Friday, September 18, 2009
What is a Warm Up and (why) do we need one ? Research and Practice Overview
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Do you warm up before you work out? what's part of your warm up? do you know what backs up that practice? The point of this article is to look at what a warm up is in terms of performance enhancement, injury prevention and even DOMS reduction - and what it isn't, too. We'll look at what kinds of things you can do for a warm up to customize yours to your practice.
The Idea Behind the Warm Up
The main idea behind a warm up is literally to warm up
the core temperature of the body and get blood flowing to the extremities rather than focusing on the internal organs and brain as it does when we're just sitting around. The warm up alerts the muscles and tissues about new demands to be hitting other parts of the body.
Performance Benefit When warm, he muscles can contract and release faster when the body is warm, less resistance within the system when warm, so easier to do a move/less fuel taken, less taxing (movement economy). Likewise better oxygen uptake when blood is flowing, so all around better perfromance.
Warm Enough? A traditional heuristic of being ready to go is that we have broken a sweat. That the body's internal cooling mechanism has kicked in, which means when combinded with light activities pre work out, that blood is perfusing all systems - and also (in the z-health sense) that the body is better prepared to move (see threat modulation in this post).
When muscles are warmed up by blood profusion they contract and relax more readily. Likewise stretching those muscles) is easier. Any increased activity also starts a hormonal response that prepares the body to flee, which means the carbs (and fats) needed for the work ahead are getting prepped to be available.
The Warm Up as Different Activity to Main Activity
All this sounds simple enough and seems to make good sense, but there's usually an uber reason as to why we go through this systems prep. The usual rationale is: in order to prevent injury. The logic seems pretty fair: if the body is physically more ready to do work when it's been prepped, it's less likely for the demands of that work to cause harm. Hence riding a bike for ten minutes causes one to break a sweat and have the resulting body prepping benefits. The idea here is that a bike or jumping rope is a safe way to get all these systems firing.
The warm up activity is traditionally different from the actual activity about to be practiced. Why? The thinking seems to be (and i stress seems; i have no hard and fast evidence for this) that the actual activity - whether kicking a ball in a soccer game or lifting weights - is somehow riskier for the unprepared body than something as constrained as riding a stationary bike .
Stretching? How does that Warm Up the Core?
It's challenging in the literature to find discussions of warm ups that don't include stretching. In fact in some
places when we see warm up, people mean stretching. It seems this minimize risk during the warm up by doing something safe like stationary biking has lead to using static stretching as part of most warm ups. That's even slower than biking, and it's also stretching muscles which is what a warm up is supposed to help. Stretching seems to be the anti-warm up, however. How does stretching raise heart rate or get the blood circulating? How does it *warm* up the system? It doesn't, really. But it's not neutral either. Indeed some suggest that static stretching (like simply bending over and trying to touch one's toes - holding that) has been shown to have some negative effects on strength performance. And in simple muscle testing, pre and post static stretching, we usually see strength drop. Here's a recent example.
A very recent article suggests, however, there are more individual differences in response to types of warm up/stretch activities that we may have thought, but not in the actual final outcome - the vertical jump:
Unlike the study previous to these two, one uses static stretching, too. And it does not suggest that static stretching is detrimental to power outcomes; indeed nothing seems better or worse on outcomes, but that dynamic is better than static for enhancing performance. Just not necessarily hugely (to statistical significance).
We'll come back to consideration of dynamic stretching by contrast to static stretching in a moment, but for now it's important to note that static stretching as a warm up has been seen to have a negative effect on muscular strength (not what we want before lifting a heavy weight) but not on vertical jump height.
So static stretching before a physical activity does not seem to be a great idea (going from detrimental to neutral). But based on what we've said are the physiological reasons for carrying out a warm up, is "static stretching = strength reducing" the same as saying a warm up is a bad idea?
Is a warm up unnecessary or unavoidable?
When folks say they don't warm up, physiologically this is not necessarily the case. What folks are actually doing is not doing an activity for warm up that is separate from their main event. But, just to state the obvious, when we start our work out we go through the same physiological changes induced by a formal warm up: heart moves up, core temp goes up, perfusion gets underway and hormones for fat mobilization are released. We just happen to initiate that process within the Formal Activity of Interest rather than before it. In other words, the first minutes of the activity becomes the warm up. It's an essential consequence of movement.
Just to take kettlebell'ing as an example: remember in a warm up the idea is to move the blood from the core to the periphery (and get the core temp up) assuming the periphery is where there is demand for muscular support. But in most kettlebell moves, most of the muscular activity takes place not too far from the core. KB moves, such as the swing, are also great for getting perfusion going - potentially more so than using a stationary bike since a swing is whole body work, and potentially more safely than doing a bunch of jumping jacks as there's no impact. WIthin a few swings the heart is up, the blood is circulating, the hormones are moving. The KB embodies its own warm up.
