Stretching and Performance

Introduction

Just about anyone starting an exercise regimen has had curiosities concerning flexibility or mobility and how to best improve these aspects of fitness. Static stretching is probably the most popular method and is clearly effective for increasing the range of motion for a given joint (2), but it is optimal for the bodybuilder or strength athlete? Let’s dig into that topic and see if we can’t clear up some of the confusion and help you down the path of silky-smooth movement.

Definitions

First off, let’s define static stretching. Static stretching consists of holding a position to the point of pain onset for a given amount of time. A common example is a simple toe-touch stretch for the hamstrings. You bend forward until your hamstrings request that you go no further and then hold that position for time. This form of stretching can definitely improve flexibility – all you have to do is pick a particular stretch or position and hold it for 30-seconds once per day (2). Stretching more often or for longer periods of time doesn’t appear to make a difference (2).

By now you may have noticed that we’re separating flexibility from mobility. Many in the fitness field will use the terms interchangeably but that’s not exactly correct. Flexibility is simply the ability of a joint to move through a range of motion. Mobility, however, is the ability of a joint to be strong and stable in a range of motion. Mobility, then, appears to be much more important for sport and training (10,11).

Stretching Before Training

So now that we’ve got a baseline understanding from the dictionary of suppleness, how should you go about improving your own flexibility and ultimately, mobility? The common practice seems to be including static stretching exercises into your warmup (5,16,17), but we’re here to tell you to stop that. Immediately. Yesterday, preferably. Stretching before exercise leads to significant decreases in muscle force output (1,3,6,8,9,13,17,18) and can even negatively affect overall power production (17), though the jury seems out on that component. In fact, one researcher states that the increase in muscle compliance from stretching may cause tissue to rupture more easily. It is also suggested that stretching before most activities is inappropriate as common exercises are not performed in excessive ranges of motion. Ultimately, this researcher proposes that static stretching is ineffective for injury prevention, the exact reason that most utilize it (16).

Since stretching before your workout seems terrifying now, what exactly should you do for your warmup? According to several sources, the majority of the positive effects associated with a warmup are simply due to the increase in muscle tissue temperature (4,5,14,15). This increase in tissue temperature can improve blood flow to and through the muscle which increases overall oxygen delivery to the muscle tissue and helps remove metabolic waste products. Raising tissue temperature may also increase metabolic activity within the muscle which can boost overall training performance (5). Muscle temperature seems to dramatically increase during the first 3-5 minutes of exercise and then reaches equilibrium between 10 and 20 minutes so a 10-minute warmup that gets you sweating should be a good start (5).

Warm-up Details

Okay, so far we’ve nailed down that stretching before a workout isn’t exactly fantastic, and that your warmup should be about 10-minutes long. But what should your warmup consist of since stretching is out? One study actually found that a 4-minute jog before testing improved performance when compared to other types of warmups, all of which included stretching. They even found that running combined with stretching didn’t improve performance over the control group – stretching literally masked all of the positive benefits from running (17). If you hate running there’s still good news to be heard. Any warmup that consists of high intensity exercises, such as plyometrics, short sprints, and jumps appears to both increase tissue temperature and improve subsequent exercise performance through a process known as “post-activation potentiation” (5,7,19).

Post-activation potentiation is defined as an increase in muscle performance following previous contractile activity – the more intense the previous activity, the more powerful the potentiation. There’s several physiological and mechanical pathways that may contribute to this but those are outside the scope of this piece. Just know that plyometrics and running variations seem to be the most effective method of warming up if your goals include producing force and power during your workout – which directly correspond to your workout stimulus and overall gains.

We got a little off topic when warming up was mentioned but that’s an extremely important takeaway that we can’t stress enough – do not stretch before your workout! As far as improving flexibility goes, it’s very much worth noting that resistance training, especially when using full ranges of motion, improves flexibility just as much as static stretching does (10,11). In fact, one study compared a resistance training routine and a static stretching routine on overall joint flexibility and strength. Both study groups increased flexibility over a control group but the resistance training group had higher increases in muscle strength in addition to this flexibility (11). Wait, increased strength through a range of motion? That sounds like… mobility! Yes! Strength training, when using a full range of motion, is just as effective as static stretching for improving flexibility AND improves muscle strength to increase overall joint mobility.

