Exercise-induced muscle damages (EIMD) are microscopic tears and inflammation that occur when muscles are stressed. It can be caused by extreme physical exertion, resulting in pain and soreness for days to weeks after the exercise session.
EIMD is a common problem for athletes and fitness enthusiasts. If you’re among the physically active people, it’s essential that you understand its causes, symptoms, and prevention methods so you can manage your training effectively.
EIMD is the physiological and biochemical disruptions in skeletal muscle that occur due to intense exercise. Specifically, they’re microscopic tears and inflammation that occur after high-intensity or long periods of endurance training.
Eccentric muscle contractions are most likely to cause EIMD. They’re one type of muscle contraction in which force is generated by lengthening the involved muscles rather than shortening them (i.e., concentric contractions). For example, when you lift a heavy weight, the eccentric phase is when the muscle becomes longer, whereas it contracts and shortens during the concentric phase.
Eccentric contractions cause greater mechanical stress on the affected muscle fibers than concentric contractions. The greater the degree of muscular contraction during eccentric exercise and the greater muscle mass involved, the more damage will occur. Many factors, including the following, influence the degree of damage:
Apart from eccentric exercises, other causes of EIMD include:
- Heavy resistance training (e.g., lifting weights);
- High-intensity aerobic activity (e.g., running sprints);
- Injury to muscles or tendons (such as with overuse or repetitive motions); and
- Repetitive contractions (such as gripping or holding).
Another cause of most EIMDs is high-volume training in terms of length or intensity. It can be caused by overtraining. For example, If you’re used to going for a walk around the block every morning and suddenly decide to add extra miles each day, your body may not have time to adapt. You’ll get hurt if you do this too quickly.
The symptoms of EIMD can range from mild to severe, depending on how much damage has been done. Generally, it’s often characterized by pain and tenderness. They’re typically localized to the area of muscle exertion, but they may also radiate to other areas of the body. EIMD may also cause muscle weakness, stiffness, and swelling of your limbs or torso.
EIMD is the most common cause of muscle soreness, which is commonly referred to as DOMS (delayed-onset muscle soreness). It typically appears 24–72 hours after exercising, peaking at 48–72 hours and disappearing within 7–10 days. Additionally, it’s only associated with eccentric exercise, which is again where the muscle is being stretched while contracting.
Other immediate symptoms of EIMD are pain and swelling, which typically occur within a day or two of exercise and last for about one to two days after exercising. This is followed by muscle swelling that lasts for about five days after exercising. The third group includes weakness caused by inflammation or bleeding within muscles that results in muscle soreness lasting up to four weeks post-exercise.
Chronic symptoms include muscle atrophy. It occurs when your body’s ability to repair damaged tissue slows down or stops entirely over time due to a lack of proper nutrition for proper recovery processes like regeneration or remodeling of injured tissue after an injury (or even during exercise).
Common indicators of EIMD that can be measured by:
- Creatine kinase levels;
- Myoglobin levels in urine (myoglobinuria);
- Decreased muscle strength and power,
- Reduced range of motion around affected joints,
- Swelling in the affected area(s); and
- Injury-associated inflammation (elevated C-reactive protein).
Prevention Method and Nutritional Strategies
EIMD can be reduced by designing an exercise program to minimize eccentric exercise. This solution should reduce the volume and intensity of resistance training, taper before and after events or competitions, and increase the frequency of training sessions.
For instance, do push-ups instead of bench presses. Another example is switching to incline surfaces like steep hills if you’re running downhill. These areas can reduce the impact on your joints while still getting the same benefits from increased resistance.
Additionally, reduce total training volume. A high total amount of work will increase the likelihood of overloading your muscles without giving them enough time to recover between sets or workouts.
For example, do the following to decrease this risk:
- perform fewer repetitions per set;
- do fewer sets;
- rest more between sets;
- take longer breaks between workouts (such as one day off every seven days);
- reduce overall workout time; or
- mix different workouts so they don’t place too much stress on any single set of muscles at one time.
Furthermore, to help your muscles recover from exercise-induced muscle damage, it’s crucial to ensure you’re getting enough protein. It’s the primary building block of muscle, so it helps to repair damaged muscle tissue. Increase your protein intake by eating more foods like eggs, fish, or chicken. You can also supplement with whey protein powder if you don’t eat enough animal products regularly.
In addition to protein, get enough Vitamin C and E too. These vitamins help reduce oxidative stress caused by intense exercise, leading to muscle damage. They work together by reducing inflammation while increasing the flexibility of blood vessels and preventing cholesterol from oxidizing (which causes atherosclerosis).
EIMD is common after new or high-intensity workouts but can happen anytime you push yourself too hard. Sometimes, it may mean you need to rest for a few days before going back to exercise again. However, with proper attention and treatment, it’s possible to avoid repeated bouts in the future.