sprintingIn a sprint race, such as the 100m 200m or 400m, one hundredth of a second can mean the difference between winning and losing.  Optimizing performance, through an effective training program, has included  pre-activity stretching as a stalwart constituent of training  for many years.  In the past decade, the purpose and benefits of static stretching have been questioned, dissected and essentially repurposed due to large volume of evidence that propose pre-activity stretch-induced performance deficits. These findings have led to a paradigm shift on the justification  and mode of application of  static stretching prior to the performance of speed and power events.

An early study, published in 2001 in the Canadian Journal of Applied Physiology  investigated  factors underlying  force loss occurring after prolonged, static, passive stretching.  In this study, subjects were tested before and 5 to 10 minutes  following 20 minutes of static, passive stretching of the quadriceps while a control group performed a similar period of no stretch. Followup measurements included isometric maximal voluntary contraction force, surface integrated electromyographic  activity of the quadriceps and hamstrings, evoked contractile properties (twitch and tetanic force), and quadriceps inactivation as measured by an interpolated twitch technique.  Following stretching, there was a significant 12% decrement in maximal voluntary contraction with no significant changes in the control group.  In addition, muscle inactivation as measured by the interpolated twitch technique and integrated electromyographic  activity increased by 2.8% and 20.2%, respectively.  This study indicates that static stretching reduced neural activation of muscle contraction concomitant with a decrease in contraction force

A subsequent systematic review in 2004  explored the evidence  whether acute or regular long-term stretching affectssprinters starting blocks tests of sport performance.  Twenty three articles identified the outcomes of isometric force, isokinetic torque, running speed or jumping height following static stretch.  The results of this review suggests that stretching immediately prior to exercise decreases the results on performance tests that require isolated force or power.

 

starting blocks girlHowever, while a predominant theme that acute muscle stretch significantly impaired muscle performance, several studies and reviews led to ambiguous results and methodological faults in study design which raised questions regarding the efficacy of this belief.  Additionally,  some researchers believed that previous systematic reviews lacked focus on the acute effects of sole performance of static stretching on maximal muscle efforts whereas several reviews included multimodal interventions (static stretching performed with dynamic stretching, strength activities or proprioceptive neuromuscular facilitation, etc.)

A systematic review presented in 2012 in the journal Medicine and Science in Sport and Exercise focused its attention on studies that solely addressed the effects of static stretch on muscle performance.  The study showed that forty-four percent of all variables included in the analysis (144 findings) from 106 studies identified significant reductions in maximal strength, power, or speed dependent performance.  Specifically, the review denoted that static muscle stretches totaling less than 45 seconds can be used in preexercise routines without risk of significant decreases in strength, power, or speed dependent task performances.  Longer stretch durations (e.g., greater than 60 seconds) are more likely to cause a small or moderate reduction in performance.

A 2013 meta-analysis  presented in the Scandinavian Journal of Medicine and Science in Sports reviewed the acute effects of pre-exercise static stretching on strength, power, and explosivestarting blocks muscular performance. A computerized search of articles published between 1966 and December 2010 presented a total of 104 studies.  Results were not related to subject’s age, gender, or fitness level; however, they were more pronounced in isometric vs dynamic tests, and were related to the total duration of stretch, with the smallest negative acute effects being observed with stretch duration of ≤ 45 s. The authors concluded that the usage of static stretch as the sole activity during warm-up routine should generally be avoided.

As the advocacy and application of static stretching prior to speed and power events became less prevalent, the promotion of sport specific dynamic stretches or movement patterns ensued.  Several studies have reported improved range of motion and tissue mobility as well as facilitation of power, speed and jump performance through dynamic stretching.

sprint A study by Skoff and Strojnik, in 2007,  had seven runners perform 2 different warm-up protocols, one of which included slow running, stretching, and bounding and sprinting exercises, while the other consisted of slow running and stretching only. Before and after warm-up, contractile properties of the vastus lateralis and quadriceps femoris were monitored with a single twitch test, maximal torque, and the level of muscle activation during maximal voluntary knee extension. The two types of warm-up protocols showed statistically significant differences in the increase of peak knee extension torque and muscle activation level. After the dynamic warmup, maximal twitch torque was increased and twitch contraction time was shortened in addition to the increase of maximal torque and the level of activation.  Parameter changes after static stretching were similar to those after dynamic stretching but not statistically significant.  The authors concluded by stating that sprinting and bounding as part of athletes’ warm-up improve muscle activation.

starting blocks2Samukawa, et al in 2011, had subjects engage in dynamic stretching of plantar flexors for 30 seconds, repeated for 5 sets.  Dynamic stretching was shown to be effective in increasing ankle joint flexibility as well as a significant distal displacement of the myotendinous junction up until the second stretching set. Outcomes that could have indicated changes in muscle tissue (such as the pennation angle and fascicle length) were unaltered. However, a significant displacement of the myotendinous junction was found, indicating some change in the tendon tissues.  The authors concluded that dynamic stretching of the plantar flexors was considered an effective means of lengthening the tendon tissues. This study indicated that dynamic stretching was effective in improving range of motion as well as some musculotendinous tissue components.

