Understanding Acute Muscle Soreness
You’re grinding in the gym, day in and day out. During your set of side delt raises, you feel the small deltoid muscle screaming in agony… 10, 11, 12 – you push through the pain, these are the championship reps… 13, 14, 15! You put the weights away, shake your arms and breathe heavily. A part of you asks yourself why in the world you do this. You look in the mirror and flex your arms seeing progress coming along. That’s the other part answering why.
That burning sensation you’re feeling during those reps, that’s Acute Muscle Soreness. This is caused by a build up of metabolites like lactic acid. Lactic acid builds ups in the muscle when the cells burn carbohydrates faster than your lungs and blood can bring in oxygen. The burning sensation is caused by the acid breaking down into lactate and hydrogen ions. The hydrogen ions stimulate the pain receptors in your cells and tell your brain “hey! Look at this!” Once you stop the tension (remember: time under tension is a big factor in muscle growth!), the muscles can relax and your body can wash away the built up lactic acid. It’s why some people instinctively shake their arms after a set. Acute Muscle Soreness can last anywhere from a minute to 24 hours after your exercise.
Delayed Onset Muscle Soreness (DOMS)
The next day, your alarm goes off, you go to get up out of bed and stretch – oh, wow… that’s a lot more stiff and sore than you expected! Now you’re dealing with DOMS: delayed onset muscle soreness. DOMS usually occurs 24 to 72 hours after exercise. The reasons for DOMS aren’t understood 100%. A few theories are that the soreness derives from small little microtraumas in the muscle during the negative portions of the lift, from the left over build up of metabolites, or – a more recent theory – from the microtrauma in the fascia tissue.
Regardless, the point is you’re sore. You don’t need to understand the science behind why stubbing your toe hurts if all you really need to know is it hurts. The same rings true here. The simple fact is that your body is experiencing inflammation from your exercise. This inflammation is a good thing (to a degree, you would know if it’s too much or if you’re injured). It’s your body’s way of adapting to a stimulus.
Aiding Recovery
Another takeaway is also that if you’re sore, moving your body will help recover. Inflammation is a process of your immune system. By moving around, you help promote blood flow allowing healing nutrients to be brought in and warmth to ease the stiffness. This also ties into performing light recovery work like:
- Foam rolling
- Brisk walks
- Light lifting
- Active stretching
These actions aid in recovery by – you guessed it – promoting blood flow. Even though we’re not sure why or how it works, it does. You don’t have to overthink things like this.
A quick caveat: unless you need to perform to the best of your abilities in the next training session (playing a sport or Olympic Weightlifting for example) I wouldn’t suggest taking an anti-inflammatory. If the inflammation is a reaction to exercise and the results we want is that adaptation, I don’t believe it’s beneficial to wash away the workers before they’re done working.
Is DOMS Necessary for a Good Workout?
Now, a good question would be is if DOMS is necessary or a sign that you had a good workout. For a long time, people believed that if they didn’t have this muscle soreness that they weren’t growing. This is a myth. Growth can occur with or without DOMS. Instead of using DOMS as a marker of a good workout, focus on your performance and following your routine. If you’re continuing to progress in volume (either increased weight or repetitions) then it’s a sign you’re doing something right. If you’re looking for muscle growth, give it time and use things like progress pictures or how your clothes fit. Training isn’t something you’re going to notice astounding growth in overnight. It takes time.