Of course the same is true in any sports activities: as one begins to move, one warms up, but we might ask is there greater value in a formal warm up outside the context of the formal activity. Unlike the stand in one spotness of a kettlebell swing or a barbell deadlift, in a sport, we are moving within a space, relying more on our senses and muscular responses, especially if navigating obstacles like other players.
In the sports context, the argument for warm ups is very much focused on prepping the body to reduce injury. For instance, if one's out on the field before warming up, goes to kick a ball, the extremity does not have the blood supply, it tweaks, the athlete goes down, that's a preventable injury. Does the research support the philosophy? It's not clear. There is indeed a bit of a tug of war as to whether studies of sports show that warm ups (that do other things than stretching) actually reduce injury.
For instance, a survey published only a couple years ago suggests that we just did't know; we just don't have the evidence:
Aside: Brett Jones and Gray Cook may suggest that injury rates may have nothing to do with warm ups or not, but whether or not the population tested had greater or lesser asymmetries in their individual movements. Their work suggests that injury rates in football teams goes down with that change alone.
I'd also like to know when in an event injuries usually happen: well into play or when a player steps onto the field?
A year after the above review was published, another survey came out saying we do have a clearer picture about warm ups, and a key element depends on how we define warm up and injury, and by the way we define it, we see some pretty clear injury reducing benefit:
Aside from injury reduction, there's one place where a warm up may also have benefit: reducing delayed onset muscle soreness in a very particular (but non unusual) case, unaccustomed eccentric effort.
Summary of Results: So what do we know about Warm Ups When and Where?
In cases like swinging a kettlebell or powerlifting, there's reason to see the activity itself as a warm up: the actions are progressive/iterative/repetitious, and by trained practitioners, safe. They are therefore going to have the effect of warming up the person.
In a sports context, where other factors that the push or the pull come into play taxing the body, perceptual systems and mind, the literature tends to be moving towards support of warm ups that are richer than simply stretching. The most current study (2009) shows that considering factors like neuromuscular control are a good idea.
Recommendation: What is a Warm up again?
With respect to the warming up of the body, in activites like kettlebell work, the action of the main repetitious activity effectively creates its own warm up. But there's more going on, as the latest research article sited above shows, when injury reduction is a goal beyond optimum performance. The article mentions neuromuscular control.
If we look at something like Enter the Kettlebell, the core text on learning how to begin (and sustain) practice with kettlebells (review/overview), practitioners are advised to being a session with range of motion work like pumps and halos. These moves take the body through the range of motion they'll be performing in the working sets. They do so enabling user-paced control. The pump works the hip flexors and spine at a much slower pace and lighter force than applied in a swing. The halos take the shoulders through a larger range of motion than presses will use, with weight, and with two handed control. The weight adds load to the joint motion.
These are safe ways to fire off the mechanorecptors in the joints and muscles and prep the body for the work to come. This is neuromuscular preparation.
Some of us likewise find performance benefits from doing Z-Health I-Phase movement matching mobility work throughout our reps/sets or during breaks in a sport activity. Part of the Z-Health philosophy here is that *practicing* range of motion movements that may be common in one's sport while in a safe space helps prep the body for being more responsive, less threatened in a real situation. An example may be before a press doing shoulder circles with the arm in the sticking point position of the press.
Dynamic vs static stretching came up in some of the articles above. A dynamic stretch is something like a walking lunge. Note that the walking lunge exaggerates the range of motion of a walking or potentially a running stride. This lunge may well be mainly effective because of its mechanoreception firing, more so than the local phenomena of stretching a muscle fiber (especially in a cold bod where the blood hasn't started to flow more to that limb to support the stretch).
It may well be possible to replicate the effect of big dynamic stretch sets with neuromuscular work like the Z-Health drills for the same or enhanced benefit for being so mapped to the sport movements. I only have anecdotal evidence of working with clients and observing Z-Health trainers during an RKC cert achieve similar hip range of motion improvements with toe pulls than with dynamic or static lunges. Smaller faster gesture seemed to offer the same effect.
In more active sports where awareness of terrain and others comes into play, S-phase practice also trains the perceptual systems so that they too have been rep'd under high cognitive loads to be able to perform better in live obstacle-charged environments.
Might these neuro-muscular approaches be considered "warm ups" ?
In the sense that some of the joint work does not physically warm up the core of the body, likely not, but in the sense of that these movements prepare the body (and all its interconnected systems) to respond in a less threat-ful (where we tighten up) and thus less injury inducing way, yes (more about threat and the neuromatrix in this article).
So perhaps if we see warm ups as a kind of threat reduction practice that prepares the body optimally for the work it's about to do - so that it feels as safe as possible to do it no matter the complexity or intensity of the situation, that may help us think through what kinds of activities best match prepping the kinds of practice we're doing.
