The Impact Of Smoking On Muscle Growth
Smoking influences your muscle growth negatively. Numerous evidence has been published suggesting that smoking reduces the ability of your muscles to regenerate, reduces the strength of your muscles, and also may lead to other health implications. Although smoking negatively impacts your muscle growth and strength, its effects can be reversed.
How Does A Muscle Grow?
Muscle growth, also known as hypertrophy, is a complex process involving several mechanisms. It is driven by various factors like hormones, including testosterone and growth hormone, and is also dependent on the availability of amino acids and other nutrients [1].
Muscle growth happens through [2, 3, 4]:
- the increase in muscle fiber size
- the addition of nuclei from muscle stem cells to existing fibers
For instance, when you engage in intense exercise, such as weightlifting, your muscles undergo trauma. This process activates cells on the outside of the muscle fibers which then try to repair the damage by joining together. In return, this process increases the muscle fiber [5].
In addition, the muscle growth can also be influenced by biomechanical factors. For example, both the active and passive fiber stress in striated muscle fibers can affect transverse and longitudinal growth respectively [6].
Overall, muscle growth varies from individual to individual and can be affected by genetics, resistance training, and proper protein intake. The latter two are key to increasing the rate of protein synthesis, which is also salient in muscle growth [1].
What Affects Muscle Growth?
As above mentioned, the growth of muscles can be influenced by multiple factors.
Primarily muscle growth can occur through:
- an increase in muscle cell numbers
However, the growth in cell numbers is limited to the prenatal and immediately postnatal period, the growth of the muscle can only occur through these mechanisms in adulthood [3]:
- an increase in muscle fiber diameter
- an increase in the fiber length
Further, nutrition and a proper diet are also essential for muscle growth. To achieve optimum muscle growth adequate diet consisting of protein needs to be adopted. Protein restriction can undermine muscle function in the long term and affect skeletal muscle development at both the transcriptional and methylation levels [7].
Hormones also play an important role in muscle growth. For instance, insulin, testosterone, and growth hormone are all involved in muscle growth [1, 8].
Let’s use Medisearch to find out how:
Lastly, our genetics is a big determinant of our muscle growth. It can both limit and induce muscle growth. It has been hypothesized that there is likely a finite ability for muscular adaptation and a plateau in muscle growth, which has been attributed to genetic potential [9].
Does Smoking Stop Muscle Growth?
Smoking is a commonly observed behavior among people, this is regardless of age, sex, or socioeconomic background. But does it stop muscle growth?
Cigarette smoking has been shown to have a significant impact on muscle growth and strength. This is mostly because cigarette smoke and cigarettes consist of a complex mixture of toxic chemicals which may lead to muscle damage and catabolism (when muscle uses the muscle mass to get energy rather than carbohydrates or fat) [10].
According to a study investigating whether the rate of skeletal muscle protein synthesis is influenced by smoking, the investigators found that this rate is lower in smokers compared to non-smokers. Such phenomenon was ascribed to the increased expression of genes associated with impaired muscle maintenance, including myostatin, a muscle growth inhibitor, and MAFBx (a component of the protein degradation pathway [11].
Additionally, smoking has been associated with a decrease in muscle strength. Consumption of 100g of tobacco a week in the form of smoking, resulted in the reduction of 2.9% in knee muscle strength in men and 5% in women [12].
Furthermore, smoking has been linked to higher muscle fat infiltration, which can have significant health implications, especially for older adults. This is because muscle fat infiltration is associated with poor physical function, falls, and hip fractures [13].
However, it's important to note that many of the effects of smoking on skeletal muscle are likely reversible with smoking cessation [14, 15]. For instance, one study found that quitting smoking led to increases in body weight, lean mass, fat mass, bone mineral content, bone mineral density, and handgrip strength, and predicted one-repetition maximum of chest press and leg press [16].
In conclusion, smoking can negatively affect muscle growth and strength, however, it does not stop the muscles from growing. However, even these negative effects of smoking can be reversed with smoking cessation.