1 - Stretch consistently to increase and maintain flexibility
Flexibility is probably the most common as well as measurable benefit of stretching. A 2000 study in the Journal of Athletic Training (De Pino et al), found that four consecutive 30-second stretches significantly improved hamstring flexibility. However, the caveat was that the flexibility only lasted for about 3 minutes after stretching stopped. A 2004 study in the same publication took the research a step further and had subjects perform the same 30-second stretches, 3 times per week for 6 weeks. The results revealed significant increases in flexibility, even though the testing took place two days after the most recent stretching session. The takeaway here is that in order to maintain the increases in flexibility, stretching routines must have a certain level of consistency and continuity. Unless you maintain your regular stretching routine you’re at risk of losing any flexibility you gained from it.
2 - Stretch after a training session to relax the nervous system
We are all aware that somehow, stretching does feel good. It is calming, relaxing, and very associated in our minds with tranquility. There is very little knowledge in the scientific community as to why, but a recent study did find that the rest and regeneration response in our nervous systems (called the parasympathetic nervous system) is much higher after stretching activities (Farinatti et al, 2011). This supports the overwhelming feeling that stretching has a healing effect on our nerves, as the parasympathetic nervous system is responsible for all the resting functions of our bodies. In fact, it defines how well we recover from session in the gym. Stretching after a training session puts our bodies back into parasympathetic mode, quickly starting the regenerative response to get us ready for the next session.
3 - Stretching before exercise won’t prevent injury
Static stretching prior to activity in order to prevent injury had been a staple part of athletic preparation for decades, with experts even supporting this position (Safran, 1989). However, studies that are more recent are simply unable to find any meaningful correlation between stretching and injury. Although there some evidence of stretching actually increasing the risk of injury, researchers have simply not found enough evidence to either endorse or recommend discontinuing a pre-exercise stretching routine (Thacker et al, 2004).
If you are looking for a more definite answer about whether you should keep stretching before physical activity, look no further. A group of researchers from the department of rehabilitation sciences at Ghent University in Belgium found that activities or sports with a high degree of bouncing or jumping or other movements that require stretching and shortening muscles at a high intensity may benefit the most from stretching. This is because these activities require a compliant muscle-tendon unit in order to stay injury-free – and this type of compliance in can be achieved by a stretching protocol (Witvrouw et al, 2004).
4 - Stretching does not prevent or heal muscle soreness
The scientific community has known for almost 20 years that stretching before or after exercise does nothing to prevent delayed onset muscle soreness (High et al, 1988). However, it is also important to realize that stretching does not do very much to alleviate the soreness once it is already set on either. A study (Buroker & Schwane, 1989) in The Physician and Sportsmedicine actually tested the effect of stretching 3 days after exercise, once the soreness was already quite apparent. The results revealed it had no effect. More recent studies have also confirmed these findings (Herbert & Noronha, 2007).
5 - Stretching could be necessary for healthy, pain-free movement
Pain free mobility is indeed associated with better health and with lower rates of mortality (Feeny et al, 2012). Moving freely throughout a variety of daily activities (including exercise) requires a good range of motion around the joints – which means flexibility is key.
Many of us spend the majority of our days sitting at a desk, and find our muscles and tendons regularly feeling too tight, to move comfortably, in life or in the gym. This is when a regular stretching routine becomes highly beneficial.
To sum up, if you feel tight and restricted when moving in daily life, or when training any movement such as the squat or overhead press, you need a regular stretching routine that is tailored specifically to fix those tight muscles and tendons. That routine will work for as long as you continue to adhere to it. If you do it after your training sessions, it will also have the added benefit of relaxing your body and helping you recover better for the next session. It will not have much of an effect on sore muscles or injury prevention, but it could still help you feel looser, more relaxed, and more mobile.
Most importantly, your stretching routine should specifically address the areas that you and your trainer feel are lacking in mobility and flexibility. Develop the right post-training stretch routine, stick to it, and reap the benefits.
Buroker, K.C. & Schwane, J.A. (1989). Does Postexercise Static Stretching Alleviate Delayed Muscle Soreness? The Physician and Sportsmedicine. 17(6).
Depino, G.M., Webright, W.G., & Arnold, B.L. (2000). Duration of Maintained Hamstring Flexibility After Cessation of an Acute Static Stretching Protocol. Journal of Athletic Training. 35(1), 56-59.
Farinatti P.T., Brandão C., Soares P.P., Duarte A.F. (2011). Acute effects of stretching exercise on the heart rate variability in subjects with low flexibility levels. The Journal of Strength and Conditioning Research. 25(6), 1579–1585.
Feeny, D., Huguet, N., McFarland, B. H., Kaplan, M. S., Orpana, H., & Eckstrom, E. (2012). Hearing, mobility, and pain predict mortality: a longitudinal population-based study. Journal of Clinical Epidemiology, 65(7), 764–777.
High, D.M., Howley, E.T. & Franks, D.B. (1989). The Effects of Static Stretching and Warm-Up on Prevention of Delayed-Onset Muscle Soreness. Research Quarterly for Exercise and Sport. 60(4).
Nelson, R.T. & Bandy, W.D. (2004). Eccentric Training and Static Stretching Improve Hamstring Flexibility of High School Males. Journal of Athletic Training. 39(3), 254-258.
Robert, R.D. & Noronha, M.D. (2007). Stretching to prevent or reduce muscle soreness after Exercise. Cochrane Database of Systemic Reviews. Cochrane Bone, Joint and Muscle Trauma Group.
Safran, M.R., Seaber, A.V. & Garrett, W.E. (1989). Warm-Up and Muscular Injury Prevention. An Update. Sports Medicine. 8(4), 239-249.
Thacker, S.B., Gilchrist, J., Stroup, D.F. & Dexter, K. (2004). The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature. Medicine & Science in Sports & Exercise.
Witvrouw, E., Mahieu, N., Danneels, L. et al. (2004). Stretching and Injury Prevention. An Obscure Relationship. Sports Medicine. 34(7), 443-449.