 

Turki, et al in 2011, had 20 athletes engage in 6 different protocols following 10 minutes of dynamic stretching including:  3 sets of 3 repetition maximum deadlift exercise,  3 sets of 3-second maximum voluntary contraction back squats, 3 sets of 3 tuck jumps, 3 modified drop jumps,  dynamic stretching only and a control protocol.  Before the intervention and at recovery periods of 15 seconds, 4, 8, 12, 16, and 20 minutes, the participants performed 1-2 maximal countermovement jumps.  The authors found that 10 minutes of dynamic stretch had a 95-99% likelihood of exceeding the smallest worthwhile change for vertical jump height, peak power, velocity and force, thus indicating that dynamic stretching was greater than the control group in enhancing power output with jumping.

Frantz and Ruiz, in 2011, studied the effects of dynamic warm-up on lower body explosiveness among collegiate baseball players.  Participants were progressed through 3 different warm-ups on weekly testing dates over a 7-week period. After the warm-up routines, participants were measured for vertical jump height and long jump distance.  Results indicated that the participants jumped significantly higher in both experimental conditions while under the influence of the dynamic warm-up.  Additional long jump analysis determined that individuals jumped significantly further after no warm-up compared to after a static warm-up.  The results show that dynamic warm-up increases both vertical jump height and long jump distance. Specifically, these findings indicate that athletes could gain nearly 2 in. on his or her vertical jump by simply switching from a static warm-up routine to a dynamic routine.

Ultimately, with the research identifying the detriments in performance associated with static stretching while supporting the benefits of dynamic warmups,  is there still a consideration to include static stretching in a warmup?

sprint2Murphy, et al in 2010,  speculated that there are a number of sports where improved static flexibility may facilitate performance.  Examples of the necessity of a pronounced static range of motion in sport were given including: a goalie in ice hockey who must abduct their legs when in a butterfly position, gymnasts performing a split position, wrestling, martial arts, synchronized swimming and figure skating.   The researcher examined whether range of motion could be improved with a short duration and volume of static stretching within a warm-up, without negatively impacting performance.  In the study, ten recreationally active participants completed 2 separate protocols to examine changes in range of motion and performance, respectively, with different warm-ups. The warm-up conditions for the  range of motion protocol were static stretching , consisting of 6 repetitions of 6 second stretches; 10 min of running prior to the static stretching; and 5 minutes of running before and after the static stretching. The performance protocol also included a control condition of 10 minutes of running. Measures for the range of motion protocol included hip flexion range of motion, passive leg extensor tension, and hamstring electromyographic (EMG) activity at pre-warm-up, and at 1, 10, 20, and 30 minutes post-warm-up. Performance measures included countermovement jump height, reaction time, movement time, and balance at pre-warm-up and at 1 and 10 min post-warm-up.  The 5 minutes of running before and after the static stretch produced greater range of motion overall than the static stretch and 10 minutes of running before static stretch conditions with benefits persisting for 30 min. There were no significant alterations in passive muscle tension or EMG outcome.  Results indicate that 5 min of running before and after the static stretch method can provide ROM improvements for 30 min with either facilitation or no impairment in performance.

Further research also investigated the use of sport specific dynamic activity  with dynamic stretching

dynamic warmupSamson, in 2012, in the Journal of Sports and Science in Medicine The purpose of the study was to determine the effects of static and dynamic stretching protocols within general and activity specific warm-ups. Nine male and ten female subjects were tested under four warm-up conditions including a 1) general aerobic warm-up with static stretching, 2) general aerobic warm-up with dynamic stretching, 3) general and specific warm-up with static stretching and 4) general and specific warm-up with dynamic stretching. Following all conditions, subjects were tested for movement time (kicking movement of leg over 0.5 m distance), countermovement jump height, sit and reach flexibility and 6 repetitions of 20 meter sprints. Results indicated that when a sport specific warm-up was included, there was an 0.94% improvement in 20 meter sprint time with both the dynamic and static stretch groups. The static stretch condition also increased sit and reach range of motion  by 2.8% more than the dynamic condition. These results would support the use of static stretching within an activity specific warm-up to ensure maximal ROM along with an enhancement in sprint performance.

