When a muscle releases or relaxes after being contracted, it can produce a range of sensations and feelings depending on the circumstance. The release of muscle tension is often associated with feelings of relief, comfort and reduced pain. However, the specific sensations felt when a muscle relaxes depends on why the muscle was contracted in the first place.
Relief from strenuous exercise
One of the most common circumstances in which you may feel muscle relaxation vividly is after strenuous exercise. When exercising, muscles are contracting and working hard against resistance to move the body. This leads to build up of tension in the active muscles.
When the exercise ends, the cessation of the strenuous activity leads to the muscle rapidly relaxing. The feeling is often described as a pleasant sensation of loosening and unwinding. There is a release of muscle tightness and tension that was built up during the exercise.
This sensation of release can be quite palpable and distinct after strength training with weights or resistance bands. The heavily worked muscle groups like the quadriceps, biceps or hamstrings seem to unlock and go limp after bearing the weight. Lifters often shake out their limbs or do cool down stretches to optimize this feeling of muscle relief.
The phenomenon occurs due to the stopping of motor unit recruitment in the muscles. Motor units are small bundles of muscle fiber that are innervated by a single motor neuron. When exercising, increased motor unit activation in the muscle leads to contraction. Once the activity stops, the motor units are deactivated and the constant tension created by their coordinated contraction dissipates.
This leads to the cathartic feeling of release one associates with muscle relaxation after exercise. The intensity of sensation depends on the amount of exertion performed. More strenuous exercise leads to greater build up and release of tension.
Relief from muscle cramps and spasms
The feeling of muscle release can also be very distinct when it provides relief from painful cramping or spasms. This could be in contexts ranging from leg cramps at night to painful spasms from medical conditions like multiple sclerosis.
When the cramping or involuntary spasm ends, you feel an almost instant easing of the pain and tension in the affected muscle group. The violent and energy consuming contractions of the cramped muscle rapidly dissipate and are replaced by comfortable stillness and lack of disturbance in the area. The transition from disturbance to stillness is very palpable.
Research suggests that muscle cramps and spasms occur due to aberrant functioning of motor neurons that activate muscle fibers and lead to sustained contraction. When this hyperactivity stops, there is quick release from the pressure and tightness created in the muscle. Blood flow improves, pain diminishes and you feel the muscle going limp and loose. Massage, hot compresses and stretching provides relief by deactivating motor units and aiding this release.
Soothing effect of massage
Muscle relaxation techniques like massage leverage the sensations associated with muscle release to provide therapeutic benefits. The main aim of massage is to manually stimulate pressure points and muscle tissue to ease tension. This is achieved by helping contracting muscle fibers disengage and relax.
The feeling of release is very noticeable and satisfying when knots and adhesions in the muscle tissue are broken up during deep tissue massage. Built up muscle tension from repetitive strain or injuries is released. This is also why massage is commonly used by athletes for recovery after intense training sessions.
Furthermore, the sensation of muscle release during massage is deeply soothing due to activation of the parasympathetic nervous system. Gentle pressure on the skin and muscle triggers signals to the brain to initiate the relaxation response. This induces feelings of comfort and calmness. The release of endorphins also enhances mood after a good massage.
Relief from chronic muscle tension
Muscle relaxation techniques can also provide therapeutic release of chronic tension that builds up due to poor posture, psychological stress and repetitive strain injuries. For example, those with desk jobs may habitually hold the shoulders tensed up during long hours of computer work. Relief from this chronic tension is felt as a major release when the muscle finally relaxes.
Muscle relaxation exercise involves tensing up target muscle groups for a few seconds and then stopping to allow full release. This stimulates the Golgi tendon organ which triggers reflexive muscle relaxation. Gentle stretches, myofascial release and trigger point therapy can also provide release from habitual muscle tension.
The release enables muscles that are stuck in contraction to fully disengage. This provides significant relief both physically and mentally. Muscles feel looser, more supple and free of knots or tightness. Mental relaxation follows physical relaxation.
Yoga and meditation
Muscle relaxation is a core part of mind-body practices like yoga and meditation. During yoga poses and meditation, habitual patterns of muscle tension are consciously released. This induces overall calming of the mind and body.
For example, a shoulder stand pose engages muscles to support the body. But counterposes involve complete release of this tension. This creates sensations of expansion and freedom. The feeling of muscle release is amplified when paired with focused breathing.
During meditation, the instruction is to scan the body and notice areas of tightness. Deliberately relaxing these muscle groups induces the sensation of letting go of tension. This progressive muscle relaxation method creates a wave of release moving through the body.
As muscle tension reflects mental tension, the physical release creates parallel emotional release and relief. Letting go of chronic tightness in the shoulders and neck leads to easing of stress and anxiety. The muscle relaxation kickstarts an overall calming response.
Nervous system regulation
The sensations of muscle release tie closely into the nervous system calm down response. Muscles relax when motor neuron stimulation is withdrawn and the fight-or-flight sympathetic nervous system activity diminishes.
Nervous system regulation is behind soothing sensations of muscle release during massage, meditation or yoga nidra. Deliberate relaxation of muscle tension triggers changes in heart rate, blood pressure, respiration and metabolic rate. This regulates the overactivated sympathetic system.
The parasympathetic system activates leading to biochemical changes that produce relaxation. The release of acetylcholine, nitric oxide and endorphins facilitates unwinding. Thus satisfying feelings of muscular release also reflects nervous system relaxation.
Opioid peptide release
The familiar experience of muscle pleasure and relief occurring alongside release of tension has a biological explanation. When muscle tension dissipates, the body synthesizes and releases natural opioid peptides called endorphins.
