Exercise pain can act as a deterrent toward physical fitness, making you think twice about strenuous workouts. The popular belief is that the pain stems from a buildup of lactic acid in the body's tissues. While lactic acid production does occur, it is not the cause of post-exercise pain. Rather other biological mechanisms create the discomfort you feel if you have worked out too hard.
Exercise Effects
Ironically, the process of building muscle mass requires the damage of muscle fibers. When you work out, your activity causes tears in muscle tissue. The body responds to the trauma by building additional fibers around the site of damage, resulting in an increase in mass. However, the recovery period takes time, up to one to three days for full repair. This is the reason that experts recommend a day of rest before and after strength training sessions.
DOMS
Delayed onset muscle soreness, or DOMS, occurs during the period following exercise. Untrained individuals or seasoned athletes may experience it following certain types of exercise or from training too strenuously. Researchers differ on the precise cause. What is known is that muscle damage elicits an inflammatory response by the body. Red blood cells as well as muscle are damaged during exercise. White blood cells called neutrophils cause inflammation to occur while other cells remove the damaged tissue. Some researchers think that the swelling of tissue may press against nerves, causing the pain associated with exercise, according to "Principles of Anatomy and Physiology."
Eccentric Movements
Exercise pain may also occur because of the type of movement. A 2001 study by Auburn University identified eccentric exercises as a source of exercise pain. These movements occur when you perform actions such as downhill skiing. The muscle lengthens in combination with increasing tension as when maneuvering back and forth downhill. The result is added damage to the muscle fibers, resulting in muscle soreness.
Lactic Acid
Lactic acid production occurs when the body begins producing energy through processes that do not require oxygen. This may happen because the demand exceeds the oxygen availability. For a long time, people believed lactic acid was behind muscle pain. However, the 2001 Auburn University study refutes these beliefs, stating that lactic acid dissipates within an hour after exercise. Considering that the post-exercise pain occurs hours after a workout, these findings stand true. In order to reduce exercise pain, you should begin your workouts with a warm-up session. You should also slowly get your body used to the rigors of exercise. Above all, listen to your body. No-gain-without-pain is a dated and inaccurate exercise philosophy.
References
- University of Maryland Medical Center: Step 6: Why Use Weights?
- Sports Fitness Advisor: Delayed Onset Muscle Soreness (DOMS)
- "Principles of Anatomy and Physiology"; G. Tortora et al; 2005
- "Strength and Conditioning Journal"; Recommendations for the Avoidance of Delayed-Onset Muscle Soreness; D. Szymanski; August 2001
- Washington University: Blood, Sweat, and Buffers: pH Regulation During Exercise
