Static stretching has long been used in a warm-up, with the aim of enhancing performance and reducing the risk of injury. Recent reviews of the literature surrounding the role of static stretching question this practice. There is little, if any, evidence that stretching pre- or postparticipation prevents injury or subsequent muscle soreness. Although static stretching before activity might increase performance in sports that require an increased range of motion, such as gymnastics, static stretching can compromise muscle performance. In these cases it is important that the strength and conditioning professional perform a benefit-risk analysis when choosing whether or not to include static stretching in a warm-up.
Although some studies demonstrated that static stretching had no effect on subsequent performance, static stretching has also been shown to lead to a decrease in force production, power performance, running speed, reaction and movement time, and strength endurance. Additionally, both proprioceptive neuromuscular facilitation (PNF) stretching and ballistic stretching have been shown to be detrimental to subsequent performance.
Dynamic stretching does not seem to elicit the performance reduction effects of static and PNF stretching and has been shown to improve subsequent running performance. Given these findings, the use of static, PNF, and ballistic stretching in warm-up needs to be questioned. Based on current evidence, dynamic stretching would be the preferred option for stretching during a warm-up.
The degree of stretching required in the warmup depends on the type of sport. Sports in which increased flexibility is needed, such as gymnastics or diving, require a greater degree of stretching. Additionally, those with high demands for a stretch-shortening cycle of high intensity, as in sprinting and American football, are likely to require more stretching than those with low or medium stretch-shortening cycle activity, as in jogging or cycling. Strength and conditioning professionals should look at the specific range of motion and stretch-shortening cycle requirements of the sport or activity and use this information when designing an appropriate warm-up regimen.
A total warm-up program includes the following two components:
- A general warm-up period may consist of 5 to 10 minutes of slow activity such as jogging or skipping. Alternatively, low-intensity sport-specific actions such as dribbling a soccer ball can be productive at this time. This provides a very sport-specific general warm-up that aids in skill development and raises body temperature. The aim of this period is to increase heart rate, blood flow, deep muscle temperature, respiration rate, and perspiration and to decrease viscosity of joint fluids.
- A specific warm-up period incorporates movements similar to the movements of the athlete’s sport. It involves 8 to 12 minutes of dynamic stretching focusing on movements that work through the range of motion required for the sport, such as the walking knee lift. This is followed by sport-specific movements of increasing intensity such as sprint drills, bounding activities, or jumping. The more power necessary for the sport or activity, the more important the warm-up becomes.Including high-intensity dynamic exercises can facilitate subsequent performance. This phase should also include rehearsal of the skill to be performed.
The warm-up should progress gradually and provide sufficient intensity to increase muscle and core temperatures without causing fatigue or reducing energy stores. It is likely that there are optimal levels of warm-up and that these will be related to the sport, the individual, and the environment.
This is an excerpt from Essentials of Strength Training and Conditioning, Third Edition