The burning sensation you feel in your muscles when you exercise is due to the buildup of lactic acid, a byproduct of anaerobic metabolism. After intense workouts, your body enters into a state of exercise-induced metabolic acidosis as it produces energy without the use of oxygen.
An intense workout is thought to be beneficial for the body, but why do muscles become so sore? The burning sensation in the muscles can last anywhere from 24 to 72 hours after an intense workout. It is part of the body’s adaptation as it builds muscle in response to the new physical demand placed on it. The body has to be stimulated with a certain degree of difficulty for muscles to be challenged enough to stimulate growth. The burning sensation you feel is an inevitable part of muscle building.
How to Identify “Good Pain” from Exercise
After a strenuous exercise routine, “good pain” signals that your muscles are adapting to the new activity and becoming stronger. Another name for this type of pain is DOMS (Delayed Onset Muscle Soreness). It is natural for your muscles to burn when engaged in a new challenging activity. The soreness becomes more intense one or two days after the workout.
More than being in a painful state, you will feel discomfort and soreness. This type of “good pain” quickly goes away and comes gradually, it is not an immediate sensation.
Identifying Discomfort vs Pain
Muscle discomfort or soreness is much different than actual pain. Normal muscle soreness presents as extreme fatigue that makes it difficult to engage in normal activities with the same level of stamina. Pain, on the other hand, does not present gradually but rather suddenly. It is usually associated with an injury of a muscle, tendon, or joint.
Pain is constant and intense compared to the gradual and mild achiness of muscle soreness. Pain can become so intense that it can interfere with sleep and does not seem to go away easily. Muscle soreness has a gradual onset and goes away in a few days. Pain can occur immediately and go on for several weeks if the root cause is not resolved.
How to Know the Difference
Your body has an innate wisdom and when you are tuned in, you will notice when something is wrong. Exercise can become intense, but it should never cause sharp pain. It is normal to feel fatigued and sore after workouts, but even so, you will be able to move around without excruciating pain.
In comparison, when the body feels pain from an injury, you will notice a significant change in your range of motion and ability to perform normal daily activities. This is a sign that something may be wrong. When this occurs, it is best to see a specialist that will be able to assess you properly. X-rays can detect fractures and ultrasound or MRI tests can identify soft tissue injuries.
The Burning Sensation in Muscles Due to Exercise
When you take your body through a new workout routine that demands a higher intensity, you will experience some level of muscle soreness. It is felt one or two days after the workout and it gets better with time. The burning sensation should not last more than three days at the same level of intensity.
When Should I Worry About Burning Muscles?
The lactic acid buildup that occurs after a workout is responsible for causing muscle soreness. Stretching and drinking plenty of water after a workout alleviates the burning sensation. However, when you experience muscle-burning for no apparent reason, or it does not go away in a few days after your workout, there may be an underlying medical condition that must be investigated.
For example, chronic exertional compartment syndrome is a condition that abnormally affects nerves and muscles after exercise. It is a painful condition that usually involves the lower legs producing cramping, swelling, and pain. When these types of symptoms are recurrent or become worse over time, it is a sign that you may need a medical diagnostic assessment.
Another worrisome state is when muscles burn with no or very little exertion. According to the American Academy of Orthopaedic Surgeons, painful common injuries from exercise include bruises, sprains, and strains. To avoid further damage, a normal exercise routine cannot take place until these injuries have fully resolved. In this case, it is best to seek immediate medical attention.
What is Delayed Onset Muscle Soreness?
Delayed onset muscle soreness (DOMS) is a symptom of exercise-induced muscle damage. It is a sensation of pain and stiffness in the muscles that lasts several hours to a few days after strenuous physical activity. The condition is caused by exercise that causes microtrauma to muscle fibers. To prevent injury, the muscles quickly adapt and rebuild causing soreness.
What is Known as Lactic Acidosis?
According to WebMD, lactic acidosis is the unpleasant feeling of burning and aches in muscles. It is caused by intense exercise when excessive acid builds up in the bloodstream.
Lactic acidosis is also commonly seen during serious medical conditions that cause blood pressure to drop and not enough oxygen is able to reach the body’s tissues. Some of these conditions include respiratory failure, sepsis, AIDS, cancer, and other critical conditions.
The Lactate Threshold
A medical dictionary defines lactate threshold as the fastest speed you can perform physical activity at which your body produces and clears out lactate at an equal rate. Reaching this point allows your blood lactate levels to stay steady. It is an indicative measure where your body changes from using aerobic (with oxygen) to anaerobic (without oxygen) energy.
Lactate Production
Lactate otherwise known as lactic acid is a byproduct of anaerobic respiration. This is where the body produces energy without the use of oxygen. Lactic acid is deposited in our bloodstream by muscle and red blood cells.
Is Muscle Soreness Caused by Lactic Acid?
Lactic acid is associated with muscle soreness. It is a source of fuel that powers muscles during exercise. However, some scientists believe that muscle soreness is caused by the microdamage that muscles endure after intense exercise. The buildup of lactic acid is thought to cause muscle fatigue and soreness.
How to Prevent Lactic Acidosis
To prevent lactic acidosis, it is best to start with aerobic exercise such as walking or running. Increase the level of difficulty gradually so that your body has time to adapt as it builds tolerance to the new activity. As your lactate threshold increases, you will be less likely to experience lactic acidosis.
How Can I Prevent Lactate Buildup?
The best way to prevent lactate buildup is to increase the intensity of exercise gradually. It is recommended to start slow and progress incrementally without putting your body into an extremely intense physical challenge. Health experts suggest also providing your body with proper fuel such as Beta-alanine3, which is thought to delay the accumulation of lactate.
Should I Try to Eliminate Lactate?
It is not possible or necessary to completely eliminate lactate. There are ways to keep it at proper levels so that is does not create muscle soreness. To decrease lactic acid in your body, you may try these methods:
- Decrease the level of intensity during workouts
- Rest after exercise
- Breath deeply during workouts
- Stretch and massage muscles
Questions
Why do my muscles burn during exercise?
Scientists attribute muscle soreness to two main reasons: the buildup of lactic acid and the microdamage to muscles.
Is it good to feel the burn when working out?
It is normal to feel a burning sensation during and after your workout. However, be sure the burning is gradual and goes away in 24 to 72 hours. Muscle burning is a sign that the body is becoming stronger and adapting to the new demands.
Should I stop exercising if my muscles burn?
It is important to allow your muscles to rest after a workout. The recovery phase is when muscles have the opportunity to rebuild. Interfering with this stage by adding more stress, can weaken muscles and create other issues.
Does muscle burn mean growth?
Muscle growth is stimulated by physical overload, not by the burning sensation. Although the burning sensation is associated with muscle growth by some fitness enthusiasts, it does not necessarily mean that the muscles are growing.
How to treat burning muscles?
The best way to alleviate burning muscles is by stretching and resting. It is also beneficial to elevate sore muscles to promote healthy blood flow and reduce inflammation. The use of ice packs and warm baths with Epsom salts are also great ways to treat sore muscles after workouts.
Why do my muscles burn so quickly?
The burning sensation in muscles after intense workouts is associated with the buildup of lactic acid and the microdamage muscles endure. The onset of this burning sensation occurs within hours after intense workouts as the muscles prepare for recovery.
Muscles burning for no reason?
If there is no reason for your muscles to burn, it may be an indication of an underlying medical condition that must be diagnosed by a doctor.
Muscles burning with little exertion?
If you experience muscle soreness without significant physical exertion, it may be a sign of a medical condition. A doctor will be able to properly diagnose this type of event.