Why are the quadriceps and calves muscles difficulty to grow up?

Answer 1

the 2 biggest problems are from lack of using sufficient intensity (not training heavy enough) when training them and a general lack of flexibility.

many don't understand the relationship with being flexible and muscle mass. the more relaxed a muscle is at rest the more force it can generate over it's entire range of motion. so a relaxed/flexible muscle is more efficient, it can perform more work. to effectively stimulate a muscle enough to grow it must me exercised over it's entire range of motion using a load that is close to 80% of the 1RM for a time under tenstion of 45-60 seconds. so each set should take 45-60 seconds which typically equates to 8-10 reps. so if your max squat is 100 lbs to stimulate growth you would need to do sets of 8-10 reps with 80 lbs.

ultimately the diet determines the size of the muscles. so you use heavy weights to tear down the muscles forcing them to adapt and a high calorie diet allows them to recovery from exercise and grow larger.

Answer 2

Heavy squats are great for overall leg development. Also do squats inside a smith machine with your feet closer than shoulder width apart. The hack squat machine makes it easy to isolate the quads and/or you can do leg sled with feet close together. One of the best exercises that no one else even mentioned is heavy leg extensions the machine where you are seated, the pads are on your shins and you straighten or extend your legs which hits the quads hard).
Do heavy calf raises with your heels hanging off the edge of a box to blow them up. I'd recommend using a smith machine so you don't need to worry more about balance rather than hitting the calves hard (if that's not an option use heavy dumbells)
Good luck and train hard!!

Answer 3

i actually find them easier to build up. see they can support alot of weights as most peoples legs are like their strongest body part.

for quad developement there is nothing like squats....go as heavy as possible for 8-12 reps and you will get legs..

do weighted calf rises as heavy as possible and eat well with rest and they too shall grow