Heuristics for Building an Appropriate Warm Up Practice:
UPDATE:
one place i have found improved performance is warming up prior to a snatch test or long cycle clean and jerks - not a lot - but ten or so reps both sides, three minutes before starting works wonders. Thanks to Coach Randy Hauer for the tip. Related in discussion of heart rate monitors and kb work
Related Posts/Resources
Citations
Do you warm up before you work out? what's part of your warm up? do you know what backs up that practice? The point of this article is to look at what a warm up is in terms of performance enhancement, injury prevention and even DOMS reduction - and what it isn't, too. We'll look at what kinds of things you can do for a warm up to customize yours to your practice.The Idea Behind the Warm Up
The main idea behind a warm up is literally to warm up
the core temperature of the body and get blood flowing to the extremities rather than focusing on the internal organs and brain as it does when we're just sitting around. The warm up alerts the muscles and tissues about new demands to be hitting other parts of the body.Performance Benefit When warm, he muscles can contract and release faster when the body is warm, less resistance within the system when warm, so easier to do a move/less fuel taken, less taxing (movement economy). Likewise better oxygen uptake when blood is flowing, so all around better perfromance.
Warm Enough? A traditional heuristic of being ready to go is that we have broken a sweat. That the body's internal cooling mechanism has kicked in, which means when combinded with light activities pre work out, that blood is perfusing all systems - and also (in the z-health sense) that the body is better prepared to move (see threat modulation in this post).
When muscles are warmed up by blood profusion they contract and relax more readily. Likewise stretching those muscles) is easier. Any increased activity also starts a hormonal response that prepares the body to flee, which means the carbs (and fats) needed for the work ahead are getting prepped to be available.
The Warm Up as Different Activity to Main Activity
All this sounds simple enough and seems to make good sense, but there's usually an uber reason as to why we go through this systems prep. The usual rationale is: in order to prevent injury. The logic seems pretty fair: if the body is physically more ready to do work when it's been prepped, it's less likely for the demands of that work to cause harm. Hence riding a bike for ten minutes causes one to break a sweat and have the resulting body prepping benefits. The idea here is that a bike or jumping rope is a safe way to get all these systems firing.
The warm up activity is traditionally different from the actual activity about to be practiced. Why? The thinking seems to be (and i stress seems; i have no hard and fast evidence for this) that the actual activity - whether kicking a ball in a soccer game or lifting weights - is somehow riskier for the unprepared body than something as constrained as riding a stationary bike .
Stretching? How does that Warm Up the Core?
It's challenging in the literature to find discussions of warm ups that don't include stretching. In fact in some
places when we see warm up, people mean stretching. It seems this minimize risk during the warm up by doing something safe like stationary biking has lead to using static stretching as part of most warm ups. That's even slower than biking, and it's also stretching muscles which is what a warm up is supposed to help. Stretching seems to be the anti-warm up, however. How does stretching raise heart rate or get the blood circulating? How does it *warm* up the system? It doesn't, really. But it's not neutral either. Indeed some suggest that static stretching (like simply bending over and trying to touch one's toes - holding that) has been shown to have some negative effects on strength performance. And in simple muscle testing, pre and post static stretching, we usually see strength drop. Here's a recent example.Alan J. Pearce1 Contact Information, Dawson J. Kidgell2, James Zois3 and John S. Carlson1In other words, these folks are pretty clear that static stretching is NOT good in the context a vertical jump. Even more work published this past year says that passive stretching has zero impact on vertical jump performance. Interesting that it's at least not "detrimental" which the above authors found with static.
Accepted: 23 September 2008 Published online: 11 October 2008
Abstract Evidence suggests that static stretching inhibits muscular power. However, research does not reflect practice whereby individuals follow up stretching with secondary activity. This study investigated muscular power following stretching, and after a second bout of activity. Participants (n = 13) completed 3 randomized testing sessions which included a 5 min warm-up, followed by a vertical jump (VJ) on a force platform; an intervention (static stretching, dynamic, or control), followed by a second VJ. Participants then completed a series of movements, followed by a VJ, up to 60 min post activity. Immediately following the intervention, there was a 10.7% difference in VJ between static and dynamic stretching. The second warm up bout increased VJ height following the dynamic intervention, whereas the static stretching condition did not show any differences. The novel finding from this study demonstrates a second exercise bout does not reverse the effects of static stretching and is still detrimental to VJ.
1: J Strength Cond Res. 2008 Nov;22(6):1826-31.LinksThe important thing in the above is that static stretching was not considered. So in the case of a vertical jump, PNF (passive, being done to) or dynamic or nothing - all after a jog - make no difference.
The effects of proprioceptive neuromuscular facilitation and dynamic stretching techniques on vertical jump performance.
Christensen BK, Nordstrom BJ.
