Acute muscle soreness
Acute muscle soreness(AMS) is the pain felt inmusclesduring and immediately, up to 24 hours, after strenuousphysical exercise.The pain appears within a minute of contracting the muscle and it will disappear within two or three minutes or up to several hours after relaxing it.[1]
There are two causes of acute muscle soreness:[1]
- Accumulation of chemical end products of exercise in muscle cells such as lactic acid and H+
- Muscle fatigue(the muscle tires and cannot contract anymore)
Cause[edit]
Muscle soreness can stem from strain on thesarcomere,the muscle's functional unit, due to the mechanism of activation of the unit by the nerves, which accumulatescalciumthat further degrades sarcomeres.[2]This degradation initiates the body inflammatory response, and has to be supported by surrounding connective tissues. Theinflammatory cellsandcytokinesstimulate the pain receptors that cause the acute pain associated with AMS. Repair of the sarcomere and the surrounding connective tissue leads todelayed onset muscle soreness,which peaks between 24 and 72 hours afterexercise.[citation needed]
AMS may also be caused by cramping following strenuous exercise, which has been theorized[by whom?]to be caused by two pathways:
Dehydration[edit]
The dehydration theory states thatextracellular fluid(ECF) compartment becomes contracted due to the excessivesweating,causing the volume to decrease to the point until the muscles are contracted until the fluids can re-inhabit thevacuum.[3]Excessive sweating can also cause the electrolyte imbalance theory, which is sweating disturbs the body's balance ofelectrolyte,which results in excitingmotor neuronsand spontaneous discharge.[citation needed]
The feeling of soreness can also be attributed to the lack of contraction from the muscle, which can lead to overexertion of the muscle. The decrease in contraction has been theorized to have been caused by the high level of concentrations ofprotoncreated byglycolysis.[3]Excess in protons displacescalciumions which is used within the fibers in activating the sarcomere, resulting in a reduced contractile force.[citation needed]
Electrolyte imbalance[edit]
When exercising,lactic acidbecomes lactate and H+ through glycolysis. With more lactic acid consumed during the process, there will be a higher H+ concentration, thus lowering theblood’spH level.This low pH level will affect the energy production process through the inhibition ofphosphofructokinase.Phosphofructokinase is a keyenzymein the glycolytic process, which produces energy. A higher concentration of H+ will also cause the loss ofcontractile forcethrough the misplacement of calcium inmuscle fiber,which will disturb the formation of theactin-myosincross-bridge.[4]
Treatments[edit]
There is conflicting research in terms of treatments of muscle soreness.[citation needed]
Stretching and muscle soreness[edit]
Stretching immediately before or after a workout does provide some help, but is not significant enough to be considered as a preventative measure.[5]
References[edit]
- ^ab"Why am I sore after exercise? Should I workout with sore muscles?".www.cfaortho.com.Retrieved2024-04-11.
- ^Nelson, Nicole L.; Churilla, James R. (August 2016). "A narrative review of exercise-associated muscle cramps: Factors that contribute to neuromuscular fatigue and management implications: Exercise-Associated Muscle Cramps".Muscle & Nerve.54(2): 177–185.doi:10.1002/mus.25176.PMID27159592.S2CID206297548.
- ^abLayzer, Robert B. (November 1994). "The origin of muscle fasciculations and cramps".Muscle & Nerve.17(11): 1243–1249.doi:10.1002/mus.880171102.ISSN0148-639X.PMID7935546.S2CID20514056.
- ^Myers, Jonathan; Ashley, Euan (1997-03-01)."Dangerous Curves: A Perspective on Exercise, Lactate, and the Anaerobic Threshold".Chest.111(3): 787–795.doi:10.1378/chest.111.3.787.ISSN0012-3692.PMID9118720.
- ^Herbert, Rob D; Gabriel, Michael (2002-08-31)."Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review".BMJ.325(7362): 468.doi:10.1136/bmj.325.7362.468.ISSN0959-8138.PMC119442.PMID12202327.