How Long Do Biceps Take to Get Big?

According to the American Council on Exercises (ACE), there are two components that make up the rate of muscle development: genotype and phenotype. Genotype is the genetic code of an individual and encompasses factors such as sex and genetic make-up. Phenotype includes the observable physical characteristics of a person. There are certain factors that relate to phenotype or the combination of genotype with the environment, such as:

• Training load, duration, frequency and history
• Age
• Carbohydrate, protein and caloric intake
• Level of hydration
• Hormones

While you cannot control certain factors, such as your genetic make-up, you can control certain elements of your training process. Namely, how often you work out, how much you work out and when you begin training.

Read more: The 6 Rules of Gaining Muscle Mass

You now know that genetics play a role in muscle gain, but do you know how they influence muscle growth? Certain individuals simply possess a predisposition to large muscles, while others do not.

A young man with a genetic predisposition along with a large percentage of fast-twitch muscle fibers — fibers that respond most easily to muscle growth — may gain 2 pounds per month of lean mass. Over time, as his muscles adapt, the rate of growth will decrease.

One July 2018 study published by Frontiers in Physiology found that there are several genetic factors that affect muscle growth variation from person to person.

Those who responded well to several weeks of strength-training exercises may have had a proliferation of what are called satellite cells, a type of stem cell that's fundamental for the repair and replacement of muscle fiber. Therefore, you can say that a person with more satellite cells has a higher chance of rapid muscle growth than someone lacking them.

Increases in strength related to short-term resistance training are the result of what's called neural adaptations. Neural adaptability is associated with the recruitment of motor units, which includes the motor neuron and the muscle fibers it affects.

According to ACE, adaptations in the early stages of strength training may be construed as muscle gain, but it takes time for the body to develop new muscle tissue. It's only after an average of three to six months that you experience hypertrophy or a gain in muscle mass. That said, genetics play a critical role in the development of muscle growth, so the adaptability and growth timeline will vary from person to person.

Good news for former athletes: it's easier to rebuild old muscle than to gain new muscle. This occurs due to a phenomenon called muscle memory. New research suggests that muscle nuclei may be responsible for these gains in once-fit muscles.

The nuclei gained during previous growth will persist, even after muscle mass is lost. They will allow these muscles to then regain fitness at a later time. Researchers had previously thought that once the muscle mass is lost, it disposes of the nuclei, but a January 2019 study in Frontiers in Physiology found that's not the case.

In an NPR report on the 2019 study, muscle biologist and University of Kentucky professor Charlotte Peterson posits that you shouldn't be so quick to assume the persistence of the nuclei in previously fit muscles. Different muscles or a longer period of atrophy could produce different results.

Read more: 7 Tips to Help You Regain Muscle

The rate at which you gain muscle may also be linked to levels of stress. A July 2014 study in the Journal of Strength and Conditioning Research found that people with more stress recovered at a slower rate after training compared with those subjected to less stress.

Studies have also pointed to the role of diet in muscle growth. According to one July 2015 study in the journal Applied Physiology, Nutrition and Metabolism, a diet high in lean proteins promotes muscle growth. The study found that consuming 25 to 35 grams of high-quality protein during each meal fosters muscle health.

In order for muscles, such as the biceps, to grow, a consistent strength-training regimen should be enforced. To get the most out of your bicep workouts and gain muscle at a steady rate, the Better Health Channel has a few recommendations:

• Give yourself at least 48 hours of rest between strength-training workouts.
• Switch up your workout routine to allow your muscles to adapt and strengthen.
• Warm up your body before strength training.

According to Mayo Clinic, you can start to see improvement in strength after two to three weight training sessions per week at 12 to 15 reps per set.

A November 2016 study published in Sports Medicine found that strength training twice a week promotes superior muscle growth outcomes than for those who trained once a week for the same amount of time. That's to say that spreading out strength-building exercises may be more beneficial than lumping them into one workout.

The secret to big arms is that there is no secret, just patience, determination, certain lifestyle choices and a bit of genetic luck. Of course, there are factors, such as age and gender, that are out of your control. Likewise, you can't control your number of satellite cells nor can you control which muscles are more likely to respond to muscle memory.

What you can control are the number of sets and reps you do and the number of times you work out your arms per week. Practicing a strength-training regimen on a regular basis, eating enough protein and diminishing stress should set the foundation for stronger and bigger arms.