The purpose of this study was to investigate the effects of 3 different warm-ups on vertical jump performance. The warm-ups included a 600-m jog, a 600-m jog followed by a dynamic stretching routine, and a 600-m jog followed by a proprioceptive neuromuscular facilitation (PNF) routine. A second purpose was to determine whether the effects of the warm-ups on vertical jump performance varied by gender. Sixty-eight men and women NCAA Division I athletes from North Dakota State University performed 3 vertical jumps on a Just Jump pad after each of the 3 warm-up routines. The subjects were split into 6 groups and rotated between 3 warm-up routines, completing 1 routine each day in a random order. The results of the 1-way repeated measures analysis of variance showed no significant differences in the combined (p = 0.927), men's (p = 0.798), or women's (p = 0.978) results. The results of this study showed that 3 different warm-ups did not have a significant affect on vertical jumping. The results also showed there were no gender differences between the 3 different warm-ups.
A very recent article suggests, however, there are more individual differences in response to types of warm up/stretch activities that we may have thought, but not in the actual final outcome - the vertical jump:
J Strength Cond Res. 2009 Sep;23(6):1811-9.Click here to read Linksand related
Acute effects of dynamic stretching, static stretching, and light aerobic activity on muscular performance in women.
Curry BS, Chengkalath D, Crouch GJ, Romance M, Manns PJ.
The purpose of this study was to compare three warm-up protocols--static stretching, dynamic stretching, and light aerobic activity--on selected measures of range of motion and power in untrained females and to investigate the sustained effects at 5 and 30 minutes after warm-up. A total of 24 healthy females (ages 23-29 years) attended one familiarization session and three test sessions on nonconsecutive days within 2 weeks. A within-subject design protocol with the testing investigators blinded to the subjects' warm-up was followed. Each session started with 5 minutes of light aerobic cycling followed by pretest baseline measures. Another 5 minutes of light aerobic cycling was completed and followed by one of the three randomly selected warm-up interventions (static stretching, dynamic stretching, or light aerobic activity). The following posttest outcome measures were collected 5 and 30 minutes following the intervention: modified Thomas test, countermovement jump, and isometric time to peak force knee extension measured by dynamometer. Analysis of the data revealed significant time effects on range of motion and countermovement jump changes. No significant differences (p > 0.05) were found between the warm-up conditions on any of the variables. The variation in responses to warm-up conditions emphasizes the unique nature of individual reactions to different warm-ups; however, there was a tendency for warm-ups with an active component to have beneficial effects. The data suggests dynamic stretching has greater applicability to enhance performance on power outcomes compared to static stretching.
Department of Exercise Science, University of South Carolina, Columbia, South Carolina, USA. jaggersj@mailbox.sc.eduAbstract
Stretching before performance is a common practice among athletes in hopes of increasing performance and reducing the risk of injury. However, cumulative results indicate a negative impact of static stretching and proprioceptive neuromuscular facilitation (PNF) on performance; thus, there is a need for evaluating other stretching strategies for effective warm-up. The purpose of this study was to compare the differences between two sets of ballistic stretching and two sets of a dynamic stretching routine on vertical jump performance. Twenty healthy male and female college students between the ages of 22 and 34 (24.8 +/- 3 years) volunteered to participate in this study. All subjects completed three individual testing sessions on three nonconsecutive days. On each day, the subjects completed one of three treatments (no stretch, ballistic stretch, and dynamic stretch). Intraclass reliability was determined using the data obtained from each subject. A paired samples t-test revealed no significant difference in jump height, force, or power when comparing no stretch with ballistic stretch. A significant difference was found on jump power when comparing no stretch with dynamic stretch, but no significant difference was found for jump height or force. Statistics showed a very high reliability when measuring jump height, force, and power using the Kistler Quattro Jump force plate. It seems that neither dynamic stretching nor ballistic stretching will result in an increase in vertical jump height or force. However, dynamic stretching elicited gains in jump power poststretch.
Unlike the study previous to these two, one uses static stretching, too. And it does not suggest that static stretching is detrimental to power outcomes; indeed nothing seems better or worse on outcomes, but that dynamic is better than static for enhancing performance. Just not necessarily hugely (to statistical significance).
We'll come back to consideration of dynamic stretching by contrast to static stretching in a moment, but for now it's important to note that static stretching as a warm up has been seen to have a negative effect on muscular strength (not what we want before lifting a heavy weight) but not on vertical jump height.
So static stretching before a physical activity does not seem to be a great idea (going from detrimental to neutral). But based on what we've said are the physiological reasons for carrying out a warm up, is "static stretching = strength reducing" the same as saying a warm up is a bad idea?
Is a warm up unnecessary or unavoidable?
When folks say they don't warm up, physiologically this is not necessarily the case. What folks are actually doing is not doing an activity for warm up that is separate from their main event. But, just to state the obvious, when we start our work out we go through the same physiological changes induced by a formal warm up: heart moves up, core temp goes up, perfusion gets underway and hormones for fat mobilization are released. We just happen to initiate that process within the Formal Activity of Interest rather than before it. In other words, the first minutes of the activity becomes the warm up. It's an essential consequence of movement.
