It makes sense to me that different body parts would respond well to different rep schemes. It probably has a lot to do with two things:
1.) Total muscle activated. 2.) Total bar path length.
Just think of the total distance the bar travels when doing 5 squats and the total distance the bar travels when doing 5 shrugs. I think as a very vague and general rule that the longer the lift takes, that you should do relatively less repetitions than a shorter lift.
This is one of the reasons I like doing timed sets. It also keeps you focused on really moving the bar quickly- as long as you don't sacrifice form.
A few years ago when I wanted to add size/strength to my thighs in a big way I followed the following routine:
20,15,12,10,8,6,4,2 rep range on my squats with each set at least approaching failure and sometimes hitting failure (or at least as close as one could come on a movement like squats)
I did that for about 8 months and achieved noticeable size and strength gains. Also, last summer I trained with a buddy of mine and at the end of all of our squatting sessions we would drop the weight way down and load the bar with 225 and do what we liked to call "sets of death"...Pretty simple, just do as many as you can physically tolerate. Shaking, Vision loss, full body numbness all were expected and welcomed by the end of those sets. My best was 31...
Give it a try...you'll hate me for it
That didn't really answer your question, but if you're looking for size in your thighs this might do the trick.
There aren't any magical numbers which produce super-fast hypertrophy of certain muscle groups. It's two things - doing more and doing something different.
If you lift with more sets, reps, weight, difficulty level....whatever - it will produce growth. If you've been doing 3x15 and in 6 weeks you're doing 4x25 with the same weight you will grow. You can train in different rep ranges and progress in both of them simultaneously. Then after a while you switch out the exercises, cut volume and increase weight. Then begin building up reps and sets all over again.
"Ooooo triceps respond best to 4-6 reps!" I feel sorry for the fucker who's repetition range is limited to differ by 3-4reps.
I have definitely found that for the lats, hamstrings and calves, the best approach is to do HEAVY weight mini sets of 3-5 perfect reps, but to do many mini sets with less than 60 seconds rest. I may even go down to one perfect single every 30 seconds for as long as I can tolerate. Perfect does not mean slow, but it does mean an intense contraction at the end.
Actually this works for other exercises as well.
With squats I have tried 20 rep routines. The problem is that the exercise gets easier near the top. I would prefer multiple sets of 3 with short rest periods, but including bands to make make the load increase on the way up. With 20 rep squats, its just a powerful push with the glutes, and then you glide throught the rest.
Almost anything can be done for heavy triples with short rest periods and you can go from about 70% load that you might do for sets of 10 up to about 85%, and still get the same number of reps in 5 minute time frame.
The time that I would do sets of 10 instead would be when you might have supportive structures that can't keep you in the right position with the heavier load.
What you have read on this thread by some very good posters is that there are many ways to train and they are all beneficial!
I have always looked at muscles the way they were intened to work. Legs were obviously intended for higher rep movements because of the amount of "reps" that they take in steps each day. Hence, I train legs with higher reps and have always had good success.
The one set of 20 reps squats works for a reason.
Take what you normally would do for 10 clean reps and go to 20. make sure you do a couple of warm up sets prior.
If you think about it you will be able to figure out pretty quickly what rep range each muscle should be trained under.
Forearms are another high rep muscle group as they are being used all of the time.
Don't get me wrong, it's also good to change up rep patterns every so often for shock value.
Of all the posts I believe this is the most accurate answer. Your body is made of primarily 2 types of muscle fibers. Slow twitch/red muscle fibers and fast twitch/white muscle fibers. Slow twitch fibers are weak but have very good endurance cababilities where as fast twitch are very powerful but fatigue easily.
Certain bodyparts like calves and quads have a higher concentration of slow twitch/red muscle fibers so therefore they need to be stimulated with higher reps unless you always train them with heavy weight and lower reps in which case the body eventually adapts to the stress and develops more fast twitch fibers in that muscle. The reason you should variate between high/low reps is to bomb both fast/slow fibers.
And as I mentioned some bodyparts like calves need a higher stimulus so do predominately higher reps but every couple workouts throw in some heavy/low reps sets.