I'm my experience as a weight lifter, calves, neck, and forearms are the slowest to show significant growth. Easiest would definitely be chest for males.
Calves. Calf muscles are also considered as one of the most difficult to grow in the gym, to the point where many people give up trying.
Answer and Explanation: (a) The muscle type that is slow to contract is smooth muscle. It is known to produce slow contractions because the smooth muscle has calcium channels which open much more slowly that other muscles.
Generally speaking, your body's largest muscle groups, such as those in your back, chest, and legs, are likely to respond most quickly to strength training.
This theory is supported by the finding that the pecs are the slowest muscle group to recover following training (11). I think 2x/week for chest training is plenty as the pecs will need at least a few days to recover between sessions.
Remember, weighted squats trigger a flood of growth hormone into the body because of the sheer amount of muscles being activated. It's one of the reasons your legs are likely to grow faster than your arms.
Cardiac muscle cells are cylindrical and branched. They are involuntary in nature. They do not undergo the fatigue. They are present only in the human heart.
Your heart muscle does something truly incredible-it expands and contracts, non-stop, every moment of every day of your entire life. By comparison, if you tried to squeeze and release the muscles in your hand, they would grow fatigued and need to rest probably within an hour.
The cardiac muscle does not relax and prepare for the next heartbeat simply by ceasing contraction; it occurs in an active process called Lusitropy.
Typically, muscle mass and strength increase steadily from birth and reach their peak at around 30 to 35 years of age. After that, muscle power and performance decline slowly and linearly at first, and then faster after age 65 for women and 70 for men.
Unfortunately, it is harder to build muscle after age 50. Your muscle growth trajectory peaks in your 20s and 30s, and it starts to decline noticeably after 50. While you're working on strength training, your aging body is losing muscle mass.
Progressive overload and overload in and of itself is pretty difficult to achieve with the biceps. You need to do something dramatically different in your arm workouts to stimulate those muscles, and that is to vary the way in which you're performing your biceps curls!
Muscles like your quadricep or gluteal muscles are relatively big, and they're involved in a lot of different sitting and standing motions, so these will take more time to recover.
However, it's incredibly difficult to grow your lats, and if you're trying to do so, you might be frustrated due to a lack of progress.
Auricular Muscles
Aside from those special few that are able to wiggle their ears as a party trick, most people are not capable of manipulating these muscles at all. Evolution has deemed the auricular muscles unnecessary.
Muscles can pull but not push, so skeletal muscles are often arranged in pairs that pull bones in opposite directions. The body has some 640 skeletal muscles, accounting for about 40 percent of body weight. Skeletal muscles are attached to bones by tough fibrous connections called tendons.
The strongest muscle based on its weight is the masseter. With all muscles of the jaw working together it can close the teeth with a force as great as 55 pounds (25 kilograms) on the incisors or 200 pounds (90.7 kilograms) on the molars.
The heart is still a muscle, much like the bicep or the hamstring, but the heart never tires. The reason for this rather crucial detail of anatomy keeps us alive, as without a pumping heart death will shortly follow. Hearts, although muscles, are made up of different fibres than their counterparts.
Skeletal muscle gets fatigued very soon.
Genetic variants are linked to 44% of the differences seen following cardiovascular fitness exercises. Additionally, genetic variants caused 10% of the differences in outcomes following exercises to improve anaerobic power, which is key for movement and agility.
Arm span grows proportionally more than stature in children until about age 15 years in females and about age 25 years in males, followed by a plateau in the ASHR until about age 45 years, when the ratio increases almost linearly with age (fig. 2).
The Genetics of Defined Muscles
Part of how muscular you look comes down to genes, notes Westcott. "Some people are born with long muscles and short tendons," he says. And this is ideal for that super-defined look.