Just to take kettlebell'ing as an example: remember in a warm up the idea is to move the blood from the core to the periphery (and get the core temp up) assuming the periphery is where there is demand for muscular support. But in most kettlebell moves, most of the muscular activity takes place not too far from the core. KB moves, such as the swing, are also great for getting perfusion going - potentially more so than using a stationary bike since a swing is whole body work, and potentially more safely than doing a bunch of jumping jacks as there's no impact. WIthin a few swings the heart is up, the blood is circulating, the hormones are moving. The KB embodies its own warm up.
Of course the same is true in any sports activities: as one begins to move, one warms up, but we might ask is there greater value in a formal warm up outside the context of the formal activity. Unlike the stand in one spotness of a kettlebell swing or a barbell deadlift, in a sport, we are moving within a space, relying more on our senses and muscular responses, especially if navigating obstacles like other players.
In the sports context, the argument for warm ups is very much focused on prepping the body to reduce injury. For instance, if one's out on the field before warming up, goes to kick a ball, the extremity does not have the blood supply, it tweaks, the athlete goes down, that's a preventable injury. Does the research support the philosophy? It's not clear. There is indeed a bit of a tug of war as to whether studies of sports show that warm ups (that do other things than stretching) actually reduce injury.
For instance, a survey published only a couple years ago suggests that we just did't know; we just don't have the evidence:
J Sci Med Sport. 2006 Jun;9(3):214-20. Epub 2006 May 6.Click here to read LinksThe above is an important result: it says there are only five studies that meet the warm up criteria and of those 3 say yes two say no.
Does warming up prevent injury in sport? The evidence from randomised controlled trials?
Fradkin AJ, Gabbe BJ, Cameron PA.
BACKGROUND: The practice of warming up prior to exercise is advocated in injury prevention programs, but this is based on limited clinical evidence. It is hypothesised that warming up will reduce the number of injuries sustained during physical activity. METHODS: A systematic review was undertaken. Relevant studies were identified by searching Medline (1966-April 2005), SPORTDiscus (1966-April 2005) and PubMed (1966-April 2005). This review included randomised controlled trials that investigated the effects of warming up on injury risk. Studies were included only if the subjects were human, and only if they utilised other activities than simply stretching. Studies reported in languages other than English were not included. The quality of included studies was assessed independently by two assessors. RESULTS: Five studies, all of high quality (7-9 (mean=8) out of 11) reported sufficient data (quality score>7) on the effects of warming up on reducing injury risk in humans. Three of the studies found that performing a warm-up prior to performance significantly reduced the injury risk, and the other two studies found that warming up was not effective in significantly reducing the number of injuries. CONCLUSIONS: There is insufficient evidence to endorse or discontinue routine warm-up prior to physical activity to prevent injury among sports participants. However, the weight of evidence is in favour of a decreased risk of injury. Further well-conducted randomised controlled trials are needed to determine the role of warming up prior to exercise in relation to injury prevention.
Aside: Brett Jones and Gray Cook may suggest that injury rates may have nothing to do with warm ups or not, but whether or not the population tested had greater or lesser asymmetries in their individual movements. Their work suggests that injury rates in football teams goes down with that change alone.
I'd also like to know when in an event injuries usually happen: well into play or when a player steps onto the field?
A year after the above review was published, another survey came out saying we do have a clearer picture about warm ups, and a key element depends on how we define warm up and injury, and by the way we define it, we see some pretty clear injury reducing benefit:
Sports Med. 2007;37(12):1089-99.A year after that, a survey shows that even static stretching in a sports context doesn't stop all kinds of injuries but it does seem to reduce incidents of muscular-tendinous (like a groin pull) type injury in a sports context.
Warm-up and stretching in the prevention of muscular injury.
Woods K, Bishop P, Jones E.
Muscular injury is one of the major problems facing today's athletes, both recreational and professional. Injuries to skeletal muscle represent >30% of the injuries seen in sports medicine clinics. As a result, it is imperative to utilise the most effective means to aid in deterring these injuries. However, there are conflicting opinions regarding methods of reducing muscular injury through warm-up and stretching techniques.Therefore, the purpose of this article is to examine the potential of a warm-up and/or stretching routine in deterring muscular injury during physical activity. The article examines a variety of studies regarding warm-up, stretching and muscular injury. The article also provides a definition of warm-up and stretching to provide clarity on this topic. Many of the differences within previous research were due to conflicting definitions. We also address this issue by examining research on muscular injury and physical adaptations to muscular injury and training.This article provides contradictory evidence to conclusions that have been drawn in previous review articles, which determined that warm-up and/or stretching protocols did not deter injury. The research included here conveys that certain techniques and protocols have shown a positive outcome on deterring injuries. As a result, a warm-up and stretching protocol should be implemented prior to physical activity. The routine should allow the stretching protocol to occur within the 15 minutes immediately prior to the activity in order to receive the most benefit. In addition, current information regarding improvements in flexibility is reviewed.
