Why Are We Sore After We Work Out or Exercise?

After a good workout or sweat session, our muscles get sore. Though it’s unpleasant, feeling sore may be weirdly satisfying because it seems like a physical confirmation that you crushed your workouts and your body will soon reap the benefits. Muscle soreness is totally fine and an even desirable result of exercise. After all, no pain, no gain – right?

But let’s be honest: whether you look forward to working out or not, it seems like we all dread feeling sore afterward. That quivering quads and can’t-walk aching leave us with questions like why muscles get sore after exercise?  

When you exercise in the same way regularly, your body gets used to working particular muscles. Still, if you start a new fitness regime or decide to work out longer than usual, you may wake up the next day with sore muscles, making it hard to move. Chances are, you won’t be leaping out of bed to rush to the gym when basic stuff like holding your arm up to brush your teeth hurts.

So, what is the explanation behind all these? In this article, learn everything you need to know about what’s happening in and to your muscles and what’s making them sore. You can also learn how to reduce the pain associated with muscle soreness the next time you want to push yourself more on your workouts.

Are Sore Muscles a Good Sign?

a person with sore leg

Sore muscles can be a sign that your body has undergone physical stress or strain, such as from exercise or physical activity. Generally, this can be a good sign as it may indicate that your muscles are adapting and getting stronger.

Workout-related soreness is typically productive, as it means that your muscles were challenged and your workout did the job. As long as you give your muscles ample rest and proper nutrition to recover, soreness is only a step in the process of becoming stronger and fitter.

However, it’s important to note that soreness alone isn’t necessarily an indicator of a good workout or physical progress. It’s possible to experience soreness without making progress, and it’s also possible to make progress without feeling particularly sore.

When experiencing sore muscles in the days after the exercise, it’s best to take active recovery – referring to doing less strenuous activities undertaken after an intense workout. It allows the muscles to rest while keeping the body active. Examples of active recovery include walking, yoga, swimming, and cycling.

Why Do Muscles Get Sore After Working Out?

a man suffering from painful shoulders after working out

When you work out with a personal trainer, a fitness instructor, or a YouTube exercise video, you’ve probably heard them saying, “This burn feels so good; you’ll going to feel this tomorrow.” But that thing you’ll feel the next day is pain.

Have you ever wondered why your muscles might feel sore after exercising? This phenomenon is commonly referred to as delayed onset muscle soreness (DOMS) and typically occurs after a workout session, often set in the next day. DOMS usually happens when you engage in physical activity that your body isn’t accustomed to, whether it’s a new type of exercise or a more strenuous workout than usual. Even regular athletes can experience muscle soreness when trying new skills or engaging in a new sport.

The soreness you experience following exercise is believed to be caused by micro-damage to the muscle and the subsequent inflammation that follows. While aching muscles during active exercise are thought by some to be due to a build-up of lactic acid, post-exercise soreness is often attributed to micro-tears within the muscle, which leads to an inflammatory response as the body adapts and transforms into a stronger version of itself.

The inflammatory markers (including white blood cells, red blood cells, and cytokines) and lactic acid all help the muscle tissue repair itself. They build up in your just-worked muscles in the hours and days after the workout, causing soreness. Inflammation is necessary for proper recovery and remodeling of the muscle tissue.

What Does Lactic Acid Have to Do with Muscle Soreness?

Lactic acid is often associated with muscle soreness, but its actual role in causing soreness is a matter of debate among experts. While some researchers believe that lactic acid build-up during exercise can contribute to muscle fatigue and soreness, others believe that it is not a primary cause of muscle soreness.

During intense exercise – like sprinting, weight lifting, high-intensity interval training (HIIT), and plyometrics – the body’s demand for energy increases and the muscles break down glucose to produce ATP, the primary source of energy for muscle cells. The body makes energy anaerobically (without oxygen) because oxygen won’t get to the muscles fast enough to keep up with the amount of energy the muscle needs.

As glucose is broken down, lactic acid is produced as a byproduct. Lactic acid can accumulate in the muscles, and by the time you’re done with vigorous exercise, your muscles can be chock-full of it. Some researchers believe that this build-up can cause muscle fatigue and soreness. But all this lactic acid is generally gone within an hour after the exercise.

Simply put, lactic acid clears out well before muscle soreness even begins. And this is why the link between lactic acid build-up during exercise and muscle soreness after exercise has been almost completely disproven.

In fact, lactic acid build-up after a tough workout might cue muscle regeneration, signaling that your muscles have worked hard and need to be repaired. If anything, the lactic acid build-up is desirable because the more you have, the more your body understands that the area needs attention.

Factors that Affect How Sore You Get

Now that you know what happens in the body that makes you feel sore, you’re also probably wondering why you feel fine after exercising but unable to bend down to tie your shoes or raise your arm to brush your teeth the next day.

The truth is, how sore you get depends on how much muscle micro-trauma your sweat session has caused. And how much micro-trauma there is depends on a few things:

1. How new are you to working out

If you are new to working out or returning after a break, you are more likely to experience muscle soreness than someone who has been exercising regularly for years. People with a tolerance to exercise are typically less sore after workouts than beginners. As you continue to exercise, your body becomes more accustomed to the stress, resulting in fewer micro-tears in the muscle tissue and a reduced need for repair.

2. How often do you work out

The frequency of your workouts can impact your likelihood of experiencing muscle soreness. People who exercise more frequently are more likely to experience soreness due to the increased stimulus on their muscles. This is particularly true if you train specific muscle groups, such as your legs, multiple times a week. When you don’t give your muscles enough time to fully recover and repair between sessions, you increase the chances of experiencing soreness after exercise.

