FITNESS MYTH: STATIC STRETCHING BEFORE EXERCISE/PERFORMANCE
Last winter I attended a high school basketball game for my nephew. We arrived early enough to watch the athletes warm up and I was surprised to see many of them performing static stretches prior to the game. Having been immersed in fitness for many years, both academically and occupationally, I’ve forgotten that some of these glaring myths/mistakes are still lingering despite the vast body of evidence contradicting them.
There are many reasons why we want to warm up before exercising or competing in an athletic event. A well thought out warm up session can prepare us both mentally and physically for the occasion (Haff & Triplett, 2016). Many of the physiological benefits can be categorized into temperature and non-temperature-related outcomes of a warmup. Increasing our internal temperature can break up connective tissue bonds and increase neural function (Haff & Triplett, 2016). Some non-temperature responses include postactivation potentiation, increased blood flow to the targeted muscles and better oxygen consumption. These effects on the physiological processes within our body have been studied to offer great benefits to performance. Hoffman (2002) showed that warmups lead to faster muscular contractions and relaxations. Asmussen et al. (1976) showed that increased muscular temperature increases reaction time and the rate at which we can develop force. McArdle et al. (2007) explained how higher temperatures also increase oxygen delivery due to the Bohr effect causing hemoglobin and myoglobin to release oxygen. Haff & Triplett (2016) go on to include other benefits such as better metabolic reactions, increased strength and power, lubricated joints, and psychological preparedness.
Warmups are generally separated into two different phases, being the general and specific warmup phases. General warmups are simple but should be a staple to every exercise session and athletic performance. This is usually done through light aerobic activity like slow jogging, cycling, rowing, or something similar (Haff & Triplett, 2016). The duration is short, usually between 5-10 minutes and should be kept at a low intensity. During this time period our joints will become more lubricated, deep muscle temperature is increased along with our respiration and heart rate. Whether or not people actually do this phase may be up for debate, but there is little argument being presented to contradict it’s validity.
During the specific warmup phase is where much of the controversy arises. Referring back to the high school basketball game, I saw both teams perform some low intensity drills that could conceivably be labeled as a mixture of both phases. Aspects were general and slow but others were specific to the movements that the athletes would be performing during the game. The issue came after this when some athletes made their way to the center of the court to perform static stretches while others kept shooting. Research has shown that static stretching can decrease muscle activity, while dynamic stretching can significantly increase it (Amiri-Khorasani & Kellis, 2013). Fletcher and Jones (2004) studied that static stretching slowed down sprint performance while dynamic stretching made the athletes run faster. Similarly it has been studied that dynamic stretching improves jump height while static stretching can impair it (Perrier et al., 2011). Sprinting and jumping are both important aspects of basketball and I doubt that any competitive player would want to run slower and jump lower.
There are some ideas as to why static stretching can decrease performance. Obviously if static stretching is decreasing our muscle activity then we can only expect to see a decrease in performance. Furthermore, Fletcher and Jones (2004) proposed that static stretching increases musculotendinous laxity, which decreases it’s ability to store elastic energy in the eccentric phase. Much of our performance can be effected by the stretch shortening cycle of our muscles and tendons. Similar to a rubber band, when our muscles get eccentrically stretched, they want to return to their origin. If done quickly, this elastic energy can be converted to kinetic energy that propels our performance. Static stretching may make our musculotendinous units more like a stretched out rubber band.
These results have an obvious carryover to sports that require strength and power output, but what about a regular gym session? I’ve often seen people within the gym start their lifting session with a series of static stretches and foam rolling. As stated, I would always recommend a general warmup on the bike or treadmill or any other light aerobic modality. But during the specific warmup phase I would not recommend static stretching. Power production and developing our stretch-shortening cycle is very important for anyone who wants to get stronger. Given that multiple studies cited within this article have demonstrated increase laxity and lower muscle fiber activity associated with static stretching makes it easy to conclude that it shouldn’t be done before lifting. But, foam rolling has actually been studied to increase flexibility more than static and dynamic stretching on the hamstrings without compromising strength output (Hsuan et al., 2017). I will say that this may be limited to a single joint action and would need to be further explored to see the effects on compound lifts such as back squats.
A more effective use of the specific warmup phase would be to perform movements similar to the movements that are going to be exercised that day. This can be easily facilitated by just doing warmup sets of the specific exercise you are about to perform at lighter weights than the prescribed working weight. This is especially important for high weight, low repetition situations. As previously stated, dynamic stretches (warmup sets count) increase strength and power production (Perrier et al., 2011). Although there may be no need to perform a specific warmup if you only intend to perform single joint exercises at a medium-to-high repetition range since the first repetitions are truly warmups themselves (Ribeiro et al., 2014).
Traditional sport athletes should start with a 5-10 minute general warmup that is of low intensity and aerobic in nature. Afterwards they should begin the specific phase of their warmup that is centered around dynamic stretches that are specific to the movements that they are about to perform. Gym-goers should also start with a 5-10 minute general warmup. Some foam rolling could be performed after, but the lifter would likely see more benefit performing warm up exercises at low intensities before reaching their working weight. Static stretches should be reserved for after the workout session and only be performed if there is a specific need/reason to further increase mobility.
Amiri-Khorasani, M., & Kellis, E. (2013). Static vs. dynamic acute stretching effect on quadriceps muscle activity during soccer instep kicking. Journal of Human Kinetics, 39, 37-47.
Asmussen, E., Bonde-Peterson, F., & Jorgenson, K. (1976). Mechano-elastic properties of human muscles at different temperatures. Acta Physiologica Scandinavica, 96, 86-93.
Fletcher, I. M., & Jones, B (2004). The effect of different warm-up stretch protocols on 20 meter sprint performance in trained rugby union players. Journal of Strength and Conditioning Research 18(4), 885-888.
Haff, G. & Triplett, N. (2016). Essentials of strength and conditioning (4th Edition). Champaign, IL: Human Kinetics, 318.
Hoffman, J. (2002). Physiological aspects of sports training and performance. Champaign, IL: Human Kinetics, 156.
Hsuan, S., Nai-Jen, C., Wen-Lan, W., Lan-Yuen, G., & I-Hua, C. (2017). Acute effects of foam rolling, static stretching, and dynamic stretching during warm-ups on muscular flexibility and strength in young adults. Journal of Sport Rehabilitation, 26(6), 469-477.
McArdle, W. D., Katch, F. I., & Katch, V. L. (2007). Exercise physiology: Energy, nutrition and human performance (6th Edition). Baltimore, MD: Lippincott Williams & Wilkins, 574-575.
Perrier, E. T., Pavol, M. J., & Hoffman, M. A. (2011). The acute effects of a warm-up including static or dynamic stretching on countermovement jump height, reaction time, and flexibility. Journal of Strength & Conditioning Research, 25(7), 1925-1931.
Ribeiro, A. S., Romanzini, M., Schoenfeld, B. J., Souza, M. F., Avelar, A., & Cyrino, E. S. (2014). Effect of different warm-up procedures on the performance of resistance training exercises. Perceptual and motor skills, 119(1), 133-145.