Res Sports Med. 2008;16(3):213-31.And most recently, looking just at stretching and injury we see more support for stretching.
A systematic review into the efficacy of static stretching as part of a warm-up for the prevention of exercise-related injury.
Small K, Mc Naughton L, Matthews M.
A systematic review of the literature was undertaken to assess the efficacy of static stretching as part of the warm-up for the prevention of exercise-related injuries. Computer-aided literature search for articles post-1990 and pre-January 2008 related to static stretching and injury prevention using MEDLINE, SPORT Discus, PubMed, and ScienceDirect databases. All relevant randomised clinical trials (RCTs) and controlled clinical trials (CCTs) satisfying inclusion/exclusion criteria were evaluated by methodological assessment to score the studies using accredited criteria. Seven out of 364 studies met the inclusion/exclusion criteria. All four RCTs concluded that static stretching was ineffective in reducing the incidence of exercise-related injury, and only one of the three CCTs concluded that static stretching did reduce the incidence of exercise-related injury. Three out of the seven studies noted significant reductions in musculotendinous and ligament injuries following a static stretching protocol despite nonsignificant reductions in the all-injury risk. All RCTs scored over 50 points (maximum possible score = 100), whereas all CCTs scored under 45 points. There is moderate to strong evidence that routine application of static stretching does not reduce overall injury rates. There is preliminary evidence, however, that static stretching may reduce musculotendinous injuries.
Br J Sports Med. 2009 Jun 11.And in the same year, getting back to warm ups for sports again where studies of warm ups have also included more than just stretching, the trend seems again to say it's a good idea. The important thing is to see what's meant by warm up.
A pragmatic randomised trial of stretching before and after physical activity to prevent injury and soreness.
Jamtvedt G, Herbert RD, Flottorp S, Odgaard-Jensen J, Håvelsrud K, Barratt A, Mathieu E, Burls A, Oxman AD.
OBJECTIVE: To determine the effects of stretching before and after physical activity on risks of injury and soreness in a community population. DESIGN: Internet-based pragmatic randomised trial conducted between January 2008 and January 2009. SETTING: International. PARTICIPANTS: 2,377 adults who regularly participated in physical activity. INTERVENTIONS: Participants in the stretch group were asked to perform 30-second static stretches of 7 lower limb and trunk muscle groups before and after physical activity for 12 weeks. Participants in the control group were asked not to stretch. Main outcome measurements: Participants provided weekly on-line reports of outcomes over 12 weeks. Primary outcomes were any injury to the lower limb or back, and bothersome soreness of the legs, buttocks or back. Injury to muscles, ligaments and tendons was a secondary outcome. RESULTS: Stretching did not produce clinically important or statistically significant reductions in all-injury risk (HR = 0.97, 95% CI 0.84 to 1.13), but did reduce the risk of experiencing bothersome soreness (mean risk of bothersome soreness in a week was 24.6% in the stretch group and 32.3% in the control group; OR = 0.69, 95% CI 0.59 to 0.82). Stretching reduced the risk of injuries to muscles, ligaments and tendons (incidence rate of 0.66 injuries per person-year in the stretch group and 0.88 injuries per person-year in the control group; HR = 0.75, 95% CI 0.59 to 0.96). CONCLUSION: Stretching before and after physical activity does not appreciably reduce all-injury risk, but probably reduces the risk of some injuries, and does reduce the risk of bothersome soreness. Trial registration: anzctr.org.au 12608000044325.
BMJ. 2008 Dec 9;337:a2469. doi: 10.1136/bmj.a2469.The key thing to note in the above article is that the warm up was doing considerably more than looking at raising core temperature: it focused on strength, awareness and neuromuscular control during movement. This sounds very reminiscent of what z-health s-phase training teaches athletes in devising approaches to practice in safe environments the kinds of loads placed on perceptual as well as neuro-muscular systems in competition.
Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial.
Soligard T, Myklebust G, Steffen K, Holme I, Silvers H, Bizzini M, Junge A, Dvorak J, Bahr R, Andersen TE.
