Science of Soreness: What Causes Sore Muscles After Workout Sessions?

Science of Soreness: What Causes Sore Muscles After Workout Sessions?

Anyone that has ever exercised knows the feeling of sore muscles after workout sessions. Learn why sore muscles happen and how to cope with it.

Dread working out because of sore muscles?

Knowing why you get sore muscles after workout activities is key to having an effective workout recovery plan that helps reduce discomfort, boost athletic performance, and keep you and your muscles in the best possible shape.

This is true if you’re new to the gym or a sport for fun or if you’re an Olympic athlete. Take Team USA athletes in 2016 in Rio for the Olympics. They had Rick Reiff, in charge of their Olympic training recovery and the entire Olympics’ Recovery Center in Rio.

Reiff knows the science behind soreness and puts recovery up there with training in importance. This is true for all levels of workouts. At Rio, he stuck to a specific plan, including muscle cooling for gymnast Laurie Hernandez — think ice bath or cryotherapy — and hydration. 

Treatment of muscle soreness can be simple at all levels too. Keep reading for the basic science behind muscle soreness and some easy treatment options. Then, get back to your favorite workout with your recovery plan intact when those sore muscles hit.

The Reason You Get Muscle Soreness After a Workout

You work out more intensely than usual or do a new physical activity that uses muscles you didn’t even know you had and two or three days later muscle soreness sets in.

Even something that doesn’t feel like a workout can do it, like building a sandcastle where you’re doing the squat motion unbeknownst to you. A lengthy pillow fight where you’re doing arm extensions and presses unbeknownst to you can do it as well and so can going up and down all those stairs on that pyramid on your last holiday getaway. 

What’s happening is that you’re putting stress on your muscles by pushing them further than they’re used to, and this causes micro-tears in the muscle fibers. About 12 hours to 48 hours later, your body sets out to heal the tears. 

It creates inflammation in the area and rebuilds the muscle, making it bigger/stronger than before. The inflammation puts pressure on nerves, and that’s what causes the pain or soreness. Everyone is different in how they experience the discomfort, hence the spectrum. 

The name for this post-muscle exertion soreness is delayed onset muscle soreness or DOMS for short. 

In More Scientific Speak

To quickly get a little more scientific on you, let’s describe that muscles soreness process again. 

When you first push your muscles, your muscles metabolize their energy and lactic acid comes out. Lactic acid can cause soreness but it’s usually gone a few hours after the workout so it’s not the problem a few days later that lasts another few days.

That’s the inflammation we talked about. White blood cells rush into the muscle to fix the torn fibers, which are microscopic myofibrils. Myofibrils are protein contractile units.

Anti-inflammatories called prostaglandins also rush in to help the white blood cells, as do more helpful fluids and nutrients. They work together and fill the muscle compartment while doing their job. Hence the swelling. 

The repair of these myofibrils is a building-up process called anabolism. So, the good news is that when you feel the soreness, the muscle growth should follow shortly. 

Other Culprits

The DOMS soreness is the normal reaction your body has to stress on muscles. The degree of soreness varies by a few factors including the intensity of a workout, regularity of workouts, and even hormones.

For example, estrogen can keep the soreness at bay, which is why men tend to experience DOMS more than women.

Generally, however, the soreness or pain or difficulty in using muscles from one big workout goes away in three to five days, and if you experience more chronic soreness, there might be something else going on.

You might have a muscle injury or something going on with the connective tissue surrounding your muscles and joints. 

Or there may be an issue with your vestibular system, which is in your ear! Yes, so many things in our bodies are interconnected. In this case, you would approach your muscle soreness differently, like through vestibular rehab. This is why it’s important to know your body, how it works, and how so many processes are interconnected. 

Muscle Recovery

Below are recovery tips for DOMS. If you think it’s vestibular, check the vestibular rehab option. If you think it’s something else, check with a professional.

Having typical DOMS means you’re in a good spot. Your goal is simply to keep blood flowing to the muscles. Don’t stop moving. The blood helps get fluids to the area so your muscle tears heal faster and muscles can grow.

Do easy things, like walking. Roll on a foam roller. Get a massage. All these promote blood flow to the area.

Don’t push muscles again until the soreness subsides, especially if you have a lot of soreness and/or pain. Pushing a muscle in recovery can lead to muscle tears and, sometimes, irreparable damage. 

You can also do what Olympic athletes do to give your muscle repairing process a boost and keep discomfort at a minimum:

  • Cool muscles to reduce the pain of swelling with ice or a cold shower
  • Compress muscles with massage or compression clothes
  • Hydrate by drinking plenty of water
  • Replenish energy by refueling with fresh, healthy food after a workout

In addition, rest and/or slow down after the intense workout that caused the DOMS.

Avoiding Soreness

You can’t completely avoid DOMS but you can warm up muscles lightly before a workout to diminish the chance or injury.

Also, if you’re in the game to push yourself to get stronger and better at an activity, you can use the “10 percent rule.” This rule encourages you to only increase your workout by 10 percent a week.

Sore Muscles After Workout Days Are a Good Thing

Now that you know the up-side for having sore muscles after workout and training days, you can exhale and get back to it. Be sure to set up a good plan that includes recovery time and sore-muscle recovery treatments as needed. 

Remember, you can do it like the Olympic athletes do without spending the big bucks or investing tons of time. You just need to commit to and stick to your muscle recovery plan. Then, enjoy the process as you watch your muscles recover and get stronger and your athletic abilities increase.

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