It’s the part of the workout too many people skip, the warm-up. Few fitness professionals would suggest starting a workout without warming up first. It’s clear that a warm-up has benefits. When you warm your body up before the main portion of the workout, it boosts blood flow to your working muscles. The heightened blood flow reduces muscle stiffness and gets the muscles ready to move. It also jump-starts your nervous system and preps it for the workout ahead.
Another underappreciated benefit of a warm-up is the impact it has on your heart and blood vessels. If you were to jump into a high-intensity workout too hastily, your heart would be forced to speed up fast, forcing it to do too much too quickly. That places undue stress on your heart. It’s best to gradually increase body temperature and heart rate to give your heart and blood vessels a chance to adapt to the stress of exercise. The more intense the exercise, the more important a warm-up is. Plus, the older you get, the more you should ease into exercise with a longer warm-up.
Warm-Ups and Injury Prevention: Is There a Link?
You might think that injury prevention is another reason not to skip the warm-up. Although it might be drilled into your head that warming up before a workout prevents injury, the evidence isn’t as clear-cut as you might think. Studies don’t universally support this idea.
What is the evidence that warming up lowers the risk of injury? A meta-analysis published in the Journal of Science and Medicine in Sport was inconclusive. Three of the studies showed modest benefits of warming up before a workout, but two found no link between warming up and a lower incidence of injury.
Another study in 2004 was also disappointing. In this study, researchers conducted an extensive analysis of databases of studies focused on pre-workout stretching and injury. It found that stretching before a workout wasn’t associated with a significant reduction in injury rate. An additional 2010 study failed to show that a combination of warm-up and stretching lowered the risk of overuse injuries.
Post-Workout Muscle Soreness and the Warm-Up
How about the muscle soreness you get after a workout you’re unaccustomed to? Post-workout soreness is called delayed-onset muscle soreness or DOMS. It’s the achy feeling and stiffness you get when you try to move the muscles you worked. The discomfort typically comes on 8 to 24 hours after a workout and hangs around for a few days. When you have delayed-onset muscle soreness, it’s hard for your muscles to generate the same degree of force, so it impacts your workout too. Fortunately, your muscles adapt quickly, so the next time you do a similar workout, you won’t feel as sore.
Can warming up reduce DOMS? Unfortunately, the evidence that warming up has any impact on DOMS is weak. A Cochrane review analyzed 10 studies and found no indication that warming up impacts delayed-onset muscle soreness at all. It’s important to note that these studies looked at static stretching as the mode of warm-up. Static stretching has fallen out of favor as a way to warm-up before a workout. The emphasis has shifted to dynamic stretches, like arm swings, kicks, etc.
However, a study published in the Journal of Human Kinetics found that warming up reduced soreness in the central portion of the muscles that were worked, but not the distal part. Why is there conflicting evidence? The studies use different exercises and exercise protocols. So, these studies aren’t the final word, but it doesn’t appear that a warm-up significantly impacts DOMS based on the existing studies.
Should You Still Warm Up?
Don’t skip the warm-up. There’s more than one reason to warm your body up before an exercise session. Even if doing so doesn’t reduce the risk of injury or ease post-workout soreness, it still gets your heart, brain, and muscles ready to work. Intuitively, it makes sense you don’t want to suddenly work out with muscles that are cold and non-compliant.
The best way to warm up is with dynamic movement. Some examples of dynamic movements include:
- Jumping jacks
- High knees
- Knee to chest
- Lunges with a twist
- Upper body punches
- Jogging in place
- Kicks
These dynamic movements increase blood flow to your muscles without forcing you to hold the muscle in a stretched position. There’s some evidence that static stretches can reduce exercise performance. According to the National Strength and Conditioning Association, static stretching prior to an event may reduce power capabilities, force production, strength endurance, running speed, and reaction time.
Save the static stretching until the end of your workout. A workout feels easier if you gradually ease into it with dynamic movements rather than shocking your body by asking cold muscles to generate force.
The Bottom Line
It’s unclear whether a warm-up prevents injury. Studies are mixed, but it makes sense that warm muscles are more likely to perform well and may be less subject to injury. Even if a dynamic warm-up doesn’t reduce injury risk, there are other reasons to warm up. You need warm, pliable muscles to perform your best.
Plus, a dynamic warm up where you gradually increase your heart rate is less stressful on your heart and cardiovascular system. Also, static stretching at the end of a workout helps improve range-of-motion, so you can do other tasks more easily. So, keep warming up and stretching!
References:
- Journal of Science and Medicine in Sport. June 2006. Volume 9, Issue 3, Pages 214–220.
- com. “Warm Up and Cooldown: Why so important for heart patients?”
- J Hum Kinet. 2012 Dec; 35: 59–68.
- com. “Static Stretching and Performance”
- Cochrane Library. “Stretching to prevent or reduce muscle soreness after exercise”
- Med Sci Sports Exerc. 2004 Mar;36(3):371-8.
- Woods K, Bishop P, Jones E. Warm-up and stretching in the prevention of muscular injury. Sports Med. 2007;37(12):1089-99. doi: 10.2165/00007256-200737120-00006. PMID: 18027995.
- McHugh MP, Cosgrave CH. To stretch or not to stretch: the role of stretching in injury prevention and performance. Scand J Med Sci Sports. 2010 Apr;20(2):169-81. doi: 10.1111/j.1600-0838.2009.01058.x. Epub 2009 Dec 18. PMID: 20030776.
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5 Reasons You Should Never Skip or Skimp on the Warm-Up
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