Warm-up exercises should promote flexibility, exert sufficient effort on the musculoskeletal system to raise the body temperature, stimulate the circulatory system, enhance coordination, and promote freer movement patterns. Stretching has been commonly practiced as a part of warm up prior to exercise and athletic events. There are amount of ongoing debates on stretching and its potential risks or benefits.
Many questions arise in recent years, these including:
- Does stretching make me more prone to injury?
- Should I stretch or not?
- Should I stretch before or after?
1. Effect of stretching on injury risk
- Pre-participation stretching in addition to warm up will have no impact on injury risk during activities where there is a preponderance of overuse injuries (van Mechelen et al., 1993; Pope et al., 1998, 2000).
- There are some evidences to indicate that pre-participation stretching does reduce the risk of muscle strains (Ekstrand et al., 1983; Bixler & Jones, 1992; Amako et al., 2003; Hadala & Barrios, 2009). However, further research is needed in this area.
Injury risk in sports is multi-factorial. There may be intrinsic risk factors such as age, strength and flexibility, as well as extrinsic risk factors, such as stretching, warm up, training errors, protective equipment and rules.
2. Effect of stretching on performance
- There is no stretch-induced strength loss with dynamic stretching (Herda et al., 2008; Hough et al., 2009).
- Stretch-induced strength loss was not apparent with eccentric contractions in one study (Cramer et al., 2006) but was apparent in another (Sekir et al., 2009).
- Stretch-induced strength loss has been shown not to occur at longer muscle lengths (Nelson et al., 2001; Herda et al., 2008; McHugh & Nesse, 2008).
An acute bout of stretching will reduce the ability to generate a maximal force. However, these effects are less apparent when tests of muscle power are studied and may not be apparent when the pre-participation stretching is combined with other activities in a warm up, such as practice drills and low intensity movements.
Murphy et al. (2010) suggests that there are a number of sports where increased in static flexibility could improve the performance. A goalie in ice hockey must abduct their legs when in a butterfly position, gymnasts perform a split position, wrestling, martial arts, synchronized swimming, figure skating, are examples of the necessity of large range of motions in various joints. Some dynamic stretching studies have reported similar increases in static flexibility as static stretching (Beedle and Mann, 2007; Herman and Smith, 2008), but other studies have indicated that dynamic stretching is not as effective at increasing static flexibility as static stretching (Covert et al., 2010; O'Sullivan et al., 2009). Thus, it could be important to include static stretching for sport specific flexibility.
Static stretching is probably the most familiar warm up program. Feel a pulling sensation in the muscles within one's level of tolerance and hold the stretch for 15-20 seconds. Each muscle group should be stretched three to five times for maximal benefit. An alternative approach to stretching that is grown increasingly popular in recent years is dynamic stretching. Perform gentle and controlled movements of multiple muscle groups to gradually increase range of motion with each successive repetition. The difference is the body is not moving in static stretching, and with the other, the body is moving.
Both static and dynamic stretching can help to prepare for exercise, but it is the best to assess your workout goals. Static stretching plays an important role in sport specific flexibility, while dynamic stretching may be a perfect complement to a vigorous workout.
References:
1. M. P. McHugh and C. H. Cosgrave. 2010. To Stretch or Not To Stretch: The Role of Stretching in Injury Prevention and Performance. Scand J Med Sci Sports 20: 169–181.
2. Craig A. Smith. 1994. The Warm-up Procedure: To Stretch or Not to Stretch - A Brief Review. Journal of Orthopaedic & Sports Physical Therapy 19: 12-17.
3. Michael Samson, Duane C. Button, Anis Chaouachi and David G. Behm. 2012. Effects of Dynamic and Static Stretching within General and Activity Specific Warm-Up Protocols. Journal of Sports Science and Medicine 11: 279-285.