By: Mike Zourdos, MS, CSCS
Ph.D. Student – The Florida State University
Skeletal Muscle Laboratory

I. Introduction
“Preparation is the key that unlocks the door to success.” You’ll find this quotation in my signature as reference to taking the necessary steps in order to put yourself in a position to succeed on competition day. This preparation must encompass the mental capacity and desire to undergo long training cycles, however, preparation must also be of the utmost importance each day when optimizing a warm-up routine. Just as a lifter looks to optimize their nutritional intake and frequency of training, the daily preparation in terms of warm-up development should be no different. As lifters we all strive to get the most out of our ability, therefore we must to use all of the tools at hand to indentify how to prepare properly. These tools begin with analyzing commonly used warm-up techniques and understanding what is beneficial and what may be detrimental to performance. After all, proper preparation may not guarantee a victory or personal record total on meet day, but improper preparation will certainly guarantee that a lifter does not reach their optimal potential.

II. Static Stretching
Static Stretching, the practice of reaching a stretch position and holding that position for a period of 10-30 seconds, is perhaps the most widely used method of pre-training preparation for any sport. Even though static stretching has been used for many years by lifters and other athletes as a pre-training routine it has only been properly researched over the past 10-15 years.

2.1.1: Pre-Exercise Negative Performance Effects
Despite its widespread use as a warm-up protocol, in recent years static stretching has been shown to decrease maximal strength (1,2,3), bench press power (4), muscular endurance performance (1), sprinting speed (5), and jump height (6) among trained athletes. From these results it seems clear that static stretching causes a decline in force production, which is detrimental to any sort of training a powerlifter may utilize. The mechanism of the negative effects seems to be that static stretching causes a decrease in muscle stiffness stiffness allowing less energy to be stored, which results in a less-effective stretch shortening cycle (7).
Now, let’s explain what this means, exactly how this occurs, and why it’s detrimental to strength performance. Each muscle and the tissues surrounding it, together known as the musculotendinous unit (MTU), have a certain beginning stiffness. The stiffer the MTU the more force that is produced and as one gets stronger the stiffness of the MTU increases. Therefore, it is understood that decreasing stiffness may have deleterious performance effects and static stretching does just this. Stretching itself place “stress” on the muscle, which results in a lengthening of that muscle and the tissues around it. Now, when the muscle is lengthened less force is produced to hold the MTU at the longer length and this is known as the stress-relaxation (8). This stress-relaxation is the mechanism, which directly serves to decrease MTU stiffness.

Okay, so now it’s starting to come together a little bit. Essentially because less force is produced at the longer length there is also less energy stored, which results in a decline in strength and activity of the stretch shortening cycle. In practical terms we know that it is more difficult to perform only the concentric (muscle-shortening) portion of an exercise than it is to perform the concentric following the eccentric (muscle-lengthening). This is so directly due to the activation of the stretch shortening cycle as a result of the eccentric phase, so clearly compromising the effects of the stretch-shortening cycle is a negative for our performance when performing a squat or a bench press which utilizes an eccentric phase on a maximal attempt. Finally, the negative effects of static stretching inhibit strength performance for at least 60-minutes (2).

2.1.2: Static Stretching – Injury and Recovery
While this article will focus on reviewing the efficacy of a warm-up protocol utilizing static or dynamic stretching it is important to note a commonly discussed relationship between static stretching and its effects on injury prevention and acute recovery from a training session. This relationship, in fact, seems to be a myth as the data shows that pre-training stretching does not prevent injury (9) and post-training stretching does not increase recovery time nor does it decrease the magnitude of delayed onset muscle soreness (DOMS) (9). The effects of static stretching on flexibility will be noted later in this review.

III. Dynamic Stretching
Dynamic stretching, which involves moving through a stretch position without holding it, has rivaled static stretching in popularity in recent years and sometimes is used in conjunction with its counterpart. The data collected on dynamic stretching is even more recent than that of static, however, its effects on maximal strength and anaerobic performance seem to be overwhelmingly positive.



3.1.1: Pre-Training Positive Performance Effects
First and foremost dynamic stretching is more specific than static stretching to any training task that a powerlifter takes on yielding its superiority to static stretching. Furthermore, the data supports its efficacy by showing dynamic stretching warm-up protocols to increase maximal strength (10) and 20-meter sprint performance (11). The mechanisms responsible for this increase seem to be specificity to the activity, increased core temperature, and increased resting VO2 (the amount of O2 being consumed) (12). Due to these findings it has been suggested that dynamic stretching does not result in the stress-relaxation (13) and possibly increases stiffness, which as we know would increase force production and strength performance,

3.1.2: Acute Flexibility
The most common question posed at this point is usually, “What about flexibility and Range of Motion (ROM), if I don’t static stretch will dynamic stretching increase my joint ROM sufficiently before training?” The answer to this is a resounding ‘YES’ as new data from our lab shows acute increases in flexibility from both modes of stretching to be the same. Wilson et al. (2009) utilized 15 minutes of static stretching to increase ROM 16-17% (14), while Zourdos et al. (2010) showed the same 16-17% ROM increase after 15 minutes of dynamic stretching (13).

