Proper and frequent stretching is responsible for multiple body adaptations, including an increase in the spinal stretch reflex, muscle mass, flexibility and control. Resistive and free active stretches that isolate a single muscle instead of a full range of motion is helpful in bolstering flexibility to overcome muscle weaknesses, according to Dr. Donald DeFabio. This type of stretching, however, is not ideal for everyone or all activities.
How It's Done
Active stretching works by activating the reciprocal inhibition reflex. An actively contracting muscle is accommodated through an adequate relaxation of its opposite muscle -- the antagonist. Since the antagonist muscle usually contracts in resistance to a stretch through the action of muscle spindles and the nervous system, active stretching seeks to cushion the antagonist muscle from any forces, allowing it to relax.
Stretch Reflex Initiation
If you've tried doing splits in your bedroom, you must swear ballet dancing and gymnastics are witchcraft, and if not you must wonder how much pain those brave enough to do it for a living must go through. However, that was just the stretch reflex at the behest of the nervous system, which is not convinced you have the stability and strength to do splits. According to Michael Alter, a gymnastics coach and judge, a stretch reflex is a protective muscle contraction that regulates the length of a skeletal muscle. The nerve activity rises when a muscle spindle is stretched, increasing the alpha motor neuron, forcing the muscle to contract in resistance to stretching. This raises the muscle tension that renders connective tissues more difficult to stretch.
Counterproductive In Warm-Ups
Stretching is a critical part of any routine. It should follow a general warm-up and precedes sport-specific activities, according to a study published in the April 2009 issue of the BMC Musculoskeletal Disorders Journal. It should raise the body’s temperatures, loosen stiff muscles, bolster coordination, awareness, muscle contractibility and elasticity, and cardiovascular and respiratory systems’ efficiency, while also making for a better performance. Improper warm-ups heighten the risk of injury, and active stretching is just one way of how not to warm up. Alter says that active stretching is likely to result in tiring out the stretched muscles, reducing their ability to perform in subsequent physical activities.
Ineffective With Injuries
Active stretching may not be very effective in the presence of some injuries and dysfunctions like serious inflammations, fractures and sprains. If you suffer from any dysfunction, you are best off with external assistance stretches, which produce sufficiently longer stretches necessary for the tissues and the entire body to adapt to a certain range of stretch. Without help and care, active stretching is likely to exacerbate pre-existing physical dysfunctions through muscle damage, soreness, further injury and even fatigue.
For effectiveness, active stretching requires you to adopt the right stretching position and hold a stretch for a certain time, which allows the muscles to adapt to the range. There is really no time standard since each stretch is supposed to vary with every individual’s specific flexibility. This means that for every stretch, you are forced to strike a balance between doing too little and wasting your time, or doing too much, at the risk of injury.
Susan Resneck has been a nutrition and fitness writer since 2000. Resneck has worked as a nutrition specialist and dietitian since 2000, focusing on metabolic and hormonal balancing. Her articles have appeared both online and in print for publications such as Simple Abundance, "Catskill Country Magazine" and "Birds and Blooms.