OBJECTIVE: To examine the effect of a comprehensive warm-up programme designed to reduce the risk of injuries in female youth football. DESIGN: Cluster randomised controlled trial with clubs as the unit of randomisation. SETTING: 125 football clubs from the south, east, and middle of Norway (65 clusters in the intervention group; 60 in the control group) followed for one league season (eight months). PARTICIPANTS: 1892 female players aged 13-17 (1055 players in the intervention group; 837 players in the control group). INTERVENTION: A comprehensive warm-up programme to improve strength, awareness, and neuromuscular control during static and dynamic movements. MAIN OUTCOME MEASURE: Injuries to the lower extremity (foot, ankle, lower leg, knee, thigh, groin, and hip). RESULTS: During one season, 264 players had relevant injuries: 121 players in the intervention group and 143 in the control group (rate ratio 0.71, 95% confidence interval 0.49 to 1.03). In the intervention group there was a significantly lower risk of injuries overall (0.68, 0.48 to 0.98), overuse injuries (0.47, 0.26 to 0.85), and severe injuries (0.55, 0.36 to 0.83). CONCLUSION: Though the primary outcome of reduction in lower extremity injury did not reach significance, the risk of severe injuries, overuse injuries, and injuries overall was reduced. This indicates that a structured warm-up programme can prevent injuries in young female football players.
Aside from injury reduction, there's one place where a warm up may also have benefit: reducing delayed onset muscle soreness in a very particular (but non unusual) case, unaccustomed eccentric effort.
1: Aust J Physiother. 2007;53(2):91-5.In the above study, warm up consisted of walking uphill (3degrees) on a treadmill at 4-5km/h for 10 minutes. We'll look at DOMS in more detail in another article.
Warm-up reduces delayed onset muscle soreness but cool-down does not: a randomised controlled trial.
Law RY, Herbert RD.
The University of Sydney, Australia.
QUESTION: Does warm-up or cool-down (also called warm-down) reduce delayed-onset muscle soreness? DESIGN: Randomised controlled trial of factorial design with concealed allocation and intention-to-treat analysis. PARTICIPANTS: Fifty-two healthy adults (23 men and 29 women aged 17 to 40 years). INTERVENTION: Four equally-sized groups received either warm-up and cool-down, warm-up only, cool-down only, or neither warm-up nor cool-down. All participants performed exercise to induce delayed-onset muscle soreness, which involved walking backwards downhill on an inclined treadmill for 30 minutes. The warm-up and cool-down exercise involved walking forwards uphill on an inclined treadmill for 10 minutes. OUTCOME MEASURE: Muscle soreness, measured on a 100-mm visual analogue scale. RESULTS: Warm-up reduced perceived muscle soreness 48 hours after exercise on the visual analogue scale (mean effect of 13 mm, 95% CI 2 to 24 mm). However cool-down had no apparent effect (mean effect of 0 mm, 95% CI -11 to 11 mm). CONCLUSION: Warm-up performed immediately prior to unaccustomed eccentric exercise produces small reductions in delayed-onset muscle soreness but cool-down performed after exercise does not.
Summary of Results: So what do we know about Warm Ups When and Where?
In cases like swinging a kettlebell or powerlifting, there's reason to see the activity itself as a warm up: the actions are progressive/iterative/repetitious, and by trained practitioners, safe. They are therefore going to have the effect of warming up the person.In a sports context, where other factors that the push or the pull come into play taxing the body, perceptual systems and mind, the literature tends to be moving towards support of warm ups that are richer than simply stretching. The most current study (2009) shows that considering factors like neuromuscular control are a good idea.
Recommendation: What is a Warm up again?
With respect to the warming up of the body, in activites like kettlebell work, the action of the main repetitious activity effectively creates its own warm up. But there's more going on, as the latest research article sited above shows, when injury reduction is a goal beyond optimum performance. The article mentions neuromuscular control.
If we look at something like Enter the Kettlebell, the core text on learning how to begin (and sustain) practice with kettlebells (review/overview), practitioners are advised to being a session with range of motion work like pumps and halos. These moves take the body through the range of motion they'll be performing in the working sets. They do so enabling user-paced control. The pump works the hip flexors and spine at a much slower pace and lighter force than applied in a swing. The halos take the shoulders through a larger range of motion than presses will use, with weight, and with two handed control. The weight adds load to the joint motion.
These are safe ways to fire off the mechanorecptors in the joints and muscles and prep the body for the work to come. This is neuromuscular preparation.
Some of us likewise find performance benefits from doing Z-Health I-Phase movement matching mobility work throughout our reps/sets or during breaks in a sport activity. Part of the Z-Health philosophy here is that *practicing* range of motion movements that may be common in one's sport while in a safe space helps prep the body for being more responsive, less threatened in a real situation. An example may be before a press doing shoulder circles with the arm in the sticking point position of the press.
Dynamic vs static stretching came up in some of the articles above. A dynamic stretch is something like a walking lunge. Note that the walking lunge exaggerates the range of motion of a walking or potentially a running stride. This lunge may well be mainly effective because of its mechanoreception firing, more so than the local phenomena of stretching a muscle fiber (especially in a cold bod where the blood hasn't started to flow more to that limb to support the stretch).