Conclusion

If you really love stretching there’s no reason to delete it from your exercise regimen – you can perform it up to 2-hours before exercise and anytime post-workout with no negative effects on force and power production (10,12). Just keep in mind that stretching does not necessarily improve overall mobility – you have to strengthen the muscles around a joint to increase both flexibility and mobility. There’s not much point in improving range of motion if you don’t increase strength in that range of motion as well – you’re just inviting injury in that new, but weak, range of motion (16).

So, if one of your training goals is improving flexibility and overall mobility, keep lifting! Make sure that you are utilizing full range of motion, compound movements to improve mobility at all joints. These improvements in mobility can greatly increase your quality of life and can directly improve the functionality of your training.

References

1. Avela, J., Kyrolainen, H., & Komi, P. V. (1999). Altered reflex sensitivity after repeated and prolonged passive muscle stretching. Journal of Applied Physiology, 86(4), 1283-1291.
2. Bandy, W. D., Irion, J. M., & Briggler, M. (1997). The effect of time and frequency of static stretching on flexibility of the hamstring muscles. Physical Therapy, 77(10), 1090-1096.
3. Behm, D. G., Button, D. C., & Butt, J. C. (2001). Factors affecting force loss with prolonged stretching. Canadian Journal of Applied Physiology, 26(3), 262-272.
4. Bergh, U., & Ekblom, B. (1979). Influence of muscle temperature on maximal muscle strength and power output in human skeletal muscles. Acta Physiologica Scandinavica, 107(1), 33-37.
5. Bishop, D. (2003). Warm up I: Potential Mechanisms and the Effects of Passive Warm Up on Exercise Performance. Sports Medicine, 33(6), 439-454.
6. Fowles, J. R., Sale, D. G., & MacDougall, J. D. (2000). Reduced strength after passive stretch of the human plantarflexors. Journal of Applied Physiology, 89(3), 1179-1188.
7. Güllich, A., & Schmidtbleicher, D. (1996). MVC-induced short-term potentiation of explosive force. New Studies in Athletics, 11, 67-84.
8. Knudson, D., Bennett, K., Corn, R., Leick, D., & Smith, C. (2001). Acute effects of stretching are not evident in the kinematics of the vertical jump. The Journal of Strength & Conditioning Research, 15(1), 98-101.
9. Kokkonen, J., Nelson, A. G., & Cornwell, A. (1998). Acute muscle stretching inhibits maximal strength performance. Research Quarterly for Exercise and Sport, 69(4), 411-415.
10. Kraemer, W. J., Ratamess, N. A., & French, D. N. (2002). Resistance training for health and performance. Current Sports Medicine Reports, 1(3), 165-171.
11. Morton, S. K., Whitehead, J. R., Brinkert, R. H., & Caine, D. J. (2011). Resistance training vs. static stretching: effects on flexibility and strength. The Journal of Strength & Conditioning Research, 25(12), 3391-3398.
12. Power, K., Behm, D., Cahill, F., Carroll, M., & Young, W. (2004). An acute bout of static stretching: effects on force and jumping performance. Medicine & Science in Sports & Exercise, 36(8), 1389-1396.
13. Rosenbaum, D., & Hennig, E. M. (1995). The influence of stretching and warm‐up exercises on Achilles tendon reflex activity. Journal of Sports Sciences, 13(6), 481-490.
14. Sargeant, A. J. (1987). Effect of muscle temperature on leg extension force and short-term power output in humans. European Journal of Applied Physiology and Occupational Physiology, 56(6), 693-698.
15. Shellock, F. G., & Prentice, W. E. (1985). Warming-up and stretching for improved physical performance and prevention of sports-related injuries. Sports Medicine, 2(4), 267-278.
16. Shrier, I. (1999). Stretching Before Exercise Does Not Reduce the Risk of Local Muscle Injury: A Critical Review of the Clinical and Basic Science Literature. Clinical Journal of Sports Medicine, 9, 221-227.
17. Young, W. B., & Behm, D. G. (2003). Effects of running, static stretching and practice jumps on explosive force production and jumping performance. Journal of Sports Medicine and Physical Fitness, 43(1), 21-27.
18. Young, W.B., & Elliott, S. (2001). Acute effects of static stretching, proprioceptive neuromuscular facilitation stretching, and maximum voluntary contractions on explosive force production and jumping performance. Research Quarterly for Exercise and Sport, 72(3), 273-279.
19. Young, W. B., Jenner, A., & Griffiths, K. (1998). Acute enhancement of power performance from heavy load squats. The Journal of Strength & Conditioning Research, 12(2), 82-84.