Some controversy surrounds the role that stretching exercises play in regard to fitness training, especially group fitness classes. Perhaps more than ever, debate is brewing about the proper time and place to stretch. Exactly when and what type of stretching exercises do we need to include in our classes? Although little definitive research is available on the subject, fitness experts are trying to reach a consensus.

Do We Really Need to Stretch?

For several years, the American College of Sports Medicine (ACSM) has recommended that people perform not only cardiovascular activity and strength training but also regular flexibility training. According to ACSM, flexibility improves joint range of motion and function and enhances muscular performance. ACSM recommends that flexibility training be performed a minimum of two to three days per week (Pollock 1998).

But not everybody agrees that flexibility training is crucial in the fitness arena. “Stretching is probably not that important for the regular fitness athlete,” says Mike Bracko, EdD, CSCS, director of the Institute for Hockey Research in Calgary, Alberta. “After all, how much flexibility do you need to go for a fitness run?”

Yet most experts do agree that flexibility training—while perhaps not necessary to excel in step training or indoor cycling—does help individuals better perform daily activities. Douglas Brooks, MS, a Mammoth Lakes, California, based exercise physiologist and personal trainer, believes such training, which he defines as an “aggressive” approach to improving flexibility at the joints, can keep individuals active throughout life. “Flexibility training will help maintain range of motion around the joints,” Brooks says. A good example is the shoulder joint. If you lose range of motion in that joint, you might be unable to reach a cereal box on the top of a shelf.

Complicating this issue is the debate about whether muscles should be warmed before they are stretched. “No matter when you stretch, whether it’s before or after your workout, you have to be warmed up,” Brooks says. “Muscles, after all, are like taffy.” Brooks says that just as cold taffy will snap and warm taffy will stretch, muscles are vulnerable to heat and cold. Muscles that are cold resist lengthening. By trying to stretch cold muscles, you stand a greater chance of becoming injured. Yet after a five- to 10-minute aerobic warm-up, muscles are more prone to lengthening, so your chance of gaining flexibility increases while your risk of injury decreases.

Not everyone agrees that warming up is essential for flexibility. “Warming up may not have as much impact on stretching as we once thought,” Bracko says. He points to employees who take stretch breaks, without warming up, to prevent occupational injuries. However, Bracko does concur that flexibility can reduce the risk of injury, especially the kinds of injury that occur in the workplace. “Stretching is extremely important to prevent and perhaps reverse occupational muscle imbalances.”

What Are Our Stretching Choices?

As if all of this isn’t confusing enough, here’s one more issue to cloud the debate: What kinds of stretches are appropriate in a group fitness class? Although several types exist, perhaps the most common are static stretches and dynamic stretches. Dynamic stretches can involve either single joints or multiple joints.

Most of us are familiar with static stretches, or stretches that are held for 20 to 60 seconds; an example of a static stretch is a standing calf stretch. Single-joint dynamic stretches, which have reigned in cardio class warm-ups for the past decade, involve movement around one joint; examples of these stretches include toe tapping and side-to-side head turns. Multijoint dynamic stretches combine various joint actions; these stretches include squats with front raises.

The group fitness setting offers three seemingly logical times to stretch:

  • the warm-up, prior to any cardio activity
  • the warm-down, immediately after the cardio activity
  • the cool-down, at the end of class after the entire workout has been completed (if you include abs or resistance training after the warm-down)

So, exactly which of these times is best? And what kind of stretching works best for each workout segment?

What Doesn’t Work in a Warm-Up?

Although research has shown that warming up before exercising prevents injury, no research has proven that stretching before exercising wards off injury. This is especially true of static stretching. In fact, a major study from the University of Sydney in Australia proved otherwise (Pope et al. 2000). Researchers divided 1,538 young male subjects into two groups. One group warmed up and then performed static stretches before exercising, while the other group only warmed up. The results? There was little difference in injury rates between the two groups, leading researchers to conclude that the static stretching exercises had little effect on injury prevention.

“[Static] stretching is not a warm-up and does not get the muscles ready for more intense work,” says Bracko. He feels that the need for stretching before a workout may be psychological. “You think you’re going to get a better workout if you stretch, but that’s not the case.”

In fact, slowing down to perform static or single-joint stretches before a workout might actually be detrimental. “These types of stretches [which do not involve large movements] can inhibit the flow and rhythm of the warm-up,” says Shirley Archer, JD, MA, a Stanford University health educator who has created mind-body stretching programs.

Keep in mind that, during a warm-up, your goal is to gradually increase heart rates and core temperatures so participants are prepared for more intense work. Any interruption—even for just a few minutes of single-joint or static stretching—will cause heart rates and core temperatures to drop, thus defeating the purpose of the warm-up. Also, muscles may not be warm enough at that point to confer any gains in flexibility. “Why stop to do a stretch that won’t be effective, when you could spend that time doing something that would benefit participants more?” asks Paula Anderson, MS, co-owner of Fitness ETC in Pismo Beach, California, and a frequent presenter of stretch sessions.

What Does Work in a Warm-Up?

To determine what is most effective during the warm-up, let’s consider two common teaching scenarios.

“Instructor A” fully warms up his participants for eight minutes by having them perform large body movements that involve multiple joints and dynamic ranges of motion. He then has the participants perform static stretches, holding each major muscle stretch about 30 seconds. Next, he moves on to single-joint dynamic stretches, such as shoulder rolls, neck rolls and ankle flexing. He then goes back to a second three-minute movement warm-up before leading into the cardio workout.