It may well be possible to replicate the effect of big dynamic stretch sets with neuromuscular work like the Z-Health drills for the same or enhanced benefit for being so mapped to the sport movements. I only have anecdotal evidence of working with clients and observing Z-Health trainers during an RKC cert achieve similar hip range of motion improvements with toe pulls than with dynamic or static lunges. Smaller faster gesture seemed to offer the same effect.
In more active sports where awareness of terrain and others comes into play, S-phase practice also trains the perceptual systems so that they too have been rep'd under high cognitive loads to be able to perform better in live obstacle-charged environments.
Might these neuro-muscular approaches be considered "warm ups" ?
In the sense that some of the joint work does not physically warm up the core of the body, likely not, but in the sense of that these movements prepare the body (and all its interconnected systems) to respond in a less threat-ful (where we tighten up) and thus less injury inducing way, yes (more about threat and the neuromatrix in this article).
So perhaps if we see warm ups as a kind of threat reduction practice that prepares the body optimally for the work it's about to do - so that it feels as safe as possible to do it no matter the complexity or intensity of the situation, that may help us think through what kinds of activities best match prepping the kinds of practice we're doing.
Heuristics for Building an Appropriate Warm Up Practice:
- Neuro-muscular practice like range of motion work - I-Phase, loaded controlled range of motion work - for all movement performance activities seems a good idea
- For activities where the movements are repeated such that they themselves warm up the body and keep the body warm, they seem to act as that core temp upping, blood circulating, hormone pumping action. The action is the warm up.
- For more cognitively demanding activities like a field sport especially where there is more stopping and starting, a more formal core temp raising practice (like some KB swings) may also be appropriate to combine with the neuro-muscular work
- Test and Retest: what helps the athlete (that's you and me) best reduce threat (often seen as restricted movement) and enhance performance (more open, relaxed movement) of perfect reps, or perfectly "efficient" movement?
UPDATE:
one place i have found improved performance is warming up prior to a snatch test or long cycle clean and jerks - not a lot - but ten or so reps both sides, three minutes before starting works wonders. Thanks to Coach Randy Hauer for the tip. Related in discussion of heart rate monitors and kb work
Related Posts/Resources
- ALL ABOUT DOMS: what is it and doesn't work to cure it; what does work
- Perfect Rep and Movement Efficiency
- I-Phase - what is it
- S-phase: the complete athlete DVD
- Enter the Kettlebell review
- US Kettlebells || UK Kettlebells
Citations
Pearce, A., Kidgell, D., Zois, J., & Carlson, J. (2008). Effects of secondary warm up following stretching European Journal of Applied Physiology, 105 (2), 175-183 DOI: 10.1007/s00421-008-0887-3Tweet Follow @begin2dig
Christensen BK, & Nordstrom BJ (2008). The effects of proprioceptive neuromuscular facilitation and dynamic stretching techniques on vertical jump performance. Journal of strength and conditioning research / National Strength & Conditioning Association, 22 (6), 1826-31 PMID: 18815572
FRADKIN, A., GABBE, B., & CAMERON, P. (2006). Does warming up prevent injury in sport?The evidence from randomised controlled trials? Journal of Science and Medicine in Sport, 9 (3), 214-220 DOI: 10.1016/j.jsams.2006.03.026
Jaggers JR, Swank AM, Frost KL, & Lee CD (2008). The acute effects of dynamic and ballistic stretching on vertical jump height, force, and power. Journal of strength and conditioning research / National Strength & Conditioning Association, 22 (6), 1844-9 PMID: 18841078
Woods K, Bishop P, & Jones E (2007). Warm-up and stretching in the prevention of muscular injury. Sports medicine (Auckland, N.Z.), 37 (12), 1089-99 PMID: 18027995
Weldon, S. (2003). The efficacy of stretching for prevention of exercise-related injury: a systematic review of the literature Manual Therapy, 8 (3), 141-150 DOI: 10.1016/S1356-689X(03)00010-9
Jamtvedt, G., Herbert, R., Flottorp, S., Odgaard-Jensen, J., Havelsrud, K., Barratt, A., Mathieu, E., Burls, A., & Oxman, A. (2009). A pragmatic randomised trial of stretching before and after physical activity to prevent injury and soreness British Journal of Sports Medicine DOI: 10.1136/bjsm.2009.062232
Law RY, & Herbert RD (2007). Warm-up reduces delayed onset muscle soreness but cool-down does not: a randomised controlled trial. The Australian journal of physiotherapy, 53 (2), 91-5 PMID: 17535144
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COACHING with dr. m.c. 
2 comments:
Here's a thought: I wonder if the weather/environment has any effect on the need for a warmup? I live in Thailand; it's bloody hot all the time. I don't feel any need for a warmup other than a few lighter/ramping sets of the exercise. But when I lived in a colder area, I certainly did.
Brahma, thanks for dropping by
If you're in a hot place, you may indeed find that it's easier to get your blood flowing to your muscles - you may be sweating just sitting down :)
makes great sense.
mc
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