Additionally, it is important to discuss the importance of sequencing the order of static stretching and dynamic warmup.

running drillsFor example, Chaouachi, et al in  2010,  investigated the effects of static and dynamic stretching alone and in combination on subsequent agility, sprinting, and jump performance.  In the study, eight different stretching protocols: (a) static stretch  to point of discomfort; (b) static stretch less than point of discomfort; (c) dynamic stretching ; (d) static stretch to point of discomfort combined with dynamic stretch; (v) static stretch less than point of discomfort combined with dynamic stretch; (vi) dynamic stretch combined with static stretch to point of discomfort; (vii) dynamic stretch combined with static stretch less than point of discomfort; and (viii) a control warm-up condition without stretching were implemented with a prior aerobic warm-up and followed by dynamic activities.  Test measures included a 30 meter sprint, agility run, and jump tests. The results showed that the control condition showed significant differences  for faster times than the dynamic stretch combined with static stretch less than point of discomfort in the 30 meter sprint.  No other significant differences were found.  The authors conclude by stating that trained individuals who wish to implement static stretching should include an adequate warm-up and dynamic sport-specific activities with at least 5 or more minutes of recovery before their sport activity.

Similarly, Sim in 2010,  in the Journal of Strength and Conditioning Research  examined the effects of static stretching during warm-up on repeated sprint performance and also to assess any influence of the order in which dynamic activities (i.e., run-throughs and drills) and static stretching are conducted. Thirteen athletes completed a repeated sprint ability test consisting of three sets of maximal 6 x 20-m sprints (going every 25 seconds) after performing one of three different warm-up protocols. Each warm-up protocol involved an initial 1000-m jog, followed by either dynamic activities only, static stretching followed by dynamic activities, or dynamic activities followed by static stretching. Mean time was slowest in the dynamic activities followed by static stretch group.  Overall, these results suggest that 20-m repeated sprint ability may be compromised when static stretching is conducted after dynamic activities and immediately prior to performance.

running drills3Kistler, in 2010, in the Journal of Strength and Conditioning Research  expanded upon these result by determining what would happen to these effects at longer distances such as those seen in competition. This study investigated the effects of passive static stretching vs. no stretching on the 60- and 100-m sprint performance of college track athletes after a dynamic warm-up. Eighteen subjects completed both the static stretching and the no stretching conditions in counterbalanced order across 2 days of testing. On each day, all subjects first completed a generalized dynamic warm-up routine that included a self-paced 800-m run, followed by a series of dynamic movements, sprint, and hurdle drills. At the end of this generalized warm-up, athletes were assigned to either a static stretching or a no-stretching condition. They then immediately performed 2 –  10 -meter trials with timing gates set up at 20, 40, 60, and 100 m. Results revealed a significant slowing in performance with static stretching  in the second 20 (20-40) m of the sprint trials. After the first 40 m, static stretching exhibited no additional inhibition of performance in a 100-m sprint. However, although there was no additional time loss, athletes never gained back the time that was originally lost in the first portion of the trials. Therefore, in strict terms of performance, it seems harmful to include static stretching in the warm-up protocol of collegiate male sprinters in distances up to 100 m.

As presented above, this study indicates that proper balancing of static stretch with dynamic warmup can satisfy instances when sport specific activities demand a greater degree of range of motion thus indicating the use of static stretching  without negatively impacting speed and power output.

In addition, one needs to consider counterbalancing static stretch with dynamic warmup for the athlete who is recoveringrunning drills4 from a loss of joint or musculotendinous range of motion as related to  injury or post workout tissue tightness.  This is an indication for improving or regaining  range of motion, through static stretching,  prior to engaging in full training or competitive endeavors without compromising speed and power output

Current evidence has transformed our view of static stretching and has reconfigured its importance and mode of application as a part of warmup prior to speed and power events.  In summary, the following points are to be considered:

  1. Static stretching has been shown to improve range of motion for activities that require extremes of motion for optimal  performance
  2. Static stretching when performed > 45 seconds appears to inhibit speed and power performance whereas stretches less than 45 seconds show lower to no inhibition
  3. When performed in proper sequence, the application of static and dynamic stretching can improve mobility required for sport activities without impairment of speed and power output
  4. The application of sport specific warmup activities along with static and dynamic stretching, performed in appropriate sequence can offer improved range of motion while optimizing speed and power output

As a result, based upon research evidence, the following sequencing of warmup activities is suggested:

  1. Perform a general aerobic warmup, followed by:
  2. static stretching (duration of stretch < 45 seconds), when necessary  to improve mobility, followed by:
  3. sport specific dynamic activities, followed by:
  4.  dynamic stretching

 

running drills2

The next question is: How does static stretching affect endurance performance?

 

Dr Peter J Vilasi MPT DPT is Doctor of Physical Therapy and a USATF Level 2 certified endurance running coach at ExcelRunner

 

 

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