One good thing about Exercise Science is; we’ve come a long way baby. Gone are the days of practice with everyone commencing by lining up for toe touches and quad stretches: holding your ankle up and behind you in an unnaturally, uncomfortable position!
Understanding the proper type of stretching before and after activity is essential to enhancing performance and avoiding injury. When young athletes engage in physical activity, they are often encouraged by coaches and parents to stretch prior to activity. The goal is to prepare muscles for sports, to enhance performance and decrease risk of injury, including sprains and strains. In the past, advice regarding stretching has referred to static (or passive) stretching prior to activity. That is, stretching held for 15-60 seconds in a stationary position to improve the flexibility of one muscle group at a time. However, recent research confirms the benefits of dynamic stretching prior to physical activity in both children and adults. Dynamic stretching uses functional, activity-specific motions with constant movement to warm-up. Static stretching then becomes important in the cool down after activity.
A thorough warm-up period is designed to prepare the body for physical activity by:
- Increasing core body temperature
- Stimulating blood flow to the arms and legs
- Enhancing coordinated movement
- Improving range of motion
- Developing body awareness of joint position sense and movement
- Using movement to expand muscle and tendon flexibility
These benefits of a good warm-up, which were once associated with static stretching prior to activity, are now attributed to dynamic stretching activities. In fact, evidence now suggests that static stretching prior to physical activity and sports may be detrimental to performance involving vertical jumps, shorts sprints, muscle endurance, maximum muscle contraction, balance and reaction time (McMillian 2006). Studies have also shown that static stretching can result in less force and power production not only in adults, but also in children, especially in jumping and sprinting performance (Faigenbaum 2006). Because the goal of the warm up period is to prepare the body for specific functional movements related to a sport, dynamic stretching appears to provide that service without being harmful.
While holding a “runners lunge” prior to practice or a game may be a thing of the past, static stretching is still very important for the cool-down phase and should not be skipped. During the cool-down, athletes are led through a program to allow the body temperature to return to normal levels and prepare the body for the healing process. During vigorous activity, muscle fibers tear at microscopic levels and need to undergo a reparation process that is essential for building new fibers, and as a result, increasing strength. As muscles cool down, they tend to heal in the position in which they are left. This highlights the importance of passive stretching after physical activity: low-load long duration static stretching allows the muscles to stay in a lengthened position as the muscle cools down. This provides a greater length through which the muscle can contract to generate force during the next time activity is initiated. Thus, static stretching serves a greater benefit to young athletes post-exercise.
When designing dynamic and passive stretching programs, here are some common considerations:
Dynamic stretching programs (Mann 1999):
- Move continuously, typically in laps for 10-15 minutes overall
- Vary the program according to the level of the athlete
- Start slow and progress to quicker and more advanced movements
- Avoid movements too intense that fatigue the muscles
- Incorporate the whole body and imitate movements used in specific sports
Passive stretching programs:
- Stay in one position per muscle group
- Hold the stretch for 20-30 seconds
- Repeat the stretch 2-3 times per muscle group
- Address all muscle groups used in the specific sport
Avery D Faigenbaum, James E McFarland, Jeff A Schwerdtman, Nicholas A Ratamess, Jie Kang, and Jay R Hoffman. Dynamic Warm-Up Protocols, With and Without a Weighted Vest, and Fitness Performance in High School Female Athletes. J Athl Train. 2006 Oct-Dec; 41(4): 357–363.
Danny J. McMillian, Josef H. Moore, Brian S. Hatler and Dean C. Tayler. Dynamic vs. Static-Stretching Warm Up: The Effect On Power and Agility Performance. Journal of Strength and Conditioning Research, 2006, 20(3), 492–499.
Douglas P. Mann and Margaret T. Jones, CSCS. Guidelines to the Implementation of a Dynamic Stretching Program. Journal of Strength & Conditioning Research. 1999. Volume 21, Number 6, pages 53–55.