Muscle Damage for Muscle Growth

by Dr. Jacob Wilson, Ph.D., CSCS*D

January 17, 2018


Muscle growth is an intriguing topic. I’ve spent the better part of my career helping others maximize the process. One of the areas we must understand is how muscle growth occurs. There are at least three primary ways muscle may be triggered to grow. Mechanical tension (the strain and load on the muscle is one of them. Tension, whether high or moderate and sustained over time can cause growth. The outcome of tension we are unaccustomed to is an elevation in muscle damage. While we are uncertain if muscle damage causes growth we do know it results from novel training and that novel training results in growth. In my years of study, I have come to the conclusion that training that results in small to moderate amounts of muscle damage may stimulate growth while extreme amounts may do the opposite. Thus in this article, I will answer your questions from what muscle damage is, how you can trigger it and what steps you can take to NOT OVERDO it.

What is Muscle Damage and How Does It Happen?


Muscle damage occurs when you lift heavy or do eccentric training. In a muscle fiber, you have a chain of sarcomeres, which are the contractile units of a muscle fiber. Some of these are weaker than others. When a muscle fiber is stressed with heavy weight or repeated loads these weaker sarcomeres essentially are injured beyond repair. This leads to soreness, swelling, and a decrease in strength.

Muscle damage occurs during lengthening or eccentric contractions. The natural repair process involves inflammation, swelling, and pain. However, if nutrition is ideal afterward, you will gain muscle mass and potentially strength.

Does the Type of Contraction You Do Impact Muscle Damage?


Lifting involves upwards (concentric), downwards (eccentric) and squeezing (isometric) phases. Muscle damage is highest when you lower the weight. For this reason, doing heavy or forced eccentric exercise can cause a lot of soreness the next day. Therefore, if you are trying to shock the muscle to grow this may be a good technique. In contrast to a recovery workout, try using lighter weights and focusing on a pump on the concentric portion of the lift.

Can you Cause Too Much Muscle Damage?


We like to always assume that if some of a good thing gets us gains that a lot must be even better. Thus athletes like to think that as muscle damage goes up that growth goes up at the same time. However, it seems that this is only true up to a moderate amount of damage. If it is too high such that it lasts over a week you may damage and actually lose size. In the end, you will actually cause a small loss of muscle (Foley et al. 1999). This usually occurs when you have taken time off for a long time, are a beginner or just push past the point of no return. Shawn Ray one of the greatest bodybuilders of all time always said to “stimulate, don’t annihilate.”

When should you be most concerned about causing too much damage? The answer is when you are not well trained or if you have taken time off. For example, one study found that after high volume training that deconditioned individuals lost muscle and it remained smaller for months (Foley et al. 1999)! For this reason, we will discuss what causes muscle damage and then how we can first make the muscle protected against extreme damage.

Intensity and Muscle Damage

Intensity is defined by how heavy of a weight you are lifting. Research shows that heavier weights cause more muscle damage (Nosaka et al. 2002). Thus, your heavier days (5-8 reps with 3-5 minutes rest) will cause muscle growth through mechanical trauma. However, if you are doing a recovery workout you might increase your reps (12-15) and lower your rest to cause growth through more metabolic stress.

How Does Rep Speed Effect Muscle Damage?


Many people think that going slower on the way down of a lift will make you grow faster. In reality, it’s the opposite. Faster reps cause more muscle damage. Thus if the goal is to trigger mechanical trauma to induce growth to use faster reps with control. Why is this the case? You will get more training volume and be able to lift heavier loads (Chapman et al. 2008). It’s important to understand that purposely slowing the speed of a rep will by nature lower the amount of weight you can lift with that weight (Sakamoto et al. 2006).

In addition to this what you must realize is that the amount of weight you lift and the amount of fatigue you have will naturally slow the weight down anyway (Duffey et al. 2000). This means that the first half of a set may be fast but as you fatigue, each rep will naturally become slow. Similarly, if you lift 100 lbs it will be faster than if you lifted 200. Thus use a speed that allows you to have good form and let the weight and fatigue dictate the rest.

How Does Training Volume Effect Muscle Damage?


The easiest way to define volume is simply how much total weight you lift in a workout. The more sets you perform generally speaking the higher your volume. Studies show greater training volumes result in more muscle damage and often growth (Brown et al. 1992). Thus, for days you are trying to grow, select out higher volumes, but not so high as to annihilate. This will inevitably vary with your conditioning. For example, if you are untrained 4 sets may be high volume, while someone with high levels of experience may be able to handle 20 to 30. In general, if you lift high volume every week and every workout your body won’t be able to recover. Thus if your low volume is 8 sets do that week one, and week 2 to 12 and week 3 16 to 20 per set. Then back down to 8 per body part the following week.

Other Thoughts on Muscle Damage

Range of Motion

The range of motion you use when training can dramatically increase muscle damage. Partial reps do not trigger as much muscle damage or growth when you compare them to full range of motion. Therefore, we recommend using full range-of-motion-on when lifting any weight. Unless you are going to failure on your sets and using failure training, then you can use partial reps.



A question I commonly get asked is, “does active recovery help with muscle damage?” The answer to this is that warming up doesn’t necessarily speed recovery from muscle damage or help you recover strength. However, it does have a pain-relieving effect. This to relieve pain from training. So add an extra 5 to 10 minutes to your workouts for warming up.

Repeated Bout Effect


Another question I am asked is, “why do I stop getting sore from lifting weights?” The answer to this is that muscle damage does decrease over time. If you do the same workout over and over again your body adapts by adding new muscle fibers & cells. This may be why we stop growing. While too much muscle damage may be a bad thing, I believe a little is good for growth. To combat this “bulletproof vest” make sure you continually change the exercises you select and rep or set ranges. In fact, for bodybuilding, every month I would change all the exercises you are doing entirely!


Muscle damage is an extremely complex topic. Too much damage and you can impair gains, while a small amount may increase muscle size and strength. Overall the key is to keep damage to low to moderate levels in your training by introducing new training regimes, new exercises, and by properly progressing from one phase to another.