IV. Application and Optimizing Warm-Up In Your Training
It is of strong importance to point out that the negative effects of static stretching discussed in this article are due to its use immediately before training. The decrease in stiffness and force production lasts for a bout of training, but then returns to normal, making the decline in stiffness acute. A study specifically using powerlifters demonstrates that chronic static stretching remains a positive mechanism when performed on its own for increasing flexibility and force production of the aforementioned stretch-shortening cycle (15). These findings validate the use for a chronic stretching routine, which is not performed before or after training (Example: Stretching in this case should be performed on its own maybe upon waking in the morning or before sleep at night).

In recent years myofascial release techniques or more specifically foam rolling have been commonly used in the powerlifting community. At this point there is no specific data on foam rolling to make a judgment (positive or negative) on its efficacy. However, from a practical perspective it is possible that the depression of the muscle caused by foam rolling may result in a stress-relaxation similar to that of static stretching, which would be a negative for pre-training use. As for recovery the goal is to increase blood flow via vasodilation and foam rolling has not been investigated in this aspect either. Even though there is no data in this area the widespread us of foam rolling warrants its mentioning.

This data presented clearly shows the positive effects of dynamic stretching and the negative effects of static stretching, while also demonstrating the mechanisms in play. Moreover, these findings do shed light on a way in, which lifters can properly prepare for training. It is recommended that when warming up lifters refrain from static stretching, but do utilize dynamic stretching to increase performance of their training session. When selecting dynamic stretching exercises there are many to choose from. The exact length of a dynamic stretching protocol is not known, however, it does seem that one, which does not deplete muscle glycogen is most effective. That being said below is a link to a video demonstrating a simple and effective warm-up protocol to optimize performance. Again this video shows just a few of the exercises that may be used.

I’m always happy to discuss further or answer any questions via my email below.
Mike Zourdos, MS, CSCS
Ph.D. Student
The Florida State University
Skeletal Muscle Laboratory
mzourdos@fsu.edu
“Preparation is the key that unlocks the door to success.”

References
1. Nelson, AG, Kokkonen, J and Arnall, DA. Acute muscle stretching inhibits muscle strength endurance performance. J Strength Cond Res 19: 338-343, 2005.
2. Fowles, JR, Sale, DG and MacDougall, JD. Reduced strength after passive stretch of the human plantarflexors. J Appl Physiol 89: 1179-1188., 2000.
3. Kokkonen, J., Nelson, A.G., and A., Cornwell. Acute stretching inhibits maximal strength performance. Res. Q. Exerc. Sport. 69:411-415. 1998.
4. Fry, A.C., McLellan, E., Weiss, L.W., and Rosato, F.D. The effects of static stretching on power and velocity during the bench press exercise. Med. Sci. Sports Exerc. 35(5):S264. 2003.
5. Nelson, AG, Driscoll, NM, Landin, DK, Young, MA and Schexnayder, IC. Acute effects of passive muscle stretching on sprint performance. J Sports Sci 23: 449-454, 2005.
6. Behm, DG., and Kibele, A. Effects of differeing intensities of static stretching on jump performance. Eur. J. Appl. Physiol. 101:587-594, 2007.
7. Stone, M., Ramsey, M.W., Kinser, A.M., O’Bryant, H.S., Ayers, C., and Sands, W.A. Stretching: Acute and Chronic? The Potential Consequences. St. Cond. J. 28(6):66-74, 2006.
8. Spernoga, S.G., Uhl, T.L., Arnold, B.L., and Gansneder, B.M. Duration of maintained hamstring flexibility after a one-time, modified hold-relax stretching protocol. J. Athl. Train. 36(1):44-48, 2001.
9. Herbert, R.D., and Gabriel, M. Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. Br. Med. J. 325:1-5, 2002.
10. Yamaguchi, T and Ishii, K. Effects of static stretching for 30 seconds and dynamic stretching on leg extension power. J Strength Cond Res 19: 677-683, 2005.
11. Fletcher, IM and Jones, B. The effect of different warm-up stretch protocols on 20 meter sprint performance in trained rugby union players. J Strength Cond Res 18: 885-888, 2004.
12. Bishop, D. Warm Up II: Performance Changes Following Active Warm Up and How to Structure the Warm Up. Sports Med 33 (7): 483-498, 2003.
13. Zourdos, M.C., Wilson, J.M., Ugrinowitsch, C., Sommer, B.A., Lee, S.R., Park, Y.M., Henning, P.C., Panton, L.B., Kim, J.S. Effects of dynamic stretching on energy cost and running endurance performance in trained male runners. J. Strength Cond. Res. In Review, 2010.
14. Wilson, JM, Hornbuckle, LM, Kim, JS, Ugrinowitsch, C, Lee, SR, Zourdos, MC, Sommer, B and Panton, LB. Effects of static stretching on energy cost and running endurance performance. J Strength Cond Res 2009 Nov 13. [Epub ahead of print].
15. Wilson, G.J., Elliot, B.C., and Wood, G.A. Stretch shortening cycle performance enhancement through flexibility training. Med. Sci. Sports Exerc. 24:116-123, 1992.