Research/Science Update: "Stretching" the Truth
Yet, in the past 10 years, the relevance of stretching for these purposes has been challenged by exercise scientists — especially since one bombshell study found that runners who stretched occasionally have a higher injury rate than runners who don't stretch. Another research paper got coaches' attention when it showed that overstretching is the third major cause of injury to distance runners. Nevertheless, personal trainers, athletic trainers, physical therapists and coaches continue to recommend stretching, at least for rehabilitation and warm-up purposes. So, the debate rages to this day.
What the experts sayFollowing are 24 summaries and conclusions from more than 20 different research papers published in respected and reputable research journals. The research on the benefits of stretching are contradictory at the very best, and many are unfavorable toward the activity. In particular, pay attention to those summarizing research against stretching — they're eye-openers.
Flexibility and injury reduction — conflicting evidence
Research/arguments in favor of stretching for injury prevention.
Flexibility and performance — more conflicting evidence
Research/arguments in favor of stretching for performance improvement.
Using common senseCertainly many of these conclusions against stretching, if true, are of concern to the personal trainer. The potential implications that a) athletes are getting injured from stretching, b) athletes who stretch seem to have a higher incidence of injury, c) stretching may actually cause loss of muscular power and force production, d) stretching does not appear to improve running economy and e) runners with increased range of motion may have impaired performance, are undesirable outcomes for exercisers, athletes and runners of any level.
What appears to be at the crux of the matter, according to researchers who venture an opinion, is that, "when the type of sports activity contains low-intensity or limited-stretch shortening cycles (e.g., running, cycling and swimming), it is not necessary to have a very compliant muscle/tendon unit."15 This is because most of its power generation is derived from active (contractile) muscle work that is directly transferred (by the tendon) to the articular system to generate forward motion. Therefore, stretching (and thus making the tendon more compliant) may not be advantageous.
Thus, it appears that much of the purported benefits of stretching and improved flexibility may depend entirely on the nature of the sport or activity. And this may well have implications for fitness and weight-training aficionados who work out several times a week. The evidence that static stretching before resistance training may affect one's ability to use explosive power (because it causes the muscles to lose energy stored in its elastic tissue) is at least enough to make one reconsider the necessity of stretching before lifting weights.
Perhaps one researcher is close to the truth with this conjecture: "While increased flexibility is important for performance in some sports that rely on extremes of motion for movement, decreased flexibility may actually increase economy of movement in sports that only use the mid portion of range of motion such as running."15
So, where does this leave the exerciser who is following a flexibility program now, or contemplating taking up a stretching program? Perhaps common sense should help dictate whether you should recommend stretching, and how much your clients should stretch. If your clients have been stretching and remain uninjured, then they should continue with the stretching program. If they've been stretching consistently and getting injured consistently, perhaps you should have them back off the stretching or reduce its intensity. If, however, your clients are contemplating starting up a stretching program, proceed with caution because it may not be the best thing for them, depending on why they're exercising.
Fitness stretchingHere are some practical tips for start-up stretchers in the fitness setting:
Avoid overstretching. There are enough studies showing that stretching may cause injuries or make people more prone to getting injured. Make sure your clients and members don't overdo it.
Warm up before stretching. Five to 10 minutes of easy aerobic activity (e.g., treadmill, cycle, elliptical trainer) will help ease exercisers into stretching. And, recent research shows that clients are better off performing some easy stretches at the end of their workout, rather than before a training session.
Stretch within the body's limits, and without straining. Do not allow clients to force a stretch to the point of pain! Straining at a painful stretch will not allow the body to relax because it activates stretch reflexes — exactly what your clients are trying to override. Perhaps this is why some studies show impaired performance and loss of muscular power from stretching.
Spread it out. It's probably not necessary for clients to stretch every day, but three to four times each week will show an improvement in range of motion. But be warned that your clients might just get what they want — increased range of motion — which may reduce running, cycling or swimming economy.
Hold the stretch. Clients should be able to hold the stretch for five to 10 minutes. (They should not actually hold the stretch for this long, but the stretch should be mild enough to hold it for that amount of time.) In light of the mentioned studies, your clients are better off performing a few easy static stretching exercises for 10 to 30 seconds each, rather than a lengthy session.
Be patient. It will take a minimum of two to eight weeks to see long-term improvements in flexibility. Clients' short-term flexibility increases after stretching will last from 90 minutes to 24 hours, according to research. But, if they stop stretching, they will start to lose their newly gained flexibility in about four weeks.
Breathe naturally. Clients should breathe calmly and relax when stretching. Encourage them to avoid comparing their flexibility to other people. Help them develop a liking and routine for stretching.
What to stretch. What regions should be stretched? The shoulders, chest and arms can all be stretched with one or two common stretches. Hip flexors and abdominals can be stretched with two common stretches. The back, gluteals and hamstrings can be stretched with a few common stretches. Clients can stretch their quadriceps and calves with separate stretches.
What not to stretch. Clients should avoid these stretches: hurdler stretch with the knee back, deep knee bends, a standing toe touch, a back arch/bridge, a standing torso twist with broomstick and the "yoga plow."
Stretching shouldn't be tortureIt seems ironic that a widely practiced sports technique was used several centuries ago as a technique to make hapless victims confess to crimes (on the "rack"). Stretching may be appropriate for certain activities and sports that are performed through a wide range of motion, but fitness professionals may want to reexamine its use for repetitive and rhythmic sports that involve a shorter range of motion.
Facility of the Week
Cowichan Lake Sports Arena Renovation and Addition