After a long hike in Camelback mountain, stretching your sore leg muscles seems to provide some relief. However, you may be doing more damage than good to your muscles. Muscle soreness after exercise can be caused by microscopic tears in the connective tissues of the muscle, according to the American Council on Exercise. Stretching can delay the healing process, even if it does feel good.
Stretching Mechanisms
The stretching sensation is caused by two muscle sensors in your muscle fibers and tendons. Muscle spindles are located throughout the muscle, and their job is to prevent overstretching of the muscle fibers. When you stretch a muscle, muscle spindles send signals to your brain that tell it how far to stretch. As the stretch increases -- especially if it's quick and forceful -- the signal increases, which causes the muscle to start contracting. However, if the stretch is slow and gradual, there isn't enough signal to tell the muscle spindles to contract, which allows the muscle fibers to lengthen. The Golgi tendon organs, located in the tendons, relax the muscle fibers when they're stimulated, allowing them to lengthen.
Modified Perception
The feel-good sensation is more likely contributed by your nervous system rather than any change in sore muscle length. In a 2010 review published in "Physical Therapy," the authors asserted that muscle length does change during a stretch, but its effects are short-term, leading to the likelihood that the stretching sensation is due to modified perception of the nervous system. Because stretching reduces neural activity in your muscles, the soreness sensation also decreases. However, it doesn't mean that the damage isn't there. You've just put a temporary anesthetic on your sore muscles.
Effects of Stretching
Stretching can cause more tension buildup in the muscle, causing it to get tighter and heal improperly. A 2003 article published in "Sports Medicine" reported that stretching does not alleviate muscle soreness; however, exercise and movement are the most effective means of alleviating muscle pain and soreness. Massage therapist and rolfer Todd Hargrove of Better Movement recommends that you avoid movements that build tension in the healing muscle. For example, if your hamstrings feel sore, avoid stretching and heavy lifting.
Alternatives to Stretching
Aside from medications, doing relaxing, mindful and low-intensity exercises, such as yoga, brisk walking and pool-wading, are a way to alleviate muscle soreness. Spending a couple of minutes in a dry sauna releases endorphins, which are your body's natural painkillers. It also increases your heart rate similarly to doing light cardio, allowing your blood to remove wastes quickly while your muscles rest.
References
- Physical Therapy: Increasing Muscle Extensibility: A Matter of Increasing Length or Modifying Sensation?
- Canadian Fitness and Education Services: The Physiology of Stretching
- Better Movement: Should You Stretch a Sore Muscle?
- Journal of Applied Physiology: Altered Reflex Sensitivity After Repeated and Prolonged Passive Muscle Stretching
- Delayed Onset Muscle Soreness: Treatment Strategies and Performance Factors
- American Council on Exercise: Q: What Causes Muscle Soreness and How Is It Best Relieved?
Resources
Writer Bio
Nick Ng has been writing fitness articles since 2003, focusing on injury prevention and exercise strategies. He has covered health for "MiaBella" magazine. Ng received his Bachelor of Arts in communications from San Diego State University in 2001 and has been a certified fitness coach with the National Academy of Sports Medicine since 2002.