Endorphins belong to the same class of compounds as morphine and have analgesic effects. They generate feelings of euphoria. So the physical sensation of muscle fibers unwinding and softening is coupled with the emotional pleasure of endorphins diminishing pain and discomfort.
Massage, exercise, yoga and other relaxation techniques may derive many of their mood boosting and pain relieving effects from endorphin release facilitated by muscle relaxation.
Metabolic changes
The relaxation response induced by muscle release also leads to measurable biochemical changes that lower stress. For example, muscle relaxation lowers blood lactic acid levels. Lactic acid builds up with sustained muscle contraction and physical stress.
Muscle relaxation also reduces levels of potassium and other electrolytes that become elevated during muscle activity. Muscle tension is fuelled by energy demanding processes that use up glycogen and ATP molecules. Relaxing muscles stops these metabolic processes.
Lowering of cortisol and adrenaline leads to slowing of heart rate and metabolism. These parasympathetic changes save energy and restore homeostasis disrupted by the fight-or-flight response. The measurable metabolic shifts contribute to the pleasant feelings of muscle release.
Relief of stiffness and soreness
Releasing muscle tension provides palpable relief from the stiffness and soreness arising from muscle overuse and microscopic strain injury. Strenuous exercise leads to microscopic tears in muscle tissue and leakage of proteins like creatine kinase.
Continuing tight muscle contraction after exercise aggravates these micro-injuries due to ischemia and shortage of oxygen and nutrients. Relaxing the muscle allows improved circulation and transport of nourishment for recovery. The sore fibers can relax and heal.
Massage accelerates this muscle healing process from intense exercise like sprints or heavy weightlifting. The feeling of release allows stiff and damaged muscle tissue to loosen up. The sensations of softening and lengthening indicate healing as the muscle returns to a recovered state.
Mood enhancement
Due to the biochemical, nervous system and metabolic effects associated with muscle relaxation, the subjective feelings are often described in terms of emotional enhancement. Chronic muscle tension is associated with mood disorders like depression and anxiety.
Releasing muscle tightness seems to lift one’s mood and induce calmness. This is often reported after massage. There may also be psychological benefits to consciously releasing muscle tension related to feeling more in control of one’s body.
Letting go of stressful, worried or fearful thoughts coupled with deliberate physical relaxation provides holistic mind-body relaxation. The muscle release facilitates mental relaxation, boosts mood and creative visualization.
Relief from muscle fatigue
Deep muscle fatigue after intensive training sessions or repetitive motions is widely seen in sports and occupational settings. The release and relaxation of fatigued muscles provides distinct sensory relief and comfort.
Research suggests that muscle fatigue builds up due to accumulation of lactic acid from anaerobic respiration. Metabolic waste products interfere with calcium release channels required for muscle contraction. This makes further exertion difficult.
Relaxing the muscle helps clear out the byproducts of fatigue like lactic acid. Fresh circulation removes waste and provides oxygen and nutrients. The drained, exhausted fibers can relax and recover their contractile capacity. This tangible release provides relief from the unpleasant tension and burn of a fatigued muscle.
Restoring range of motion
Sustained tightness and shortening of muscle tissue can restrict mobility of joints and reduce range of motion. This deteriorates posture and athletic performance. Chronic shortening or spasming of muscle fibers leads to a misleading perception that the muscle has shrunk in size.
Gentle stretching and massage help counter such myofascial contractions. The release felt in the muscle corresponds with a restoration of flexibility and range of motion. For example, foam rolling exercises help muscles like the ITB recover length and function after contracting reflexively due to overuse.
Such self myofascial release provides lasting relaxation effects. The subsequent freedom of movement reaffirms the autogenic relaxation facilitated by releasing constricted muscles.
Relief from trigger points
Muscle knots and taut bands of muscle fiber called trigger points contribute to local and referred pain patterns in the body. Muscle release techniques like trigger point pressure therapy help relieve this myofascial pain.
The release of a trigger point feels like a local easing of tension and ache. This is often coupled with a tingling, spreading sensation as the referred pain pattern also subsides. Physical compression helps trigger points release contracted sarcomeres and restore normal length to muscle fibers.
Release and spontaneous ease of long held trigger points can provide considerable pain relief and improved range of motion. The accompanying sensations reinforce the value of muscle relaxation in myofascial pain management.
Prevention of muscle atrophy
Long term immobilization or disuse of a limb can lead to wasting and atrophy of muscles due to inactivity and loss of contractile proteins. Splinting, casting or bed rest often results in these consequences. Muscle contraction through exercise is needed to maintain size and strength.
Even during inactivity, gently tensing and releasing muscles with isotonic contraction exercises helps preserve muscle tone and prevent atrophy until mobilization. The sensations of release and relaxation are helpful biofeedback on the effects of keeping muscles stimulated despite immobility.
Regular short duration muscle contraction followed by relaxation serves a useful protective function in this context of injury, illness or confinement.
Conclusion
The feeling of muscle release provides both physical and psychological relief in various contexts of exercise, injury, illness and stress management. Smooth coordination and alternation between muscle contraction and relaxation is vital for optimal musculoskeletal function, performance and recovery.
Deliberately inducing the sensation of muscle release through massage, stretches, compression or relaxation techniques has demonstrated therapeutic value. The pleasant sensations reflect beneficial processes occurring during muscle relaxation – from metabolic changes and circulation enhancement to endorphin release and regulating the nervous system. Consciously releasing chronic muscle tension improves both muscular and mental health.