3. The type of workout you do

The intensity and familiarity of your workout can impact how much muscle soreness you experience. For instance, if you abruptly increase the number of squats you do or lift significantly heavier weights, the resulting increased stimulus is likely to cause more muscle soreness than your usual leg workout.

How to Reduce Muscle Soreness

Several strategies may help reduce muscle soreness after exercise, such as:

  • Gradually increase exercise intensity and duration to allow your body to adapt to the new stimulus.
  • Stretch before and after exercise to improve flexibility and reduce muscle tension.
  • Stay hydrated before, during, and after exercise to prevent dehydration and muscle cramps.
  • Apply heat or ice to sore muscles to reduce inflammation and pain.
  • Get enough sleep to allow your body to recover and repair.
  • Eat a balanced diet with adequate protein to support muscle recovery.
  • Consider taking a warm bath or getting a massage to promote muscle relaxation and blood flow.

Remember that a certain amount of muscle soreness is normal and may indicate that your muscles are adapting to the exercise stimulus. However, if you experience severe or persistent pain, it’s important to consult a healthcare professional to rule out any underlying injuries or medical conditions.

Tips for Working Out When Feeling Sore

a woman in workout clothes suffering from ankle pain

You must not let muscle soreness put them off exercise. If you’re feeling sore, there are still ways you can do to so you can still work out when feeling sore:

Take it easy

If you’re feeling particularly sore, taking it easy and doing a less intense workout is okay. Listen to your body, and don’t push yourself too hard. Take it easy for a few days while the body adapts, or engage in a light exercise like walking or swimming to keep the muscles in motion and provide some relief.

Warm-up

To potentially reduce DOMS, engaging in a thorough warm-up before exercise is recommended. One way to warm up is through dynamic stretching, which involves slowly moving through a full range of motion to stimulate muscles and joints. Another option is to perform a few low-stress movements at a lighter weight or intensity to prepare the muscle groups and joints for the workout ahead.

Stretching and flexibility are often overlooked, but they can help break the cycle of soreness, leading to muscle spasms, contraction, and tightness.

Work out different muscle groups

If a particular activity is difficult or painful due to muscle soreness, it is recommended to avoid it for a few days until the symptoms ease. Instead, a person can try exercising a different part of the body. Although exercise physiologists and athletic trainers have not discovered a cure for DOMS, several remedies such as ice, rest, anti-inflammatory medication, massage, heat, and stretching have been reported to be helpful in the recovery process.

Always start gradually

When starting an exercise, always increase intensity or speed gradually. Gradually increasing the intensity and duration of exercise can help reduce the likelihood of developing DOMS. Start with exercises that your body is used to doing. If it feels like you’re doing too much, you probably are. Do not force yourself to do intense workouts two days in a row.

Stay hydrated

Drinking plenty of water before, during, and after your workout can help to prevent dehydration and reduce the risk of further muscle soreness.

How to Reduce DOMS

As the body becomes more accustomed to specific workouts, the incidence of DOMs may lessen. But people may also be able to reduce the severity of DOMS with some post-workout habits, such as:

Rest

Rest is crucial for muscle recovery, so make sure to give your muscles time to rest and recover after exercise.

Get a massage

Massage can help reduce muscle soreness by improving blood flow and reducing inflammation. Sports massages may have a small but significant effect on alleviating DOMS symptoms and overall flexibility. It’s also one of the most effective methods of reducing DOMS and perceived fatigue. You may want to apply anti-inflammatory creams to lessen soreness as you massage.

Use a foam roller

A foam roller can help to relieve muscle tension and soreness by providing a deep tissue massage. Use it gently and roll over the sore areas.

Engage in active recovery

Engaging in low-intensity exercise, known as active recovery, can help increase blood flow to the muscles and reduce DOMS. However, research suggests that active recovery is most effective during a short time frame after exercise. Its ability to assist in recovery decreases after this time period.

Eat a balanced diet

A balanced diet with enough protein can help repair and rebuild muscles after exercise. Protein is important in muscle recovery. Also, foods high in antioxidants and certain supplements may help reduce the effects of exercise-induced muscle damage. Make sure to eat a healthy breakfast as you start the day.

Apply heat

Applying heat to sore muscles can help to increase blood flow and promote healing. Use a heating pad or take a warm bath before your workout.

Take a cold bath

After you have rested after your workout, take a cold bath or shower to help reduce inflammation and prevent DOMS. Cold water baths and cryogenic treatments are popular among elite athletes.

Injury vs. Soreness

Muscle soreness should not last too long. Regardless of your newness to exercise or the intensity of your workout, the soreness should generally appear and fade away within a certain timeframe. The soreness you feel as a result of the inflammatory process must kick in within 24-28 hours after your workout. From there, muscle soreness usually sticks around for up to four days as the muscles finish the necessary repairs.

If you experience excessive soreness or pain that persists for an extended period of time, it may be a sign of injury or overexertion. In those cases, it’s important to rest and seek medical attention if necessary. Excessive or chronic muscle soreness can indicate that you’re overtraining or placing more stress on the body than it can adapt to, leading to muscle breakdown.

A person who is sore may experience stiffness, pain, or warmth in the affected area but not acute pain. However, muscle injuries may result in swelling, bruising, acute pain, and physical impairment.

If a person suspects they have an injury, they must stop exercising immediately.

Summary

Exercise causes stress on muscle tissues, resulting in muscle soreness. While this may seem uncomfortable, it’s actually a good sign that your body is responding to your workout and making gains.

It’s important to allow your body enough time to recover after exercising. Muscle soreness can last for several days and is especially common in beginners or those who are increasing the intensity of their workouts. Micro-tears in the muscles cause DOMS, which can be reduced by gradually warming up and increasing muscle load.

Also, adding massages, cold water baths, foam rolling, and antioxidant-rich foods to your post-workout routine may help reduce the risk of DOMS.