Some people love being sore after a workout because it feels like an affirmation that they put the work in. Other people want to avoid it at all costs because it discourages further workouts for them. Personally, as a workout enthusiast myself, I don’t mind feeling sore, but no matter which boat you fall in, understanding muscle soreness is important.
So, does soreness mean muscle growth? Does it mean you are doing the right things during your workouts to see progress? Keep reading to find out!
Does soreness mean muscle growth?
Muscle soreness after a workout is often seen as a sign that you’ve worked hard and that your muscles are growing. However, soreness alone doesn’t necessarily mean your muscles are getting bigger or stronger. It’s possible to build muscle without experiencing much soreness at all, especially as your body adapts to your training routine.
Soreness, known as delayed onset muscle soreness (DOMS), usually happens when you try new exercises or increase intensity. An NIH study reported that “DOMS is most prevalent at the beginning of the sporting season when athletes are returning to training following a period of reduced activity. DOMS is also common when athletes are first introduced to certain types of activities.” These findings can translate to generally active individuals as well.
While it indicates that your muscles have experienced stress, it mostly reflects microscopic muscle damage rather than actual growth. Muscle growth happens over time through a combination of proper training, nutrition, and recovery.
So, soreness can be a helpful signal that your workout challenged your muscles, but it’s not a guaranteed marker of progress. At the end of the day, it is more important that you focus on consistent training and measurable improvements rather than chasing soreness.
What actually causes muscle soreness?
Muscle soreness, especially DOMS, usually appears 24 to 48 hours after unfamiliar or intense exercise. It is primarily caused by tiny tears in the muscle fibers and the surrounding connective tissue. These microtears trigger an inflammatory response as your body works to repair the damage.
The soreness also comes from the buildup of metabolites like lactic acid during exercise, although this is a more temporary factor and fades quickly after working out. The real culprit behind the soreness sensation is the inflammation and swelling that follow muscle damage.
Eccentric movements—where muscles lengthen under tension, such as lowering a dumbbell or running downhill—are more likely to cause soreness. Over time, as your muscles adapt to the stress, the soreness decreases, even if your workouts remain intense. Understanding this helps clarify that soreness signals muscle repair processes, not just muscle growth.
How does muscle growth occur?
Muscle growth, or hypertrophy, happens when the repair process after muscle damage results in increased muscle fiber size. When you work out, especially with resistance training, you create microscopic damage in the muscle fibers. Your body responds by activating satellite cells that repair and strengthen these fibers.
This repair involves synthesizing new proteins to rebuild the damaged fibers to be thicker and stronger than before. Nutrition plays a vital role here as well; consuming enough protein and calories provides the building blocks necessary for muscle repair and growth.
Besides damage, muscle growth is stimulated by mechanical tension (lifting weights), metabolic stress (the “burn” during exercise), and progressive overload, which involves gradually increasing the resistance or intensity over time.
Rest and recovery are critical because muscles actually grow during your off days, not during exercise. Without proper recovery, muscle growth slows or stops, even if you are putting adequate effort into your training.
Ways to track your progress beyond soreness
Tracking progress beyond soreness gives a clearer picture of muscle growth and fitness improvements. One effective way is to monitor strength gains—if you’re lifting heavier weights or performing more reps over time, it indicates muscle adaptation. Fitness tracking apps can help with that.
Another useful method is taking regular body measurements or progress photos. Changes in muscle size or body composition can be subtle and gradual, so tracking these visually or with a tape measure helps recognize growth.
Performance improvements, like increased endurance, better form, or faster recovery between sets, also show progress. Additionally, tracking consistency in your workouts and nutrition supports long-term results.
Listening to your energy levels, mood, and overall well-being provides important feedback, as excessive fatigue or pain might signal overtraining.
Using a combination of these methods offers a well-rounded, motivating way to measure growth without relying solely on the presence or absence of soreness.
Frequently asked questions
Is it okay to work out when sore?
Yes, it’s generally okay to work out when sore, especially if the soreness is mild to moderate. This kind of discomfort, often caused by delayed onset muscle soreness (DOMS), is common after new or intense workouts. Just listen to your body and avoid training the same muscle group too hard again the day after.
Do muscles grow on rest days?
Yes, muscles grow on rest days. During rest, your body repairs the microscopic tears caused by resistance training, leading to muscle growth and strength gains. Without adequate recovery—including sleep, nutrition, and rest days—your muscles can’t rebuild efficiently. Recovery is just as important as the workouts themselves for building muscle.
How long is too long to be sore?
Being sore for more than 72 hours after a workout may be too long and could indicate overtraining or injury. Mild soreness usually peaks within 24 to 48 hours and then fades. If soreness persists or worsens, it’s important to rest and consider consulting a healthcare professional if needed.