“Instructor B” avoids any static or single-joint stretches during the warm-up, opting instead to concentrate solely on large body movements that involve multiple joints and dynamic ranges of motion. (For more information on multijoint warm-ups, please refer to “The Active Range Warm-Up” in the April 2000 issue of IDEA Fitness Edge.) Her goal is to prepare the participants for the work ahead by asking them to mimic the actions they’ll do later in class. For example, when teaching step training, she incorporates knee lifts, hamstring curls and side leg lifts. If she’s teaching indoor cycling, she starts the class lightly pedaling at low tension. After five to 10 minutes at this moderate pace, she begins the cardio workout.

Which instructor do you think is achieving the goals of the warm-up more effectively and efficiently? The jury is still out, but more authorities point to instructor B.

Anderson is one expert who advocates skipping static and single-joint dynamic stretches during the warm-up. Instead, she recommends introducing movements and joint actions akin to the activities participants will be doing in the workout and then gradually increasing the range of motion of those moves. “Your goal is to move the muscles from a resting state to a workout state by gradually increasing ranges of motion around the joints that will be active,” Anderson says.

During a kickboxing warm-up, for example, you might introduce low kicks and then increase the height of those kicks as the warm-up progresses. If you’re teaching a low-impact class where you’ll be moving students laterally, incorporate side abduction exercises and lateral moves into the warm-up.

There’s yet another bonus to doing multijoint dynamic stretches before a workout. During these stretches, muscles continuously contract, which helps increase their warmth.

This doesn’t mean, though, that static stretches have no place prior to a workout. While they are not essential and may not prevent injury, Brooks says static stretches can enhance performance if you’re going to be working at your maximum effort. For example, if you want to run your fastest 5K, stretching before you run may help you achieve larger ranges of motion in your muscles, and this can boost performance. But to make stretching effective, Brooks says, you should warm up, then stretch, then warm up again to increase your heart rate before you start your run.

Once again, however, some experts disagree. “[Static] stretching prior to a high-intensity or physically demanding workout may actually put a person at risk for an injury,” says Bracko. He cites something called the “stretch lag” period, a poststretching interval of about 15 minutes when muscles can stay in a stretched, and thus weakened, state. During that time, participants are at potential risk for injury. Bracko feels that proper warm-up, good nutrition and hydration, and adequate rest are the best preparation for hard work.

So the case is not yet closed on the “best” preworkout approach to stretching. As always, we must look at our specific application and goals, all the while weighing the risks and benefits. However, multijoint dynamic stretches seem to be the way to go in our fitness class warm-ups.

What About Stretching During the Warm-Down and Cool-Down?

Most experts do agree on the effectiveness of stretching after a cardio workout, during either the warm-down or the cool-down segment of class. At that point, muscles are warm and thus can be lengthened. “You can ‘reset’ the resting length of a muscle and make great gains in flexibility,” Archer says. These gains can improve and maintain range of motion around the joints, enhance recovery and reduce muscle soreness.

There is yet another advantage to stretching during the warm-down or cool-down phase, when the body is at its warmest. Participants can stretch muscles that have become shortened or tight as a result of maintaining chronic occupational positions, according to Bracko. Participants might also be able to correct muscle imbalances caused by improper training.

But should we stretch immediately after the cardio phase? Is it better to wait until the end of class, after any additional floor-work is over? Or should we do both?

Bracko recommends waiting until the very end of class, once again citing the stretch lag period. If stretching—especially static stretching—is done after the cardio workout but before the strength phase of class, muscle lengthening during those 15 minutes could increase your participants’ risk of injury.

Anderson also likes to wait until the end, so that she can create a smooth, peaceful transition as participants exit the workout scene and re-enter their stressful lives. She feels this transition leaves her participants feeling more relaxed and less stressed.

Of course, the main drawback to waiting until the end of class is that some participants regularly leave class early, skipping the stretching portion entirely. Believe it or not, Brooks says this is okay as long as stretching exercises are done at some other time. “It’s not bad [for someone] to leave after a workout without stretching as long as that individual participates in some kind of flexibility training two or three times a week,” he says. For instance, you needn’t be concerned if a participant skips the stretching after your class but regularly practices yoga several times a week.

Archer, however, disagrees. “A workout is not complete without stretching,” she says. “Doing repetitive motion will lend itself to shortening of the muscle over time, and if you don’t incorporate stretching to avoid that, you’ll increase your risk of injury.” Therefore, Archer often incorporates stretches throughout the warm-down or cool-down. For example, after the cardio phase, she might do static stretches for large muscles that were used in the cardio workout. If she’s incorporating strength training in the class, she might also stretch after each strength training set.

Again, we have no definitive research on exactly what type of stretching is best after a workout. But most experts agree that static stretching—designed to increase flexibility and correct muscle
imbalances—is perhaps the most appropriate choice during the warm-down or cool-down.

To make static stretches effective and to use time efficiently, ask your participants to hold each stretch 15 to 30 seconds. Shorter may short-change flexibility goals; longer may waste time. Archer prefers to complete two sets of 30-second stretches for each muscle. You could also consider doing two different stretches for each muscle group. During all phases of the workout, instructors should remind participants to back off if they experience pain.

So, What Gives With Stretching Exercises?

As instructors, our challenge lies in determining our specific class and segment goals, then deciding on a stretching plan of action. Although no black-and-white answers exist, most experts concur that warm-up is the time to move; cool-down is the time to hold still. What could be simpler?