Sore Muscle

Why Are My Muscles Sore?

Muscle pain from exercise can be divided into three categories.

  1. Pain or discomfort during or immediately after exercise.
  2. Pain or discomfort 2-3 days after unaccustomed exercise (referred to as Delayed Onset Muscle Soreness, (DOMS).
  3. Pain from involuntary muscle contractions or cramps that last for several seconds.

Delayed Onset Muscle Soreness (DOMS) “results from strenuous exercise that goes beyond the intensity or duration for which the muscle is accustomed to performing.”  This soreness usually occurs 24 hours after exercise and peaks 48-72 hours thereafter and it is perfectly normal. This may continue for a full week (7-10 days).  Scientists still have not proved what causes delayed muscles soreness, but there are numerous theories that doctors, physical therapist, personal trainers, and athletic trainers discuss in the industry to possible causes and remedies that novice exercises can utilize for relief of (DOMS).

Theories of DOMS

Lactic Acid accumulation in the muscles was originally thought as the cause of Delayed Onset Muscle Soreness.  However, researchers believe that this is the cause of discomfort during exercise, not two days later.  There is no evidence to explain how Lactic Acid could cause soreness 24-48 hours after exercise.

“DeVries proposed that exercise could cause ischemia in the active muscle, which in turn would result in the production of a pain substance.  If too much of this substance accumulated, pain endings would be stimulated.  This resulting pain would in turn produce more reflex spasms that would prolong the ischemia and initiate a vicious cycle.”

Some researchers believe that since muscles are elastic and connective tissue is stiff, connective tissue damage may be the cause of DOMS.  During vigorous resistance training, connective tissues become damaged causing soreness.

Recent research suggests the primary cause of muscle soreness is damage to the muscle itself.  When exercising a muscle beyond what it is accustomed to (Overload Principle), the muscle becomes damaged.  Researchers believe this causes slight tears in the muscle.  This can especially be seen when performing exercises that accentuates eccentric training, such as lowering a weight at a slow speed or sprinting downhill.

Inflammation to the damaged area may be another cause of delayed onset muscular soreness.  The inflammatory process begins immediately following exercise. When the inflammatory process reaches a certain level, the nerve endings for pain respond, resulting in muscular soreness.

Research shows that Delayed Muscles Soreness is most prevalent in the beginning stages of physical activity. The body needs to adjust to the physical activity level as the muscles grow. This is why athletes often cross-train and vary their routines to continue to challenge and develop their muscle strength. It is important to distinguish the difference between moderate muscle soreness induced by exercise and muscle overuse or injury. If soreness prevents you from performing daily activities associated with living and work, then it’s time to rest.

Suggestions for Alleviating the DOMS Pain

The best way for alleviating Delayed Onset Muscle Soreness is giving the muscle time to rest. Many therapist and trainers will recommend Rest, Ice, Compression, and Elevation (RICE). Ice definitely helps with inflammation and can be applied for 15-20 minutes on and off daily to relieve soreness. Compression can be applied with kinesotaping, ace bandage or compression sleeves or socks.

Many exercise enthusiasts do not like to miss exercise sessions, so there are some alternative methods to help with the pain and recovery process.  A light recovery workout that keeps the blood flowing with low-moderate intensity is best for recovery from DOMS.  It is recommend that you train different muscles groups giving your sore muscles a break from activity. For example, train your lower body (legs) if your upper body is sore from training. Cross-training can also help prevent DOMS by

Stretching can provide some relief allowing your muscles some time to recover and relax. Yoga offers a great workout that can reduce stress, soreness, and offer recovery for the mind, body, and spirit.

Self-myofascial release is also another very effective technique that helps eliminate pain and reduced muscle soreness. Foam rolling is a self-myofascial release (SMR) stretching technique that involves applying a sustained pressure into the myofascial connective tissue that can help with muscle relaxation, improved range of motion, and reduced muscle soreness. It is important to select a foam roller that is comfortable to your touch and pain tolerance to focus on restoring optimal muscle motion and function. The more you foam roll the more comfortable it will become and the faster you will recover.

Massage is also another great technique for delayed muscle soreness. A deep tissue massage can help relieve the lactic acid build up and inflammation in the muscles offering muscle relaxation, improved circulation, reduced stress and muscle tension.

Other methods include using anti-inflammatory pain relievers such as ibuprofen, help to reduce inflammation and soreness.

By Allison Milano- Stolar, MA MPH
Health Fitness Specialist


Dierking, Jenny K. & Bemben, Michael G.   Strength and Conditioning Journal.                           “Delayed Onset Muscle Soreness.” August 1998.  Pgs. 44-47.

Dierking, Jenny K. & Bemben, Michael G.   Strength and Conditioning Journal.                           “Recommendations for the Avoidance of Delayed Onset Muscle Soreness.” August 2001.