducing muscles stiffness.

Interestingly, endurance runners have been found to be less flexible than non-athletic populations (Saunders et al. 2004). This phenomenon has been hypothesised due to increased muscle hypertrophy & biomechanical adaptations as the body adapts to reduce energy expenditure. Due to the high training loads demanded for an endurance athlete I wanted to review two recovery outcomes following static stretching, namely delayed onset muscle soreness (DOMS) and injury prevention. These two outcomes are likely to have the greatest influence on an athletes’ performance and are discussed below.  

Delayed-onset Muscle Soreness (DOMS)  

DOMS is defined as muscular pain, soreness & stiffness following unaccustomed or strenuous exercise. Symptoms are more pronounced after repetitive eccentric activities where muscles work to slow lengthening muscles, for example downhill running or heavy-slow resistance training. Symptoms normally peak around 48 hours after activity & can cause temporary loss of muscle power & increasing muscular stiffness. DOMS can interfere with training programmes & reduce performance in subsequent exercise sessions. Therefore, it’s only natural for endurance athletes to reduce these after effects following training. A review of 12 randomised-controlled studies investigating stretching as part of a warm-up routine found stretching does not reduce muscle soreness in healthy adults (Herbet et al. 2011). Whilst this review investigated studies across all stretching disciplines it provides an interrogation of the belief in warm-up stretching as being advantageous.

Further studies have added to this consensus in athletic populations. Boobphachart et al. 2017 found no reduction in muscle soreness using static stretching 72 hours after intensive eccentric exercises. Xie et al 2018 found no difference between static and dynamic stretching on muscle soreness 5 days following intense exercise to exhaustion.   

Injury Prevention

It is well understood that athletes who have had previous injuries are at a higher risk of suffering further injuries (Green et al, 2020). Overuse injuries are common in endurance athletes, often due to training load demands. Injuries can cause, in severe cases, significant deconditioning, emotional distress and reduced quality of life.

No strong evidence has found stretching before or after exercise prevents injuries in athletic populations (Thacker et al. 2004). These findings have been endorsed by further studies. Small et al. 2007 investigated studies across an 18-year period (1990 – 2008) finding no benefit in static stretching during warm-up routines. Baxter et al. 2017 systematically reviewed studies for endurance runners’ injury risk and again found stretching provided no significant reduction in chronic overuse injuries. 

If static stretches are to be used it should be after exercise, when the muscles are warm, or in a separate context such as yoga/pilates.

Conclusion

Based on the currently available evidence, static stretching before endurance exercise does not provide any significant benefits to athletes insofar as reducing muscle soreness or chronic injury risk are concerned. Additionally, there remains a poor correlation between an individuals’ flexibility & injury risk (Baxter et al. 2017). This is also true for performance measures as less flexible distance runners were found to have significantly better running economies than their more flexible counterparts (Jones. 2002).

Importantly, static stretching does not have a negative effect on muscle soreness, injury risk or performance. However, endurance athletes should be aware that no benefits currently exist for the use of static stretching in a warm up routine. It could remain habitual, just not effective.

Take Home Message

1.       It’s probably fair to say that some of us need to look again at certain stretching techniques and ask why we do them.  It isn’t necessary to incorporate static stretches into a warm-up routine.

2.       It is more effective to complete a progressive active warm-up lasting 5 – 10 minutes beginning with walking or jogging. This could include some active mobility exercises (those that take the muscles dynamically through the full range of movement), starting slowly & building up to sports-specific speeds. These mobility exercises also help prime the brain/body connection by optimising neuromuscular coordination.

3.       If static stretches are to be used it should be after exercise, when the muscles are warm, or in a separate context such as yoga/pilates.

4.       Stronger clinical evidence supports the use of a graduated resistance training in improving athletic performance. Bi-weekly strength training sessions incorporating high-resistance multi-joint exercises should be integrated into an endurance athlete’s programme as a more robust way of preventing injuries.  

References

ACSM’s Guidelines for Exercise Testing and Prescription. 2014.

Baxter, C., Mc Naughton, L.R., Sparks, A., Norton, L. and Bentley, D., 2017. Impact of stretching on the performance and injury risk of long-distance runners. Research in Sports Medicine, 25(1), pp.78-90.

Behm, D., 2002. Should static stretching be used during a warm-up for strength and power activities?

Boobphachart, D., Manimmanakorn, N., Manimmanakorn, A., Thuwakum, W. and Hamlin, M.J., 2017. Effects of elastic taping, non-elastic taping and static stretching on recovery after intensive eccentric exercise. Research in Sports Medicine, 25(2), pp.181-190

Green B, Bourne MN, van Dyk N, et al.  Recalibrating the risk of hamstring strain injury (HSI) - A 2020 systematic review and meta-analysis of risk factors for index and recurrent HSI in sport.  British Journal of Sports Medicine Published Online First: 16 April 2020. doi: 10.1136/bjsports-2019-100983

Herbert, R.D., de Noronha, M. and Kamper, S.J., 2011. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database of Systematic Reviews, (7).

Hutchinson, A. 2020. Your warm-up doesn’t matter as much as you think. Outside Magazine (Online). Available at: http://outsideonline.com/2411000/warm-up-research

Jones, A.M., 2002. Running economy is negatively related to sit-and-reach test performance in international-standard distance runners. International journal of sports medicine, 23(01), pp.40-43.

Saunders, P., Pyne, D., Telford, R. & Hawley, J. (2004). Factors affecting running economy in trained distance runners. Sports Medicine, 34(7), 465-485.

Shrier, I. 2005. Stretching Perspectives. Current Sports Medicine Reports, 4(5), pp. 237-238.

Small, K., Mc Naughton, L. and Matthews, M., 2008. A systematic review into the efficacy of static stretching as part of a warm-up for the prevention of exercise-related injury. Research in Sports Medicine, 16(3), pp.213-231.

Thacker, S.B., Gilchrist, J., Stroup, D.F. and Kimsey Jr, C.D., 2004. The impact of stretching on sports injury risk: a systematic review of the literature. Medicine & Science in Sports & Exercise, 36(3), pp.371-378.

Xie, Y., Feng, B., Chen, K., Andersen, L.L., Page, P. and Wang, Y., 2018. The efficacy of dynamic contract-relax stretching on delayed-onset muscle soreness among healthy individuals: A randomized clinical trial. Clinical Journal of Sport Medicine, 28(1), pp.28-36.