For years, the tradition at many sports practices has been to “circle up” at the beginning of the session, and perform a series of static (holding one position) stretches anywhere from 30 to 90 seconds. Even the professional baseball players who train at SPARTA talk about the “stretching lines” at spring training. Participation in a group warm-up can be very beneficial to a team, with each player knowing that it is time to focus on the practice time ahead. However, the inclusion of static stretches in these warm-ups can not only decrease performance, but also can lead to serious injury.
The vast majority of sports require some type of explosive movement. Whether it is maximal effort throwing, jumping, or sprinting, the stress on an athlete’s muscles and connective tissues (tendons and ligaments) is greatest during these very high speed movements. The force an athlete can produce during these movements is not only dependent on the strength of the muscles that are being used, but the elastic nature of these muscles and the connective tissues involved. It’s easiest to think about the elasticity of your muscle as a highly efficient rubber band gun. Energy is stored when you stretch the rubber band, and when the stretch is released, so is the energy (the rubber band goes flying). Your muscle and tendons store energy the same way. A quick stretch applied to a muscle, creates a force contraction of that muscle.
We’ve all seen rubber bands that have lost their elasticity. Static stretching can turn your muscles and connective tissues into loose rubber bands, permanently deforming your tendons and ligaments. It is important for high speed, explosive movements to keep a certain amount of stiffness in your muscles and connective tissues. Sayers, at Middle Tennessee State University tested sprinting speed of elite level female soccer players. The group that performed static stretching before the sprints had slower acceleration, lower maximal speed, and slower overall time in a 30 meter sprint than the group who did not static stretch before the sprints. In a study conducted by Holt, at the University of Evansville, 64 collegiate football players were tested in the vertical jump. All subjects did a general warm up, and then were divided into four groups. One group did no more warm up, one group completed static stretching, one group completed dynamic stretching, and the last group completed a dynamic flexibility routine. The group who static stretched had the lowest average vertical jump of all the groups.
Not only can static stretching decrease performance, but it can also leave an athlete more susceptible to injury. Static stretching can decrease the sensitivity of pain receptors in muscles. The danger of this is that when a muscle is over-stretched during rigorous competition, the muscle’s defense system (pain receptors) are less sensitive, resulting in more muscle pulls and strains. A safer, and more effective alternative to static stretching is moderate, dynamic (moving), full range of motion exercise. An example would be starting a sprint workout with a series of lunges, skips and less intense runs lasting no more than 30 seconds.
At SPARTA, athletes complete a three-part warm-up before each intense training session. The first ten minutes is a general warm up to increase circulation and the temperature of acting muscles. The second part is a series of dynamic body-weight movements, done in a full range of motion, including several lunge variations. The third part is a more intense reactive warm-up, where muscles are quickly stretched and contracted during higher speed movements like jumps and medicine ball throws.