Stretching was always a mainstay for distance runners in an effort to both reduce injuries and improve performance. Over the past decade, however, a lot of research has come out that seems to contradict that popular belief.

In fact, according to Running Research News, almost twice as many research studies advise against stretching compared to those that advocate stretching. A recent article of theirs listed quotes from recent studies that they had gone through, with 14 quotes advising against stretching while only 8 quotes could be construed as advising stretching. There were 4 inconclusive quotes.

I’ve included their list of quotes below, since the format from the original article is really difficult to read and follow. I’ve asked them for a list of the studies where these quotes were pulled from for future reference:

Research/Arguments in favor of Stretching for Injury Prevention

1. Improving flexibility through stretching is another important preparatory activity that has been advocated to improve physical performance.
2. Experts in the field of training and conditioning agree that good flexibility is essential to successful physical performance, although their ideas are based primarily on practical experience rather than experimental evidence.
3. Maintaining good flexibility aids in the prevention of injuries to the musculoskeletal system.
4. Current sport research shows improving flexibility or increasing joint ROM is significant in its contribution to movement efficiency, amplitude of movement, and prevention of soft tissue injury.
5. Athletic trainers and physical therapists feel that maintaining good flexibility is important in prevention of injury to the muscle and tendon.
6. Our statistical analysis indicates an association between using a static stretching program and a decreased incidence of muscle and tendon strains in Division III college football players.

Inconclusive Research for Stretching and Injury Prevention

1. No conclusive statements can be made about the relationship of flexibility to athletic injury.
2. Due to the paucity, heterogeneity and poor quality of the available studies no definitive conclusions can be drawn as to the value of stretching for reducing the risk of exercise-related injury.
3. There is not sufficient evidence to endorse or discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes. Further research is urgently needed.
4. Static stretching decreased the incidence of muscle-related injuries but did not prevent bone or joint injuries.

Research against Stretching for Injury Prevention

1. In summary, we see no strong evidence proving that flexibility or stretching is associated with rates of strains, sprains, or overuse injuries that can be applied across all sports or levels of competition.
2. New evidence suggests that stretching immediately before exercise does not prevent overuse or acute injuries.
3. Incidence of injury was not significantly different for the experimental and control groups.
4. This intervention was not effective in reducing the number of running injuries.
5. There was no significant effect of pre-exercise stretching on injury risk rate between the stretch group and the control group.
6. A typical muscle stretching protocol performed during preexercise warm-ups does not produce clinically meaningful reductions in risk of exercise-related injury in army recruits.
7. In this study the number of lower extremity overuse injuries was significantly increased in infantry basic trainees with increased hamstring flexibility.
8. Injured runners were more likely to have stretched before running.
9. Although stretching to increase flexibility is widely recommended to prevent training injuries, data to support the practice are lacking. Our data indicate that both the most flexible and least flexible individuals are at higher risk of lower body injuries. Subjects in the least flexible and most flexible quintiles were 2.5 and 2.2 times more likely to get injured than subjects in the middle quintile.
10. The results of this review do not support the role of pre-exercise or postexercise stretching as an intervention addressing postexercise muscle soreness. In addition, the evidence presented in this review does not support the role of pre-exercise stretching in the reduction of lower extremity injury risk.

Research/Arguments in favor of Stretching for Performance Improvement

1. Our results show that stretching may favorably influence the force-velocity relationship of the trained muscle as well as the shape of the torque curve during movements at a given velocity.
2. Regular stretching improves force, jump height, and speed, although there is no evidence that it improves running economy.

Research against Stretching for Performance Improvement

1. Greater flexibility may impair performance in sports that do not require a high degree of flexibility such as running. Runners with less flexibility are actually more efficient at running.
2. Intense static stretching may reduce maximum force production. The loss of voluntary strength and muscular power may last up to one hour after the static stretch.
3. Based on these results, performing stretching before a vertical jump test would be detrimental to performance.
4. Observations by coaches and athletes have called into question the universal prescription of stretching for the purpose of enhancing sport performance, and this skepticism is being supported by the growing body of empirical data.

(More Info: Running Research News)